Cell Subset-Specific Chimerism Testing by Short Tandem Repeats Analysis for Engraftment Monitoring After Hematopoietic Stem Cell Transplantation.

Chimerism is the unique state when cells from genetically different individuals coexist. Chimerism testing allows measuring the donor and recipient immune cell subsets in recipient blood and bone marrow following stem cell transplantation. Chimerism testing is the standard diagnostic test for monitoring engraftment dynamics and early relapse prediction in the recipient following stem cell transplantation. Chimerism testing is also helpful to detect graft-versus-host disease following liver transplantation. Herein, we describe a step-by-step procedure of an in-house-developed method assessing chimerism levels using fragment length analysis of short tandem repeats.

Concurrent use of two independent methods prevents erroneous HLA typing of deceased organ donors - An important strategy for patient safety and accurate virtual crossmatching for broader sharing.

Comprehensive and accurate human leukocyte antigen (HLA) typing within a short turnaround time is a crucial initial step for allocating deceased donor organs for transplantation. Erroneous HLA typing of deceased donors can be catastrophic and result in recipient death, failed transplant, and organ wastage due to inappropriately matched donors. The real-time polymerase chain reaction method is widely used as the sole method for HLA typing of deceased donors because of its simplified workflow. Herein, we have reported cases of four deceased donors showing discrepant HLA typing discovered using two independent methods concurrently. The HLA typing of these donors could have been erroneously reported if a single method had been used, which would have profound patient safety implications. In one case, the drop out of HLA-DR7 using a single method could have resulted in harmful organ allocation if the organ was transplanted after a virtual crossmatch to a sensitized candidate showing strong donor-specific HLA-DR7 antibodies. In conclusion, this case series suggests that concurrent dual typing is essential for accurate HLA typing of deceased donors. This strategy is vital because precise HLA typing is critical for accurate virtual crossmatching, which facilitates continuous distribution and broader geographic sharing of the deceased donor organ.