Antibody class capture assay (ACCA) for rubella‐specific IgM antibody

Abstract

Enzyme-linked immunosorbent assays for IgM antirubella were carried out on 1,546 sera, using an IgM capture method with a F (ab')2 conjugate (ACCA). Under the conditions described, sera containing IgM antirubella bound up to 15 times as much enzyme activity as negative specimens. Paired serum specimens from 27 patients, serial serum specimens from 6 patients, and single serum specimens from 15 patients who had had recent rubella were examined by the haemagglutination inhibition test (HAI) in the presence and absence of 2-mercaptoethanol following sucrose density gradient centrifugation (SDGC). ACCA confirmed all the results found with HAI following SDGC. Specimens were examined from ten patients with congenital rubella; ACCA confirmed the results found with both immunofluorescence following SDGC and radioimmunoassay. Pre- and post-vaccination specimens from 123 patients who had been vaccinated against rubella were examined. An IgM response could only be demonstrated in the 57 cases when IgG was absent in the first specimen. The specificity of the assay was confirmed by testing 31 serum specimens from rubella immune patients that also contained rheumatoid factor, 163 serum specimens from patients with acute infections other than rubella, and 12 serum specimens from infants with miscellaneous neonatal abnormalities other than congenital rubella. The ACCA proved a simple, sensitive, and specific test for IgM antirubella and the results compared favourably with those obtained by the SDGC technique.

Use of monoclonal antibodies to human immunoglobulin M in "capture" assays for measles and rubella immunoglobulin M

“…The availability of anti-mu chain reagents of this source can be expected to overcome some of the problems that have been encountered in the past with reagents of low specificity and sensitivity. Some reports on the use of standard anti-mu chain reagents in capture assay systems for viral IgM antibodies have noted high background absorbance, which was overcome by using antibody-negative human sera or normal animal sera in diluents for the test reagents (13,18). However, with our monoclonal reagent we encountered I little or no background reactivity, and only low concentrations of bovine serum albumin were required in the diluents.…”

“…Our assay system differed from other capture assays that have been described recently for determination of rubella and measles IgM antibody (4,(13)(14)(15)(16)18) in that it was a fourrather than a three-phase system. This provides greater versatility for assay of IgM antibodies to a variety of viruses, since the only labeled immunoglobulins required are those directed against the species in which the viral antibodies are produced, and these labeled immunoglobulins are available from commercial sources.…”

Assay of measles virus IgM and IgG class antibodies by use of peroxidase-labelled viral antigens

“…In many earlier reports on the use of direct type EIAs in antibody detection (3,4,5,6,8,15,17,19,21,23,26) the specificity has been high and the interference of rheumatoid factor in IgM assay minimal. The results from the present study, too, support these findings.…”

“…S o m e of these r e p o r t s (4,5,6,8,15,23) h a v e had a t e s t principle according to which immunoglobulins c a p t u r e d on the solid p h a s e h a v e b e e n detected b y first using viral antigens a n d t h e n labelled antibodies, or directly labelled antigen (3,17,18,19,21,26). Thus the effect of rheumatoid factor as well as the competition b e t w e e n different classes of immunoglobulins has been a l m o s t totally eliminated.…”

Characteristics of different solid-phase immunoassay formats for the measurement of BK virus immunoglobulin M in sera of patients on renal dialysis or with kidney allografts

“…The sensitivity of these assays depends upon a high proportion of virus-specific IgM antibody in sera, since other IgM-class antibody, including RF, can reduce the sensitivity of antibody capture EIAs by competing with virus-specific IgM for binding sites on the solid phase. RF bound to the solid phase has been shown to produce false-positive results in a number of different assays (11,15,20,32). This may occur as a result of RF binding enzyme-labeled antiviral antibodies directly or by complexing with serum antiviral IgG antibodies which bind viral antigen (11).…”