Bone Marrow Transplant Testing
Background
Indications for Testing
Testing Methodology
Potential Outcomes and Interpretation of Test Results
Specimen Requirements
Caution
For More Information
Background
Bone marrow transplantation is an important adjunct to therapy in a number of hematologic, oncologic and genetic/metabolic disorders. Following a bone marrow transplant or peripheral blood transfusion, patient hematopoietic and lymphoid cells are replaced by cells derived from the donor. The percentage of donor versus host cells is indicative of the success of the engraftment, and can be used to track, or characterize, the engraftment process. In order to define the percentage of cells from two different individuals, host and donor cells must be distinguished from each other. This is done by DNA fingerprinting. This analysis requires three specimens: 1) a source of DNA from the recipient before transplantation; 2) a source of DNA from the donor; and 3) a source of DNA from the recipient after transplantation (blood or bone marrow).
Indications for Testing
- Assessment of engraftment of donor bone marrow following transplantation.
Testing Methodology
DNA Fingerprinting: Bone marrow transplant follow-up is performed by studying microsatellite markers in varying regions of the genome, and a sex differentiating marker (D5S818, vWF, D13S317, THO1, D7S820, TPOX, CSF1PO, D8S1179, D21S11, D3S1358, D16S539, D2S1338, D19S433, D18S51, FGA and AMELX/Y). These markers differ greatly between people, and so can be used to distinguish between host and donor cells. PCR amplification of these targeted regions followed by gel electrophoresis allows comparison of these markers in the donor and recipient.
Test Sensitivity: Mixtures of donor: recipient DNA can be detected at ratios as low as 1:9.
Potential Outcomes & Interpretation of Test Results
The pattern of markers, the DNA ‘fingerprint’, are compared pre- and post-transplant to determine if donor cells are being produced in the recipient after the transplant. This comparison is also used to determine the proportion or percentage of donor cells present in post-transplant samples from the recipient, a measure of engraftment.
Specimen Requirements
Both pre-transplant (blood or cheek cells) and post-transplant (blood or bone marrow) samples are needed from the recipient, as well as a blood sample from the donor.
Caution
- This test was developed and its performance characteristics validated by the Molecular Genetics Laboratory at the Hospital for Sick Children. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. This test is used for clinical purposes
For More Information:
- Ginsbirg D, Antin JH, Smith BR, et al (1985) Origin of cell populations after bone marrow transplantation: Analysis using DNA sequence polymorphisms. Journal of Clinical Investigation 75: 596-603.
- Min GL, Hibbin J, Arthur C, Apperley J, Jeffreys A, Goldman J (1988) Use of minisatellite DNA probes for recognition and characterization of relapse after allogenic bone marrow transplantation. British Journal of Haematology 68: 195-201.
- Blazar BR, Orr HT, Arthur DC, Kersey JH, Filipovich AH (1985) Restriction fragment length polymorphisms as markers of engraftment in allogenic marrow transplantation. Blood 66: 436-44.
- Nollet F, Billiet J, Selleslag D, Criel A (2001) Standardization of multiplex Fluorescent short tandem repeat analysis for chimerism testing. Bone Marrow Transplantation 28: 511-18.