Effect of slow lymphocyte recovery and type of graft-versus-host disease prophylaxis on relapse after allogeneic bone marrow transplantation for acute myelogenous leukemia

Allogeneic BMT is potentially curative for patients with acute myelogenous leukemia (AML) in first remission. However, many patients relapse after tra nsplantation. Various immunotherapeutic options have been attempted with va riable success in preventing relapse. Early identification of patients at h igh risk for relapse could allow prompt intervention. We examined the effec t of slow lymphocyte recovery after sibling-matched allogeneic BMT on the r isk of relapse in patients with AML. We also examined the effect of prednis one-containing GVHD prophylaxis on the rate of lymphocyte recovery. Patient s with absolute lymphocyte count (ALC) <150 x 10(6)/l by day +30 had a 3.5- fold higher risk of relapse (P = 0.0088) and a lower overall survival (P = 0.0079) than patients with a higher ALC. We did not find correlation betwee n lymphocyte count determined earlier in the post-transplantation course (d ay +21) and the risk of relapse. Patients receiving prednisone had a signif icantly lower ALC at day +30 than those who did not receive prednisone (289 vs 549 x 10(6)/l, P = 0.002). We conclude that a slow lymphocyte recovery after allogeneic BMT for AML is strongly predictive of subsequent relapse a nd that the type of GVHD prophylaxis should be considered when analyzing ly mphocyte recovery.