In vitro stimulation of lymphocytes by different strains of cytomegalovirus.

The in vitro stimulation of lymphocytes from 15 healty adult donors by 5 different stains of CMV resulted in a positive stimulation ratio of lymphocytes from CMV seropositive donors with each of the 5 different strains. Differences in the absolute strength of the response was observed among the 5 strains for each individual, but we concluded that the use of antigen prepared with 1 strain of CMV is sufficient to obtain a positive or negative result. A maximum value for the in vitro lymphocyte stimulation test, however, will only be obtained using different antigen concentrations from several different CMV strains simultaneously.