Immunodeficiencies Flashcards
X-linked (Bruton) Agammaglobinemia
B-cell
- BTK (tyrosine kinase), u-hc, Iga, BLNK
- X-linked
- No B-cell maturation (increased pro-B-cells)
- Rec. bact/enterovirus/giardia after 6mo
- No peripheral B-cells, Decreased Ig (all), absent/scanty LN’s and tonsils
- Avoid live vaccines
Selective IgA deficiency
B-cell
- Unknown (most common primary ID)
- Asymptomatic (most)
- Airway and GI
- Autoimmune
- Atopy
- Anaphylaxis with IgA containing blood products
- Associated with celiac disease
Common variable immunodeficiency
B-cell
- Many causes
- Defective B-cell differentiation
- Acquired in 20s-30s
- Autoimmune
- Bronchiectasis, Lymphoma, Sinopulmonary infections
- Decreased plasma cells and Ig’s
- Low to normal B-cells
Thymic aplasia (DiGeorge Syndrome)
T-cell
- 22q11 del (failed 3rd/4th pouches)
- Absent thymus and parathyroid
- Tetany, rec. viral/fungal, conotruncal abnormalities (TOF, TA)
- Decreased T-cells, TRECs, PTH, Ca
- Absent thymic shadow (CXR)
IL-12 receptor deficiency
T-cell
- Decreased Th1 response
- AR
- Disseminated mycobacterial and fungal (possible post-BCG vaccine)
- Decreased IFN-y
AD hyper-IgE syndrome (Job syndrome)
T-cell
- STAT3 mutation (decreased Th17)
- Impaired recruitment if neutrophils to site of infect
- FATED (coarse Facies, cold (noninflammed) staph. Accesses, primary Teeth, hyper-IgE, Dermatological (eczema), bone fractures
- Increased IgE, decreased IFN-y, eosinophilia
Chronic mucocutaneous candidiasis
T-cell
- Many causes
- Noninvasive candida albicans of skin/mucosa
- T-cells don’t respond to candida Ag
Transient Hypogammaglobinemia of Infancy
B-cell
- IgM, IgG or IgA greater than 2SD below mean
- Normal Ab production to polio and HA vaccines
- intact cellular immunity
- rec. non-serious infections
IFN-y receptor def
T-cell
- Disseminated TB early in life (inc. from BCG)
Severe Combined Immunodeficiency (SCID)
B and T cell
- IL-2R gamma chain (X-linked), ADA (AR), MHC-II def, JAK3 (AR), IL-7R alpha chain, IKBKB
- Failure to thrive, chronic diarrhea, thrush
- Rec. viral, bact, fungal, protozoal
- Vaccine susceptible
- Decreased TRECs
- Absent thymic shadow, germinal centres, T-cells
- Rx: BM transplant, isolation, gene Tx
Ataxia-telangiectasia
B and T cell
- ATM gene
- Failed ds break repair (DNA) causing cell cycle arrest
- Ataxia (cerebellar), spider Angiomas, IgA def.
- Increased AFP
- Decreased IgA, IgG, IgE
- Lymphopenia and cerebellar atrophy
Hyper-IgM syndrome
B and T cell
- Defective: CD40L (XR), CD40 (AR)
- Class switching defect
- Severe pyogenic infections early in life
- Opportunistic infections: Pneumocystis, Cryptosporidium, CMV
- Increased IgM
- Decreased IgG, IgA, IgE
Wiskott-Aldrich syndrome
B and T cell
- WAS gene (XR)
- T-cells unable to reorganize actin cytoskeleton (necessary for APC - Tcell synapse)
- WATER (Wiskott-Aldrich: Thrombocytopenic purpura, Eczema, Reccurent infections)
- Increased risk of autoimmune and malignancy
- Decreased to normal IgG, IgM
- Increased IgE, IgA
- Fewer and smaller platelets
Leukocyte adhesion deficiency (type 1)
Phagocyte
- Defect in LFA-1 integrin (CD18)
- Impaired migration and chemotaxis
- Autosomal recessive
- Rec. bacterial skin and mucosa infections
- No pus formation
- Impaired wound healing
- Delayed separation of umbilical cord (>30days)
- Increased neutrophils (absent at infection site)
Leukocyte adhesion deficiency (type 2)
Phagocyte
- RARE, E-selectin ligands (Sialyl-Lewis X or CD15s) absent (no rolling)
- E-selectin contains fucose: if defect with de novo give oral fucose, if defect with fucose transport to golgi, oral does nothing)
- mental retard, short, distinctive facies
Chediak-Higashi syndrome
Phagocyte
- Defect: lysosomal trafficking regulator gene (LYST) [AR]
- Microtubule dysfnc in phagosome-lysosome fusion
- Rec. pyogenic infections w/ staph and strep
- Partial albinism
- Peripheral neuropathy
- Progressive neurodegeneration (+ vision)
- Infiltrative lymphohistiocytosis
- Giant granules in granulocytes and platelets
- Pancytopenia, mild coagulation defects, neutropenia
Chronic Granulomatous disease
Phagocyte
- NADPH oxidase defect (XR most common)
- Susceptible to catalase positive (Need PLACESS: Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, Serratia)
- Acne, gingivitis, massive LAD, 50% have chronic gut inflammation similar to Chron’s
- Abnormal dihydrorhodamine (flow cytometry) test
- Nitroblue tetrazolium dye reduction test is negative (colourless)
MPO deficiency
Phagocyte
- Most asymptomatic
- increased candida infection
- NBT test positive (blue)