Determining the relative amounts of donor and recipient cells in a specimen
An indicator of bone marrow transplant success
Initial Chimerism Testing:
Complete chimerism analysis requires 3 specimens. These specimens should be submitted when collected. An interpretive report will be provided once all specimens are received.
-CHRGB / Chimerism-Recipient Germline (Pretransplant), Varies
-CHIDB / Chimerism-Donor, Varies
-CHIMU / Chimerism Transplant No Cell Sort, Varies
See Chimerism-Recipient Germline Testing Algorithm in Special Instructions.
Polymerase Chain Reaction (PCR) Amplification/Capillary Electrophoresis
Bone Marrow DNA Typing Transplant Eval., Post-Transplant
Bone Marrow Post-Trans Eval
Bone Marrow Transplantation
Chimerism Evaluation
Transplant Analysis
Transplant Evaluation
Initial Chimerism Testing:
Complete chimerism analysis requires 3 specimens. These specimens should be submitted when collected. An interpretive report will be provided once all specimens are received.
-CHRGB / Chimerism-Recipient Germline (Pretransplant), Varies
-CHIDB / Chimerism-Donor, Varies
-CHIMU / Chimerism Transplant No Cell Sort, Varies
See Chimerism-Recipient Germline Testing Algorithm in Special Instructions.
Varies
This test is for the post-bone marrow transplant evaluation of the donor specimen. For post-bone marrow transplant testing to determine the relative amounts of donor and recipient cells, see CHIMS / Chimerism Transplant Sorted Cells, Varies.
Complete chimerism analysis also requires submission of CHRGB / Chimerism-Recipient Germline (Pretransplant), Varies and CHIDB / Chimerism-Donor, Varies specimens. These tests must be ordered on both the pre and donor specimens under separate order numbers. While the 3 specimens do not need to be submitted at the same time, the CHRGB and CHIDB specimens must be received before this test can be performed.
Specimen must arrive within 7 days (168 hours) of collection. Collect and package specimen as close to shipping time as possible.
The following information is required:
1. Pertinent clinical history
2. Specimen source
3. Donor identifier and donor date of birth
4. Donor date of collection
Question ID | Description | Answers |
---|---|---|
MP026 | Specimen Type |
Peripheral Blood Bone Marrow |
Submit only 1 of the following specimens:
Specimen Type: Blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 4 mL
Collection Instructions:
1. Only 1 tube is required.
2. Invert several times to mix blood.
3. Send specimen in original tube. Do not aliquot.
4. Label specimen as blood.
Specimen Type: Bone marrow
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send specimen in original tube. Do not aliquot.
3. Label specimen as bone marrow.
1. Chimerism Analysis Information Sheet (T594) in Special Instructions.
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Blood: 3 mL
Bone Marrow: 2 mL
Lesser volumes may be acceptable, depending on white cell count.
Call 800-533-1710 or 507-266-5700 with questions.
Gross hemolysis | Reject |
Moderately to severely clotted | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Ambient (preferred) | 7 days | PURPLE OR PINK TOP/EDTA |
Refrigerated | 7 days | PURPLE OR PINK TOP/EDTA |
Determining the relative amounts of donor and recipient cells in a specimen
An indicator of bone marrow transplant success
Initial Chimerism Testing:
Complete chimerism analysis requires 3 specimens. These specimens should be submitted when collected. An interpretive report will be provided once all specimens are received.
-CHRGB / Chimerism-Recipient Germline (Pretransplant), Varies
-CHIDB / Chimerism-Donor, Varies
-CHIMU / Chimerism Transplant No Cell Sort, Varies
See Chimerism-Recipient Germline Testing Algorithm in Special Instructions.
Patients who have had donor hematopoietic cells infused for the purpose of engraftment (ie, bone marrow transplant recipients) may have their blood or bone marrow monitored for an estimate of the percentage of donor and recipient cells present. This can be done by first identifying unique features of the donor's and the recipient's DNA prior to transplantation and then examining the recipient's blood or bone marrow after the transplantation procedure has occurred. The presence of both donor and recipient cells (chimerism) and the percentage of donor cells are indicators of transplant success.
Short tandem repeat (STR) sequences are used as identity markers. STRs are di-, tri-, or tetra-nucleotide repeat sequences interspersed throughout the genome at specific sites. There is variability in STR length among people and the STR lengths remain stable throughout life, making them useful as identity markers. Polymerase chain reaction is used to amplify selected STR regions from germline DNA of both donor and recipient. The lengths of the amplified fragment are evaluated for differences (informative markers). Following allogeneic hematopoietic cell infusion, the recipient blood or bone marrow can again be evaluated for the informative STR regions to identify chimerism and estimate the proportions of donor and recipient cells in the specimen.
An interpretive report will be provided.
An interpretive report will be provided, which defines unique features of the donor's cells.
It is most useful to observe a trend in chimerism levels. Clinically critical results should be confirmed with 1 or more subsequent specimens.
Sensitivity varies with the proportions of donor and recipient cells in the specimen. For this reason, results are reported as approximate and rounded to the nearest 5% or 10%, depending on the calculated percentage of donor cells. For example, if the percent donor is 10% or less, it is reported as 5% donor cells. If the percent donor cells are 90% or greater, it is reported as 95% donor cells. In rare cases (eg, matched related stem cell transplants), short tandem repeat (STR) patterns may be identical (ie, noninformative) and chimeric status cannot be determined with this test.
1. Antin JH, Childs R, Filipovich AH, et al: Establishment of complete and mixed donor chimerism after allogenic lymphohematopoietic transplantation: recommendations from a workshop at the 2001 Tandem Meetings of the International Bone Marrow Transplant Registry and the American Society of Blood and Marrow Transplantation. Biol Blood Marrow Transplant. 2001;7:473-485
2. Tang X, Alatrash G, Ning J, et al: Increasing chimerism following allogeneic stem cell transplantation is associated with longer survivial time. Biol Blood Marrow Transplant. 2014 August;20(8):1139-1144. doi: 10.1016/j.bbmt.2014.04.003
3. Ludeman MJ, Zhong C, Mulero JJ, et al: Developmental validation of GlobalFiler PCR amplification kit: a 6-dye multiplex assay designed for amplification of casework samples. Int J Legal Med. 2018 Nov;132(6):1555-1573. doi: 10.1007/s00414-018-1817-5
4. Tyler J, Kumer L, Fisher C, Casey H, Shike H: Personalized chimerism test that uses selection of short tandem repeat or quantitative PCR depending on patient's chimerism status. J Mol Diagn. 2019 May;21(3):483-490. doi: 10.1016/j.jmoldx.2019.01.007
5. Lion T, Watzinger F, Preuner S, et al: The EuroChimerism concept for a standardized approach to chimerism analysis after allogeneic stem cell transplantation. Leukemia. 2012 Aug;26(8):1821-1828. doi: 10.1038/leu.2012.66
Genomic DNA is extracted from blood or bone marrow aspirate samples using an automated extraction machine and used in a commercial kit GlobalFiler PCR Amplification KIT following the manufacturer's instructions. Briefly, 20 different short tandem repeat (STR) marker regions are amplified in single multiplex polymerase chain reaction (PCR) using primers labeled with fluorescent tags. The products are analyzed for size and amount using capillary electrophoresis on a genetic analyzer. For the initial sample on any patient, the test is performed on 3 separate DNA samples: donor germline DNA, recipient germline DNA, and recipient posttransplant sample for chimerism determination. The STR profile of the germline samples is used to identify markers that can distinguish between the donor and recipient. Based on these profiles, the percentage of donor and recipient DNA is then determined in the post-transplant sample using the assumptions and calculations outlined in Thiede et al. Subsequent samples for chimerism evaluation do not need to be accompanied by samples for donor and recipient germline evaluation, as the profiles from the initial testing are kept on file for comparison.(Package insert: GlobalFiler PCR Amplification Kit. User Guide. Applied Biosystems; 2019; Thiede C, Florek M, Bornhauser M, et al: Rapid quantification of mixed chimerism using multiplex amplification of short tandem repeat markers and fluorescence detection. Bone Marrow Transplant. 1999;23:1055-1060)
The sensitivity of this analysis is approximately 5% in a posttransplant specimen (donor and recipient DNA mixed chimerism).
Monday through Friday
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
81267-Chimerism (engraftment) analysis, post hematopoietic stem cell transplantation specimen, includes comparison to previously performed baseline analyses, without cell selection
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
CHIMU | Chimerism Transplant No Cell Sort | 34574-4 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
MP026 | Specimen Type | 31208-2 |
37313 | Final Diagnosis | 34574-4 |