Immunodeficiencies Flashcards
- Recurrent viral, fungal, and protozoal infections
- hypocalcemia and tetany
- congenital heart defects
Thymic aplasia (DiGeorge) -due to 22q11 deletion most commonly
DiGeorge syndrome
- 3rd and 4th pharyngeal pouches fail to develop
- leads to no mature T cells and no parathyroids
- results in recurrent viral/fungal/protozoal infections + hypocalcemia/tetany
T cell dysfunction resulting in recurrent candida infections
Chronic mucocutaneous candidiasis
Prophylaxis for chronic mucocutaneous candidiasis
ketoconazole
Mycobacterial and fungal infections
IL-12 receptor deficiency
X-linked B-cell deficiency that leads to recurrent bacterial infections after 3-6 mo. of age
Bruton agammaglobulinemia
- defective tyrosine kinase gene –> low levels of ALL immunoglobulins
- seen in boys
Sinus and lung infections, associated with atopy and asthma
Selective IgA deficiency
-concern for anaphylaxis with blood products
Severe recurrent infections (chronic mucocutaneous candidiasis, fatal or recurrent HSV/VZV/RSV/measles/flu/paraflu, PCP)
Chronic diarrhea
Failure to thrive
no thymic shadow on CXR
Severe combined immunodeficiency (SCID)
Major defect leading to SCID
adenosine deaminase deficiency - leads to defect in early stem cell differentiation
sinus and lung infections, cerebellar ataxia, poor smooth pursuit of moving targets with eyes, telangiectasia of face after age 5, elevated AFP
Ataxia-telangiectasia
Components of ataxia-telangiectasia
ATAXIA - ataxia, telangiectasia/trafficking difficulty, lymphoma/leukemia risk, X-ray sensitive (avoid X-ray), IgA deficiency, increased AFP
- increased AFP after 8 months
- avg. age of death is 25 yrs
- IgA and T cell deficiency –> lung and sinus infections
Wiskott-Aldrich Syndrome components
WAITER - Wiskott-Aldrich, immunodeficiency, thrombocytopenia and purpura, eczema, recurrent pyogenic infections
- X-linked
- no IgM –> no defense against encapsulated bugs
- low IgM, high IgA
Hyper-IgM syndrome
- increased IgM, other isotypes decreased
- Autosomal recessive is due to no CD40 on B cells
- X-linked is due to no CD40 ligand on helper T cells
Defect in Chronic Granulomatous disease
lack of NADPH oxidase –> phagocytes are not effective against catalase + organisms
Features of Chronic granulomatous disease
- X-linked
- staph aureus and aspergillus infections
Which bugs are pts with Chronic granulomatous disease esp. susceptible to?
Staph aureus, Aspergillus
Diagnosis of Chronic granulomatous disease
negative nitroblue tetrazolium (NBT) test
- no yellow to blue-black oxidation
Treatment of Chronic granulomatous disease
Prophylactic TMP-SMX and itraconazole; IFN-gamma as well
Defect in Chediak-Higashi syndrome
defective LYST gene –> defect in lysosomal transport in phagosomes –> giant cytoplasmic granules in PMNs are diagnostic
Classic triad of Chediak-Higashi syndrome
partial albinism
recurrent respiratory tract and skin infections
neurologic disorders
Classic presentation of Leukocyte adhesion deficiency syndrome
delayed separation of umbilical cord
Defect in Leukocyte adhesion deficiency syndrome
abnormal integrins –> inability of phagocytes to exit circulation
Classic presentation of Hyper-IgE syndrome
eczema, recurrent cold S. aureus abscesses, coarse facial features (frontal bossing, broad nose, prominent forehead, deep-set eyes, doughy skin)
- also can have retained primary teeth –> two rows of teeth
- high IgE and eosinophils
Defect in Hyper-IgE syndrome
mutation in gene for STAT3 signaling protein –> impaired differentiation of Th17 cells and impaired recruitment of neutrophils
