Detection of immunoglobulins from explant cultures of periapical lesions

The presence of immunoreactive cells in periapical inflammatory lesions suggests that immune responses participate in the disease process. The purpose of this study was to determine the presence and concentration of immunoglobulins in the supernatant fluids of explant cultures of periapical lesions. Ninety periapical lesions that had been contiguous with the apex of a root were removed and maintained in explant cultures for 96 h. Tissue culture medium was replenished at 24, 48, 72, and 96 h. Double diffusion in agarose assays demonstrated the presence of IgG in 100% of the 24-h supernatant fluids and IgA in 65% of the 24-h supernatant fluids. However, IgM was not detected. Radial immunodiffusion assays were used to detect and quantitate IgG, IgA, and IgM in samples of 24-h supernatant fluids from 90 explant cultures. IgG was the predominant immunoglobulin followed by IgA. A radioimmunosorbent test was used to detect and quantitate IgE in samples of 24-h supernatant fluids from 90 explant cultures. Forty of the 90 supernatant fluids contained measurable IgE. All detected immunoglobulins decreased in concentration in daily supernatant fluids with time (24, 48, 72, and 96 h) in the culture.