Autoimmune haemolytic anaemia due to anti-phospholipid antibodies.

The clinical course and laboratory findings of a patient with autoimmune haemolytic anaemia due to anti-phospholipid antibodies and secondary to a systemic lupus erythematosus-like syndrome are described. IgG and IgM with anti-phospholipid activity coexisted in both sera and acid eluates prepared from the patient's red cells, as demonstrated by ELISA using a panel of anionic and neutral phospholipids. The anti-erythrocyte binding activity of eluted autoantibodies, determined by a radioactive antiglobulin technique, was totally inhibited by absorption with phospholipid micelles. The patient's serum also contained an IgM warm haemolysin detectable with enzyme-treated cells only, as well as anti-C, -E and -S alloantibodies.