BackgroundAlthough the AB0 blood group is one of two major antigen systems of relevance for transplantation in humans, there are still conflicting data concerning the influence of AB0 incompatibility on transplant outcome. This study investigated the effect of AB0 incompatibility in recipients of bone marrow transplants from unrelated donors.

SummaryChronic graft-versus-host disease (GVHD) remains the major cause of late morbidity and mortality after allogeneic stem cell transplantation. We retrospectively analysed 2937 patients who underwent bone marrow transplantation from an unrelated donor (UR-BMT) facilitated by the Japan Marrow Donor Program (JMDP) and survived beyond day 100 after transplantation. The cumulative incidence of chronic GVHD (limited + extensive) or extensive chronic GVHD at 5 years post-transplant was 45AE8% and 28AE2%, respectively. On multivariate analysis, seven variables predicting chronic GVHD were identified: recipient age over 20 years, donor age over 30 years, primary diagnosis of chronic myeloid leukaemia, human leucocyte antigen (HLA)-A or -B mismatch, total body irradiationcontaining regimen, platelet count not having reached 50 · 10 9 /l by day 100, and prior acute GVHD. Among 2609 patients with haematological malignancy, overall survival was significantly higher in patients with limited chronic GVHD but lower in patients with extensive chronic GVHD compared with those without chronic GVHD. The cumulative incidence of relapse among patients with limited or extensive chronic GVHD was significantly lower than that among patients without chronic GVHD. Our results suggest that limited chronic GVHD provides a survival benefit to patients with haematological malignancies by reducing the risk of relapse without increasing the risk of death from chronic GVHD.

on behalf of the GVHD Working Group of the Japan Society for Hematopoietic Cell Transplantation Few studies have evaluated the risk factors for chronic GVHD and organ involvement associated with different graft types, including unrelated cord blood (U-CB). We retrospectively studied 4818 adult patients who received their first allogeneic transplantation and survived for at least 100 days. The incidence of chronic GVHD at 2 years was 37%. The following factors were associated with the development of chronic GVHD: female donor/male recipient, CMV-Ab seropositivity, matched related peripheral blood grafts vs matched related BM grafts, no in vivo T-cell depletion and the occurrence of grade II-IV acute GVHD. Among these factors, the association with acute GVHD occurrence was consistently significant across donor subtypes. The use of U-CB was not associated with chronic GVHD, but was associated with a low incidence of extensive chronic GVHD. Chronic GVHD patients who had received U-CB transplants showed less frequent involvement of the oral cavity (28% vs 55%), eye (12% vs 26%), liver (20% vs 44%), lung (11% vs 25%) and joint (0% vs 6%) than those with matched related BM grafts. In conclusion, we found that U-CB transplants were associated with a low incidence of extensive chronic GVHD and less frequent involvement of the oral cavity, eye, liver, lung and joints.

We analysed 86 patients with CML who received unrelated cord blood transplantation (UCBT), identified through a registry of the Japan Cord Blood Bank Network. At transplantation, the median patient age was 39 years (range, 1-67 years); 38 patients were in chronic phase (CP), 13 in the accelerated phase (AP) and 35 in blast crisis (BC). Median duration from diagnosis to UCBT was 1.5 years (range, 0.2-14.6 years). A nucleated cell (NC) dose of more than 3.0 Â 10 7 per kg was sufficient to achieve neutrophil (91%) and platelet recovery (86%), whereas the lower dose of NC achieved only 60 and 61%, respectively. The duration and type of pre-transplant treatment did not affect neutrophil or platelet recovery. Results of multivariate analysis indicated that older patients (450 years) had a higher incidence of transplant-related mortality. Advanced-disease stage and lower doses of NCs were significantly associated with lower leukaemia-free and event-free survival. At 2-year survival for patients in CP, AP and BC was 71, 59 and 32%, respectively (P ¼ 0.0004). A pre-transplant European Group for Blood and Marrow Transplantation scoring system was effective in predicting the outcome of UCBT. We conclude that UCBT is a reasonable alternative therapy for patients with CML.

The combination of cyclophosphamide (CY) and total body irradiation (TBI) has been used as a standard conditioning regimen for allogeneic transplantation. Several studies showed an advantage of adding high-dose cytarabine (HDCA) to this regimen. To clarify the significance of additional HDCA, we conducted a retrospective multicenter study and compared the clinical results of these two regimens. From June 1985 to March 2003, 219 patients with hematological malignancies underwent allogeneic transplantation after conditioning with CY þ TBI 12Gy (n ¼ 73) or CA þ CY þ TBI 12Gy (n ¼ 146). Engraftment, overall survival, transplantrelated mortality (TRM), relapse rate and incidence of graft-versus-host disease (GVHD) were compared according to risks and donors. Addition of HDCA had no impact on the relapse rate in all subgroups, and it was associated with lower TRM among standard-risk patients after related transplantation, and with higher TRM and worse survival among standard-risk patients after unrelated transplantation. The incidence of acute GVHD was not significantly different between the two regimens, and HDCA resulted in a higher incidence of chronic GVHD among standard-risk patients after related transplantation. In summary, addition of HDCA is not beneficial for high-risk patients, and is not recommended for standardrisk patients receiving unrelated transplantation.