Flow Cytometry, T Cell Subsets (CD3, CD4 and CD8)
GENERAL INFORMATION
Test Name:
Flow Cytometry, T Cell Subsets (CD3, CD4 and CD8).
PC/NPS Test Code:
FLOW TSUB
CPT Code(s):
86359, 86360
Methodology:
Flow Cytometry
Days of Week Performed:
M, Tu, W, Th, F
Routine TAT:
24-48 hours (excluding weekends and holidays)
Clinical Utility:
T helper cells (CD4+ lymphocytes) are key to regulation of cellular immunity, and low levels result in susceptibility to infections. In general practice, CD4 counts are used primarily to monitor HIV infection, which selectively depletes T helper cells. In oncology practices, CD4 counts are also ordered to detected low levels incidental to chemotherapy. If the CD4 count is very low, prophylactic antibiotic therapy may be prescribed to prevent potentially life-threatening infections. CD8 may be ordered in addition to CD4, in order to obtain the CD4/CD8 ratio which is very low with T helper cell suppression.
COLLECTION AND HANDLING:
Collection Instructions:
1 lavender (EDTA) tube. Specimens are stable 24 hours (optimal); 48 hours (maximum).
Collection Containers:
N/A
Specimen Transport Requirements:
Refrigerate if testing will not be performed within 1-2 hours.
Specimen Labeling:
YLabel tubes with two patient specific identifiers.
Rejection Criteria:
Specimens >48 hours old; marked hemolysis; frozen or clotted specimens.
Specimen Retention Time:
Surplus samples are saved 7 days in the refrigerator.
