Chimerism

Message

BGMC - Lab only orderable to UAGC
AZ Locations lab only orderable - send to U of A in Tucson
BDMC, BUMCP, BTMC, BUMCT, BUMCS - refer to Chimerism/Engraftment performed at BUMCT main campus.

Test Code

PESOT/CHIMERISM

Alias/See Also

Chimerism, Post-Transplant Testing
Chimerism, Pre-Transplant Analysis, Recipent
Chimerism, Pre-Transplant Analysis, Donor

CPT Codes
Pre and Post CPT 81265 (ZB45G); Post BMT CPT 81267 (Z00B0)

Preferred Specimen

Test: Pre-transplant analysis, donor
Specimen type: Whole blood, minimum 2 mL in lavender (EDTA) or yellow (ACDA) collection tube.
Test: Pre-transplant analysis, recipient
Specimen type: Whole blood, minimum 2 mL in lavender (EDTA) or yellow (ACDA) collection tube OR DNA*.
Test: Post-transplant chimerism testing
Specimen type: Whole blood, minimum 2 mL OR bone marrow, minimum 1 mL in lavender (EDTA) or yellow (ACDA) collection tube OR DNA*.

Minimum Volume

Minimum 2 mL whole blood or 1 mL of bone marrow

Other Acceptable Specimens

Test: Pre-transplant analysis, recipient
Alternatively: 2 buccal brushes^ each in a 2 mL tube with 650 uL of Lysis Buffer (only if engraftment has already occurred).

*DNA samples should be received only if they are the only samples available. DNA specimens are only accepted if the nucleic acid isolation occurred in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or the CMS. Such samples will be processed however, a successful outcome may not be guaranteed.

^A buccal swab alternative source of DNA may only be used if there is an acceptable confidence level to determine the recipient’s genotype.

Instructions

Please contact UAGC – Gina Delgado at 520-626-5002 or Taylor Edwards 520-626-3645 when there is a sample ready for pick up from Banner UMC-Tucson or when specimen is shipped directly to UAGC.

See clinical website for additional details -http://uagcclinical.arizona.edu/test/chimerism-testing/

Transport Temperature

Package and ship specimen cold, but not frozen.
AZ Locations, please send via Fed Ex to the location below:

University of Arizona Genetics Core – Clinical Services

Attn: Gina Delgado

1657 E Helen St Rm 111

Tucson AZ 85721

Specimen Stability

Ambient: 72 hours
Refrigerated: 1 week

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Each sample submitted for Chimerism Testing for Engraftment Analysis must be accompanied by a completed requisition form. It is critical that all information received electronically matches the physical sample(s). Additional rejection criteria for this test includes incorrect fixative or sample out of limits of storage conditions

Methodology
Chimerism testing (engraftment analysis) by DNA employs methodology commonly used in human identity testing and is accomplished by the analysis of genomic polymorphisms called short tandem repeat (STR) loci. These loci consist of a core DNA sequence that is repeated a variable number of times within a discrete genetic locus. The term STR, also referred to as a microsatellite, relates to the number of base pairs of a tandemlyrepeated core DNA sequence which ranges from 2-8 base pairs in length. These loci exhibit alleles that may differ in length between individuals and are inherited as codominant Mendelian traits. The GenePrint 24 System is a 24-locus multiplex system designed to generate a multi-locus human DNA profile from a variety of human-derived biological sources. This five-color system allows co-amplification and fluorescent detection of the following autosomal STR loci: CSF1PO, FGA, TH01, TPOX, vWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, D10S1248, D22S1045, D2S441, D1S1656, D12S391, D2S1338, D19S433, Penta D and Penta E plus Amelogenin for gender determination. In addition, the male-specific DYS391 locus is included to identify null Y allele results for Amelogenin. Data analysis is facilitated by fragment analysis software (ChimerMarker) which sizes the DNA fragments using an internal lane standard run with the sample and assigns genotypes by comparison to an STR allelic ladder. This provides distinct STR genotypic profiles for the donor and for the transplant recipient. STR loci that are polymorphic (i.e. informative) between these individuals are used to assess relative amounts of recipient and donor DNA in the post-transplant sample.

FDA Status
High-complexity laboratory developed test

Report Available

5 working days from receipt of the tissue sample(s) by UAGC-CS and are based on business hours of the laboratory: Monday through Friday, 9am-5pm Arizona Time. Contact UAGC-CS for expedited turn around.

Limitations

Minimum of 3 informative loci between donor and recipient required for reporting.

Reference Range

5%-95%

Clinical Significance

The intended use of this assay is for routine post-transplant documentation of the donor/recipient origin of white blood cells in peripheral blood and/or bone marrow. Additional clinical indications include:

Prognostic testing for risks of graft rejection and recurrence of disease.
Document presence of donor cells in post-transplant patient with residual disease or prior to donor lymphocyte infusion (DLI).
Evaluate donor/recipient cells in patients with inadequate marrow function.
Determine if malignancy is a recurrence or new occurrence from donor cells.
Differentiate donor cell populations in recipients who have received multiple transplants.

Performing Laboratory
University of Arizona
Tucson, AZ

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.