Flashcards in Immunodeficiencies of the Adaptive Immune System Deck (15):
Discuss X-linked Agammaglobulinemia
Failure of B-cell precursors to develop into mature B cells.
Describe clinical presentation of X-linked agammaglobulinemia.
All Ig isotypes are decreased; Mature B lymphocytes and plasma cells are absent. Normal T cell function
Discuss Selective IgA deficiency
Inability to make IgA; Normal levels of other Igs. Frequent respiratory and GI tract infections.
Discuss Common Variable Immunodeficiency (CVID)
Reductions in IgG and IgA; Defects in Ig alpha chains or B cell differentiation. Antibody production is impaired and plasma cells are absent.
Discuss Hyper IgM syndrome
Defective isotype switching in B cells resulting in high IgM levels with little to no IgG, IgA or IgE.
Describe Hyper IgM syndrome in clinical presentation.
No memory B cells, No germinal center; Myelocyte/Promyelocyte differentiation block
Discuss Bare Lymphocyte Syndrome (MHC2 deficiency)
Absence of MHC2 expressoion; No humoral or cell mediated immune response. T and B cell numbers are normal
Discuss Wiskott-Aldrich syndrome
Defective gene for WAS protein which functions in the immune synapse formation between T cells and APCs
How does Wiskott-Aldrich present clinically?
Lymphopenia, Eczema and thrombocytopenia; IgM levels are low, IgE and IgA are high
Discuss X-linked SCID
Marked by presence of small thymus which has no Hassall's corpuscles and is devoid of lymphocytes; No tonsils are present
Discuss Adenosine deaminase deficiency
An enzye thats involved in purine metabolism and adenosine homeostasis. Catalyzes the deamination of adenosine and 2-deoxyadenosine; Two toxic metabolites. Impacts developing T cells. Lymphopenia
Discuss DiGeorge Syndrome.
Abnormal neural crest cell migratioin. Thymic aplasia, no T cells in lymph nodes, spleen or peripheral blood
How does DiGeorge Syndrome present?
Congenital cardiac defects, thymic aplasia, hypocalcemia due to absence of parathryoid glands. Downward slanting eye, low set ears
Describe the acute phase of AIDS
Initial response to HIV infection in immunocompetent patient.