PID Flashcards
in xla, defects in b lymphocyte development result in __
- severe hypogammaglobulinemia
- absence of circulating b cells
- small to absent tonsils
- no palpable lymph nodes
protein affected in xla
burton tyrosine kinase (btk): expressed at high levels in all b lineage cells and myeloid series
suspect xla if:
- lymphoid hypoplasia on pe
- serum igg, iga, igm, ige are below 95% confidence limits
- low levels of natural antibodies to type a and b rbc polysaccharide
- low antibodies to immunizations
- absence of b cells in flow cytometry
treatment for xla
- replacement of immunoglobulin
- general supportive care
t/f cvid has only one genetic component
false, composed of several defects with autosomal dominant inheritance.
common: iga deficiency
clinical manifestations of cvid
- autoantibody formation
- normal sized or enlarged tonsils and lymph nodes
- recurrent/chronic infections
most common well defined immunodeficiency disorder
selective iga deficiency
genetics of selective iga deficiency
- autosomal dominant
- common in people with cvid (iga d -> cvid)
clinical manifestations of iga deficiency
- infections in the respiratory, gi, and urogenital tracts
- normal other igs
- igg against cow’s milk and ruminant serum proteins
- celiac like syndrome
- autoantibodies and malignancy higher risk
diagnosis and treatment for iga def
- diagnose only in >4 yo with low iga, normal igg ang igm
- can have elevated igm and low igg2
can resolve spontaneously
tx: 5 times washed normal donor erythrocytes OR blood products from other iga deficient individuals
IVIG NOT INDICATED
treatment of choice for patients with primary t cell defects
transplantation of thymic tissue or mhc or half-matched parental hematopoietic stem cells
thymic hypoplasia results from __
dysmorphogenesis of 3rd and 4th pharyngeal pouches during early embryogenesis -> hypoplasia/aplasia of thymus and parathyroid glands
catch 22 syndrome
cardiac defects abnormal facies thymic hypoplasia cleft palate hypocalcemia
charge association
seen in complete digeorge syndrome
- Coloboma
- Heart defect
- choanal Atresia
- growth or developmental Retardation
- Genital hypoplasia
- Ear anomalies (deafness)
clinical manifestations of digeorge syndrome
- suggested by hypocalcemic seizures during neonatal period
- partial: infections but grow normally
- complete: like severe combined immunodeficiency (opportunistic infections + gvhd from nonirradiated blood)
diagnosis and tx of digeorge syndrome
- low cd3 t cell
- low for age absolute lymphocyte
- pcr based genotyping (TBX1)
tx: cultured unrelated thymic tissue transplants, nonirradiated unfractionated bone marrow, peripheral blood transplants from hla-identical sibling
pathogenesis of scid
mutation in genes that encode components of immune system crucial for lymphoid cell development
clinical manifestations of scid
- extremely low or absent t cells and ig
- recurrent or persistent diarrhea, pneumonia, om, sepsis in first months
- opportunistic infections
- gvhd
- diagnosed with nbs
treatment for scid
hla-identical or t cell depleted haploidentical parental hematopoietic stem cell transplant
distinguishing features of ada scid
- affects primarily t cell function (normal nk and b cells)
- rib cage abnormalities
- abnormalities of chondro-osseous dysplasia
distinguishing features of reticular dysgenesis
- <1 g thymus, no hassall corpuscles, no thymocytes
- adenylate kinase 2 mutation
- tx: myeloablative matched sibling bone marrow transplant
how to distinguish cid and scid
cid has low but not absent t cell function, neutropenia and eosinophilia
characteristics of wiskott aldrich syndrome
wiskott and aldrich have ABS
- atopic dermatitis
- (bleeding diathesis) thrombocytopenic purpura with normal appearing megakaryocytes but small defective platelets
- susceptibility to infection (opportunistics)
cells affected in wiskott aldrich syndrome
- platelets: microthrombocytopenia = excessive bleeding
- helper t cells and b cells = impaired immune response
- t cells and nk cells = impaired defense to pathogens and cancer
normal or low igg and igm, high ige and iga
