Autoimmune haemolytic anaemia in patients with chronic lymphocytic eukaemia treated with 2‐chlorodeoxyadenosine (cladribine)

: Autoimmune haemolytic anaemia (AIHA) is one of the major complications in chronic lymphocytic leukaemia (CLL). Treatment with alkylating agents and the adenosine analogue, fludarabine, might trigger the development of AIHA in CLL patients despite the reduction of leukaemic clone. The influence of 2-chlorodeoxyadenosine (2-CdA) on AIHA in patients with CLL is undefined so far. In a group of 114 patients treated at our clinics with this agent, AIHA with direct antiglobulin test (DAT) positively was observed in 25 (21.9%) patients. In 23 patients AIHA was noticed before the starting of 2-CdA and in 2 patients DAT became positive after 2-CdA treatment. In 6 patients the drug caused complete resolution of haemolysis and DAT became negative. Eight patients exhibited partial resolution of haemolysis with significant improvement in haemoglobin level but DAT test remained positive. In 11 patients there was no response to 2-CdA in relation to autoimmune haemolysis. Two patients with no previous history of haemolysis developed AIHA after 5 and 6 courses of 2-CdA therapy and their DAT became positive 1–2 months after the last course of the drug. One of them entered severe haemolytic crisis and severe thrombocytopenia and died because of haemorrhagy to the central nervous system. In the other patient AIHA was controlled by steroids and chlorambucil treatment. Our study indicates that 2-CdA may suppress autoimmunohaemolytic process in some patients with CLL and trigger the development of AIHA in others.