Primary Immunodeficiency 1
Utility: General evaluation for T, B and natural killer (NK) cell populations.
Specimen: 4 - 10 mL peripheral blood in sodium heparin (green top).
CPT codes: 86359, 86360, 86355, 86357, 88184, 88185 x 4, 88187.
Clinical indication/general description
Primary immunodeficiencies (PIDDs) and secondary immunodeficiencies present with recurrent upper and lower respiratory tract infections (encapsulated and atypical bacteria), deep-seated infections, recurrent or deep-seated abscesses, intractable diarrhea and failure to thrive. In addition, PIDDs also can present with autoimmune manifestations and malignancies. Evaluation of patients with these manifestations includes enumeration of the different types of lymphocytes (T cells, B cells and NK cells) because an absolute lymphocyte count from a complete blood count differential can miss important deficiencies in specific subsets of lymphocytes.
The PID1 assay enumerates the numbers of helper (CD4) and cytotoxic (CD8) T cells, B cells and NK cells. Numerous immunodeficiencies associated with decreased numbers of T cells, B cells or NK cells can be detected with this assay including DiGeorge syndrome (low T cell numbers will be detected), AIDS (low CD4 cell counts will be detected), X-linked agammaglobulinemia (low B cells will be detected) and NK cell deficiencies (low NK cell numbers will be detected).
The assay is designed to enumerate the percent and absolute cell counts of T helper cells (CD3+CD4+), T cytotoxic cells (CD3+CD8+), B cells (CD19+) and NK cells (CD3-CD16+/CD56+).
Note: This assay does not detect neutrophil adhesion defects (leukocyte adhesion deficiency) or signs of immune activation.