[Evaluation of bone marrow grafts and hemopoietic chimerism using PCR hypervariable sequencing with variable number...

PCR amplification of highly polymorphic variable number of tandem repeat (VNTR) sequences could be particularly useful in documentation of engraftment and characterization of chimerism following allogeneic bone marrow transplantation (BMT). We have monitored a 31-year old male patient treated with allogeneic BMT for chronic myeloid leukaemia. The recipient's DNA samples were obtained before the transplant and on day 28, 100 and 150 after BMT. The donor's DNA (patient's sister) was also obtained as a reference. ACT B2 locus on chromosome 6 was chosen for the analysis. In addition a deletion polymorphism locus within the pseudoautosomal region of chromosome X and Y (amelogenin gene) was also analysed. On day 28 after BMT both donor and recipient specific alleles were detected in the recipient's sample. However, on day 100 and 150 the recipient specific alleles were no longer detectable. The aforementioned pattern was observed for both markers analysed. The disappearance of recipient specific alleles correlated with clinical symptoms of chronic graft-versus host disease.