lilyo's version from 2016-06-05 21:13


Question Answer
X-linked (Bruton) agammaglobulinemia defectdefect in BTK (tyrosine kinase gene) --> no B-cell maturation
X-linked (Bruton) agammaglobulinemia presentationrecurrent bacterial and enteroviral infections after 6 months
X-linked (Bruton) agammaglobulinemia findingsAbsent B cells in peripheral blood,􏰂 decreased Ig of all classes, absent/scanty lymph nodes and tonsils.
Selective IgA deficiency presentationmajority asymptomatic, can see airway and GI infections, Autoimmune disease, Atopy, Anaphylaxis to IgA-containing products.
Selective IgA deficiency findingsdecreased IgA with normal IgG, IgM levels
Common variable immunodeficiency defectdefect in B-cell differentiation
Common variable immunodeficiency presentationCan be acquired in 20s–30s; 􏰀risk of autoimmune disease, bronchiectasis, lymphoma, sinopulmonary infections.
Common variable immunodeficiency findingsdecreased plasma cells, decreased immunoglobulins
Thymic aplasia (DiGeorge syndrome) defect22q11 deletion; failure to develop 3rd and 4th pharyngeal pouches --> absent thymus and parathyroids
Thymic aplasia (DiGeorge syndrome) presentationtetany (hypocalcemia), recurrent viral/fungal infections (T-cell deficiency), conotruncal abnormalities (eg tetralogy of Fallot, truncus arteriosus)
Thymic aplasia findingsdecreased T cells, decreased PTH, decreased Ca2+, absent thymic shadow on CXR, 22q11 deletion detected by FISH
IL-12 receptor deficiency defectdecreased Th1 response
IL-12 receptor deficiency presentationdisseminated mycobacterial and fungal infections, may present after administration of BCG vaccine
IL-12 receptor deficiency findingsdecreased interferon-gamma
Autosomal dominant hyper-IgE syndrome (Job syndrome) defectDeficiency of Th17 cells due to STAT3 mutation􏰁 --> impaired recruitment of neutrophils to sites of infection
Autosomal dominant hyper-IgE syndrome (Job syndrome) presentationFATED: coarse Facies, cold (noninflamed) staphylococcal Abscesses, retained primary Teeth, increased 􏰀IgE, Dermatologic problems (eczema).
Autosomal dominant hyper-IgE syndrome (Job syndrome) findingsincreased IgE, decreased interferon-gamma
Chronic mucocutaneous candidiasis causeT-cell dysfunction
Chronic mucocutaneous candidiasis presentationNoninvasive Candida albicans infections of skin and mucous membranes.
Chronic mucocutaneous candidiasis findingsAbsent in vitro T-cell proliferation in response to Candida antigens. Absent cutaneous reaction to Candida antigens.
Severe combined immunodeficiency defectSeveral types including defective IL-2R gamma chain (most common, X-linked), adenosine deaminase deficiency (autosomal recessive).
Severe combined immunodeficiency presentationFailure to thrive, chronic diarrhea, thrush. Recurrent viral, bacterial, fungal, and protozoal infections. Treatment: bone marrow transplant (no concern for rejection).
Severe combined immunodeficiency findingsdecreased T-cell receptor excision circles, absence of thymic shadow (CXR), germinal centers (lymph node biopsy) and T cells (flow cytometry)
Ataxia telangiectasia defectDefects in ATM gene􏰁 --> failure to repair DNA double strand breaks --> 􏰁cell cycle arrest.
Ataxia telangiectasia presentationTriad: cerebellar defects (Ataxia), spider Angiomas (telangiectasia), IgA deficiency.
Ataxia telangiectasia findingsincreased AFP, decreased IgA, IgG, IgE, lymphopenia, cerebellar atrophy
Hyper-IgM syndrome defectmost commonly due to defective CD40L on Th cells 􏰁class switching defect; X-linked recessive.
Hyper-IgM syndrome presentationSevere pyogenic infections early in life; opportunistic infection with Pneumocystis, Cryptosporidium, CMV.
Hyper-IgM syndrome findingsnormal or increased IgM, decreased IgG, IgA, IgE
Wiskott-Aldrich syndrome defectmutation in WAS gene, T cells unable to reorganize actin cytoskeleton, X-linked recessive
Wiskott-Aldrich syndrome presentationWATER: Wiskott-Aldrich: Thrombocytopenia, Eczema, Recurrent infections, increased 􏰀risk of autoimmune disease and malignancy.
Wiskott-Aldrich syndrome findingsdecreased to normal IgG and IgM, increased IgE and IgA, fewer and smaller platelets
Leukocyte adhesion deficiency (type 1) defectDefect in LFA-1 integrin (CD18) protein on phagocytes; impaired migration and chemotaxis; autosomal recessive.
Leukocyte adhesion deficiency (type 1) presentationRecurrent bacterial skin and mucosal infections, absent pus formation, impaired wound healing, delayed separation of umbilical cord (> 30 days).
Leukocyte adhesion deficiency (type 1) findingsincreased􏰀 neutrophils, absence of neutrophils at infection sites.
Chediak-Higashi syndrome defectDefect in lysosomal trafficking regulator gene (LYST). Microtubule dysfunction in phagosome-lysosome fusion; autosomal recessive.
Chediak-Higashi syndrome presentationRecurrent pyogenic infections by staphylococci and streptococci, partial albinism, peripheral neuropathy, progressive neurodegeneration, infiltrative lymphohistiocytosis.
Chediak-Higashi syndrome findingsGiant granules in granulocytes and platelets. Pancytopenia. Mild coagulation defects.
Chronic granulomatous disease defectDefect of NADPH oxidase --> decreased 􏰁􏰂reactive oxygen species (eg, superoxide) and􏰂 decreased respiratory burst in neutrophils; X-linked recessive most common.
Chronic granulomatous disease presentation􏰀increased susceptibility to Catalase ⊕ organisms (Cats Need PLACESS to Belch their Hairballs): Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E coli, Staphylococci, Serratia, B cepacia, H pylori
Chronic granulomatous disease findingsAbnormal dihydrorhodamine (flow cytometry) test (􏰂decreased green fluorescence). Nitroblue tetrazolium dye reduction test obsolete.