Cell-mediated immunity and antibodies to Herpesvirus hominis type 1 in oral leukoplakia and carcinoma.

Cell-mediated and humoral immune responses to Herpesvirus hominis type 1 (HVH1) and Candida albicans were studied in patients with leukoplakia, showing a histological spectrum of changes from epithelial keratosis to acanthosis and atypia, and in patients with carcinoma. The results were ranked according to increasing values of stimulation indices of lymphocyte transformation to HVH1, and the corresponding macrophage migration inhibition indices, and complement fixing antibody titres of each patient were correlated. This revealed that most patients with epithelial atypia were clustered to that end of the spectrum which had the highest stimulation and migration indices to HVH1; this relationship was not evident with C. albicans. In patients with keratosis and acanthosis there was a significant lack of correlation between lymphocyte transformation and migration inhibition to both HVH1 and C. albicans. In carcinoma the indices of lymphocyte transformation and migration inhibition to HVH1 and C. albicans were depressed. Furthermore, a significant negative correlation was found between lymphocyte transformation and migration inhibition to HVH1, unlike the positive correlation in control subjects. Complement fixing antibodies to HVH1, HVH2, cytomegalovirus and adenovirus, and fluorescent antibodies to C. albicans failed to show a significant change in titre in any one group of subjects tested. The results suggest a cell-mediated immune defect in leukoplakia, with a dissociation between lymphocyte transformation and macrophage migration inhibition to HVH1 and C. albicans in cases of keratosis or acanthosis. A specific increase in cell-mediated immunity to HVH1 in leukoplakia with epithelial atypia and the sequential changes argue in favour of a possible participation of HVH1 in carcinomatous transformation of some leukoplakias.