Inflammatory & Immunologic Response PDF

TERMINOLOGY! ***Antigen -The structural part of the invading or attacking organism that is responsible for stimulating antibody production. ***Antibody aka immunoglobulin is a protein produced by the body's immune system when it detects harmful substances, called antigens. Structures involved 1....

TERMINOLOGY! ***Antigen -The structural part of the invading or attacking organism that is responsible for stimulating antibody production. ***Antibody aka immunoglobulin is a protein produced by the body's immune system when it detects harmful substances, called antigens. Structures involved 1.Bone Marrow: Produces WBC (leukocytes) Structures involved 2.Lymphoid Tissues ü Spleen- acts as a filter. a. The red pulp is the site where old and injured red blood cells (RBCs) are destroyed. b. The white pulp contains concentrations of lymphocytes. Structures involved 2.Lymphoid Tissues ü Lymph nodes - remove foreign material from the lymph system before it enters the bloodstream. Structures involved 3.Physical and Chemical Barriers ü Physical surface barriers -Skin, mucous membranes, and cilia of the respiratory tract. -Coughing and sneezing responses ü Chemical barriers -Mucus, acidic gastric secretions, enzymes in tears and saliva, and substances in sebaceous and sweat secretions, act in a nonspecific way to destroy invading bacteria and fungi. Structures involved 4. WBCs or leukocytes Types: a. Granular leukocytes, or granulocytes: releases cell mediators, such as histamine, bradykinin, and prostaglandins, and by engulfing the foreign bodies or toxins. Structures involved 4. WBCs or leukocytes Types: a. Granular leukocytes, or granulocytes i. Neutrophils -The first cells to arrive at the site where inflammation occurs. - The most abundant type of white blood cell (60% to 70%). - Functions as phagocytic cells. Structures involved 4. WBCs or leukocytes Types: a. Granular leukocytes, or granulocytes ii. Eosinophils (1-3%) - Increases in number during allergic reactions (asthma). - Fights multicellular parasites and some bacteria. Structures involved 4. WBCs or leukocytes Types: a. Granular leukocytes, or granulocytes iii. Basophils (0.5-1%) - Has an important role in fighting parasitic infections (helminths) - Involved in various allergic reactions Structures involved 4. WBCs or leukocytes Types: a. Granular leukocytes, or granulocytes iv. Mast cells (1%) - Found in connective tissues and mucous membranes. - Role in wound healing and microbial defence. - Involved in serious allergic reactions by releasing a wide variety of inflammatory mediators Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes: Any of the white blood cells that usually lack granules in their cytoplasm. Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes i. Monocytes or macrophages (5-10%) -Functions as phagocytic cells, engulfing, ingesting, and destroying foreign bodies or toxins than granulocytes do. NOTE! ***Phagocytic immune response is the 1st line of defense : Primarily involves the WBCs (granulocytes and macrophages). Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes ii. Lymphocytes a) B cells - 10% to 15% composition in the blood - Matures in the bone marrow before entering the bloodstream - Activates “humoral immunity” (production of antibodies) TERMINOLOGY! ***Humoral Immunity- Antibodies in the body fluids bind with pathogens and mark them for destruction by phagocytes before they are able to infect cells. Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes ii. Lymphocytes b) T cells - 70% to 80% composition in the blood. - Matures in the thymus, where they also differentiate into cells with various functions. - Activates “cell-mediated immunity” TERMINOLOGY! ***Cell-mediated immunity- Does not produce antigen-specific antibodies. T lymphocytes kill infected cells by triggering apoptosis (programmed cell death). Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes b) T cells - Types: *Helper T-cells - Also known as CD4 cells - Stimulates B-cells - Helps killer cells develop Structures involved 4. WBCs or leukocytes Types: b. Nongranular leukocytes b) T cells - Types: *Killer T-cells - Also known as CD8 cells or cytotoxic T-cells - Does not attack microbes - Kills defective cells (viral infected cells or cancer cells) The basic function of the immune system is to remove foreign antigens such as viruses and bacteria to maintain homeostasis. ***Immunity- refers to the body's ability to prevent the invasion of pathogens. Types of Immunity: 1. Natural /Nonspecific immunity 2. Acquired / Specific immunity Types of Immunity: 1. Natural /Nonspecific immunity - Present at birth (innate) - Barrier immunity -Skin (desquamation, antimicrobial proteins, immune cells) - Cough reflex, enzymes in tears and skin oils, mucus (traps bacteria and small particles), stomach acid. Types of Immunity: 2. Acquired / Specific immunity - Develops after birth (adaptive). - Develops as a result of prior exposure to an antigen through immunization (vaccination) or by contracting a disease. - There are two types of Acquired immunity Types of Immunity: 2. Acquired / Specific immunity Types: a) Active acquired immunity - Developed by the person’s own body after an exposure to pathogens. - ex. Vaccination, Infectious diseases. TERMINOLOGY! ***Live attenuated vaccines contain whole bacteria or viruses which have been “weakened”(attenuated) so that they create a protective immune response but do not cause disease in healthy people. ***Inactivated vaccine uses a strain of a bacteria or virus that has been “killed” with heat or chemicals. It does not trigger an immune response that is as strong as that triggered by live- attenuated vaccines. Does not give lifelong immunity and need topping up over time, but they may cause fewer side effects than live-attenuated vaccines. Types of Immunity: 2. Acquired / Specific immunity Types: b) Passive acquired immunity - A temporary immunity transmitted from a source outside the body. Ex: - Immunity resulting from the transfer of antibodies from the mother to an infant in utero. -Breast-feeding -Injections of immune globulin. Human Immunodeficiency Virus (HIV) A virus that attacks the human body’s immune system, specifically the CD4 cells (helper T cells). Human Immunodeficiency Virus (HIV) Transmission Body fluids (blood, seminal fluid, vaginal secretions, amniotic fluid, and breast milk) that contain infected cells. Mother-to-child transmission: In utero, at the time of delivery, or through breast-feeding. Blood and blood products. Sharing infected injection drug use equipment. Having sexual relations with infected individuals. People who received organ transplants. Human Immunodeficiency Virus (HIV) Prevention of HIV Infection Encouraging the use of condoms ü Polyurethane female condom provides a physical barrier that prevents exposure to genital secretions ü Microbicides - Gels, films, or suppositories that can kill or neutralize viruses and bacteria. ü Do not reuse condoms HIV status should be checked every 3 month. Abstain Human Immunodeficiency Virus (HIV) Prevention of HIV Infection Reduce the number of sexual partners to one. Avoid anal intercourse Avoid sharing needles, razors, toothbrushes, sex toys, or bloodcontaminated articles. Human Immunodeficiency Virus (HIV) Prevention of HIV Infection Consider PrEP if regularly engage in high-risk behaviors: ü Pre-exposure prophylaxis (PrEP) - Involves taking one pill containing two HIV medications (tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg [Truvada]) daily. For infected individuals, do not donate blood, plasma, body organs, or sperm. Human Immunodeficiency Virus (HIV) Reducing the Risk of Transmission to Health Care Providers Post-Exposure Prophylaxis (PEP) - Includes taking antiretroviral medicines as soon as possible, but no more than 72 hours (3 days) after possible HIV exposure; two to three drugs are usually prescribed which must be taken for 28 days. Human Immunodeficiency Virus (HIV) Reducing the Risk of Transmission to Health Care Providers Standard Precautions ü Hand hygiene ü Personal protective equipment: Gloves, gown ,mask, eye protection (goggles), face shield ü Soiled patient equipment Human Immunodeficiency Virus (HIV) Reducing the Risk of Transmission to Health Care Providers Standard Precautions ü Needles and other sharps: Do not recap, bend, break, or hand manipulate used needles; use safety features when available; and place used sharps in a puncture-resistant container. Pathophysiology (HIV): ü HIV is a retrovirus that cannot grow or multiply by itself. It uses a host (CD4 cell) to reproduce and results in the destruction of the host cell. Pathophysiology (HIV): 1. Attachment/Binding: Glycoproteins of HIV bind with the host’s uninfected CD4 receptor. Pathophysiology (HIV): 2. Uncoating/Fusion: Only the contents of HIV’s viral core (two single strands of viral RNA and three viral enzymes: reverse transcriptase, integrase, and protease) are emptied into the CD4 T cell. Pathophysiology (HIV): 3. DNA synthesis: HIV changes its genetic material from RNA to DNA through action of reverse transcriptase, resulting in double- stranded DNA that carries instruction for viral replication.  Formation of DNA strand Degredation of RNA strand Formation of complementary DNA strand Double DNA strand Pathophysiology (HIV): CD4 nucleus 4. Integration: New viral DNA enters the nucleus of the CD4 Integrase T cell and through action of integrase is HIV DNA blended with the DNA of the CD4 T cell, resulting in permanent, lifelong infection. Pathophysiology (HIV): 5. Transcription: When the CD4 T cell is activated, the double- stranded DNA forms single-stranded messenger RNA (mRNA), which builds new viruses. Pathophysiology (HIV): 6. Translation: The mRNA creates chains of new proteins and enzymes (polyproteins) that contain the components needed in the construction of new viruses. Pathophysiology (HIV): 7. Cleavage: The HIV protease enzyme cuts the polyprotein chain into the individual proteins that make up the new virus. Pathophysiology (HIV): 8. Budding: New proteins and viral RNA migrate to the membrane of the infected CD4+ T cell, exit from the cell, and start the process all over. Stages (HIV) Acute Stage ü Interval between the appearance of detectable HIV RNA and the first detection of antibodies. ü Weeks to a month after becoming infected. Can be contagious as this stage. ü Viral load very high in the blood. A high HIV viral load is generally considered above 100,000 copies per milliliter of blood ü CD4 count is more than > 500 cell/mm3 ü Signs and symptoms are flu-like that last for a few weeks (many people don’t know they have HIV): Aches, joint pain, headache, fever, fatigue, sore throat, swollen lymph nodes, GI upset, rash Stages (HIV) Chronic Stage (Asymptomatic Stage) ü May not have any HIV-related symptoms. ü HIV continues to multiply in the body but at very low levels. ü Without ART, chronic HIV infection usually advances to AIDS in 10 years or longer, though in some people it may advance faster. ü Can still transmit HIV to others (ART can help lower this chance) ü CD4 count is more than 200 to about 499 cell/mm3 ü No opportunistic infections present at time Stages (HIV) Acquired Immunodeficiency Syndrome (AIDS) ü Last Stage ü Immune system will be completely destroyed by the virus. ü CD4 count drops to