Application of a high sensitivity aggregate-haemagglutination test for the diagnosis of autoimmune haemolytic anaemia with a negative direct antiglobulin test.

An aggregate-haemagglutination test has been used for determining antierythrocyte autoantibodies. The first antiglobulin variant of the test allows us to establish the presence of antibodies in 33 cases with a negative direct Coombs' test. The test II (antiantiglobulin variant) proved to be positive in 88 cases of auto-immune haemolytic anaemia (AIHA) that showed a negative direct Coombs' test and a negative antiglobulin variant. Immunoglobulin G has been revealed in the majority of AIHA patients. IgM has been determined in 1 case of a symptomatic form associated with chronic lymphocytic leukaemia. IgA has been recorded in 3 cases with an idiopathic AIHA form and in 6 cases of chronic lymphocytic leukaemia. Both types of light chains were found on the surface of erythrocytes in all cases of AIHA.