Pure Red Cell Aplasia Due to T-Cell Large Granular Lymphocytic Leukemia After Hematopoietic Stem Cell Transplantation

Abstract

Abstract Although reactive polytypic large granular lymphocyte (LGL) expansions after hematopoietic stem cell transplant (HSCT) due to viral infection are common, T-cell large granular lymphocytic leukemia (T-LGLL) is extremely rare and usually clinically indolent and requires no treatment in the post-HSCT setting. In contrast, here we present a case of post-HSCT donor-derived T-LGLL that led to pure red cell aplasia with severe patient morbidity. After diagnosis, the patient received immunosuppressive treatment with a dramatic response and has been transfusion independent for more than a year. To our knowledge, this is the first case of a post-HSCT T-LGLL with a documented significant adverse clinical impact requiring and responding to therapeutic intervention. It underscores the importance of recognizing such a rare entity in posttransplant patients.