Salivary IgA and IgG subclasses in oral mucosal diseases.

It was hypothesized that serum levels of immunoglobulins may play a role in the pathogenesis of oral mucosal diseases, or reflect clinical changes in these conditions, but little is known about the role of salivary immunoglobulins in the pathogenesis of these diseases. The aim of this study was to investigate possible alterations in salivary immunoglobulin A (IgA) and IgG subclasses in patients with oral mucosal inflammatory diseases. Levels of IgG1, IgG2, IgG3 and IgG4 were determined by enzyme-linked immunosorbent assay (ELISA), and IgA1 and IgA2 by radial immunodiffusion in the resting whole saliva of 31 patients with acute recurrent aphthous ulceration (RAU) (and followed in remission), 11 patients with chronic hyperplastic candidal infection (CHC), 12 patients with Sjogren's syndrome (SS), six patients with oral lichen planus (OLP), and 18 healthy volunteers using the normal saliva as a comparison point for all. IgG and IgA subclasses were increased in OLP. In CHC all IgG subclasses were increased while IgA1 was decreased, IgG1, IgG3 and IgG4 levels were increased in SS, while all IgG subclasses as well as IgA2 were increased in acute RAU in comparison with healthy controls. No differences in any immunoglobulin subclasses between major and minor acute RAU were found. In remission, IgG1 and IgG4 returned to normal values while IgG2, IgG3, and IgA2 remained increased in patients with RAU. Salivary immunoglobulin subclasses vary in different oral mucosal conditions and may play a role in oral mucosal inflammatory diseases and/or reflect clinical changes in these conditions.