Immunological abnormalities in oral carcinoma and oral keratosis.

Examination of serum concentrations of IgG, IgA, IgM, IgE, and IgD in oral carcinoma and oral keratosis confirmed a rise in serum IgA concentration in oral carcinoma and revealed a rise in IgE. In oral carcinoma, other serum immunoglobulins were present in normal concentrations. Serum IgA and IgE were not increased in oral keratosis but IgM was reduced, with normal levels of other immunoglobulins. The results may reflect changes in cell-mediated immunity rather than simply changes in humoral immunity.