A comparison of two solid phase systems for antibody detection

Two solid phase methods of antibody detection, Capture-R (CR) and Capture-R Ready-Screen (RS), were compared to determine their acceptability for use in prenatal antibody screening. Ninety-six serum samples, screened using a saline antiglobulin test, were coded and tested by CR and RS at two laboratory sites using a blinded study design. Thirty of the samples were free of antibody, and 66 samples contained antibody. Parallel testing was also performed in both laboratories on 648 prenatal samples. The sensitivity and specificity of CR, based on the 96 previously screened samples, was 95 percent and 90 percent, respectively, and the sensitivity and specificity of RS was 90 percent and 89 percent, respectively. Antibodies detected only by CR included anti-K(1), -Ch(2), -Jka(1), -Lea(1), -Fya(1), -Mca(1), and -e(1). Antibodies detected only by RS included anti-Jka(5) and -E(1). The sensitivity and specificity of CR for the 648 prenatal samples was 100 percent for each, while the sensitivity and specificity of RS was 97 percent and 100 percent, respectively. Both CR and RS are acceptable techniques for prenatal antibody screening.