Mixed-type autoimmune haemolytic anaemia: unusual cases and a case associated with splenic T-cell angioimmunoblastic non-Hodgkin's lymphoma.

The diagnosis of mixed-type autoimmune haemolytic anaemia (AIHA) is based on demonstrating the presence of "warm" IgG auto-antibody and "low titre" ( < 64 at 4 degrees C), "high thermal amplitude" (reacting at or >30 degrees C) "cold" IgM auto-antibody. Mixed-type AIHA is uncommon. Red cell agglutination on the peripheral blood film is a common finding in mixed-type AIHA and can lead, initially, to a mis-diagnosis of cold haemmagglutinin disease (CHAD). Mixed-type AIHA is rare and can be idiopathic or secondary, often associated with systemic lupus erythematosus (SLE) and lymphoma. In general, patients with mixed-type AIHA show a dramatic response to steroid therapy and frequently require few or no transfusions. We report two unusual cases of mixed-type AIHA. Case one was unusual as the patient developed AIHA while on steroid medication. Case two, we believe, is the first reported case of splenic T cell angioimmunoblastic non-Hodgkins lymphoma (NHL) associated with mixed-type AIHA. The patient failed to respond to steroids, intravenous immunoglobulin, chemotherapy and treatment with rituximab. The patient received 33 units of red cells over a 9-week period. She finally underwent splenectomy with resolution of haemolysis. DAT tested with monospecific reagents, and thorough serological investigations is required to reach the diagnosis of mixed-type AIHA. Awareness of this condition is important as management may be different from either treating warm AIHA or CHAD.