ARUP's Laboratory Test Directory

0095862: Lymphocyte Subset Panel 6 - Total Lymphocyte Enumeration with CD45RA & CD45RO

[ image for: Time Sensitive]
Time Sensitive
  

Test Mnemonic: TEXTENDED
Methodology: Flow Cytometry

Performed: Sun-Sat

Reported: 1-3 days

Specimen Required:  
Collect: One 5 mL green Hemogard (sodium or lithium heparin) or one 5 mL lavender Hemogard (EDTA), or pink Hemogard (K2EDTA), labeled with the patient's name, date and time of draw.  (Min: 3 mL)  Pour-off tubes are no longer acceptable.

Transport: 5 mL whole blood at 20-25°C. (Min: 0.5 mL)

Submit specimen according to Biological Substance, Category B, shipping guidelines.

Pediatric Collection/Transport: 0.5 mL whole blood at 20-25°C.

Submit specimen according to Biological Substance, Category B, shipping guidelines.

Remarks: CRITICAL AMBIENT. Only Hemogard tubes are acceptable. Specimens must be analyzed within 48 hours of collection. Some medications may affect immunophenotyping results and should be listed on the patient test request form.

New York State Clients: Only EDTA specimens may be submitted and must be analyzed within 30 hours of collection.

Unacceptable Conditions: Clotted, hemolyzed, refrigerated, or frozen specimens. Specimens sent in pour-off tubes. Specimens collected in ACD (yellow) tubes.  Specimens older than 48 hours.
New York State Clients: Clotted, hemolyzed, refrigerated, or frozen specimens. Specimens sent in pour-off tubes. Specimens collected in ACD (yellow) tubes or heparin. EDTA specimens older than 30 hours.

Stability: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
New York State Clients: Ambient: 30 hours; Refrigerated: Unacceptable; Frozen: Unacceptable

Reference Interval:
 
Components Age: 0-11 months Age: 12-23 months Age: 2 years and older
% CD4  (Helper T-cells)
Absolute CD4 		38-62
1580-4850 		31-54
1020-3600 		32-62
370-1540
% CD45RA (Naive helper T-cells)
Absolute CD45RA 		15-70
200-3400 		15-70
200-3400 		3-38
165-1030
% CD45RO (Memory helper T-cells)
Absolute CD45RO 		5-30
50-1500 		5-30
50-1500 		16-46
230-1290
% CD8 (Suppressor T-cells)
Absolute CD8 		16-34
680-2470 		16-38
570-2230 		12-45
183-1160
CD4: CD8 ratio 1.17-6.62 1.17-6.62 0.80-5.00
% CD3 (Total T-cells)
Absolute CD3 		58-85
2170-6500 		53-81
1460-5440 		58-87
710-2300
% CD19 (B-cells)
Absolute CD19 		11-45
430-3300 		11-45
430-3300 		6-23
117-620
% NK-cells
Absolute NK-cells 		3-19
80-340 		3-19
80-340 		4-27
72-620

Interpretive Data:
In this test, the CD4 cells are Helper T-cells because they express both CD3 and CD4. The CD8 cells are Suppressor T-cells because they express both CD3 and CD8. The B-cells express CD19 but not CD3. The NK-cells express either CD16 or CD56 (or both) but not CD3. The CD45RA cells express both CD4 and CD45RA and the CD45RO cells express both CD4 and CD45RO. Helper T-cell levels are a criterion for categorizing HIV-related clinical conditions by the CDC's classification system for HIV infection. The measurement of Helper T-cell levels has been used to establish decision points for initiating P. jiroveci prophylaxis and antiviral therapy and to monitor the efficacy of treatment. The Public Health Service (PHS) has recommended that Helper T-cell levels be monitored every three to six months in all HIV-infected persons.

The performance characteristics of this test were determined by ARUP Laboratories, Inc.



Note:
This assay is designed for enumerating the percents and absolute cell counts of lymphocyte subsets in lysed whole blood.  Whole blood is added to fluorochrome-labeled antibodies that bind specifically to cell surface antigens on lymphocytes.  After incubation, lysing and fixation, percents and absolute counts are enumerated utilizing an internal quantitation standard.  Additional CBC data is not required.

During HIV infection, antiviral therapy is often initiated when the absolute CD4 count drops below 500 cells/µL. When the absolute CD4 count drops below 200 cells/µL, therapeutic prophylaxis against PCP and other opportunistic infections may be initiated. When the absolute CD4 count drops below 100 cells/µL, prophylaxis against Mycobacterium avium complex is recommended.

The CD45RA subset delineates a "naive" helper T-cell population. The CD45RO subset delineates a "memory" helper T-cell population. With disease progression in HIV-infected individuals, a decrease in CD45RA "naive" cells may be observed.

For longitudinal studies involving serial monitoring, specimen collections should be performed at the same time of day.

CPT Code(s):
88184 First marker; 88185 x7 Each additional marker