Immunoglobulin G subclass measurements in recurrent aphthous stomatitis.

We have measured serum levels of IgG subclasses and total IgG, IgA and IgM in a group of 34 recurrent aphthous stomatitis (RAS) patients. At the time of blood collection, 23 of the 34 patients had active oral lesions. The remaining 11 patients were at an inactive stage. All measurement were performed in the Beckmann 360 Array Protein System. Serum levels of IgG2 subclass were significantly lower (P < 0.05) in the whole group of patients (34) when compared to the control group. This relationship was still significant (P < 0.05) when only the 11 patients without active oral lesions were considered but disappeared in patients at an active stage. We conclude that low serum levels of IgG2 may play a role in the pathogenesis of RAS, just as in other recurrent infectious diseases, and that serum levels of this immunoglobulin subclass, as well as total IgA, may undergo transient changes, depending on the different periods of activity and quiescence of the disease.