[Delayed response to rituximab of cold agglutinin haemolytic disease].

The anti-CD20 monoclonal antibody rituximab has shown benefit in some patients diagnosed of severe cold agglutinin disease. Here we report our experience with rituximab in a patient with chronic haemolysis due to refractory cold agglutinin disease. An increase in the haemoglobin level was observed seven months later from rituximab administration and with a follow-up of 17 months, the patient maintains the haematological response. We suggest that rituximab can play an important role in the treatment of adult patients with refractory cold agglutinin disease with anaemia requiring transfusion. However only a few case reports of rituximab treatment in this haemolytic disease is available and there is need of large prospective studies that allow elucidate the better schedule of administration, the duration of the clinical effect, factors predictive of clinical outcome, the possible benefit of the association with other drugs and the possibility to achieve delayed and maintained responses.