Levels of immunoglobulin A1 and messenger RNA for interferon γ and tumor necrosis factor α in total saliva from patients with diabetes mellitus type 2 with chronic periodontal disease

Diabetes mellitus and periodontal disease have high incidence in the general population and are associated with various degrees of dysfunction in the immune system. It has been shown that diabetic patients with severe periodontal disease have more complications of diabetes and less effective metabolic control compared with diabetic patients with healthy gingiva. Patients with diabetes and severe periodontal disease present higher levels of serous immunoglobulin A (IgA). Elevation of the IgA1 isotype is thought to contribute to this phenomenon. Another important event in the diabetes-periodontitis association is the disturbance in local and systemic production of inflammatory cytokines. In this study we tested the hypothesis that type 2 diabetic patients with chronic moderate periodontal disease have differences in salivary IgA1 titers and cytokine expression when compared with the chronic severe periodontal disease cases. We utilized a jacalin-IgA capture assay to determine the IgA1 titers in total saliva and reverse transcriptase-polymerase chain reaction to detect mRNA for interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) in total saliva samples of 13 patients with chronic moderate periodontal disease and 10 with chronic severe periodontal disease. We observed a predominance of IgA1 titers of 64 (45.5%) in saliva samples from chronic severe periodontal disease patients and titers averaging 512 (30.8%) in chronic moderate periodontal disease patients. We detected mRNA for IFN-gamma in six out of 10 chronic severe periodontal disease subjects and in two out of 13 chronic moderate periodontal disease patients. TNF-alpha expression was similar in both groups. Our data suggest that higher levels of IgA1 may exert partial protection of the periodontal tissue in chronic moderate periodontal disease diabetic patients when compared to severe periodontal disease. Despite the small number of patients, IFN-gamma expression had a trend association with severity of periodontitis and TNF-alpha gene expression did not correlate with severity of periodontal disease.