[Successful treatment of large granular lymphocytic leukemia accompanied by refractory anemia with alemtuzumab]

A 39-year-old man with anemia presented at our hospital in November 2011. Peripheral blood analysis revealed lymphocytosis with a large granular lymphocyte (LGL) count of 2,272/µl, with CD3+, CD4-, CD8+, CD56-, TCR-αβ+; Southern blotting analysis revealed clonal TCR Cβ 1 gene rearrangement, leading to the diagnosis of T-LGL leukemia. In June 2012, the patient was administered with cyclophosphamide as an initial treatment because he developed transfusion-dependent anemia. His anemia improved, and the treatment was discontinued in March 2013. However, anemia recurred in March 2014. The administration of cyclophosphamide was resumed; however, it was subsequently replaced with cyclosporine because of the risk of secondary cancer due to the long-term use of cyclophosphamide. However, his anemia did not improve. Further, the patient was administered with prednisone, methotrexate, and pentostatin; however, the transfusion-dependent state persisted with the cumulative transfusion of 186 RBC units until March 2016. After CD52 expression on the surface of LGL cells was confirmed, treatment with alemtuzumab, which is a monoclonal antibody against CD52, was initiated in April 2016 and the dose was gradually increased from 3 mg to 30 mg thrice per week. The patient's anemia began to improve 1 week after initiating alemtuzumab treatment, and he became transfusion-independent in the second week. Although alemtuzumab treatment was discontinued at the fifth week on the basis of a positive test result for CMV antigenemia, the result consequently became negative after ganciclovir treatment. To date, the patient's hemoglobin level has been maintained at approximately 12 g/dl without any treatment. Herein we reported the case of a patient having LGL leukemia with refractory anemia that was successfully treated using alemtuzumab.