Immune Syndromes Flashcards
X-linked (Bruton) agammaglobulinemia
B CELL Disorder Defect in BTK, a tyrosine kinase gene no B-cell maturation. X-linked recessive (increased in Boys). Recurrent bacterial and enteroviral infections after 6 months ( maternal IgG). Absent B cells in peripheral blood, Decreased Ig of all classes. Absent/scanty lymph nodes and tonsils.
Selective IgA deficiency
B Cell Disorder Unknown causing defect. Most common 1° immunode ciency. Majority Asymptomatic. Can see Airway and GI infections, Autoimmune disease, Atopy, Anaphylaxis to IgA-containing products. Decreased IgA with normal IgG, IgM levels.
Common variable immunodeficiency
B Cell Disorder Defect in B-cell differentiation. Many causes. Can be acquired in 20s–30s; Increased risk of autoimmune disease, bronchiectasis, lymphoma, sinopulmonary infections. Decreased plasma cells, decreased immunoglobulins.
Thymic aplasia (DiGeorge syndrome)
T Cell Disorder 22q11 deletion; failure to develop 3rd and 4th pharyngeal pouches absent thymus and parathyroids. Tetany (hypocalcemia), recurrent viral/fungal infections (T-cell de ciency), conotruncal abnormalities (e.g., tetralogy of Fallot, truncus arteriosus). Decreased T cells, Decreased PTH, decreased Ca2+. Absent thymic shadow on CXR. 22q11 deletion detected by FISH.
IL-12 Receptor Deficiency
T Cell Disorder Decreased Th1 response. Autosomal recessive. Disseminated mycobacterial and fungal infections; may present after administration of BCG vaccine. Decreased IFN-γ.
Autosomal dominant hyper-IgE syndrome (Job syndrome)
T Cell Disorder
Deficiency of Th17 cells due to STAT3 mutation impaired recruitment of neutrophils to sites of infection.
FATED: coarse Facies, cold (noninflamed) staphylococcal Abscesses, retained primary Teeth, Increased IgE, Dermatologic problems (eczema).
Increased IgE, Decreased IFN-γ.
Chronic mucocutaneous candidiasis
T-cell dysfunction. Many causes.
Noninvasive Candida albicans infections of skin and mucous membranes.
Absent in vitro T-cell proliferation in response to Candida antigens.
Absent cutaneous reaction to Candida antigens.
Severe combined immunode ciency (SCID)
B and T Cell Disorder
Several types including defective IL-2R gamma chain (most common, X-linked), adenosine deaminase de ciency (autosomal recessive).
Failure to thrive, chronic diarrhea, thrush. Recurrent viral, bacterial, fungal, and protozoal infections.
Treatment: bone marrow transplant (no concern for rejection).
Decreased T-cell receptor excision circles (TRECs).
Absence of thymic shadow (CXR), germinal centers (lymph node biopsy), and T cells ( ow cytometry).
Ataxia-Telangiectasia
B and T Cell Disorder
Defects in ATM gene failure to repair DNA double strand breaks leads tocell cycle arrest.
Triad: cerebellar defects (Ataxia), spider Angiomas (telangiectasia), IgA deficiency.
Increased AFP.
Decreased IgA, IgG, and IgE. Lymphopenia, cerebellar
atrophy.
Hyper IgM Syndrome
B and T Cell Disorder
Most commonly due to defective CD40L on Th cells results in class switching defect; X-linked recessive.
Severe pyogenic infections early in life; opportunistic infection with Pneumocystis, Cryptosporidium, CMV.
Increased IgM.
Really decreased IgG, IgA, IgE.
Wiskott-Aldrich syndrome
B and T Cell Disorder
Mutation in WAS gene (X-linked recessive); T cells unable to reorganize actin cytoskeleton.
WATER: Wiskott-Aldrich: Thrombocytopenic purpura, Eczema, Recurrent infections.
Increased risk of autoimmune disease and malignancy.
Decreased to normal IgG, IgM.
Increased IgE and IgA.
Fewer and smaller platelets.
Leukocyte adhesion deficiency (type 1)
Phagocyte Deficiency
Defect in LFA-1 integrin (CD18) protein on phagocytes; impaired migration and chemotaxis; autosomal recessive.
Recurrent bacterial skin and mucosal infections, absent pus formation, impaired wound healing, delayed separation of umbilical cord (> 30 days).
Increased neutrophils.
Absence of neutrophils at infection sites.
Chédiak-Higashi syndrome
Phagocyte Deficiency
Defect in lysosomal traficking regulator gene (LYST).
Microtubule dysfunction in phagosome-lysosome fusion; autosomal recessive.
Recurrent pyogenic
infections by staphylococci and streptococci, partial albinism, peripheral neuropathy, progressive neurodegeneration, in ltrative lymphohistiocytosis.
Giant granules in granulocytes A and platelets.
Pancytopenia.
Mild coagulation defects.
Chronic granulomatous disease
Defect of NADPH oxidase: Decrased reactive oxygen species (e.g., superoxide) and decreasedrespiratory burst in neutrophils; X-linked recessive most common.
Increased susceptibility to catalase ⊕ organisms (Need PLACESS): Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, Serratia.
Abnormal dihydrorhodamine (flow cytometry) test.
Nitroblue tetrazolium dye reduction test is ⊝.
