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Overview of Important Medical Concepts Related to Immunology and Diseases

Cells and AIDS

  • HIV Treatment: Current antiretroviral medications include:
    • Azidothymidine (RetrovirⓇ)
    • ddl (Dideoxynosine)
    • ddC (Dideoxycytidine)
  • Vaccine Development Hurdles:
    • Rapid mutation of HIV impedes the development of an effective vaccine.
    • There is a lack of suitable experimental animal models for testing HIV vaccines.
  • AIDS Prevention:
    • Preventing transmission is the only current strategy for AIDS prevention. Key methods include:
    • Safe sexual practices (e.g., condoms during intercourse)
    • Use of sterile hypodermic needles
    • Avoiding pregnancy in HIV-infected women.
    • Focus on education and safer sexual practices is essential until effective therapies or vaccines are available.

Autoimmune Diseases

  • Definition and Mechanism:
    • Autoimmunity is when the body fails to recognize its own antigens and produces antibodies against them.
  • Common Autoimmune Diseases:
    • Rheumatoid arthritis (RA)
    • Systemic lupus erythematosus (SLE)
    • Thyroiditis
    • Rheumatic fever
    • Glomerulonephritis
    • Encephalomyelitis
    • Hemolytic anemia
    • Pernicious anemia
    • Addison's disease
    • Graves' disease
    • Insulin-dependent diabetes mellitus (Type 1)
    • Myasthenia gravis
    • Multiple sclerosis (MS)
  • Therapeutic Approaches:
    • Common treatments involve immunosuppressive drugs, which can increase susceptibility to opportunistic infections.
    • Oral antigen therapy is currently being tested.

Systemic Lupus Erythematosus (SLE)

  • Characteristics:
    • Primarily affects young women and is an inflammatory disease of connective tissue.
  • Pathophysiology:
    • Damage to blood vessel walls leads to chemical release that mediates inflammation across various body systems.
  • Symptoms:
    • Painful joints, slight fever, fatigue, mouth ulcers
    • Weight loss, enlarged lymph nodes and spleen
    • Photosensitivity and rapid hair loss
    • "Butterfly rash" across the nose and cheeks
    • Severe complications can affect the kidneys, liver, spleen, lungs, heart, and central nervous systems.

Chronic Fatigue Syndrome (CFS)

  • Demographics:
    • Commonly occurs in young adults, predominantly females.
  • Symptoms:
    • Extreme fatigue for at least six months, sore throat, headaches, muscle pain, chills, and joint pain.
    • Neuropsychological complaints and sleep disturbances with rapid onset of symptoms.
  • Etiology:
    • The cause of CFS is currently unknown.

Severe Combined Immunodeficiency (SCID)

  • Description:
    • A rare genetic disorder characterized by the absence or dysfunction of both B and T lymphocytes, leading to severe immune deficiency.

Hypersensitivity (Allergy)

  • Definition: Hypersensitivity is an exaggerated immune response to an antigen.
  • Types of Reactions:
    • Localized Reactions: Include hay fever, asthma, eczema, and hives.
    • Acute Anaphylaxis: Severe systemic reaction.
  • Tissue Injury: All allergic reactions cause some degree of tissue injury.
  • Allergens: Antigens provoking allergic responses.
  • Four Basic Types of Hypersensitivity:
    1. Type I (Anaphylaxis - mediated by IgE antibodies)
    2. Type II (Cytotoxic - involves IgG or IgM antibodies)
    3. Type III (Immune Complex - results from immune complexes)
    4. Type IV (Cell-mediated - primarily involves T lymphocytes)

Tissue Rejection in Transplants

  • Mechanism: Involves both cell-mediated and antibody-mediated immune responses.
  • Preventive Measures: Minimizing rejection through matching MHC (HLA) antigens and using immunosuppressive drugs (e.g., cyclosporine).

Hodgkin's Disease (HD)

  • Overview: A typically curable form of malignant disorder, usually originating in lymph nodes.