A solid-phase test using antiglobulin and enzyme-enhanced techniques for erythrocyte antibody screening during pregnancy

We have modified previously described solid-phase tests for erythrocyte antibody screening to develop a method, suitable for antiglobulin- and enzyme-enhanced techniques (SPH-IAT and SPH-ENZ). In this study we compared the SPH tests with an autoanalyzer (AA) technique. The results were more specific with the SPH tests than with the AA. Of 4,234 unselected samples from pregnant women, screen-positive samples were reduced from 96 (2.27%) by the AA, to 56 (1.32%) by the SPH tests. This difference was due to the reduced number of false-positive reactions with the SPH tests, 0.47% compared to 1.44% with the AA. Antibodies detected by the AA and the SPH-IAT and -ENZ were: 9 Rh prophylaxis, 2 anti-c, 1 anti-K and anti-M, and 1 anti-Jka. Antibodies detected only by the SPH tests were 1 anti-K, 1 anti-Le(a) (SPH-IAT and -ENZ), 1 anti-M (SPH-IAT) and 4 anti-Jka (SPH-ENZ). One anti-C, 2 anti-D, 3 Rh prophylaxis and 1 anti-E were detected by the AA and the SPH-ENZ but failed to react by the SPH-IAT. One anti-Le(a) and 8 Rh prophylaxis antibodies were detected by AA only. All clinically important antibodies were detected by the SPH tests. We conclude that the SPH-IAT and SPH-ENZ are screening methods with high specificity that are readily adaptable to larger series of samples from pregnant women and suitable for automated handling throughout the screening and identification process.