[Comparison of STR-PCR and FISH value for monitoring chimerism after sex-mismatched allogeneic hematopoietic stem cell transplantation].

This study was purposed to compare the significance of multiplex short tandem repeat polymerase chain reaction (STR-PCR) and fluorescent in situ hybridization (FISH) for monitoring chimerism after sex-mismatched allogeneic hematopoietic stem cell transplantation (allo-HSCT). The chimerism of bone marrow or peripheral blood cells from 38 patients was analyzed by STR-PCR and FISH on days 14, 28 and at 3 months after allo-HSCT. The results indicated that on day 14, the complete chimerism (CC) was detected in 14 of 30 cases by STR-PCR and in 8 of 30 cases by FISH (p > 0.05). On day 28, the CC was detected in 26 of 31 cases by STR-PCR and in 15 of 31 cases by FISH (p < 0.01). At 3 months, the CC was observed in 22 of 24 cases by STR-PCR and 17 of 24 cases by FISH (p > 0.05). 14 cases were found to have a graft rejection or relapse among 28 cases which were continuously monitored more than 3 months post the transplants. Donor cell decrease in 9 of 14 cases was proved by FISH alone. It is concluded that FISH is more sensitive than STR-PCR in early monitoring chimerism status of post-transplant and in predicting graft rejection or disease relapse.