0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:40
820 Immunodeficiency Disorders
Absolute peripheral blood lymphocyte count
T-cell numbers: CD2, CD3
T-cell subsets: CD4, CD8
■Delayed-type hypersensitivity (DTH) skin reaction
➣Candida, mumps
■In vitro proliferative responses
➣Nonspecific: phytohemagglutinin (PHA), concanavalin A (CON
A)
➣Specific: tetanus, Candida
■Evaluation of phagocytic function
➣Enumeration of neutrophils
➣Absolute neutrophil count
■Oxidative burst assays
➣Nitroblue tetrazolium reduction test (NBT)
➣Dihydrorhodamine reductase assay (DHR), more sensitive
■Enzyme determination
➣Myeloperoxidase
➣Glucose-6-phosphate dehydrogenase
■Chemotaxis assay
➣Defective in Chediak-Higashi syndrome, hyper-IgE syndrome
■Adhesion molecules
➣Determination of CD18 surface marker: absent in leukocyte
adhesion deficiency type 1 (LAD 1)
■Evaluation of complement system
➣Determination of complement proteins, C3 & C4
➣Total hemolytic complement CH 50, screening test, extremely
low or nondetectable in complement deficiencies
➣Individual complement components determined in specialized
labsdifferential diagnosis
Antibody Deficiency Disorders
■IgA deficiency
➣Most common: 1/700 of the general population
➣IgA low or decreased w/ normal IgG & IgM
➣Variable clinical features
Asymptomatic
Assoc w/ respiratory infections (sinusitis)
Assoc w/ autoimmune disorders
■Selective IgG subclass deficiency
➣Variable decreases in IgG2, IgG3 or IgG4; normal total IgG