[Successful alemtuzumab treatment of a patient with atypical hairy cell leukaemia variant].

Although hairy cell leukaemia and hairy cell leukaemia variant are characterized by much alike clinical features, these two diseases are disparate in nature and treatment. While hairy cell leukaemia responds quite well to 2-chlorodeoxyadenosine (cladribine) treatment, hairy cell leukaemia variant has much worse response rate and has no effective treatment option yet. With other treatment modalities, including monoclonal antibody treatment, we have less experience. Alemtuzumab (Campath-1H, MabCampath) treatment has been reported in a case with hairy cell leukaemia in relaps while there is no data with alemtuzumab therapy in the treatment of hairy cell leukaemia variant. The authors present their case of a 58 year-old male who has been diagnosed with hairy cell leukaemia variant upon clinical findings and lymphocyte phenotyping. Alemtuzumab treatment was started (3 x 30 mg/week s.c. for 12 weeks). After 8 weeks of treatment haematologic remission was achieved; flow cytometry has revealed only 1.5% malignant cells. Alemtuzumab treatment can be favourable in those cases of hairy cell leukaemia and hairy cell leukaemia variant which is dominated mainly by bone marrow infiltration and present no lymphadenomegaly or splenomegaly. In our case the p53 mutation had no influence on the outcome of alemtuzumab treatment.