Relationship between anti-viral antibodies and rheumatoid factor in pregnant women.

The influence of viral infections on the incidence of rheumatoid factor in a normal population was noted by Dresner and Trombly (1959). Five per cent. of 140 normal subjects gave positive latexfixation tests for rheumatoid factor, and all seven individuals had or developed mild acute viral infections of the upper respiratory tract. In all seven subjects, tests for rheumatoid factor (RF) became negative 6 days to 6 weeks after the physical manifestations of their infection subsided. It was also noted that 83 per cent. of 35 patients with specific acute viral infections gave positive tests. In the cases followed serially, the RF activity was found to disappear in convalescence. Johnson and Hall (1958) noted positive latexfixation tests in 65 per cent. of seventeen cases of rubella. The incidence of positive tests was higher in patients with arthritis than in those without arthritis; however, no comparison was made between the magnitude of the specific anti-viral response and the titre of RF activity. On the other hand, Bach, Grieble, and Anderson (1965) found that, in a group of 231 aged individuals, C-F, anti-viral antibody responses showed a negative correlation with the presence of RF. Failure to show antibody to influenza A and B 3 months after immunization was significantly related to the presence of rheumatoid factor. Rawson, Abelson, and McCarty (1961) showed that group 0 rheumatoid arthritics have consistently lower haemagglutinin titres than do normal subjects of the same blood group. This was believed to reflect a decrease in activity associated with IgG globulins. Recently, Svec and Dingle (1965) found, in an analysis of sera from persons exposed to the 1957 influenza epidemic, that 15 per cent. of those showing a significant viral antibody response gave positive