Favorable Transplantation Outcomes Associated with Early Recovery of Lymphocytes and CD8+ Cells Following Allogeneic Stem Cell Transplantation.

Immune reconstitution is an important component for successful transplantation. The laboratory parameters regarding immune reconstitution at 3 months after allogeneic stem cell transplantation (SCT) were analyzed in the current study.

To assess the kinetics of lymphocyte subset recovery, 128 patients who underwent allogeneic SCT and survived at least 3 months after transplantation were monitored by surface markers (CD3, CD4, CD8, CD19, CD56).

Factors affecting CD4+ cell recovery at 3 months after transplantation included the use of cyclosporine instead of tacrolimus (odds ratio [OR]=0.256, p=0.007), in vivo T-cell depletion (OR=0.263, p=0.001), and use of peripheral blood stem cells instead of bone marrow (OR=0.281, p=0.016). The overall survival (OS) was better for the patients with early recovery of absolute lymphocyte counts (ANC, >1500/mm³), CD3+ (>1000/mm³), CD4+ (>300/mm³), CD8+ (>600/mm³), and CD19+ cells (>30/mm³). But CD56+ NK cell recovery (>300/mm³) failed to predict better survival. The patient group with early recovery of ANC, CD3+, and CD19+ cells showed a lower relapse rates. Treatment related mortality (TRM) was lower for the patients with early recovery of ANC, CD3+, and CD4+ cells. Chronic graft-versus-host disease (GVHD) was not related with the lymphocyte recovery. In the multivariate analysis, high risk disease status (hazard ratio [HR]=1.903, p=0.031), acute GVHD ≥grade 2 (HR=1.975, p=0.039), and HLA mismatch (HR=4.124, p=0.002) were significantly associated with lower OS, whereas, early recovery of ANC (HR=0.455, p=0.047) and CD8+ cells (HR=0.485, p=0.057) at 3 months showed a better survival.

Faster lymphocyte recovery and CD8+ cell recovery at 3 months after allogeneic SCT showed a better survival and lower TRM rate.

No relevant conflicts of interest to declare.