MONITORING AND PROGNOSTIC EVALUATION OF SEX-MISMATCHED BONE-MARROW TRANSPLANTATION BY COMPETITIVE PCR ON Y-CHROMOSOME SEQUENCES

In one case out of four, allogeneic BMT concerns a male recipient and a female donor, The monitoring of sex-mismatched BMT can be carried ou t by PCR amplification on Y-specific chromosome sequences (YCS), whate ver the hematological disease, Twelve patients with sex-mismatched non -T-depleted BMT were first studied through a qualitative PCR, which ga ve semi-quantitative results, When the qualitative PCR revealed YCS, a competitive amplification was performed in order to estimate the YCS amount in the patient blood sample, For the purpose of the study, we c lassified the patients in two categories according to the results obta ined 9 months after BMT, For 10 patients, we did not detect any YCS am plification after this time, These patients were in complete cytogenet ic and clinical remission, For the remaining two patients, we always f ound male DNA in their blood samples, These patients were in cytogenet ic remission but relapsed and died 21 and 25 months after BMT, Our res ults suggest that the persistence of male cells in peripheral blood, e ven at the low rate of 1% or 0.1%, 1 year after a sex-mismatched BMT, is a bad prognosis.