Immunological monitoring of viral infections in renal transplant recipients.

Twelve viral episodes occurred in 54 antilymphocyte globulin-treated renal transplant recipients (two primary cytomegalovirus, seven cytomegalovirus reactivations, one chickenpox, two influenza). In 11 of 12 cases the ratio between peripheral T4 and T8 subsets fell (from 1.698 to 0.986, p less than 0.01) due both to a reduction of T4+ and to an increase of T8+ cells. T10+ and 5/9 subsets also increased. Suppressor T-cell function, as measured by two simultaneous assays, was enhanced. In antibody-negative CMV patients the reversal of T4/T8 ratio preceded the appearance of specific IgM. T4/T8 ratios rapidly returned to normal in mild episodes, but remained reverted in symptomatic CMV patients for several months, despite a reduction in the immunosuppressive regimen. Symptomatic viral episodes displayed marked imbalances in T cell subset numbers and function, while in asymptomatic cases the changes were less evident.