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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: STR Engraftment Separated Lineages


CPT Code(s): 81268x2

Test Description: Test Component:

STR Engraftment Population 1 (CD3+) and STR Engraftment Population 2 (CD33+).  Both tests must be ordered at same time and should NOT be ordered individually.

Methodology: PCR

Clinical Significance: Typically used to assess proportions of donor- and recipient-derived CD3+ and CD33+ cells post stem cell transplant or in cases of suspected graft-vs-host disease.

Days Performed: Wed.

Turnaround Time: Routine: 10 days.

Specimen Requirements

Specimen: Blood

Collection Instructions: Specific sub-populations of white blood cells may be submitted for analysis. If separated by an outside lab, please identify the population on the label.

Specimens must be received by the UWHC Molecular Diagnostics Lab no later than noon on Fridays or the day before a holiday in order to be processed in a timely manner. Specimens will not remain stable for more than 24 hours.

Collection Container: Preferred: Lavender top

Collection Volume: Preferred: 8 mL
Pediatrics: 2 mL

Specimen Transport: Transport specimen to laboratory.

Stability: Ambient: 24 hours
Refrigerated: Not acceptable
Frozen: Not acceptable


Interpretive Guidelines:

Sensitivity of detection of donor(s) in recipient is assessed for each combination of donor(s)/recipient.


 > 95-98% Donor  Predominantly Donor
 < 2-5% Donor  Predominantly Recipient
 2-98%, 5-95% Donor  Donor/Recipient Chimeric

Additional Information:

The specimen collected is processed by the UWHC Molecular Diagnostics Laboratory to extract CD3+ and CD33+ cell lineages. Each lineage is tested separately to quantitate and report independently the percentages of donor-derived cells. Test requires pre-transplant DNA samples on file in the laboratory for recipient and donor.


The performance characteristics of this test were validated by UWHC Clinical Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. The UWHC Clinical Laboratories is authorized under Clinical Laboratory Improvement Amendments (CLIA) to perform high-complexity testing.

sorted chimerisms
STRCD3, STR Engraftment Population 1, CD3+
STRCD33, STR Engraftment Population 2, CD33+

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