CLINICAL-SIGNIFICANCE OF BCR-ABL GENE REARRANGEMENT DETECTED BY THE POLYMERASE CHAIN-REACTION AFTER ALLOGENEIC BONE-MARROW TRANSPLANTATION IN CHRONIC MYELOGENOUS LEUKEMIA

Although serial detection of bcr-abl positive cells by PCR appears abl e to identify distinct patient groups with different risks of relapse following BMT, there remain many unanswered questions regarding the cl inical utility and biological significance of PCR detectable cells in this disease. Many of the studies summarized have conflicting results and the influence of various clinical parameters which are known to af fect the fisk of relapse post-BMT has not yet been consistently associ ated with the ability to detect bcr-abl positive cells by PCR. These c linical parameters include GVHD, T-cell depletion and intensity of imm unosuppression following BMT. Prospective studies with larger patient numbers will be necessary to define the impact of these factors in PCR status and relapse. The answers to all these questions will increase our understanding of the biology of chronic myelogenous leukemia and h elp provide more effective therapies for the future.