Diagnosis of enteroviral meningitis with IgG‐EIA using heat‐treated virions and synthetic peptides as antigens

Abstract

Two recently developed enzyme immunosorbent assays (EIA) for the detection of significant titre increases in enteroviral IgG-antibodies were evaluated as diagnostic tools in 127 etiologically well-characterized patients with aseptic meningitis. One assay was based on heat-treated virions (H-EIA) and one on synthetic peptides (P-EIA) as antigens. The sensitivities, with virus isolation as reference method, were 0.67 by H-EIA and 0.62 by P-EIA, which were higher than by a routinely used complement fixation test (CFT, 0.51) but somewhat lower than the sensitivities found by two previously presented IgM-assays, mu-capture EIA, and solid-phase reverse immunosorbent test (SPRIST). The specificities of the two IgG-EIA techniques and CFT were apparently high, whereas the two IgM-assays showed positive reactions in some non-enteroviral cases. A relatively rapid increase in enteroviral IgG-antibodies was apparent using H-EIA and P-EIA. The two IgG-EIA tests contributed with considerable additional etiological information since significant IgG-rises were obtained in 13 patients by H-EIA and in 19 by P-EIA, respectively, out of the 56 individuals in whom enterovirus isolation was negative and a non-enteroviral diagnosis was not found. Thus, detection of enteroviral IgG-antibodies by H-EIA and P-EIA seems to be a valuable alternative to CFT for the routine diagnosis of enteroviral meningitis. The IgM-assays, mu-capture EIA, and SPRIST, may allow a relatively rapid report of an enteroviral infection. However, since both the IgM-tests are hampered by incomplete specificities, a confirmation of positive results by an IgG-assay should be carried out.