Allogeneic transplant outcomes in T-cell prolymphocytic leukemia: a single-center retrospective study.

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive malignancy with a poor prognosis. Allogeneic hematopoietic stem cell transplantation (HCT) is often used for treatment, but its effectiveness remains unclear. In this study of 33 adult patients with T-PLL who underwent HCT, 5-year progression-free survival (PFS) was 29% (95% confidence interval [CI], 14-45) and 5-year overall survival (OS) was 41% (95% CI, 24-57). Five-year cumulative incidence of non-relapse mortality was 18%, while 5-year cumulative incidence of relapse was 53%. Univariable analysis revealed that a longer time from diagnosis to HCT was significantly associated with improved PFS (hazard ratio, 0.36; 95% CI, 0.15-0.87). Analysis of immune reconstitution in 22 patients showed a relatively slow recovery of immune cells post-HCT. A higher recovery of CD3 T cells was also associated with increased risk of relapse, which may have prognostic significance and warrants further investigation as a risk factor for disease recurrence.