Large granular lymphocytosis post allogenic bone marrow transplantation is associated with better outcome - A large retrospective single center analysis

Abstract

Large granular lymphocytes (LGL) are seen in patients following allogeneic hematopoietic cell transplantation (Allo-HCT) and it has a confounding impact on patient’s prognosis. We assessed 726 consecutive patients at our institution and looked at the clinical characteristics and outcome of patients developing LGL after Allo-HCT using dual T cell depletion as GVHD prophylaxis. The cumulative incidence of LGL lymphocytosis was 15.4%. Notably, a higher proportion of patients who developed LGL had undergone dual T cell depletion as part of their graft-versus-host disease (GVHD) prophylaxis. LGL lymphocytosis was associated with a favorable outcomes, which included a higher two-year overall survival rate (85.4% compared to 53.1%), a lower incidence of non-relapse mortality (6.4% compared to 28%), improved relapse-free survival (76.3% compared to 48.4%), and enhanced GVHD-free relapse-free survival (71.1% compared to 40.1%) all of which were statistically significant. Multivariable analysis confirmed the positive impact of LGL lymphocytosis on patients’ outcome including survival.