Analysis of an autoimmune antibody (IgM class) in a case of chronic lymphocytic leukaemia

A case of an acquired circulating anticoagulant occurring in a patient suffering from chronic lymphocytic leukaemia with haemolytic anaemia and autoimmune disorders has been reported. The anticoagulant was found to belong to the IgM class. Coagulation studies show that this anticoagulant inhibits the reaction between human prothrombinase andfactor II.