Salivary immunoglobulin A in rheumatoid arthritis (RA) with focus on dental caries: a cross-sectional study

Salivary secretory immunoglobulin A (sIgA) is postulated to protect against dental caries. Dental hygiene and health are usually poor in rheumatoid arthritis (RA) due to several factors. We hypothesized higher salivary sIgA in caries-free subjects and a higher extent of caries in RA. A protocol-driven cross-sectional pilot study was carried out to determine salivary sIgA in 48 patients with RA and 102 non-RA, healthy case controls. Standard of care in clinical and dental assessments were done by experts. A decay, missing teeth, filled teeth (DMFT) index was used to classify caries. Whole unstimulated saliva was collected to assay sIgA using a commercial ELISA kit. Dental caries was diagnosed in 67% and 86% of the RA and healthy subjects, respectively. Eight percent of RA patients had visited a dental surgeon. Though they tend to be higher in caries-free status, there were no statistically significant differences (p > 0.05) between RA and non-RA subjects with respect to salivary sIgA and extent of caries. The salivary sIgA levels for both RA and healthy case control subjects in this ethnic Indian (Asian) study were much higher than that reported in literature and need further validation. Rheumatologists ought to educate patients on dental matters.