Abstract

Objectives: Graft-versus-host disease (GVHD) is an exaggerated and dysregulated response of the normal immune system to tissue damage that is intrinsic to transplantation. The aim of this study was to assess the effects of acute GVHD (aGVHD) and chronic GVHD (cGVHD) according to relapse status on the survival rate in patients with acute lymphocytic leukemia (ALL). Methods: Patients with ALL (n = 425) between 1991 and 2011, who underwent bone marrow transplantation and stem cell transplantation in Tehran (Iran), were recruited into a longitudinal study. All patient records were screened for the occurrence of adverse events including GVHD and relapse. Data were assessed using SPSS software with log-rank, univariate, and multivariate Cox regression analyses. Results: Five-year survival rate based on a Kaplan-Meier curve was 60.2 overall (95 confidence interval (CI): 54.32-66.08) and 66.6 (95 CI: 59.35-73.86) for individuals in their first complete remission (CR1) disease stage. A significantly higher survival rate was observed for patients who developed cGVHD in comparison with those who did not develop it, with a 2.7 fold increased risk of mortality for the latter group (P < 0.001). A significant Cox proportional hazard ratio of 2.3 was observed for mortality following adjustments for age and gender. The presence of cGVHD, reduced the risk of mortality for all individuals, which was observed to be significant for those patients without relapse (P = 0.004). Conclusion: This study is one of the largest studies (regarding the number of participants) done to date in the Middle East with quite a long duration (20 years). Findings suggest that cGVHD has a positive influence on the survival rates for ALL patients, which subsequently may assist physicians to make optimal treatment decisions. Additional research is now needed to determine the mechanisms around this increased survival and its influence on patients' survival.