Primary Immunodeficiency Tests

Question 1

Test for SCID

Answer 1

Lymphocytes subsets (T cells/B cells/NK cells) by flow cytometry; TREC count (indicates number of normal naive T cells)

Question 2

Test for DiGeorge Syndrom

Answer 2

DNA chromosome microarray (Preferred); FISH; PCR for TBX1

Question 3

Test for XLA, CVID

Answer 3

IgG, IgA, IgM – do not order IgG subclasses; antibody titers (dT/pneumococcus)

Question 4

Test for CGD

Answer 4

Dihydrorhodamine (DHR) test preferred

Question 5

Test for Complement Deficiency

Answer 5

CH50

If 0 then deficient; if low value than consumption issue

Question 6

In all cases which test is the first screening test?

Answer 6

CBC with differential