immune deficiency syndromes Flashcards
What are the key findings in Thymic aplasia?
Decreased T cells, decreased PTH, decreased calcium; thymic shadow absent on CXR.
What is the defect in IL-12 receptor deficiency?
Decreased Th1 response; autosomal recessive inheritance.
What are the clinical presentations of IL-12 receptor deficiency?
Disseminated mycobacterial and fungal infections, may present after administration of BCG vaccine.
What are the key findings in IL-12 receptor deficiency?
Decreased IFN-γ.
What is the defect in Autosomal dominant hyper-IgE syndrome (Job syndrome)?
Deficiency of Th17 cells due to STAT3 mutation, impairing neutrophil recruitment to infection sites.
What are the clinical presentations of Job syndrome?
Cold (noninflamed) staphylococcal abscesses,
retained baby teeth,
coarse facies, dermatologic problems (eczema),
bone fractures from minor trauma.
What are the key findings in Job syndrome?
Increased IgE, increased eosinophils decreased IFN gamma
What is the defect in Chronic mucocutaneous candidiasis?
T-cell dysfunction with impaired cell-mediated immunity against Candida species, often due to defects in AIRE.
What are the clinical presentations of Chronic mucocutaneous candidiasis?
Persistent noninvasive Candida albicans infections of the skin and mucous membranes.
What are the key findings in Chronic mucocutaneous candidiasis
Absent in vitro T-cell proliferation in response to Candida antigens, absent cutaneous reaction to Candida antigens
What is the defect in X-linked (Bruton) agammaglobulinemia?
Defect in BTK, a tyrosine kinase gene, leading to no B-cell maturation; X-linked recessive.
What are the clinical presentations of X-linked (Bruton) agammaglobulinemia?
Recurrent bacterial and enteroviral infections especially giardia after 6 months of age (due to decreased maternal IgG).
What are the key findings in X-linked (Bruton) agammaglobulinemia?
Absent B cells ( no CD19 no CD20) in peripheral blood, decreased Ig of all classes, absent/scanty lymph nodes and tonsils, live vaccines contraindicated.
what is the treatment of x linked ammaglobulinemia?
IVIg
What is the cause of Selective IgA deficiency?
Unknown; it is the most common primary immunodeficiency.
What are the clinical presentations of Selective IgA deficiency?
Majority asymptomatic; can have airway and GI infections, autoimmune disease, atopy, and anaphylaxis to IgA-containing blood products.
What are the key findings in Selective IgA deficiency?
Decreased IgA with normal IgG and IgM levels; increased susceptibility to giardiasis.
often false positive pregnancy tests
What is the defect in Common variable immunodeficiency?
Defect in B-cell differentiation; the cause is unknown in most cases.
What are the clinical presentations of Common variable immunodeficiency?
Presents in childhood or after puberty with increased risk of autoimmune disease, bronchiectasis, lymphoma, and sinopulmonary infections.
What are the key findings in Common variable immunodeficiency?
Decreased plasma cells and immunoglobulins.
what is thee difference between CVID and x linked ammaglobulinemia ?
CVID is more likely to affect females - CVID more likely to affect males
CVID has a later onset
What are the defects associated with Severe Combined Immunodeficiency (SCID)?
Several types including defective IL-2R gamma chain (most common, X-linked recessive), adenosine deaminase deficiency (autosomal recessive), RAG mutation causing VDJ recombination defect.
What are the clinical presentations of SCID?
Failure to thrive, chronic diarrhea, thrush, recurrent viral, bacterial, fungal, and protozoal infections.
What are the key findings in SCID?
Decreased T-cell receptor excision circles (TRECs), absence of thymic shadow on CXR, absence of germinal centers, and decreased T cells on flow cytometry
how is newborn screening for SCID done ?
TRECS are measured
What is the defect in Ataxia-Telangiectasia?
Defects in ATM gene leading to failure to detect DNA damage and halt cell cycle progression, resulting in accumulated mutations; autosomal recessive.
What are the clinical presentations of Ataxia-Telangiectasia?
Cerebellar defects (ataxia), spider angiomas (telangiectasia), IgA deficiency; increased sensitivity to radiation.
What are the key findings in Ataxia-Telangiectasia?
Increased AFP, decreased IgA, IgG, and IgE, lymphopenia, cerebellar atrophy.
all start with A
ataxia
derceased IgA
increased AFP
Angioma
What is the cause of Hyper-IgM Syndrome?
Most commonly due to defective CD40L on Th cells, causing class switching defect; X-linked recessive.
What are the clinical presentations of Hyper-IgM Syndrome?
Severe pyogenic infections early in life; opportunistic infections with Pneumocystis, Cryptosporidium, CMV.
What are the key findings in Hyper-IgM Syndrome?
Normal or increased IgM, decreased IgG, IgA, IgE, and failure to make germinal centers.
What is the defect in Wiskott-Aldrich Syndrome?
Mutation in WAS gene causing defective antigen presentation; X-linked recessive
What are the clinical presentations of Wiskott-Aldrich Syndrome?
Thrombocytopenia small volume platelets, eczema, recurrent pyogenic infections, increased risk of autoimmune disease and malignancy.
What are the key findings in Wiskott-Aldrich Syndrome?
Decreased to normal IgG, IgM; increased IgE, IgA; fewer and smaller platelets.
What is the defect in Leukocyte Adhesion Deficiency (type 1)?
Autosomal recessive defect in LFA-1 integrin (CD18) on phagocytes leading to impaired migration and chemotaxis.
Late umbilical seperation
Absent pus
Dysfunctional neutrophils
What are the clinical presentations of Leukocyte Adhesion Deficiency (type 1)?
Late separation of umbilical cord (>30 days), absent pus, dysfunctional neutrophils causing recurrent skin and mucosal bacterial infections.
What are the key findings in Leukocyte Adhesion Deficiency (type 1)?
Increased neutrophils in blood but absence at infection sites.
What is the defect in Chediak-Higashi Syndrome?
Defect in lysosomal trafficking regulator gene (LYST), causing microtubule dysfunction in phagosome-lysosome fusion; autosomal recessive.
What are the clinical presentations of Chediak-Higashi Syndrome?
Progressive neurodegeneration, lymphohistiocytosis, albinism, recurrent pyogenic infections, peripheral neuropathy
What are the key findings in Chediak-Higashi Syndrome?
Giant granules in granulocytes and platelets, pancytopenia, mild coagulation defects.
What is the defect in Chronic Granulomatous Disease (CGD)?
Defect of NADPH oxidase, leading to decreased reactive oxygen species and absent respiratory burst in neutrophils; X-linked form is most common.
What are the clinical presentations of CGD?
Increased susceptibility to catalase-positive organisms, recurrent infections, and granulomas.
What are the key findings in CGD?
Abnormal dihydrorhodamine test (decreased green fluorescence), nitroblue tetrazolium dye reduction test fails to turn blue
what are the organisms that cause CGD ?
staph aureus
pseudomoonas
aspergilluss
nocardia
servatia
what infection is especially associated with hyper IgM syndrome ?
pneumocystitis jirovecii
what is thee most common cause off MSMD ?
IL 12 deficiency
