FeedbackPolymerase Chain Reaction (PCR)/Fragment Analysis
Polymerase Chain Reaction/Fragment Analysis
Use to assess recipient genotype before transplant
Polymerase Chain Reaction (PCR)/Fragment Analysis
Use to assess donor genotype for additional donor
Polymerase Chain Reaction (PCR)/Fragment Analysis
Use to monitor engraftment of donor cells post allogeneic SCT
Pretransplant genotype of recipient and donor required for comparison
See Related Tests for testing that is available for sorted cells (T, B, CD33+, granulocytes, monocytes, CD34+, CD56+). This testing requires submission of the Cell Isolation Request for Chimerism, Post-Transplant, Sorted Cells form. For more information about these tests, see the Results table.
Chimerism refers to the ratio of recipient to donor hematopoietic cells after stem cell transplant (SCT). Assessing chimerism in peripheral blood and/or bone marrow via serial measurements is essential for the monitoring of donor cells after allogeneic SCT to determine successful engraftment, relapse of disease, or potential graft rejection. Serial testing provides a trend of results over time that is useful for monitoring. A transplant recipient is said to have full chimerism when there are exclusively donor cells present posttransplant. Similarly, mixed chimerism occurs when there is a combination of recipient and donor cells present. Testing to determine donor and recipient genotypes prior to transplantation must be performed to enable differentiation posttransplant.
Testing Considerations
Polymerase chain reaction (PCR) methods are more sensitive than fluorescence in situ hybridization (FISH). Additionally, FISH requires sex-mismatched donor-recipient pairs. Further, short tandem repeat (STR) genotyping is more sensitive than using human leukocyte antigen (HLA) markers for monitoring engraftment because the recipient and donor are HLA matched.
Test Description
These tests consist of a panel of STR markers with allele sizes that differ among individuals.
ARUP Laboratories' chimerism tests include PCR followed by capillary electrophoresis (CE). CE detects the following markers: D8S1179, D21S11, D7S820, D3S1358, D13S317, D16S539, D2S1338, D19S433, D18S51, D5S818, CSF1PO, THO1, vWa, TPOX, FGA, and one gender marker (amelogenin).
Test Interpretation
Analytic Sensitivity
98%
Results
| Tests | Results |
|---|---|
|
Chimerism, Donor 3005462 |
Testing provides the number of informative markers identified for the donor/recipient pair. |
|
Chimerism, Recipient, Pre-Transplant 3005449 |
|
|
Chimerism, Additional Donor 3005468 |
|
|
Chimerism, Post-Transplant 3005454 |
Testing provides the number of informative markers used in analysis and lists the mean percentage of recipient and donor cells present in the sample (95% confidence interval). Correlation with clinical status and consideration of the time interval between SCT and chimerism testing is necessary for proper interpretation of results. |
|
Chimerism, Post-Transplant, Sorted Cells (T cells) 3005393 Chimerism, Post-Transplant, Sorted Cells (B cells) 3005401 Chimerism, Post-Transplant, Sorted Cells (CD33+ cells) 3005409 Chimerism, Post-Transplant, Sorted Cells (Granulocytes) 3005417 Chimerism, Post-Transplant, Sorted Cells (Monocytes) 3005425 Chimerism, Post-Transplant, Sorted Cells (CD34+ cells) 3005433 Chimerism, Post-Transplant, Sorted Cells (CD 56+ cells) 3005441 |
Limitations
- Cannot be used if donor and recipient are identical twins
- Posttransplant testing requires a pretransplant sample for comparison.
- Minor cell populations consisting of <2% of total population may not be detected.
- Diagnostic errors can occur due to rare sequence variations.
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Antin JH, Childs R, Filipovich AH, et al. Establishment of complete and mixed donor chimerism after allogeneic 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(9):473-485.
25145701
Clark JR, Scott SD, Jack AL, et al. Monitoring of chimerism following allogeneic haematopoietic stem cell transplantation (HSCT): technical recommendations for the use of short tandem repeat (STR) based techniques, on behalf of the United Kingdom National External Quality Assessment Service for Leucocyte Immunophenotyping Chimerism Working Group. Br J Haematol. 2015;168(1):26-37.
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Lawler M, McCann SR, Marsh JC, et al. Serial chimerism analyses indicate that mixed haemopoietic chimerism influences the probability of graft rejection and disease recurrence following allogeneic stem cell transplantation (SCT) for severe aplastic anaemia (SAA): indication for routine assessment of chimerism post SCT for SAA. Br J Haematol. 2009;144(6):933-945.
Documentation of engraftment and characterization of chimerism
Martin PJ. Documentation of engraftment and characterization of chimerism after hematopoietic cell transplantation. In: Forman SJ, Negrin RS, Antin JH, et al, eds. Thomas’ Hematopoietic Cell Transplantation. Wiley-Blackwell; 2016.
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Reshef R, Hexner EO, Loren AW, et al. Early donor chimerism levels predict relapse and survival after allogeneic stem cell transplantation with reduced-intensity conditioning. Biol Blood Marrow Transplant. 2014;20(11):1758-1766.
Use to assess donor genotype