Time to relapse of acute leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is variable. The relapse kinetics may be influenced by graft-versus-leukemic (GVL) reaction mediated by donor immune cells and inflammatory cytokines. We wondered if the inflammatory cytokines released during the occurrence of the early post-transplantation inflammatory events may affect GVL effect thus influencing the relapse kinetics. We retrospectively analyzed the correlation between early post-transplantation inflammatory events and relapse kinetics in 55 patients with acute leukemia who relapsed following allo-HSCT. Patients were divided into two groups, early and late-relapsed group according to the time to relapse from transplantation. Multivariate logistic regression analysis revealed that the incidences of conditioning associated diarrhea (CAD) ≥ 500ml/day and febrile episode (FE) were significantly lower in the early-relapsed group than in the late-relapsed group (P=0.046 and 0.014, respectively). Serum levels of C-reactive protein, a surrogate marker of inflammation, on day 21 after transplantation (CRP21) were significantly lower in the early-relapsed group than in the late-relapsed group (P=0.009). FE, CAD ≥ 500ml/day and CRP21 were independent predictable factors for relapse kinetics based on multivariate Cox regression analysis (P=0.037, 0.002 and 0.025; hazard ratio=0.360, 0.221 and 0.971, respectively). Our analysis indicated the inflammatory events in early post-transplantation period could delay the relapse of acute leukemia early after allo-HSCT presumably because GVL effect was enhanced with the cytokines released by the events.
Disclosure: No relevant conflicts of interest to declare.