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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Flow Cytometry, CD4 and CD8

Test Code(s): CD48 (FCD48) / HCCD48

CPT Code(s): 86360, 86359

Test Description: Test Component:

Absolute lymphocyte count, percent and absolute numbers of CD3 (T-cells), CD3 CD4  (T-helper/inducer cells), CD3 CD8  (T-cytotoxic/suppressor cells), CD4:CD8 ratio. (Note: Absolute lymphocyte count and absolute numbers will only be done on blood specimens)

Methodology: Flow Cytometry

Days Performed: Mon-Fri, dayshift- specimens accepted at anytime.

Turnaround Time: Stat: Not available stat.
Routine: 1 - 4 days.

Specimen Requirements

Specimen: See collection instructions.

Collection Instructions: An order for a WBC and differential must accompany blood request. Outside clients should send WBC and differential results along with specimen. If no results accompany request, a WBC and differential will be added. See Transport, Limitations and Additional Information for more information.

Sample Analyzed: Whole Blood

Specimen Transport: Transport BLOOD specimens to UWHC Core Laboratory (B4/220) within 6 hours of collection. Keep specimen at room temperature. Do NOT centrifuge.

Transport BAL specimens to UWHC Core Laboratory (B4/220) within one hour of collection if a body fluid cell count is ordered.

Outreach Specimen Transport: For BLOOD specimens transport unopened tube at room temperature to UWHC Core Laboratory (B4/220) within 6 hours of collection if the WBC and Differential results do not accompany the specimen.

If sending WBC and Differential results with specimen, the specimen must be received within 24 hours of collection.

For BAL specimens that have a body fluid cell count ordered the specimen must be transported to the UWHC Core Laboratory (B4/220) within one hour of collection.

Unacceptable Criteria: Blood specimens that are hemolyzed, clotted, frozen or overheated specimens are not acceptable. Samples greater than 24 hours old at time of analysis are not acceptable.

Stability: Ambient: See additional information
Refrigerated: See additional information
Frozen: Not Acceptable


Reference Interval:

Age 18 and up:


   %  Absolute number/uL
 CD3:  59-85  760-1903
 CD3+CD4+:   37-64  494-1464
 CD3+CD8+:  14-33  247-595
 CD4:CD8 ratio:  1.2-3.7  


Please contact UWHC Flow Laboratory at (608) 263-3868 for pediatric reference intervals.


No reference ranges for Bronchoalveolar lavage specimens.

Test Limitations:

Absolute values will not be calculated for blood specimens if WBC and differential request or results are not received.

Additional Information:

Blood Specimens:

Container Volume Stability  Transport

Preferred: 4 mL

Min. 1 mL

Ambient: 8 hr if CBC & Diff is needed

Ambient: 24 hr if CBC & Diff is not needed

Refrigerate: Not Acceptable

Frozen- Not Acceptable

Transport within 6 hr if cell count needed


Transport within 22 hr if cell count not needed


BAL Specimens:


Volume Stability  Transport



Min. 1 mL

Ambient: 2 hr if cell count needed

Ambient: 24 hr if cell count not needed

Refrigerate: 2 hr if cell count needed

Refrigerate: 48 if cell count not needed

Frozen - Not Acceptable

Transport within 1 hr if cell count is needed


Transport within 22 hr if cell count not needed


This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories. This test meets the standards for clinical testing. This test should not be regarded as investigational or for research use. The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.


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