Impaired in Vitro Cell-Mediated Immunity to Rubella Virus during Pregnancy

Abstract A significant depression in cell-mediated immunity, measured by phytohemagglutinin and mixed-lymphocyte-culture responsiveness was observed in 11 pregnant women. Specific cell-mediated immunity to rubella virus, measured by a 51Cr-release microassay, was also found to be diminished during pregnancy. The mean (± S.D.) specific immune release for 13 seropositive subjects during pregnancy was 4.3 ± 5.9 per cent as compared to a mean of 19.9 ± 0.9 per cent in 14 seropositive nonpregnant women. This impairment in specific cell-mediated immunity to rubella virus was shown to be transient because there was subsequent increase in immunity in each of four subjects studied post partum. Thus, these changes in cell-mediated immunity during pregnancy may contribute to the known increased severity of viral infections in the gravid state. (N Engl J Med 289:604–606, 1973)