RELAPSE AFTER NON-T-CELL-DEPLETED ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR CHRONIC MYELOGENOUS LEUKEMIA - EARLY TRANSPLANTATION USE OF ANUNRELATED DONOR, AND CHRONIC GRAFT-VERSUS-HOST DISEASE ARE PROTECTIVE

We analyzed the incidence of posttransplant chronic myelogenous leukem ia (CML) relapse in 283 consecutive related-donor (n = 177) and unrela ted-donor (n = 106) allogeneic transplant recipients. Twenty-two of 16 5 related-donor recipients with stable or advanced disease at the time of transplant had hematologic relapse of CML following transplant (5- year Kaplan-Meier estimate of relapse, 20%; 95% confidence interval [C l], 11 to 30%). One of 12 patients transplanted in second stable phase following blast crisis also relapsed. Fifteen related-donor transplan t recipients relapsed within 5 years of transplant; however, seven rel apsed between 5 and 9 years after transplant. Factors independently as sociated with an increased risk of posttransplant relapse for related- donor recipients included prolonged interval between diagnosis and tra nsplant (relative risk, [RR], 3.81; P =.009) and bone marrow basophili a (RR, 5.62; P =.01). Related-donor recipients with posttransplant chr onic graft-versus-host disease (CGVHD) had a decreased risk of relapse (RR, 0.24; P =.005). Only two of 106 unrelated-donor transplant recip ients relapsed following transplant (5-year Kaplan-Meier estimate of r elapse, 3%; 95% CI, 0% to 7%). When both related- and unrelated-donor recipients were considered, the use of an unrelated donor was independ ently associated with a decreased risk of relapse (RR, 0.24; P =.07). Twelve of 16 relapsing patients who received further therapy (nine of 13 who underwent second transplant and three of three who received don or leukocyte infusions) remain alive. This analysis shows that relapse , sometimes occurring long after transplant, is an important adverse o ut-came in allogeneic transplantation for CML. Early transplant, postt ransplant CGVHD, and use of an unrelated donor are associated with a r educed incidence of relapse, perhaps due to allogeneic disparities enh ancing the graft-versus-leukemia effect. (C) 1996 by The American Soci ety of Hematology.