HIV and CD4+ Cells
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Questions and Answers

What is the primary consequence of HIV's effect on CD4+ cells?

  • Enhanced viral replication in host cells (correct)
  • Effective regulation of cell apoptosis
  • Increased immune response to infections
  • Decreased production of antibodies

    • How does HIV influence the immune system's CD4+ cells?

  • By strengthening their function
  • By increasing their membrane permeability
  • By promoting their reproduction
  • By causing irreversible cell damage (correct)

    • What are the typical characteristics of untreated HIV disease progression?

  • Rapid decrease in CD4+ cells (correct)
  • Temporary immune recovery
  • Consistent viral suppression
  • Stable CD4+ cell counts

    • What is the role of HAART in managing HIV infection?

    <p>It helps to achieve viral suppression</p> Signup and view all the answers

    Which factors are believed to contribute to HIV-mediated cytopathic effects?

    <p>Changes in membrane permeability</p> Signup and view all the answers

    What happens to individuals treated with combinations of antiretroviral drugs?

    <p>They see improved viral load control</p> Signup and view all the answers

    What is a potential consequence of untreated HIV infection?

    <p>Substantial immune system compromise</p> Signup and view all the answers

    What is not a characteristic of the course of HIV disease when untreated?

    <p>Regular CD4+ cell regeneration</p> Signup and view all the answers

    What is the primary function of the virus in the region of lymph nodes?

    <p>To replicate and spread to other tissues</p> Signup and view all the answers

    What is the characteristic of the protein found in the deposits?

    <p>Phenotypically identical but chemically distinct</p> Signup and view all the answers

    What is the type of tumor that develops in response to the virus?

    <p>Primary amyloidosis</p> Signup and view all the answers

    What is the site where the virus initially replicates and spreads?

    <p>Lymph nodes</p> Signup and view all the answers

    What is the outcome of the virus replication in the lymph nodes?

    <p>Spreading of the virus to other tissues</p> Signup and view all the answers

    What is the term for the deposits that form in response to the virus?

    <p>Amyloid fibrils</p> Signup and view all the answers

    What is the primary immune deficiency associated with an increased incidence of opportunistic infections, such as Pneumocystis jiroveci pneumonia and cytomegalovirus infection?

    <p>Acquired Immunodeficiency Syndrome (AIDS)</p> Signup and view all the answers

    What type of amyloid deposits are frequently observed in the brains of patients with Alzheimer's disease?

    <p>Beta-amyloid (Aβ) amyloid</p> Signup and view all the answers

    Which of the following statements accurately describes the relationship between CD4+ T cell depletion and opportunistic infections in AIDS patients?

    <p>CD4+ T cell depletion predisposes AIDS patients to opportunistic infections.</p> Signup and view all the answers

    Which of the following is NOT an example of an opportunistic infection commonly seen in AIDS patients?

    <p>Influenza A virus infection</p> Signup and view all the answers

    Which of the following conditions is NOT directly associated with amyloid deposition?

    <p>Multiple sclerosis</p> Signup and view all the answers

    Based on the information provided, what is the most likely explanation for the increased incidence of amyloid deposits in the brains of AIDS patients?

    <p>Immune system dysfunction leading to amyloid accumulation.</p> Signup and view all the answers

    Which of the following best describes the effect of amyloidosis on the liver, as depicted in the image?

    <p>Amyloidosis leads to the deposition of amyloid in the liver, interfering with normal liver function.</p> Signup and view all the answers

    What is the significance of the yellow-green birefringence observed in the amyloid deposits under a polarizing microscope, as shown in Figure 4.18 (B)?

    <p>It suggests that the amyloid deposits are composed of a unique protein structure.</p> Signup and view all the answers

    The PAS stain used in Figure 4.18 (C) reveals glycogen-rich deposits in the kidney. What does this indicate about the role of glycogen in amyloidosis?

    <p>Glycogen accumulates in the kidney as a response to the disruption of normal kidney function caused by amyloidosis.</p> Signup and view all the answers

    Based on the information provided and the images in Figure 4.18, what is a likely consequence of amyloid deposition in the glomerulus of the kidney?

    <p>Reduced blood filtration efficiency and potential for kidney failure.</p> Signup and view all the answers

    Which of the following statements accurately describes the nature of amyloid deposits, as suggested by the information provided?

    <p>Amyloid deposits are composed of abnormal, misfolded proteins that clump together and accumulate in various organs.</p> Signup and view all the answers

    How does the information provided suggest that amyloidosis can be considered a disease of the immune system?

    <p>Amyloidosis affects the immune system indirectly by damaging the organs responsible for immune function, leading to compromised immunity.</p> Signup and view all the answers

    Which of the following is NOT a direct consequence of an inherited mutation in the context of amyloid protein production?

    <p>Activation of macrophages and B-lymphocytes</p> Signup and view all the answers

    Based on the figure, what is the main difference between AL, AA, and ATTR proteins?

    <p>The source of the protein in the body</p> Signup and view all the answers

    In the context of amyloid protein production, what does "limited proteolysis" refer to?

    <p>The partial degradation of proteins by enzymes</p> Signup and view all the answers

    Which of the following factors can contribute to the formation of amyloidogenic intermediates?

    <p>Defective protein folding</p> Signup and view all the answers

    What is the role of inflammatory cytokines like IL-1 and IL-6 in the context of amyloid protein production?

    <p>They promote the production of amyloidogenic intermediates</p> Signup and view all the answers

    Based on the information provided, what is the primary difference between 'native folded protein' and 'amyloidogenic intermediate'?

    <p>Native folded proteins are functional, while amyloidogenic intermediates are not.</p> Signup and view all the answers

    What is the most likely outcome if the proteolysis of amyloidogenic intermediates is limited?

    <p>The intermediates will accumulate and form amyloid fibrils.</p> Signup and view all the answers

    Which of the following is a potential mechanism for preventing amyloid protein formation?

    <p>Blocking the production of amyloidogenic intermediates</p> Signup and view all the answers

    Which of the following statements is TRUE about amyloid protein production?

    <p>It can be caused by both genetic and acquired factors.</p> Signup and view all the answers

    What is the relationship between amyloid protein production and the immune system?

    <p>The immune system can be both a contributor to and a target of amyloid protein production.</p> Signup and view all the answers

    HIV's lipid bilayer originates solely from the host cell.

    <p>False</p> Signup and view all the answers

    HIV's genetic material is entirely composed of DNA.

    <p>False</p> Signup and view all the answers

    HIV's proviral DNA can integrate into the host cell's genome, becoming a permanent part of the host's genetic makeup.

    <p>True</p> Signup and view all the answers

    The process of reverse transcription converts DNA into RNA.

    <p>False</p> Signup and view all the answers

    The HIV glycoprotein gp120 facilitates the attachment of the virus to host cells.

    <p>True</p> Signup and view all the answers

    HIV's ability to integrate into the host cell genome ensures its eradication by the immune system.

    <p>False</p> Signup and view all the answers

    The production of new infectious virions is the final step in the HIV life cycle.

    <p>True</p> Signup and view all the answers

    HIV's entry into a host cell is mediated solely by the gp41 glycoprotein.

    <p>False</p> Signup and view all the answers

    Secondary amyloidosis deposits are primarily composed of amyloid A (AA) protein, which is produced by the liver.

    <p>False</p> Signup and view all the answers

    Chronic inflammation, like that caused by rheumatoid arthritis, can lead to secondary amyloidosis.

    <p>True</p> Signup and view all the answers

    Amyloid deposits, regardless of their origin, are always composed of the same type of protein.

    <p>False</p> Signup and view all the answers

    The amyloid deposits in secondary amyloidosis are primarily found in the brain.

    <p>False</p> Signup and view all the answers

    Primary amyloidosis is caused by a mutation in a gene that produces a protein that aggregates into amyloid fibrils.

    <p>True</p> Signup and view all the answers

    The deposition of amyloid fibrils does not significantly disrupt the normal function of the affected organs.

    <p>False</p> Signup and view all the answers

    Secondary amyloidosis is primarily associated with autoimmune disorders.

    <p>False</p> Signup and view all the answers

    The formation of amyloid fibrils is always a pathological process.

    <p>False</p> Signup and view all the answers

    A deficiency in the production of reactive oxygen species is a direct consequence of developmental defects affecting the phagocyte oxidase enzyme.

    <p>True</p> Signup and view all the answers

    Chronic granulomatous disease (CGD) is caused by mutations affecting the protein structure of the phagocyte oxidase enzyme.

    <p>True</p> Signup and view all the answers

    The development of chronic granulomatous disease (CGD) is primarily associated with an overactive immune response due to the production of large amounts of reactive oxygen species.

    <p>False</p> Signup and view all the answers

    The phagocyte oxidase enzyme is involved in the production of reactive oxygen species, which are essential for the killing of pathogens by phagocytes.

    <p>True</p> Signup and view all the answers

    Mutations affecting the phagocyte oxidase enzyme are commonly associated with an increased susceptibility to opportunistic infections.

    <p>True</p> Signup and view all the answers

    The term "chronic granulomatous disease" (CGD) refers to the formation of granulomas, which are clusters of immune cells that surround and wall off pathogens, in response to persistent infections.

    <p>True</p> Signup and view all the answers

    The text describes how mutations affecting the phagocyte oxidase enzyme can lead to a rare disease called chronic granulomatous disease (CGD), which is characterized by a deficiency in the production of reactive oxygen species.

    <p>True</p> Signup and view all the answers

    The text implies that a mutation affecting the phagocyte oxidase enzyme could lead to a decreased susceptibility to opportunistic infections, which is a condition where the immune system is weakened and unable to fight off common infections.

    <p>False</p> Signup and view all the answers

    Prolonged production of large amounts of SAA is not typically associated with chronic inflammation.

    <p>False</p> Signup and view all the answers

    Lymph nodes show typical lymphocyte depletion during acute HIV infection.

    <p>False</p> Signup and view all the answers

    Amyloidosis is a common complication of acute inflammatory diseases.

    <p>False</p> Signup and view all the answers

    A decrease in the number of CD4+ T cells occurs over a longer period due to chronic HIV infection.

    <p>True</p> Signup and view all the answers

    SAA production declines significantly in patients with chronic diseases.

    <p>False</p> Signup and view all the answers

    Opportunistic infections are less prevalent in countries with higher CD4+ T cell counts.

    <p>True</p> Signup and view all the answers

    Chronic inflammation can lead to complications such as lymph node hyperplasia.

    <p>False</p> Signup and view all the answers

    Tuberculosis is an example of a disorder that affects CD4+ T cell counts significantly.

    <p>True</p> Signup and view all the answers

    Monoclonal B cell proliferations in primary amyloidosis lead to excessive production of amyloid light chain (AL).

    <p>True</p> Signup and view all the answers

    Serum amyloid A (SAA) is a product of acute inflammation and leads to amyloid formation in reactive systemic amyloidosis.

    <p>False</p> Signup and view all the answers

    Transthyretin (TTR) mutations are primarily responsible for amyloid deposits in aging-related amyloidosis affecting the heart.

    <p>True</p> Signup and view all the answers

    Amyloid deposits are most commonly localized in the brain and are primarily linked to neurodegenerative diseases.

    <p>False</p> Signup and view all the answers

    The conversion of serum amyloid A (SAA) into amyloid A (AA) protein occurs in the liver due to an absence of chronic inflammation.

    <p>False</p> Signup and view all the answers

    Morphological examination of amyloid deposits shows localized amyloidosis primarily affecting the kidneys.

    <p>False</p> Signup and view all the answers

    Excessive production of immunoglobulins in primary amyloidosis leads to the formation of amyloid light chains exclusively.

    <p>True</p> Signup and view all the answers

    Amyloid deposits can pass through dialysis membranes without any change in their structure.

    <p>False</p> Signup and view all the answers

    What mutation effects lead to adhesion deficiencies in immune-related disorders?

    <p>Mutations that affect the functions of adhesion molecules such as integrins and selectins lead to adhesion deficiencies.</p> Signup and view all the answers

    In the context of HIV, what results from impaired leukocyte recruitment?

    <p>Impaired leukocyte recruitment results in acute inflammation and compromised immune responses.</p> Signup and view all the answers

    How do granuloma formations compensate for immune system failures?

    <p>Granuloma formations attempt to compartmentalize infections and prevent the spread of pathogens.</p> Signup and view all the answers

    What is the significance of adhesion molecule mutations in George syndrome?

    <p>Adhesion molecule mutations play a critical role in the pathology of George syndrome by impairing immune cell functions.</p> Signup and view all the answers

    What are the consequences of the body's response to neurotropic microbes when influenced by the immune system?

    <p>The immune system may unintentionally destroy healthy cells while targeting neurotropic microbes, leading to tissue damage.</p> Signup and view all the answers

    How does the immune system typically respond to the presence of HIV in the blood?

    <p>The immune system often mounts an acute inflammatory response to HIV, although it may be inefficient due to the virus's evasion strategies.</p> Signup and view all the answers

    What role do cytokines play in relation to adhesion deficiencies and inflammatory responses?

    <p>Cytokines facilitate the recruitment and activation of immune cells, but adhesion deficiencies can disrupt their effectiveness.</p> Signup and view all the answers

    What mechanism impairs leukocyte function in HIV-infected individuals?

    <p>The mechanism impairing leukocyte function is primarily the depletion of CD4+ T cells, affecting their ability to mount effective immune responses.</p> Signup and view all the answers

    What type of viruses are known to cause certain forms of amyloidosis in humans?

    <p>Oncogenic DNA viruses</p> Signup and view all the answers

    Describe the composition of reactive secondary amyloidosis deposits and explain how these deposits are formed.

    <p>Reactive secondary amyloidosis deposits are primarily composed of amyloid A (AA) protein. This protein is produced by the liver in response to chronic inflammation. During chronic inflammation, the liver produces an acute-phase reactant called serum amyloid A (SAA) protein. SAA is a precursor to AA protein. Over time, SAA can be converted to AA protein, which then aggregates into amyloid fibrils and forms the characteristic deposits of secondary amyloidosis.</p> Signup and view all the answers

    What is the term used to describe the deposits that form in response to the virus?

    <p>Amyloid deposits</p> Signup and view all the answers

    What is the characteristic of the protein found in the amyloid deposits?

    <p>Fibrillar structure</p> Signup and view all the answers

    How does chronic inflammation contribute to the development of secondary amyloidosis?

    <p>Chronic inflammation triggers the liver to produce large amounts of serum amyloid A (SAA) protein. This SAA protein is then converted into amyloid A (AA) protein, which accumulates and forms amyloid deposits in various organs.</p> Signup and view all the answers

    What are the key differences between primary and secondary amyloidosis in terms of their underlying causes and the types of amyloid proteins involved?

    <p>Primary amyloidosis is caused by a genetic mutation that leads to the production of an abnormal protein that forms amyloid fibrils. These mutations affect genes that produce proteins like immunoglobulin light chains (AL amyloidosis) or transthyretin (ATTR amyloidosis). Secondary amyloidosis, on the other hand, is triggered by chronic inflammation, leading to the production of amyloid A (AA) protein from the liver.</p> Signup and view all the answers

    What is the type of tumor that develops in response to the virus?

    <p>Kaposi sarcoma</p> Signup and view all the answers

    Explain the relationship between serum amyloid A (SAA) protein and amyloid A (AA) protein in the development of secondary amyloidosis.

    <p>SAA is an acute-phase reactant produced by the liver in response to inflammation. It serves as the precursor to AA protein. Over time, SAA can be converted to AA protein through a series of proteolytic steps. This AA protein then aggregates to form the amyloid deposits characteristic of secondary amyloidosis.</p> Signup and view all the answers

    What is the primary consequence of the virus replication in the lymph nodes?

    <p>Immune system dysregulation</p> Signup and view all the answers

    How does the deposition of amyloid fibrils in organs contribute to the pathogenesis of amyloidosis?

    <p>The deposition of amyloid fibrils disrupts the normal structure and function of the affected organs. They can interfere with cell function, lead to cell death, and ultimately cause organ dysfunction. The extent of organ damage and the severity of symptoms depend on the location and extent of amyloid deposition.</p> Signup and view all the answers

    What is the relationship between the virus and the immune system?

    <p>The virus dysregulates the immune system</p> Signup and view all the answers

    What is the term used to describe the increased incidence of amyloid deposits in the brains of patients with AIDS?

    <p>Amyloidosis</p> Signup and view all the answers

    Why is it important to understand the pathogenesis of amyloidosis?

    <p>Understanding the pathogenesis of amyloidosis is crucial for developing effective treatments and therapies. Knowing how amyloid deposits form and how they affect organs allows researchers to target specific pathways involved in amyloid production and aggregation. This could lead to the development of drugs that prevent or reverse amyloid deposition, potentially halting or even reversing the progression of the disease.</p> Signup and view all the answers

    What is the significance of the increased production of amyloidogenic proteins in patients with AIDS?

    <p>Dysregulation of the immune system</p> Signup and view all the answers

    Why are chronic inflammatory conditions often linked to secondary amyloidosis?

    <p>Chronic inflammatory conditions trigger the liver to produce large amounts of serum amyloid A (SAA) protein. This protein serves as the precursor for amyloid A (AA) protein, which forms the deposits characteristic of secondary amyloidosis. Therefore, the sustained inflammatory response in chronic conditions provides a continuous source of SAA, driving the formation of amyloid deposits.</p> Signup and view all the answers

    What are some examples of chronic inflammatory conditions that can lead to secondary amyloidosis?

    <p>Some examples of chronic inflammatory conditions that can lead to secondary amyloidosis include rheumatoid arthritis, Crohn's disease, ulcerative colitis, systemic lupus erythematosus, and chronic infections.</p> Signup and view all the answers

    Explain the mechanism by which HIV infection leads to the development of amyloid deposits in the brains of AIDS patients, incorporating the role of β2-microglobulin protein.

    <p>HIV infection triggers a chronic immune response, leading to increased production of β2-microglobulin. This protein accumulates in the bloodstream and eventually deposits in various organs, including the brain, forming amyloid fibrils. The formation of these amyloid deposits contributes to the neurocognitive decline observed in AIDS patients.</p> Signup and view all the answers

    Describe the link between HIV infection, CD4+ T cell depletion, and the increased susceptibility to opportunistic infections in AIDS patients.

    <p>HIV specifically targets and destroys CD4+ T cells, which are crucial for immune system function. As CD4+ T cell counts decline, the immune system becomes severely weakened, increasing the vulnerability to opportunistic infections, which are normally controlled by a healthy immune system.</p> Signup and view all the answers

    Compare and contrast the formation of primary and secondary amyloidosis, highlighting the underlying causes and the types of proteins involved.

    <p>Primary amyloidosis is caused by genetic mutations leading to the production of misfolded proteins that aggregate into amyloid fibrils. These deposits are primarily composed of proteins like AL, ATTR, or AA. Secondary amyloidosis, on the other hand, is triggered by chronic inflammation, leading to increased production of amyloid A (AA) protein by the liver. This protein then accumulates and forms amyloid deposits in various organs.</p> Signup and view all the answers

    Explain the significance of the yellow-green birefringence observed in amyloid deposits under a polarizing microscope, considering the molecular structure of amyloid fibrils.

    <p>The yellow-green birefringence seen under a polarizing microscope is a characteristic feature of amyloid deposits. It arises from the highly ordered and organized structure of amyloid fibrils, where protein molecules are tightly packed together in a cross-β sheet conformation, producing a distinct optical property.</p> Signup and view all the answers

    Discuss the role of inflammatory cytokines, such as IL-1 and IL-6, in the pathogenesis of secondary amyloidosis, emphasizing how they contribute to amyloid protein production.

    <p>Inflammatory cytokines like IL-1 and IL-6 play a significant role in secondary amyloidosis. During chronic inflammation, these cytokines stimulate the liver to produce high levels of amyloid A (AA) protein. This excessive production of AA protein contributes to its accumulation and deposition in various organs, leading to the development of secondary amyloidosis.</p> Signup and view all the answers

    Describe the stages of HIV infection, from the initial exposure to the development of AIDS, outlining the key events that occur in each stage.

    <p>HIV infection progresses through distinct stages. Initially, the virus replicates rapidly, leading to viremia and acute HIV syndrome. The immune system fights back, leading to a period of clinical latency where viral replication is controlled. However, over time, CD4+ T cells decline, weakening the immune system. This allows for opportunistic infections, ultimately leading to AIDS.</p> Signup and view all the answers

    Explain how HIV's ability to integrate its proviral DNA into the host cell's genome contributes to the persistence of the virus and the difficulty in eradicating it.

    <p>HIV's proviral DNA, once integrated into the host cell's genome, becomes a permanent part of the host's genetic makeup. This integration allows HIV to persist within the host, evading the immune system and traditional antiviral therapies. It also enables the virus to produce new viral particles continuously.</p> Signup and view all the answers

    Discuss the impact of amyloid deposition on the liver, considering the potential consequences for its function.

    <p>Amyloid deposition in the liver can lead to a range of functional disruptions. Amyloid fibrils can accumulate in the liver, leading to fibrosis and scarring, ultimately impairing liver function. This can cause impaired blood flow through the liver, leading to portal hypertension and ascites. In severe cases, liver failure can occur.</p> Signup and view all the answers

    Explain how the process of limited proteolysis contributes to the formation of amyloidogenic intermediates, emphasizing its role in amyloid protein production.

    <p>Limited proteolysis refers to the incomplete breakdown of proteins, resulting in the formation of partially digested protein fragments. These fragments can adopt different conformations, including amyloidogenic intermediates, which are prone to aggregation and amyloid fibril formation. This process is crucial in the development of amyloid diseases.</p> Signup and view all the answers

    Describe the mechanisms by which HIV, despite being a retrovirus, can cause persistent infection and evade the immune system, highlighting its impact on the host.

    <p>HIV's ability to integrate its genetic material into the host cell's genome is key to its persistent infection. This integration allows HIV to become a permanent part of the host's DNA, ensuring continuous viral replication. Additionally, HIV targets and destroys CD4+ T cells, which are critical for immune responses, weakening the host's defenses and facilitating viral persistence.</p> Signup and view all the answers

    What is the primary function of the amyloid protein in the context of the body's normal functioning?

    <p>The amyloid protein does not have a known primary function in the body's normal functioning. Amyloid is usually a byproduct of protein misfolding and can form deposits that disrupt organ function.</p> Signup and view all the answers

    Explain the relationship between transthyretin and amyloid deposits in the context of ATTR amyloidosis. What makes this type of amyloidosis unique?

    <p>ATTR amyloidosis is caused by mutations in the transthyretin gene, leading to the production of an abnormally folded transthyretin protein that can form amyloid deposits. This type of amyloidosis is unique because it is caused by a genetic mutation that directly affects the production of the amyloid protein.</p> Signup and view all the answers

    Based on the text, describe the key differences between primary and secondary amyloidosis. Provide specific examples to support your explanation.

    <p>Primary amyloidosis is caused by mutations in genes that produce amyloid proteins, while secondary amyloidosis is caused by chronic inflammation and increased production of serum amyloid A (SAA) protein. An example of primary amyloidosis is ATTR amyloidosis caused by mutations in the transthyretin gene, while an example of secondary amyloidosis is AA amyloidosis resulting from chronic inflammatory conditions such as rheumatoid arthritis.</p> Signup and view all the answers

    How can limited proteolysis of amyloidogenic intermediates contribute to the formation of amyloid fibrils? Explain the process and its significance.

    <p>Limited proteolysis of amyloidogenic intermediates can lead to the formation of amyloid fibrils by generating smaller, more stable fragments that are more prone to aggregation. This is because the smaller fragments have a higher surface-to-volume ratio, increasing their interaction with other molecules and promoting amyloid fibril formation.</p> Signup and view all the answers

    What are the potential consequences of amyloid deposition on the function of organs and tissues? How do these effects contribute to the overall pathology of amyloidosis?

    <p>Amyloid deposition can disrupt the normal function of organs and tissues by interfering with cellular processes, causing cell death, and leading to organ dysfunction. For example, amyloid deposits in the heart can cause cardiomyopathy, while deposits in the kidneys can lead to nephropathy. These effects contribute to the overall pathology of amyloidosis by impairing organ function and ultimately leading to organ failure.</p> Signup and view all the answers

    Discuss the role of inflammatory cytokines like IL-1 and IL-6 in the context of amyloid protein production. How do they influence the development of amyloidosis?

    <p>Inflammatory cytokines like IL-1 and IL-6 can contribute to the development of amyloidosis by promoting the production of serum amyloid A (SAA) protein, a precursor to amyloid fibrils. Increased levels of these cytokines can also stimulate the production of other amyloidogenic proteins, ultimately contributing to the formation of amyloid deposits.</p> Signup and view all the answers

    Explain how the deposition of amyloid fibrils can impact the structure and function of cells, leading to organ dysfunction. Provide specific examples.

    <p>Amyloid fibrils can disrupt cellular function by interfering with cellular processes, such as protein trafficking and signaling pathways. They can also damage cell membranes and trigger cell death. For example, amyloid deposits in the brain can disrupt neuronal function and lead to neurodegeneration, while deposits in the heart can disrupt muscle function and lead to cardiomyopathy.</p> Signup and view all the answers

    Based on the text, what is the significance of amyloid deposition in the kidney in the context of amyloidosis? How does this deposition contribute to the overall pathology of the disease?

    <p>Amyloid deposition in the kidney, specifically in the glomerulus, can lead to nephrotic syndrome. This occurs because amyloid fibrils disrupt the filtration process of the glomerulus, causing proteinuria and ultimately kidney failure. This contributes to the overall pathology of amyloidosis by impairing kidney function and leading to severe complications.</p> Signup and view all the answers

    HIV is an ______ virus whose core contains two strands of viral RNA.

    <p>enveloped</p> Signup and view all the answers

    It is estimated that there are more than 35 million ______ individuals in the world.

    <p>HIV-infected</p> Signup and view all the answers

    Approximately 70% of HIV-infected individuals are in ______.

    <p>Africa</p> Signup and view all the answers

    The disease is transmitted by direct transfer of infected ______.

    <p>fluids</p> Signup and view all the answers

    HIV involves numerous regulators of viral gene expression and ______.

    <p>replication</p> Signup and view all the answers

    As many as 1 million people die each year from the ______.

    <p>disease</p> Signup and view all the answers

    HIV encodes structural proteins, enzymes involved in viral integration, and other ______.

    <p>regulators</p> Signup and view all the answers

    The capsid proteins of HIV play a significant role in ______ the viral RNA.

    <p>encapsulating</p> Signup and view all the answers

    The ______ may be present in infected cells for years, establishing a latent infection.

    <p>virus</p> Signup and view all the answers

    As the ______ decreases, the Centers for Disease Control and Prevention (CDC) classifies HIV infection stages based on CD4+ cell counts.

    <p>count</p> Signup and view all the answers

    When an infected cell is activated, the viral ______ is transcribed, viral proteins are produced, and complete virions are released to continue the cycle of infection.

    <p>DNA</p> Signup and view all the answers

    The CDC categorizes HIV infection stages into three groups based on CD4+ cell counts: greater than or equal to 500 cells/μL, 200 to 499 cells/μL, and fewer than ______ cells/μL.

    <p>200</p> Signup and view all the answers

    The extent of viremia, measured as HIV-1 RNA levels in the ______, is a marker of disease progression.

    <p>blood</p> Signup and view all the answers

    HIV infection can lead to a decline in ______ T-cell counts, which are crucial for immune function.

    <p>CD4+</p> Signup and view all the answers

    The virus may be present in infected cells for years, establishing a ______ infection.

    <p>latent</p> Signup and view all the answers

    HIV's genetic material is entirely composed of ______.

    <p>RNA</p> Signup and view all the answers

    The viral particle is covered by a lipid ______ derived from the host cell.

    <p>bilayer</p> Signup and view all the answers

    Reverse transcription converts viral RNA to ______ DNA.

    <p>proviral</p> Signup and view all the answers

    The HIV glycoproteins ______ and gp120 are crucial for the virus's entry into host cells.

    <p>gp41</p> Signup and view all the answers

    The integration of proviral DNA into the host genome is a key step in the HIV ______ cycle.

    <p>life</p> Signup and view all the answers

    The progressive encephalopathy that can occur following HIV infection is also known as ______ disorder.

    <p>neurocognitive</p> Signup and view all the answers

    Following HIV entry into the cell, the viral RNA is converted to DNA and then ______ into the host's genome.

    <p>integrated</p> Signup and view all the answers

    The final stage of the HIV life cycle is the production of infectious ______.

    <p>virions</p> Signup and view all the answers

    HIV is typically associated with a depletion of ______+ T cells in the immune system.

    <p>CD4</p> Signup and view all the answers

    In any particular case, why ______ of forms (or not) is unknown.

    <p>amyloidosis</p> Signup and view all the answers

    A section of liver stained with Congo red reveals pink-red deposits of ______ in the walls of blood vessels and along sinusoids.

    <p>amyloid</p> Signup and view all the answers

    Note the yellow-green birefringence of the ______ when observed by a polarizing microscope.

    <p>deposits</p> Signup and view all the answers

    In the kidney, the glomerular architecture is almost totally obliterated by the massive accumulation of ______.

    <p>amyloid</p> Signup and view all the answers

    The stain, called a PAS stain, reveals ______-rich deposits.

    <p>glycogen</p> Signup and view all the answers

    __________ infections are associated with certain tumors caused by oncogenic DNA viruses.

    <p>Viral</p> Signup and view all the answers

    Secondary amyloidosis deposits are primarily composed of amyloid A (AA) protein, which is produced by the ______.

    <p>liver</p> Signup and view all the answers

    Kapos� sarcoma is associated with __________ infections.

    <p>herpesvirus</p> Signup and view all the answers

    Certain tumors are caused by __________ DNA viruses.

    <p>oncogenic</p> Signup and view all the answers

    Candidiasis, cryptococcosis, and __________ are forms of amyloidosis.

    <p>mycobacterium</p> Signup and view all the answers

    Mediterranean _________ is a disease that has systemic inflammation.

    <p>fever</p> Signup and view all the answers

    One consequence of certain infections is increased production of __________.

    <p>amyloid</p> Signup and view all the answers

    The __________ carcinoma is associated with Human papillomavirus (HPV).

    <p>cervical</p> Signup and view all the answers

    B-cell lymphoma is linked to __________ virus.

    <p>Epstein-Barr</p> Signup and view all the answers

    What is unique about the genetic material of HIV?

    <p>It is entirely composed of RNA</p> Signup and view all the answers

    What is the primary function of the enzymes involved in HIV integration?

    <p>To convert RNA into DNA</p> Signup and view all the answers

    What is the approximate percentage of HIV-infected individuals living in Africa?

    <p>70%</p> Signup and view all the answers

    What is the purpose of the core in the HIV virus?

    <p>To protect the genetic material</p> Signup and view all the answers

    How many strands of RNA are present in the HIV virus?

    <p>Two</p> Signup and view all the answers

    What is the site of initial HIV replication and spread?

    <p>Lymph nodes</p> Signup and view all the answers

    What is the estimated number of people living with HIV?

    <p>Over 35 million</p> Signup and view all the answers

    What is the approximate percentage of HIV-infected individuals living in Asia?

    <p>20%</p> Signup and view all the answers

    What is the site where the virus initially replicates and then spreads to other tissues?

    <p>Lymph nodes</p> Signup and view all the answers

    What is the characteristic of the protein found in the deposits formed in response to the virus?

    <p>Pharmacologically identical but chemically distinct</p> Signup and view all the answers

    What is the primary immune deficiency associated with the development of the deposits?

    <p>Impaired cell-mediated immunity</p> Signup and view all the answers

    What is the term for the deposits that form in response to the virus?

    <p>Amyloid deposits</p> Signup and view all the answers

    What is the outcome of the virus replication in the lymph nodes?

    <p>Immune system suppression</p> Signup and view all the answers

    What is the type of tumor that develops in response to the virus?

    <p>Primary amyloid tumor</p> Signup and view all the answers

    What is a major complication associated with AIDS due to the progressive loss of T cells?

    <p>Opportunistic infections</p> Signup and view all the answers

    Which of the following describes a characteristic of the HIV virus within lymphoid tissues?

    <p>It utilizes mucosal tissues for its entry.</p> Signup and view all the answers

    What is the reason HAART is not considered a cure for HIV?

    <p>The virus can remain dormant in the body.</p> Signup and view all the answers

    What can result from the significant side effects of HIV medications?

    <p>Development of drug resistance</p> Signup and view all the answers

    What is a significant consequence of the decline in primary CD4+ T cells?

    <p>Increased risk of opportunistic infections</p> Signup and view all the answers

    What type of diseases are NOT directly associated with the immunodeficiency caused by AIDS?

    <p>Cardiovascular diseases</p> Signup and view all the answers

    Which mechanism contributes to the complications seen in AIDS patients aside from the loss of uninfected T cells?

    <p>Altered function of immune cells</p> Signup and view all the answers

    What is a common outcome due to the persistent presence of HIV in the body?

    <p>Chronic inflammation and tissue damage</p> Signup and view all the answers

    What characteristic color and optical property can be observed in amyloid deposits?

    <p>Yellow-green birefringence under polarized light</p> Signup and view all the answers

    What is a defining feature of primary amyloidosis?

    <p>It results from mutations in genes producing amyloid fibrils.</p> Signup and view all the answers

    In the context of amyloidosis, in which organ are amyloid deposits most likely to disrupt normal function?

    <p>All of the above</p> Signup and view all the answers

    Which type of amyloidosis is primarily associated with chronic diseases like rheumatoid arthritis?

    <p>Secondary amyloidosis</p> Signup and view all the answers

    Which statement correctly distinguishes systemic amyloidosis from localized forms?

    <p>Systemic amyloidosis can affect multiple tissues in the body.</p> Signup and view all the answers

    Which factor contributes to the aging-associated amyloidosis observed in elderly patients?

    <p>Diminished immune response and protein clearance</p> Signup and view all the answers

    What potential outcome arises from limited proteolysis of amyloidogenic intermediates?

    <p>Higher likelihood of amyloid fibril formation</p> Signup and view all the answers

    How is primary amyloidosis typically characterized in terms of its effects on patients?

    <p>It generally leads to systemic complications over time.</p> Signup and view all the answers

    What is the main reason why amyloid deposits can lead to restrictive organ function?

    <p>They block normal tissue architecture.</p> Signup and view all the answers

    Which type of amyloid is characterized as having deposition related to a process in the kidneys?

    <p>AL amyloid</p> Signup and view all the answers

    What clinical complication is commonly associated with systemic amyloidosis?

    <p>Cardiomyopathy</p> Signup and view all the answers

    What does the presence of excess amyloid in tissues indicate regarding the underlying protein sequence?

    <p>It may have mutations enhancing aggregation.</p> Signup and view all the answers

    How does the prognosis of individuals with systemic AL amyloidosis typically compare to others?

    <p>They generally have a poor prognosis.</p> Signup and view all the answers

    What primarily determines the outcome of reactive systemic amyloidosis?

    <p>Management of the underlying condition.</p> Signup and view all the answers

    What type of amyloid is produced specifically in response to chronic inflammatory conditions?

    <p>AA amyloid</p> Signup and view all the answers

    Which statement accurately reflects the relationship between amyloid protein production and the primary immune system?

    <p>Certain inflammatory cytokines may influence amyloid production.</p> Signup and view all the answers

    Study Notes

    HIV and CD4+ Cell Depletion

    • HIV targets and depletes CD4+ T cells, a key component of the immune system.
    • CD4+ cell count serves as a marker for HIV disease progression and patient management.
    • The virus replicates in infected cells, leading to cytopathic effects, which further reduce CD4+ cell populations.
    • The course of the disease is typically characterized as untreated and progresses if left unmanaged.

    Mechanisms of HIV Replication

    • HIV replication potentially increases membrane permeability, affecting cellular function.
    • Current treatments combine antiretroviral drugs, offering a comprehensive approach to inhibit viral replication.
    • Highly Active Antiretroviral Therapy (HAART) prevents the development of HIV-induced cell protein synthesis impairment.

    Dendritic Cells and Viral Transmission

    • Dendritic cells in mucosal sites transport HIV to regional lymph nodes, where the virus further replicates.
    • Viral dissemination occurs from lymph nodes to other tissues, facilitating widespread infection.

    Disease Progression and Opportunistic Infections

    • Progressive loss of CD4+ T cells correlates with developing various opportunistic infections.
    • Patients with AIDS exhibit a significantly increased incidence of infections, such as Pneumocystis jirovecii and cytomegalovirus.
    • Amyloidosis may also arise, with potential links to the immune deficiency associated with HIV/AIDS.

    Amyloidosis Overview

    • Amyloidosis involves abnormal protein deposits in organs, primarily affecting the heart, kidneys, and liver.
    • Conditions leading to amyloidosis include chronic inflammation and inherited mutations.
    • Misfolded proteins aggregate to form amyloid fibrils, disrupting normal tissue structure and function.

    Diagnostic Markers and Findings

    • Congo red staining highlights amyloid deposits in affected tissues, visible under polarizing microscopy as birefringent structures.
    • PAS staining can reveal glycogen-rich deposits in kidney tissues affected by amyloidosis.
    • The intricate relationship between immune system disorders and amyloidosis underscores the complexity of human diseases.

    Defects in Innate Immunity

    • Chronic granulomatous disease (CGD) results from defective production of reactive oxygen species caused by mutations affecting the cytochrome oxidase enzyme.
    • Increased susceptibility to infections from specific pathogens, including fungi and bacteria.
    • Severe macrophage activation is a hallmark of CGD.

    Structure and Life Cycle of HIV

    • HIV is enveloped by a lipid bilayer from the host cell, featuring glycoproteins gp41 and gp120 on its surface.
    • Upon entering a host cell, HIV reverse transcribes its RNA into proviral DNA, integrating it into the host genome.
    • This integration leads to HIV-associated neurocognitive disorder in progressive encephalopathy cases.

    Reactive Secondary Amyloidosis

    • Amyloidosis involves deposits of amyloid proteins, principally serum amyloid A (SAA), derived from precursor proteins.
    • Chronic inflammation, such as from various chronic infections, can trigger excessive production of SAA.
    • Prolonged production results in amyloid deposition without severe symptoms, complicating chronic inflammatory diseases.

    Pathogenesis of Amyloidosis

    • Primary amyloidosis stems from monoclonal plasma or B cell proliferations causing excessive immunoglobulin production.
    • Reactive systemic amyloidosis results from chronic inflammation, converting SAA into amyloid A protein.
    • Transthyretin (TTR) mutations are linked to amyloid deposits with age, particularly affecting the heart.

    Morphology of Amyloidosis

    • Amyloid deposits can be identified in nearly every parenchymal organ, appearing in tissue sections as waxy or homogenous deposits.
    • Localized amyloidosis may affect specific bodily regions and can be more pronounced in certain chronic diseases.

    Immune System Disorders

    • Granuloma formation occurs in response to chronic inflammation, often from infections or foreign bodies.
    • Adhesion deficiencies result from mutations affecting immune cell function and are prevalent in conditions like leukocyte adhesion deficiency.
    • 90% of cases of Digeorge syndrome exhibit adhesion molecule abnormalities, impacting immune response.

    Infection and Inflammation

    • Acute inflammation involves leukocyte recruitment and results in tissue damage if uncontrolled.
    • Chronic viral infections, such as HIV, can lead to significant immune system decline, characterized by CD4+ T cell depletion.
    • Reactively secondary amyloidosis results from the deposition of amyloid A (AA) proteins, often generated from chronic inflammatory states.

    Viral Infections and Immunology

    • Chronic infections can trigger systemic inflammation, contributing to amyloidosis, especially in cases associated with viruses or certain tumors.
    • Oncogenic DNA viruses are linked to conditions like Kaposi's sarcoma and certain lymphomas, inducing increased inflammation.
    • Specific amyloidosis forms arise from different triggers, where SAA proteins are particularly associated with inflammation.

    HIV Progression

    • The HIV lifecycle begins with virus entry into mucosal tissues, leading to CD4 T cell death and transport to lymph nodes, establishing infection.
    • During acute HIV infection, there is a significant viral load increase, often followed by viral dissemination to lymphoid organs.
    • Clinical latency represents a stable phase where the virus persists in low levels while causing minimal symptoms but may lead to a resurgence of viral replication and AIDS development.

    Disease Dynamics

    • Progressive infection in lymphoid tissues leads to viremia, characterized by widespread viral presence in the body.
    • The immune response includes the production of anti-HIV antibodies and cytotoxic T lymphocytes, providing a partial control over viral replication initially.
    • The transition from acute to chronic HIV infection involves low-level virus production, destruction of lymphoid tissues, and eventual CD4+ T cell depletion, culminating in AIDS.### Amyloidosis Overview
    • Amyloidosis involves abnormal protein deposits that interfere with the normal function of organs, particularly the heart, kidneys, and gastrointestinal tract.
    • Cardiac amyloidosis is the most frequent complication, leading to restrictive cardiomyopathy.

    Biochemical Composition

    • Amyloid deposits are comprised of misfolded proteins, notably transthyretin.
    • Deposition can occur in various tissues, leading to conditions such as nephrotic syndrome and congestive heart failure.

    Types of Amyloidosis

    • AL (Light Chain) Amyloidosis: Caused by antibody light chains; high-risk prognosis and can lead to systemic complications.
    • ATTR (Transthyretin) Amyloidosis: Involves deposition of transthyretin; can be hereditary or age-related.
    • Gastrointestinal involvement can result in malabsorption syndromes due to amyloid deposits.

    Diagnosis and Prognosis

    • Diagnosis of amyloidosis relies on demonstrating excess amyloid deposition in tissues.
    • Poor outcomes are linked to systemic AL amyloidosis, while hereditary ATTR amyloidosis can also present severe complications.
    • Prognosis relies on the underlying conditions causing amyloidosis and the extent of organ involvement.

    Treatment Considerations

    • Management of amyloidosis focuses on controlling the underlying causes and may involve chemotherapy or other interventions.
    • Overall prognosis varies significantly based on type, systemic involvement, and response to treatment.

    Conclusion

    • Distinctions exist between genetic and acquired types of amyloidosis; understanding the underlying mechanisms is crucial for effective treatment and management.

    HIV Overview

    • HIV is an enveloped virus with a structure consisting of capsid proteins and two strands of viral RNA.
    • Over 35 million individuals globally are HIV-infected, with 70% located in Africa and 20% in Asia.
    • The virus is transmitted through direct contact with infected bodily fluids.

    Pathogenesis and Life Cycle

    • Following entry into the host cell, HIV RNA is reverse transcribed into proviral DNA.
    • This proviral DNA can integrate into the host cell genome, persisting inactive for years.
    • Activation of infected cells, often triggered by infections or inflammation, leads to the transcription of proviral DNA and production of viral proteins.

    Immune Impact

    • Loss of CD4+ T-cells due to HIV infection compromises the immune system, classified into three groups based on CD4+ counts:
      • Greater than or equal to 500 cells/μL
      • 200 to 499 cells/μL
      • Fewer than 200 cells/μL.
    • The extent of viremia is assessed by HIV-1 RNA levels, indicating the amount of virus in the blood.

    Associated Diseases

    • HIV is linked to several opportunistic infections and malignancies due to immune suppression.
    • Commonly associated infections include cryptococcosis, candidiasis, and tuberculosis.
    • Certain tumors, such as Kaposi's sarcoma (associated with Kaposi's sarcoma herpesvirus) and lymphomas (linked to Epstein-Barr virus), frequently occur in HIV patients.

    Amyloidosis

    • Amyloidosis can be a consequence of HIV and includes the abnormal deposition of amyloid in tissues.
    • Key histological features observed in affected organs include pink-red deposits in liver sections stained with Congo red and significant glomerular damage in kidneys.

    Figures and Illustrations

    • Figures illustrate the structure and life cycle of HIV, including the viral particle's lipid bilayer and glycoproteins.
    • Histological images depict the effects of amyloidosis on the liver and kidneys, highlighting changes in tissue architecture.

    HIV Overview

    • HIV (Human Immunodeficiency Virus) is an enveloped virus that causes a progressive loss of immune function.
    • An estimated 35 million individuals worldwide are HIV-infected, with the majority (70%) residing in Africa and 20% in Asia.
    • HIV consists of a core made of proteins and two strands of viral RNA, which encode for proteins essential for the virus’s lifecycle.

    Transmission and Effects

    • The virus is transmitted through direct contact with infected bodily fluids.
    • HIV leads to a depletion of CD4+ T cells, which are crucial for immune defense, resulting in immune deficiency known as AIDS (Acquired Immunodeficiency Syndrome).
    • Approximately 1 million people die each year due to HIV-related diseases.

    Mechanisms of Infection

    • HIV primarily attacks mucosal tissues, diminishing immune responses in those areas.
    • Viral replication occurs in regional lymph nodes, from where it spreads to other tissues.
    • Infected dendritic cells in mucosal sites play a role in transporting the virus to lymph nodes.

    Clinical Consequences

    • Various complications arise from HIV, including opportunistic infections and cancers due to immune suppression.
    • Treatment is not a cure but aims to manage the virus and associated symptoms through antiretroviral therapy.
    • Significant side effects from medications include insulin resistance, neuropathy, and cardiovascular, kidney, and liver diseases.

    Amyloidosis and Aging

    • Amyloidosis is characterized by the deposition of amyloid proteins in tissues, leading to organ dysfunction, commonly affecting the heart and kidneys.
    • The most prevalent type of amyloidosis is AL amyloidosis, associated with the clonal proliferation of plasma cells.
    • Primary amyloidosis is distinguished from systemic amyloidosis, which affects multiple organs.

    Diagnosis and Prognosis

    • Diagnosis of amyloidosis relies on demonstrating excess production of amyloid proteins in tissues.
    • The prognosis varies depending on the type of amyloidosis, with systemic forms often being more serious, leading to poorer outcomes.
    • Early detection and treatment of the underlying conditions can improve prognosis.

    Summary

    • Both HIV and amyloidosis highlight the complex interplay between infectious and systemic diseases, emphasizing the need for ongoing research and patient management strategies.

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    Robbins Essential Pathology - Diseases of the Immune System PDF

    Description

    This quiz explores the relationship between HIV and CD4+ cells, including how the virus depletes these cells and the consequences of this process. Learn about the role of CD4+ cells in the immune system and how HIV affects them.

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