Concentrations of immunoglobulin E in patients with chronic periapical lesions.

Ten milliliters of whole blood were withdrawn from 30 patients with one or more chronic periapical lesions measuring 10 x 10 mm or larger on radiographs taken before root canal therapy. Also, blood was withdrawn from 32 patients with known allergies (positive controls) and 30 individuals with no known allergies and no periapical or periodontal lesions (negative controls). The sera of the three groups were tested for the concentrations of circulating IgE by a radioimmunoassay. When the mean levels of circulating IgE in the sera of the experimental group were compared with those of the control groups, no significant difference was found between the experimental group and the negative control group. However, a significant statistical difference was found between the mean levels of circulating IgE in patients with known allergies and those of patients with or without periapical lesions. The results suggest that chronic periapical lesions are localized and do not elevate the levels of circulating IgE significantly.