Module 8: Universal Study Guide for Immunity and Immunology

Types of Immunity: Active and Passive\n\n* Active Immunity: This form of immunity is acquired when the body is exposed to a disease-causing organism or through the administration of a vaccine.\n * Natural Immunity: In cases of direct exposure to a disease, the causative organism triggers the immune system to produce its own antibodies.\n * Vaccine-Induced Immunity: This involves introducing a weakened or killed form of the disease into the body to stimulate antibody production without causing the full illness.\n * Characteristics: Regardless of the method of acquisition, active immunity is generally long-lasting and often provides lifelong protection. However, it typically requires several weeks to develop fully.\n\n* Passive Immunity: This occurs when an individual receives antibodies produced by another person or animal rather than producing them via their own immune system.\n * Acquisition Methods:\n * Transition of antibodies from mother to newborn via the placenta or through breast milk.\n * Administration of blood products containing specific antibodies, such as immune globulin, to protect against a specific disease.\n * Characteristics: The primary advantage is that protection is immediate. The major disadvantage is that it is temporary, typically lasting only for a few weeks or months.\n\n# Physiology of Leukocytes and the Immune Response\n\n* Leukocytes (White Blood Cells/WBCs): These serve as the primary cells in both nonspecific and specific immune system responses.\n* Leukocytosis: A condition where the bone marrow increases production of leukocytes as they move into the blood to fight infection. This results in a WBC count of greater than 10,000/mm310,000/mm^3.\n * Nursing Intervention: Always assess the patient for signs and symptoms of infection and investigate possible causes.\n* Leukopenia: A decrease in the number of circulating leukocytes. This occurs when bone marrow activity is suppressed or when the destruction of leukocytes increases.\n\n# Granulocytes: Subtypes and Functions\n\n* General Characteristics: Granulocytes constitute 60−80%60-80\% of total leukocytes. They are derived from myeloid stem cells in the bone marrow, possess a short lifespan, and play a key role during acute inflammation and infection.\n* Neutrophils (Polymorphonuclear Leukocytes or "Polys"):\n * Comprise 55−70%55-70\% of total circulating leukocytes.\n * Function: Phagocytic cells that engulf and destroy foreign agents, specifically bacteria and small particles.\n * Behavior: They are the first phagocytic cells to arrive at the site of invasion, drawn by chemicals released by damaged tissue and invading organisms.\n * Production: Produced in the bone marrow and released into circulation once mature.\n* Eosinophils:\n * Comprise 1−4%1-4\% of total circulating leukocytes.\n * Maturation: Develop in the bone marrow over 33 to 66 days.\n * Lifespan: Circulating half-life of 3030 minutes; tissue half-life of 1212 days.\n * Function: Phagocytic, though less efficient than neutrophils. They are highly concentrated in the respiratory and GI tracts.\n * Target: Protect the body from parasitic worms (e.g., tapeworms, flukes, pinworms, hookworms) by surrounding them and releasing toxic enzymes from cytoplasmic granules to destroy them.\n * Hypersensitivity: Involved in hypersensitivity responses, inactivating inflammatory chemicals released during the process.\n* Basophils:\n * Comprise approximately 0.5−1%0.5-1\% of circulating leukocytes.\n * Function: These cells are non-phagocytic.\n * Content: Granules contain proteins and chemicals including heparin, histamine, bradykinin, serotonin, and leukotrienes (slow-reacting substance of anaphylaxis).\n * Release: These substances enter the bloodstream during acute hypersensitivity reactions or stress responses.\n\n# Barrier Protection and Nonspecific Inflammatory Response\n\n* First Line of Defense: Barrier protection prevents external organisms from invading the body.\n* Physical Barriers:\n * Skin: The primary barrier when intact.\n * Mucus: Lines inner body surfaces to trap microorganisms and foreign substances.\n* Mechanical Removal:\n * Ciliary Movement: Sweeps away trapped particles.\n * Washing Action: Provided by the flow of tears or urine.\n* Chemical/Bactericidal Protection:\n * Acid: Found in gastric fluid.\n * Lysozyme: An enzyme with antibacterial properties found in tears, nasal secretions, saliva, and sweat.\n\n# Hypersensitivity Reactions (Allergic Reactions)\n\n* Definition: Immune responses that lead to tissue damage.\n* Type I: IgE-Mediated Hypersensitivity:\n * Onset: Rapid development, usually within 1515 to 3030 minutes of exposure.\n * Symptoms: Range from minor (sneezing, runny nose, itchy eyes) to life-threatening. Can have a delayed onset of symptoms between 1010 and 1212 hours.\n * Affected Areas: Skin, eyes, nasopharynx, bronchopulmonary tissues, and GI tract.\n * Severe Form: Anaphylaxis is the most severe immediate response.\n* Type II: Cytotoxic Hypersensitivity:\n * Mediators: Primarily IgM or IgG antibodies.\n * Onset: Minutes to hours.\n * Mechanism: Rupture of cells targeted by the immune response, affecting various organs/tissues.\n * Examples: Transfusion reactions, Rh incompatibility, Hashimoto thyroiditis, and Goodpasture syndrome.\n* Type III: Immune Complex-Mediated Hypersensitivity:\n * Onset: 33 to 1010 hours after exposure.\n * Mechanism: Inflammatory response in targeted tissues leads to damage. Can be general or localized to specific organs.\n * Examples: Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA).\n* Type IV: Delayed Hypersensitivity:\n * Onset: 2424 to 4848 hours after exposure.\n * Mechanism: Involves the major histocompatibility complex (MHC); tissue damage occurs at the site of antigen contact.\n * Examples: Tuberculin (Mantoux test) reaction and allergic contact dermatitis.\n\n# Transplant Rejection\n\n* Hyperacute Rejection: Occurs within minutes or hours. Signs include organ swelling, clot formation, and hemorrhage.\n* Acute Rejection: Occurs between 11 week and 33 months post-transplant. In kidney transplants, signs include decreased urine output, swelling, pain, and blood/protein in urine.\n* Chronic Rejection: Occurs months to years after transplantation. Characterized by slow, insidious organ failure due to immune-mediated damage.\n\n# Immunizations and Vaccine Types\n\n* Schedule: The average newborn receives immunizations for 1616 diseases before adulthood.\n* Routine Recommendations: Measles, mumps, rubella, polio, pertussis (whooping cough), diphtheria, tetanus, Haemophilus influenzae type b, hepatitis A and B, pneumococcus, varicella (chickenpox), rotavirus, and influenza.\n* Other Populations: Vaccines for older children, adolescents, and adults target pertussis, meningococcus, human papillomavirus (HPV), and shingles.\n* Vaccine Classifications:\n * Killed Virus: Contains dead microorganisms that still induce antibody production (e.g., inactivated polio virus).\n * Toxoid: A toxin treated to weaken toxic effects while maintaining antigenicity (e.g., tetanus toxoid).\n * Live Virus: Contains weakened organisms. Macrophages ingest them, activating T cells and B cells to produce antibodies. T and B cells assist with long-term immunity.\n * Recombinant: Organisms genetically altered for vaccine use (e.g., hepatitis B).\n * Conjugated: An altered organism joined with another substance (like a protein carrier) to increase the immune response (e.g., H. influenzae type b conjugated with tetanus toxoid).\n\n# Nursing Assessment and Independent Interventions\n\n* Assessment Components:\n * Interview/Observation: General appearance and dietary intake.\n * Physical Exam: Assessment of skin, mucous membranes (oral/nasal), lymph nodes, and musculoskeletal status (ambulation/range of motion).\n * Diagnostic Tests: Review all relevant lab work.\n* Nutrition Interventions: Nurses should assess intake and provide counseling or resources for healthy eating and weight management.\n* Exercise: Moderate exercise enhances immunity by pumping lymph fluid efficiently. However, strenuous exercise can temporarily reduce immune function during recovery.\n* Sleep and Rest: Inadequate sleep impacts immune function. Rest is vital after vigorous training to facilitate recovery.\n* Stress Management: Prolonged overexposure to stressors can compromise the immune system. Nurses assist by identifying stressors and developing coping strategies to maintain homeostasis.\n\n# Lifespan Considerations in Immunity\n\n* Infants and Children:\n * IgG: The only immunoglobulin that crosses the placenta. Newborn levels match the mother's but disappear by 6−86-8 months. Mature levels are reached at 7−87-8 years of age.\n * IgM: Low at birth, rises significantly at 11 week of age, and reaches adult levels by 11 year.\n * IgA and IgE: Absent at birth. Manufacturing begins at 22 weeks of age, but mature levels are not reached until 6−76-7 years of age.\n * Clinical Significance: Children under 66 years often fall ill due to an incomplete complement of immunoglobulins.\n* Older Adults:\n * Many experience a decrease in immune response and lowered resistance to infection.\n * Response to immunizations is often poor.\n * Changes can precipitate insulin resistance.\n * The hypersensitivity response is often reduced or delayed.\n * Vital signs may change, such as a low-grade fever resulting from the decline in immune response efficiency.", "title": "Module 8: Universal Study Guide for Immunity and Immunology"}