Inflammation and Immune Defense Mechanisms

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the meaning of inflammation, according to the content?

Inflammation is a physiological process that aims to bring back the organism to a homeostatic state by activating defense and repair mechanisms.

Which of the following are NOT included in the first line of defense against pathogens?

  • Skin
  • Innate immunity (correct)
  • Normal microbiota
  • Mucous membranes

Adaptive immunity is the first line of defense against pathogens.

False (B)

The ______ is a key transcription factor involved in regulating genes associated with inflammation.

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

What are acute phase proteins?

<p>Acute phase proteins are a group of proteins produced by the liver in response to inflammation. They are used as biomarkers for inflammation and are involved in the regulation of the immune system.</p> Signup and view all the answers

Only positive regulators of inflammation are important for understanding the state of inflammation in a patient.

<p>False (B)</p> Signup and view all the answers

Match the cytokines with their primary roles in inflammation

<p>TNF = Induces the production of chemokines and promotes leukocyte recruitment IL-1 = Associated with the activation of the hypothalamic-pituitary-adrenal axis, leading to fever and cortisol production IL-6 = Stimulates the production of acute-phase proteins in the liver. TGF-beta = Plays a regulatory role in suppressing inflammation and promoting resolution of inflammation Interleukin-10 = A potent anti-inflammatory cytokine that helps to dampen the inflammatory response. Glucocorticoids = Mediate negative feedback mechanisms to control the intensity of the inflammatory response.</p> Signup and view all the answers

What is the main difference between the kinetics of CRP and PTX3 during an acute myocardial infarction?

<p>CRP levels remain relatively stable in the first 24 hours after myocardial infarction, while PTX3 levels increase rapidly and return to baseline quickly.</p> Signup and view all the answers

High-sensitivity CRP (hs-CRP) is more useful than standard CRP for detecting low-grade, chronic inflammation.

<p>True (A)</p> Signup and view all the answers

What is the purpose of the JUPITER trial?

<p>The JUPITER trial demonstrated that statin therapy can reduce cardiovascular risk even in patients with normal LDL cholesterol levels, based on their high-sensitivity CRP levels.</p> Signup and view all the answers

Procalcitonin (PCT) is primarily produced by the thyroid.

<p>False (B)</p> Signup and view all the answers

What distinguishes PCT as a biomarker of bacterial infection?

<p>PCT levels increase more significantly in response to bacterial infections compared to viral infections or sterile inflammation. It is a good indicator of bacterial sepsis.</p> Signup and view all the answers

PCT levels are always elevated in patients diagnosed with sepsis.

<p>False (B)</p> Signup and view all the answers

Explain the importance of fibrinogen and its byproducts in tissue repair and coagulation?

<p>Fibrinogen forms a provisional matrix, essential for immediate tissue repair, and contributes to blood clotting. This process is important for wound healing and preventing further damage.</p> Signup and view all the answers

Which of the following statements is TRUE about lactate dehydrogenase (LDH)?

<p>LDH levels are increased in tissue damage and cell death. (D)</p> Signup and view all the answers

What is the role of transferrin in iron metabolism?

<p>Transferrin primarily acts as a negative acute phase protein, meaning its levels decrease during inflammation. It binds and transports iron, regulating the availability of iron for the body while preventing excess iron from reaching microbes.</p> Signup and view all the answers

How can ferritin levels assist in diagnosing iron deficiency and overload?

<p>Low ferritin levels indicate iron deficiency anemia, while elevated ferritin levels suggest iron overload conditions such as hemochromatosis or hemosiderosis.</p> Signup and view all the answers

Procalcitonin (PCT) is a more rapid marker of inflammation than CRP, with a shorter half-life.

<p>True (A)</p> Signup and view all the answers

The levels of PCT in sterile conditions, like trauma or surgery, are typically similar to levels in sepsis.

<p>False (B)</p> Signup and view all the answers

What is the key difference between SIRS and sepsis?

<p>Sepsis differs from SIRS in that it is a life-threatening organ dysfunction directlycaused by a dysregulated host response to infection.</p> Signup and view all the answers

What are the three lines of defense in the immune system?

<p>First line of defense: skin and mucous membranes, the normal microbiota Second line: inflammation and the activity of innate immunity Third line: adaptive immunity</p> Signup and view all the answers

The innate immune system is the first response to infection and takes several days to activate.

<p>False (B)</p> Signup and view all the answers

What are some of the conditions that activate inflammation?

<p>Tissue damage (A), Dysmetabolism (B), Dysbiosis (C), Infection (D), Homeostatic imbalances (E)</p> Signup and view all the answers

What is the meaning of inflammation?

<p>Inflammation is the body's response to injury or infection, aiming to return the body to its homeostatic state, activate defense mechanisms, and activate repair mechanisms.</p> Signup and view all the answers

Which of these cells are considered professional cells in innate immunity?

<p>Dendritic cells (A), Macrophages (B), Neutrophils (D), Natural killer cells (F)</p> Signup and view all the answers

What are some examples of receptors that activate an inflammatory response?

<p>NFkB transcription factor, IRF, Toll-like receptors, integrins, and sensors of viral molecules.</p> Signup and view all the answers

Acute phase proteins are produced during inflammation and can help determine whether an inflammatory response is present.

<p>True (A)</p> Signup and view all the answers

Which cytokines are the main leaders of the cytokine cascade?

<p>TNF, IL-1 and IL-6.</p> Signup and view all the answers

IL-6 acts locally, while TNF and IL-1 act at a systemic level.

<p>False (B)</p> Signup and view all the answers

What are some of the factors that IL-1 and TNF regulate in the local response to inflammation? (Select all that apply)

<p>Recruitment of leukocytes (A), Survival of leukocytes (B), Orientation of the adaptive immune response (C), Prostaglandin production (D), Colony stimulating factors (E), Chemokine production (F)</p> Signup and view all the answers

What are the main effects of IL-6 in systemic inflammation?

<p>IL-6 stimulates the liver to produce acute phase proteins, which amplifies the systemic inflammatory response. Also, IL-6 promotes the production of negative regulators, such as glucocorticoids, TGF-beta, and interleukin-10, to help modulate the inflammatory response.</p> Signup and view all the answers

The erythrocyte sedimentation rate (ESR) is a very sensitive test that is commonly used to diagnose inflammation in hospitals.

<p>False (B)</p> Signup and view all the answers

What is the definition of the erythrocyte sedimentation rate (ESR)?

<p>The rate at which red blood cells settle in one hour.</p> Signup and view all the answers

What are some of the factors that promote sedimentation in the ESR?

<p>Fibrinogen and other acute phase proteins.</p> Signup and view all the answers

What are some of the conditions that can cause a decreased ESR?

<p>Conditions such as hyperviscosity of the blood, polycythemia, sickle cell anemia, leukemia, and low plasma protein.</p> Signup and view all the answers

C-reactive protein (CRP) is a very sensitive acute phase protein with a rapid induction time and a short half-life.

<p>True (A)</p> Signup and view all the answers

What are some of the uses of CRP in clinical practice?

<p>CRP is used to diagnose and monitor inflammatory conditions, such as infections, rheumatic diseases, autoimmune conditions, trauma, and cancer. It is particularly useful in assessing cardiovascular risk.</p> Signup and view all the answers

CRP levels are affected by factors such as pregnancy and anemia, similar to the ESR.

<p>False (B)</p> Signup and view all the answers

Which of these conditions is NOT typically associated with an increase in CRP?

<p>Pregnancy (C)</p> Signup and view all the answers

What is the difference between a high-sensitivity CRP (hs-CRP) test and a standard CRP test?

<p>High-sensitivity CRP tests are more sensitive than standard CRP tests. This means that they can detect lower levels of CRP, making them more useful for detecting low-grade chronic inflammation, such as that associated with atherosclerosis.</p> Signup and view all the answers

What is procalcitonin (PCT) and how is it produced?

<p>Procalcitonin is a precursor protein for calcitonin, a hormone involved in calcium homeostasis. It is normally produced by the parafollicular cells of the thyroid and by the neuroendocrine cells of the lung and intestine. However, in inflammatory conditions, other cell types can also produce it.</p> Signup and view all the answers

PCT levels are elevated in the presence of sterile conditions.

<p>False (B)</p> Signup and view all the answers

What are some of the clinical conditions that PCT is particularly useful for diagnosing?

<p>Procalcitonin is particularly useful for diagnosing early sepsis and for monitoring the severity of sepsis.</p> Signup and view all the answers

Procalcitonin is a very sensitive marker for diagnosing early sepsis, with a longer half-life than CRP.

<p>True (A)</p> Signup and view all the answers

What is the difference between SIRS, sepsis, and septic shock?

<p>SIRS (Systemic Inflammatory Response Syndrome) is a generalized inflammatory response that can be caused by a variety of factors, including infection. Sepsis is a life-threatening condition that occurs when the body's response to infection is dysregulated, leading to organ dysfunction. Septic shock is a severe form of sepsis that results in circulatory and cellular dysfunction, and is associated with a very high risk of mortality.</p> Signup and view all the answers

Procalcitonin is a sensitive and specific marker for early sepsis, but it is not very helpful for differentiating sepsis from SIRS.

<p>False (B)</p> Signup and view all the answers

Procalcitonin is a relatively cheap and easily accessible test.

<p>False (B)</p> Signup and view all the answers

The FDA has cleared the use of procalcitonin to guide antibiotic therapy for all respiratory infections, including viral infections.

<p>False (B)</p> Signup and view all the answers

What is the role of iron in the body and why is it important to understand iron metabolism in inflammation?

<p>Iron is an essential nutrient for the body, as it is required for the production of red blood cells, which carry oxygen to the tissues. Bacteria also require iron to grow and multiply. During inflammation, the body regulates iron metabolism, which impacts both the host and the pathogen. It is important to understand iron metabolism to be able to treat infections effectively and manage inflammatory conditions.</p> Signup and view all the answers

What are some of the molecules involved in iron metabolism that are upregulated during the acute phase response?

<p>Hepcidin, ferritin, haptoglobin, and hemopexin.</p> Signup and view all the answers

What is the role of transferrin during inflammation?

<p>Transferrin is a negative acute phase protein that is downregulated during inflammation. It is involved in iron transport and plays a critical role in limiting bacterial access to iron.</p> Signup and view all the answers

Why is it important to understand ferritin levels in the context of inflammation?

<p>Ferritin is a marker of iron storage in the body. It is an acute phase protein, meaning that its levels increase during inflammation. Ferritin can be used to diagnose iron overload (e.g., hemochromatosis) or iron deficiency (e.g., anemia). Ferritin levels can also be affected by chronic liver disease, so it is important to consider this when interpreting ferritin levels.</p> Signup and view all the answers

What is fibrinogen and what is its role in inflammation and tissue repair?

<p>Fibrinogen is a clotting factor that is produced by the liver. It is an acute phase protein, meaning that its levels increase during inflammation. Fibrinogen is essential for the process of coagulation, which is the formation of blood clots. Fibrinogen is also important for tissue repair, as it forms a provisional matrix that helps to stabilize the wound and promote healing.</p> Signup and view all the answers

What is d-dimer and how is it measured?

<p>D-dimer is a degradation product of fibrin, which is the insoluble protein that forms a blood clot. D-dimer levels are measured in the blood using a variety of laboratory tests.</p> Signup and view all the answers

Elevated levels of d-dimer are a common finding in Covid-19.

<p>True (A)</p> Signup and view all the answers

What are some of the inhibitors of proteolytic enzymes that are released during the acute phase response?

<p>Al-antitrypsin, a2-macroglobulin, and a1-acid glycoprotein.</p> Signup and view all the answers

The acute phase response is a relatively recent evolutionary mechanism.

<p>False (B)</p> Signup and view all the answers

What is lactate dehydrogenase (LDH) and what is its role in the body?

<p>Lactate dehydrogenase (LDH) is an enzyme that is found in many different tissues and organs. It is an important part of the body's energy production process, and it helps to convert pyruvate to lactate when oxygen levels are low. During inflammation or tissue damage, LDH can be released into the bloodstream, where it can be measured as a marker of cell death.</p> Signup and view all the answers

Elevated LDH levels can be seen in both muscle injury and infection.

<p>True (A)</p> Signup and view all the answers

The normal range of LDH is higher in children than in adults.

<p>True (A)</p> Signup and view all the answers

Flashcards

First line of defense

The first line of defense against pathogens. It includes physical barriers like skin and mucous membranes, as well as the normal microbiota.

Second line of defense

The second line of defense, activated quickly after the first line is breached. It involves inflammation and the activity of innate immunity.

Third line of defense

The third line of defense, found only in vertebrates. It is a highly specific and adaptive immune response.

Inflammation

A process that involves the activation of defense mechanisms and repair mechanisms to restore homeostasis after tissue damage or infection.

Signup and view all the flashcards

Professional cells

Specialized cells of the immune system that are involved in sensing tissue damage or microbial moieties. These cells initiate and regulate the inflammatory response.

Signup and view all the flashcards

Non-professional cells

Cells that are not typically involved in immune responses, but can also contribute to activating inflammation when they encounter tissue damage or infection.

Signup and view all the flashcards

Receptors that activate transcription factors

Receptors that activate an inflammatory response by triggering the transcription of genes associated with inflammation, such as cytokines, interferons, and acute phase proteins.

Signup and view all the flashcards

Soluble molecules

Soluble molecules, like cytokines, that can be used as markers for the inflammatory process. They play a role in activating the immune response. Some act locally, others at a systemic level.

Signup and view all the flashcards

Cytokine cascade

A network of signaling molecules (cytokines) that amplifies and regulates the inflammatory response. They are key players in the inflammatory cascade.

Signup and view all the flashcards

Interleukin-1 (IL-1)

A cytokine produced by various stimuli like microbial moieties, tissue damage, or changes in metabolism. It regulates both local and systemic inflammation.

Signup and view all the flashcards

Interleukin-6 (IL-6)

A cytokine produced by the liver that stimulates the production of acute phase proteins, amplifying the systemic response to inflammation.

Signup and view all the flashcards

Acute phase proteins

Proteins produced by the liver during inflammation, usually in response to IL-6. They amplify and regulate the inflammatory response, and some have additional roles in tissue repair and immune function.

Signup and view all the flashcards

Erythrocyte sedimentation rate (ESR)

An ancient test that measures how quickly red blood cells settle in a tube. It's often used in developing countries due to its low cost and simplicity.

Signup and view all the flashcards

C-reactive protein (CRP)

A commonly used marker for inflammation. It is a pentameric protein produced by the liver in response to IL-6. It opsonizes microbes, dead cells, and damaged tissue, promoting their clearance by phagocytes.

Signup and view all the flashcards

High-sensitivity CRP (hs-CRP)

A high sensitivity version of the C-reactive protein test that can detect very small levels of CRP in the blood. It's especially useful in identifying subtle inflammation associated with cardiovascular disease.

Signup and view all the flashcards

Procalcitonin (PCT)

A peptide produced by the thyroid gland that is involved in calcium homeostasis. During inflammation, other cell types may produce it, making it a valuable marker for bacterial infections.

Signup and view all the flashcards

Sepsis

An inflammatory condition that affects the circulatory system, often triggered by bacterial infections. It can lead to organ dysfunction and even death. PCT is often used to help diagnose and monitor sepsis.

Signup and view all the flashcards

Pentraxin-3 (PTX3)

A member of the pentraxin family, similar to CRP but produced by a wider range of cells. It binds to microbes and damaged tissue, plays a role in innate immunity, and is a valuable biomarker for inflammatory conditions, including cardiovascular disorders and sepsis.

Signup and view all the flashcards

Lactate Dehydrogenase (LDH)

An enzyme involved in anaerobic metabolism, converting pyruvate to lactate. Its levels increase when there is tissue damage or cell death, making it a useful marker for various conditions, including muscle injury, heart attack, and infection.

Signup and view all the flashcards

Iron metabolism in inflammation

The process by which the body eliminates iron from microbes, competing for the iron needed for microbial growth. During inflammation, the body produces proteins that bind to iron, reducing its availability to microbes.

Signup and view all the flashcards

Ferritin

A protein that stores iron inside cells. It's useful for diagnosing iron deficiency, iron overload, and as a marker of inflammation because it's an acute phase protein.

Signup and view all the flashcards

Transferrin

A protein that functions as the major iron transporter in the blood. It's downregulated during inflammation, as the body needs less iron to be transported in these conditions.

Signup and view all the flashcards

Fibrinogen

A protein involved in blood clotting, produced by the liver during inflammation. It forms an insoluble clot essential in tissue repair, but it can also contribute to thrombotic disorders.

Signup and view all the flashcards

D-dimer

A soluble fragment of fibrinogen that is present in the blood during inflammation. It's used as a marker for conditions associated with excessive clotting, such as deep vein thrombosis and pulmonary embolism.

Signup and view all the flashcards

Fibronectin

A protein found in the extracellular matrix, which is involved in tissue repair and wound healing. It's produced during inflammation and helps to form a provisional matrix that supports tissue regeneration.

Signup and view all the flashcards

α1-antitrypsin

A protein produced by the liver that inhibits the activity of certain enzymes, reducing tissue damage and protecting the body during inflammation.

Signup and view all the flashcards

Acute Phase Proteins (e.g., α1-antitrypsin, α2-macroglobulin, α1-acid glycoprotein)

Proteins involved in the acute phase response, contributing to tissue repair and regulation of inflammation.

Signup and view all the flashcards

Fibrinolysis

A process by which the body breaks down fibrin clots, essential for removing the provisional matrix during tissue repair and restoring normal blood flow.

Signup and view all the flashcards

Autoimmune disorder

An inflammatory condition in which the body's immune system overreacts to a perceived threat, leading to damage to healthy tissues. It can affect various organs and systems.

Signup and view all the flashcards

Polycythemia

A condition in which the bone marrow produces an excessive number of red blood cells, increasing the viscosity (thickness) of the blood.

Signup and view all the flashcards

Sickle cell anemia

A genetic blood disorder that affects the shape of red blood cells. Red blood cells in sickle cell anemia are crescent-shaped, which can lead to problems with oxygen delivery and blood flow.

Signup and view all the flashcards

Study Notes

Inflammation

  • Inflammation is a phylogenetically conserved process of coming back to homeostasis.
  • It involves activating defense mechanisms and repair mechanisms.
  • It's always present in almost every condition, including infection, tissue damage, homeostatic imbalances, dysmetabolism, and dysbiosis.
  • Inflammation is activated by the recognition of tissue damage or microbial moieties (dysbiosis) through receptors on cells, which sense abnormalities.

Markers of Inflammation

  • The immune system has three lines of defense:

    • First line: skin and mucous membranes, normal microbiota
    • Second line: inflammation and innate immunity
    • Third line: adaptive immunity (only vertebrates)
  • Innate immunity responds in hours, while adaptive immunity takes days.

  • Inflammation is crucial for innate immune response, as well as adaptive immunity.

Professional and Non-professional Cells

  • The cells involved in sensing abnormalities are:

    • Professional cells (leukocytes): macrophages, neutrophils, dendritic cells, natural killer cells
    • Non-professional cells: epithelial cells, stromal cells, endothelial cells
  • These cells have receptors (located on cell membrane, cytoplasm, or phagosomes) to detect imbalances.

  • Soluble molecules released by these cells are also involved in inflammation.

Classification of Receptors

  • Innate Immunity involves receptors that activate transcription factors, mainly NF-κB and IRF, which regulate inflammation.

  • These receptors activate cytokines, interferons, and acute-phase proteins, including acute phase proteins (APPs).

  • These receptors include Toll-like receptors, integrins, and sensors of viral molecules.

Inflammatory Markers

  • Acute Phase Proteins (APPs): produced by the liver, and involved in inflammatory response, including:
    • C-reactive protein (CRP): Rapid induction and return to baseline, useful diagnostic marker.
    • Fibrinogen: Slow increase and sustained levels,
    • Others: Pentraxin-3, Serum amyloid A, Complement factors
  • These markers are produced in response to inflammation and play crucial roles for tissue repair, coagulation, and innate immunity. They are also involved in pathogen recognition, complement activation, and apoptotic cell clearance.

C-reactive Protein (CRP)

  • CRP is produced by the liver in response to inflammatory stimuli.
  • High levels of CRP are indicative of a wide range of conditions, including inflammation.
  • It reflects the active inflammatory state and is a useful diagnostic marker.
  • CRP levels are measured in mg/L, with typical healthy adult range between 0.8 and 3 mg/L. High levels ( >500 mg/L) indicate significant inflammation.

Erythrocyte Sedimentation Rate (ESR)

  • ESR measures the rate at which red blood cells settle in a sample.
  • Increased ESR is indicative of inflammation.
  • It's inexpensive and available in basic labs.
  • Affected by factors such as anemia and pregnancy.

Procalcitonin (PCT)

  • PCT is a biomarker for bacterial infection.
  • It's rapidly induced after bacterial infection.
  • Elevated PCT levels are associated with sepsis and severe conditions.
  • Faster response time than CRP.

Pentraxin-3 (PTX3)

  • PTX3 is another inflammatory marker produced by different cell types.
  • It's associated with more severe conditions, especially cardiovascular diseases, infections, and inflammation.
  • It has a faster response time than CRP.
  • PTX3 can be a more reliable indicator of the severity of disease, especially in chronic inflammatory conditions compared to CRP.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

More Like This

Innate Immunity and Inflammation 1
51 questions
Innate Immunity & Inflammation
29 questions
Inflammation and Immune Response
112 questions
Use Quizgecko on...
Browser
Browser