Humoral and cellular immunity in typhoid and paratyphoid carrier state, investigated by means of quantitative immunoelectrophoresis and in vitro stimulation of blood lymphocytes.

The humoral and cellular immunity of 8 Salmonella carriers and 9 non-carriers was investigated and compared to findings in normal persons. The antibody response in serum and intestinal secretions was investigated by means of crossed immunoelectrophoresis, and blood lymphocytes were investigated by in vitro stimulation. Both carriers and non-carriers showed increased levels of precipitating antibodies as well as lymphocyte responses, when compared to normal persons. No differences in the antibody responses either qualitatively or quantitatively were found between carriers and non-carriers. Only few precipitins could be detected in intestinal secretions. Lymphocyte responses to S. typhi and S. paratyphi were significantly higher in carriers and non-carriers than in the controls. No significant difference in lymphocyte response to S. typhi, S. paratyphi and mitogens was obtained between carriers and non-carriers. Thus, the carrier state seems not due to detectable major immunodeficiency.