Immunology Lec 8 Flashcards
Lecture 8:
Define immunodeficiencies and their types.
Immunodeficiencies are defects in the immune system’s functional capacity. Types include congenital (inherited) immunodeficiencies and acquired immunodeficiencies.
What are congenital immunodeficiencies?
Congenital immunodeficiencies are genetic defects impairing the immune system, affecting about 1 in 500 people in Europe and the US.
What genetic factors contribute to congenital immunodeficiencies?
They are often X-linked, making males more susceptible, with autosomal recessive disorders also common in cultures with consanguinity.
Name key defects associated with phagocyte deficiencies.
Leukocyte Adhesion Deficiencies: Impaired leukocyte recruitment.
Lazy Leukocyte Syndrome: Faulty chemotaxis in neutrophils.
Chronic Granulomatous Disease (CGD): Defective NADPH oxidase; recurrent infections and granuloma formation.
What are the key defects associated with lymphocyte deficiencies?
Severe Combined Immunodeficiency (SCID): Absence of T and B lymphocytes; commonly due to adenosine deaminase (ADA) deficiency.
DiGeorge Syndrome: Chromosome 22q11 deletion affecting thymic development and T-cell responses.
Bruton’s Agammaglobulinemia: Failure of B-cell maturation; requires frequent immunoglobulin infusions.
What are the primary causes of acquired immunodeficiencies?
Infections: HIV leading to AIDS.
Therapeutics: Chemotherapy, radiotherapy, immunosuppressive drugs.
Nutritional Deficiencies: Lack of essential micronutrients like zinc and vitamin C.
Other Factors: Stress, substance misuse, malnutrition, and surgical interventions.
How does HIV/AIDS affect the immune system?
HIV targets CD4+ cells, impairing both innate and adaptive immunity, leading to progressive immune function decline, increased susceptibility to infections and cancers.
How is HIV transmitted?
HIV is transmitted via body fluids including blood, sexual contact, and shared needles.
What is the progression and treatment of HIV/AIDS?
HIV leads to AIDS, characterized by a progressive decline in immune function. Treatment includes antiretroviral therapies (ART), which slow disease progression but do not eradicate the virus.
What is the management approach for immunodeficiencies?
Effective management involves identifying underlying causes and providing appropriate treatments such as bone marrow transplants for inherited immunodeficiencies or ART for HIV/AIDS.
