Detection of Philadelphia chromosome-positive cells by the polymerase chain reaction following bone marrow transplant for chronic myelogenous leukemia

Sixteen patients treated by allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML) were evaluated by the polymerase chain reaction (PCR) for bcr/abl-specific RNA transcripts at various time points after BMT. In reconstitution experiments, one CML cell per million normal mononuclear cells could be detected by direct agarose gel visualization of a bcr/abl-specific band following PCR. Bcr/abl message was found in ten out of 16 patients post-BMT. PCR-positive bcr/abl was present only transiently in three patients and correlated with relapse in three. One patient died in clinical remission, while two patients remain in remission despite persistence of bcr/abl-positive abl-positive cells at 180 days. Long-term follow-up of bcr/abl-positive patients in clinical remission may provide insight into the fate or residual Ph+ cells after BMT. This approach may aid in the identification of high-risk patients likely to relapse post-BMT.