Post-Transplant Hematopoietic Progenitor Chimerism. Experience from an Internationally Accredited Reference Center

Abstract

Introduction: Post-transplant chimerism analysis is used to assess the effectiveness of grafts after hematopoietic progenitor transplantation. This analysis involves pre-transplant donor and recipient studies and post-transplant monitoring at defined time intervals. Currently, the most widely used methodology in chimerism studies is the analysis of STR markers. Materials and Methods: With prior informed consent, 17,493 samples have been processed for chimerism testing from 2004 to the present date, including pre-transplant donor/recipient profiles and post-transplant recipient analyses. The analysis platforms used have been STR markers from commercial companies Applied Biosystems and Promega, using capillary electrophoresis on ABI 3130XLS and ABI 3500 equipment. Results: From May 2017 to the present date, 7,305 reports have been generated, including 2,359 recipient or donor profiles and 4,946 post-transplant analyses with the following results: 122 reports with the absence of chimerism (graft failure), corresponding to 2.5%, at various post-transplant times; 1,174 reports of mixed chimerism, corresponding to 23.7%, and 3,650 reports of total chimerism, corresponding to 73.8%.

Conclusions: Given the track record and experience of our group, post-transplant chimerism studies have been accredited by the European Federation for Immunogenetics (EFI) since 2019. Intercomparison tests are conducted with the American Association for Histocompatibility and Immunogenetics (ASHI) with 100% concordance in the intercomparison reports.