Evaluation of a commercial antibody capture enzyme immunoassay for the detection of rubella specific IgM.

Abstract

SUMMARY A commercial M antibody capture ELISA kit (Rubenz M) for the detection of rubella specific IgM was evaluated in comparison with M antibody capture radioimmunoassay. A total of 248 sera were evaluated, including sera from cases of primary postnatal rubella, congenital rubella, infectious mononucleosis, and sera which contained rheumatoid factor. No false positive results were obtained but two high positive sera gave Rubenz M values which were below the value recommended as indicative of a positive result. We therefore propose changes in the criteria used for assessing the significance of the results obtained. These changes improve the accuracy of the assay without loss of specificity.The ability to detect rubella specific IgM is an essential requirement for the serological diagnosis of primary postnatal rubella as sera are often received too late in the evolution of the illness for diagnostic rises in total antibody titre or rubella specific IgG to be shown. Even when diagnostic rises in titre are shown, the demonstration of appreciable concentrations of rubella specific IgM indicates primary rubella rather than reinfection. This latter situation is particularly applicable to subclinical infections as a reinfection appears to be of minimal risk to the fetus.' Furthermore, the detection of rubella specific IgM in neonatal sera has become an established method of diagnosing congenital rubella.Several techniques are currently available for the detection of rubella specific IgM. Sera may be fractionated by sucrose density gradient ultracentrifugation2 or by gel filtration,3 with haemagglutination inhibition or immunofluorescent detection of rubella specific antibodies being performed on the fractions containing immunoglobulin. These techniques are time consuming, only limited numbers of sera may be evaluated, and technical problems occur such as the presence of residual non-specific inhibitors of haemagglutination. These assays are now being replaced by immunological assays that do not

Evaluation of rubella IgM enzyme immunoassays

“…Rubella IgM assays have been evaluated previously, but not recently (Arista et al, 1987;Best et al, 1984;Cubie and Edmond, 1985;Echevarria et al, 1985;Enders and Knotek, 1986;Hodgson and Morgan-Capner, 1984;Hudson and Morgon-Capner, 1996;Matter et al, 1994;Revello et al, 1987). Many of those assays previously evaluated are either not currently commercially available or have since been modified.…”

Analysis of Immunoglobulin A Antibodies to Helicobacter pylori in Serum and Gastric Juice in Relation to Mucosal Inflammation

“…Both are useful in the diagnosis of H. pylori-associated diseases. Furthermore, in this type of ELISA, false-positive results are rarely obtained, though highly positive sera occasionally give relatively low values (11).…”

“…09770188) from the Japanese Ministry of Education, Science, Sports and Culture; a grant (no. [8][9][10][11][12][13][14] from the Japanese Ministry of Health and Welfare; and a grant from the Nakano Foundation.…”

Togaviridae: Rubella Virus

“…Sera should, therefore, be pretreated to remove IgM antiglobulins (Ziegelmaier et aI., 1981) or with anti-human IgG to precipitate IgG (Enders and Knotek, 1986). The most sensitive and specific techniques for routine diagnosis of postantal and congenital infections are the anti-J.L-capture RIA (MACRIA) (Mortimer et ai., 1981;Tedder et ai., 1982) and the anti-J.Lcapture EIA (MACEIA) (Bellamy et aI., 1985;Gerna et ai., 1987b;Hodgson and Morgan-Capner, 1984;Kurtz and Malic, 1981). MACEIA are commercially available.…”