IgM-class rheumatoid factor interference in the solid-phase radioimmunoassay of rubella-specific IgM antibodies.

Abstract

SUMMARY The interference of IgM-class rheumatoid factor (RF) in the solid-phase radioimmunoassay (RIA) of rubella virus IgM antibodies was studied. Acute rubella infections did not significantly activate RF. False-positive rubella antibody results were obtained, however, when patients with raised RF levels were tested. If a low rubella IgG antibody titre was present, a high level of RF was required to cause a false-positive IgM result; conversely, in sera with high IgG titres, only a low level of RF was required for interference. Although the false-positive IgM titres obtained were generally low, they did show a positive correlation to both RF levels and rubella IgG titres. False-positive results were successfully avoided by removing the RF by absorption with heat-aggregated human gamma globulin. The absorption procedure did not affect true rubella IgM antibody titres.In modern virology and microbiology, human antibodies are, to an increasing degree, detected by immunoassays using marked anti-human immunoglobulins. An indirect fluorescent antibody technique (IFAT), an immunoperoxidase technique, an enzyme-linked immunosorbent assay, and a radioimmunoassay (RIA) have all been used in rubella serology (Haire and Hadden, 1970;Voller and Bidwell, 1975;Gerna and Chambers, 1976;Kalimo et al., 1976). A great advantage of these assays is the possibility of obtaining a rapid diagnosis of a recent infection by demonstrating specific IgM-class antibodies. However, in all assays which detect IgM antibodies by anti-human-IgM immunoglobulins, IgM-class rheumatoid factor (RF) is potentially capable of causing a false-positive IgM result, as has been clearly demonstrated in the case of the IFAT by Shirodaria et al. (1973).Preliminary work indicated that the solid-phase RIA method developed in our laboratory for detection of IgM antibodies against rubella virus (Kalimo et al., 1976;Meurman et al., 1977) is affected less by the presence of the RF than is the IFAT. More detailed studies on the effect of RF in Received for publication 7 December 1977 our IgM antibody RIA, however, required an equally sensitive method for determination of RF; therefore, a solid-phase RIA for IgM-RF was developed (Ziola et al., in press). Further investigations on the interference of RF in the solid-phase rubella IgM RIA were then undertaken. The results obtained are presented in this report. Material and methods SERUM SPECIMENSA total of 199 serum specimens were tested. These included 126 serial specimens from 28 patients with an acute rubella virus infection, 61 single serum specimens from patients with rheumatoid arthritis, and 10 single serum specimens from other patients having raised RF levels. In addition, two control specimens with low RF levels were used, one being negative for both rubella-specific IgG and IgM, and the other having a high rubella IgG antibody titre but no rubella IgM antibodies.RUBELLA IgG AND IgM ANTIBODY RIA

Igm and igg anti‐f(ab )2 antibodies in rheumatoid arthritis and systemic lupus erythematosus

“…Our RIA was designed to overcome interference of endogenous RF, a problem inherent in direct tests for class specific antibodies (1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The data obtained by our RIA suggest some similarity in isotype patterns of anti-F(ab')z antibody and R F when sera of patients with RA are compared with sera of patients with systemic lupus erythematosus (SLE) or with sera of normal donors.…”

The detection of rubella-specific IgM by an immunosorbent assay with solid-phase attachment of red cells (SPARC)

“…For such techniques to be reliable with adult sera, however, a source of purified rubella antigen is usually required. Measures are also required to prevent false positive results due to the presence of rheumatoid factor (Meurman & Ziola, 1978).…”

False Positive Rubella Test In Pregnancy

“…Cytomegalovirus infection is associated with false positive results, and also can occur with other viral infections (e.g., acute Epstein-Barr virus [EBV], infectious mononucleosis, parvovirus B19 infection) and rheumatoid factor (RF) [3,6].…”

“…Other tests in limited use to detect rubellaspecific IgM include hemagglutination inhibition and immunofluorescent antibody assay [4,5]. "False positive rubella IgM test results have been reported in those with other viral infections as acute Epstein-Barr virus, infectious mononucleosis, cytomegalovirus infection, parvovirus B19 infection and the presence of rheumatoid factor'' [6,7].…”