Applicability of ABC-ELISA and protein A-ELISA in serological diagnosis of cysticercosis.

Specific antibody test in serum and cerebrospinal fluid (CSF) is still the main mode of serological diagnosis of cysticercosis. Of different techniques of antibody test, enzyme-linked immunosorbent assay (micro-ELISA) has widely been applied. This study was undertaken to observe whether diagnostic capability can be improved by applying more sensitive techniques such as Protein A-ELISA and avidin biotin complex ELISA (ABC-ELISA). When evaluated using 115 sera of human cysticercosis, the antibody positive rates were not significantly improved in Protein A-ELISA (82.6%) and in ABC-ELISA (86.1%) than in micro-ELISA (81.7%). The specificities, evaluated in 165 sera from other diseases and normal controls, were significantly improved (88.5% by micro-ELISA, 93.3% by Protein A-ELISA and 93.8% by ABC-ELISA). Antibody levels (absorbance, abs.) in individual serum were correlated well (r = 0.83-0.86) each other. An actual benefit of Protein A-ELISA and ABC-ELISA was that they needed smaller amount of test sample.