Lymphocyte Transformation in Response to Antigens of Respiratory Syncytial Virus 1

Summary

Cellular immunity to RSV was measured by lymphocyte transformation in infants, children, and adults. Lymphocyte transformation to RSV antigens occurred in 17 of 44 (39%) healthy adults. When sequential lymphocyte cultures were performed with healthy adults, 11/12 individuals had an SI ≥ 3.0 on at least one occasion. In 12 of 27 babies and children with respiratory diseases, cellular immunity to RSV was detected. In contrast, none of 21 babies and children without respiratory diseases and none of 12 neo-nates had detectable lymphocyte reactivity to RSV. Among patients with respiratory diseases, lymphocyte reactivity to RSV occurred significantly less often in babies 6 months of age or less (1/11) than in patients over 6 months (11/20). Since cellular immunity to RSV was not found in babies and children without ongoing respiratory illness, it is unlikely that preexisting cellular immunity to RSV plays a role in the pathogenesis of lower respiratory tract disease in infants with RSV infection.