Immune Disorders Flashcards
C1 esterase inhibitor deficiency
cannot prevent complementation activation on self-cells (i.e. RBC) –> hereditary angioedema.
ACE inhibitors are contraindicated
C3 deficiency
no opsonization
increased risk of recurrent pyogenic infections.
incr. TYPE III hypersensitivity
C5-C9 deficiency
inability to have neutrophil chemotaxis. No MAC complex. recurrent Neisseria bacteremia. too much IgA –> DIC
DAF (GP1 anchored enzyme) deficiency
inability to inhibit complement activation on RBCs –> paroxysmal nocturnal hemoglobinuria
X-linked Bruton agammaglobulinemia
recurrent bacterial / enteroviral infections after 6 months (no maternal IgG)
X-linked agammaglobulinemia findings
normal B cell count, deg. IgG, no lymph nodes / tonsils
X-linked agammaglobulinemia pathophys
defected BTK (tyrosine kinase) –> no B cell maturation
selective igA deficiency presentation
mostly Asymptomatic. Airway / GI infections. Autoimmune disease. Atopy, Anaphylaxis to IgA products. normal Ig G / IgM levels
common variable immunodeficiency defect / presentation
acquired in 20s-30s. increased risk of autoimmune disease. bronchiectasis, lymphoma, sinopulmonary infections.
findings: dec. plasma cells / Igs
thymic aplasia presentation
absent thymus / parathyroids –> low Ca2+ / PTH / T cells. recurrent viral / fungal infections, conotruncal abnormalities (tetralogy of Fallot, truncus arteriosus), tetany
IL-12 receptor deficiency
dec. Th1 response / IFN-y. disseminated mycobacterial / fungal infections.
AD hyperIgE syndrome
STAT3 mutation –> def. Th17 -> impaired neutrophil recruitment.
FATED acronym + Job Syndrome (AD hyper IgE syndrome)
coarse Facies, noninflamed staph Abscesses, primary Teeth, incr. IgE, Derm problems (Eczema)
chronic mucocutaneous candidiasis
T cell dysfunction –> no T-cell proliferation in response to candidda –> repeated candida infections
severe combined immunodeficiency defects
1) IL-2r gamma chain (x-linked)
2) adenosine deaminase deficiency (AR)
SCID presentation
1) recurrent viral, bacterial, fungal, protozal infections
2) failure to thrive, diarrhea, thrush
3) treatment: bone marrow transplant
SCID findings
1) dec. T cell receptor exceision circles
2) absent thymic shadow, germinal ceners, T-cells on flow cytometry
Ataxia-telangiectasia
defects in ATM –> dsDNA breaks –> cell cycle arrest:
1) ataxia
2) spider Angiomas
3) IgA deficiency
ataxia telangiectasia findings
incr. AFP, dec. IgA,IgG,IgE
Hyper IgM syndrome
defective CD40L on Th cells –> no class switching –> severe pyogenic infections + opportunistic infection (pneumocystis, cryptosporidium, CMV).
labs: lots of IgM. Low IgG, IgA, IgE
wiskott-aldrich syndrome
T cells don’t recognize actin cytoskeleton.
1) thrombocytopenia + purpura
2) eczema
3) recurrent infections
4) increased risk of autoimmune disease / malignancy
Leukocyte Adhesion Deficiency (type 1)
defective LFA-1 / Cd18 –> impaired migration, chemotaxis. –> recurrent bacterial infections. NO PUS. delayed umbilical cord separation (>30 days). increased neutrophils, but absence of neutrophils at site of infection
chediak-Higashi syndrome defect
defect in lysosomal trafficking regulator gene (LYST) –> microtubule dysfunction in phagosome-lysosome fusion. autosomal recessive
chediak-Higashi presentation + labs
1) recurrent pyogenic infections w/ stpah / strep
2) albinism
3) peripheral neuropathy
4) neurodegeneration
5) infiltrative lymphohistiocytosis
labs:
1) giant granules in neutrophils / platelets
2) pancytopenia
3) coagulation defects
chronic granulomatous disease pathophys
defective NADPH oxidase –> dec. ROS / superoxide
CGD presentation
incr. susceptibility to catalase + organisms (Pseudomonas, Listeria, Aspergillus, Candida, E Coli, S. Aureus, Serratia)
CGD labs
abnormal dihydrorhodamine (flow cytometry). nitroblue tetrazolium dye reduction test is negative
