THE VALUE OF GEL TEST AND ELAT IN AUTOIMMUNE HEMOLYTIC-ANEMIA

Three methods for detection of warm type IgG autoantibody were evaluat ed using 400 blood samples from 147 patients suspected of autoimmune h aemolytic anaemia (AIHA). Three direct antiglobulin techniques (DAT) w ere used: conventional tube DAT, gel-DAT by micromethod and gel-DAT en zyme linked antiglobulin test (ELAT). Eluate examinations confirmed th e presence of autoantibodies on red cells. These tests were compared d irectly using 126 selected blood samples from 85 patients with IgG mol ecules on their red cells detected by the gel test. In 106 of these sa mples, collected from 65 patients with clinical symptoms of AMA, the p resence of autoantibody was confirmed by acid elution, The ELAT was po sitive in 100 samples (94%), 87 samples for tube DAT (82%). The ELAT a s well as the tube DAT was negative in 20 samples with non-reactive el uates by gel test. The gel-DAT was therefore not fully specific and de tected IgG on red cells of patients with hypergammaglobulinaemia. Howe ver, due its higher sensitivity it proved useful as a screening test, The ELAT allowed changes in the number of IgG molecules per red cell t o be monitored quantitatively. Both methods play a part in the diagnos is and monitoring patients with warm type IgG autoantibody.