Severe neutropenia in T-large granular lymphocyte leukemia corrected by intensive immunosuppression

Optimum treatment of severe neutropenia, a major factor for morbidity and mortality in T-large granular lymphocyte (LGL) leukemia, is undefined. We observed a rapid improvement of the neutrophil count in a patient with T-LGL leukemia and severe neutropenia after the combined administration of anti-lymphocyte-globulin (ALG), cyclosporin A, prednisone, and granulocyte colony-stimulating factor (G-CSF). Although G-CSF treatment was terminated after 7 days, the neutrophil count has persisted above 1.0×109/l for up to 6 months now. Oral methotrexate is given continuously as treatment for T-LGL leukemia. The response to this immunosuppressive regimen suggests a T-cell-mediated mechanism as the underlying cause for neutropenia in T-LGL leukemia.