Same-day determination of chimaeric status in the immediate period following allogeneic bone marrow transplantation.

The accurate and rapid determination of the origin of haemopoietic cells may provide valuable information as to the aetiology of, and most appropriate therapy for, leucopenia following allogeneic bone marrow or peripheral blood stem cell transplantation. We describe an approach to the analysis of chimaerism post bone marrow transplantation (BMT) based on the immunomagnetic capture of white cells combined with microsatellite polymerase chain reaction (PCR) and resolution of products by polyacrylamide gel electrophoresis (PAGE). This non-isotopic method enables the chimaeric status to be determined from as little as 1.0 ml of profoundly leucopenic peripheral blood (WBC < or =0.1 x 10(9)/l) and has been applicable to all donor/recipient pairs tested so far. Results are available within 6 h of blood sampling and lineage-specific chimaerism is possible. Furthermore, blood transfusions do not interfere with the analysis.