Warm autoimmune haemolytic anaemia seen in association with primary sclerosing cholangitis in the setting of Klebsiella pneumoniae bacteraemia

Warm autoimmune haemolytic anaemia mediated by warm agglutinins is a rare and heterogeneous disease which can be idiopathic or secondary to an underlying disease. Primary sclerosing cholangitis is a chronic autoimmune cholangiopathy that is very rarely associated with haemolytic anaemia. Infections can also act as triggers for immune haemolytic anaemia. Here, we report a case of a woman in her 50s with a history of primary sclerosing cholangitis and a positive direct antiglobulin test with no evidence of haemolysis who developed overt warm autoimmune haemolytic anaemia in the setting of cholangitis and Klebsiella pneumoniae bacteraemia. She was treated conservatively with appropriate antibiotics and cautious red blood cell transfusion with complete resolution of haemolysis; immunosuppression was avoided given sepsis on presentation. This case highlights a rare association of warm immune haemolytic anaemia in the setting of K. pneumoniae bacteraemia and the role of a tailored treatment approach to treat this heterogeneous disease.