Circulating Immune Complexes in Recurrent Oral Ulcers

Serum immunoglobulins (IgG, M, A), serum complements (C3, C4) and circulating immune complexes (CIC) were measured in forty‐five patients with recurrent oral ulcers (ROU) and in forty‐one healthy controls. The serum levels of immunoglobulins in patients with ROU were significantly higher than normal values. Similar to the pattern during infections, the levels of IgM and IgA gradually decreased as the disease entered the late stage and then returned to normal; the IgG level remained significantly high in the convalescent stage. Although the serum complements were not depressed throughout the course of the disease, a significant amount of CIC was detected in various stages and types of ROU. The three stages of ROU showed an increase in the abnormal percentage of CIC in this order: active early stage (3/14; 21.4%), active late stage (15/39; 38.5%) and convalescent stage (6/15; 40%). Although all three types of ROU demonstrated the variable positivity of CIC [minor, 16/31 (51.6%); major, 3/8 (37.5%); and herpetiform, 3/6 (50%)], their differences were not significant stastistically. This study demonstrated an aberration of humoral immunity of a rather non‐specific nature in ROU, probably caused by an infective process. This may suggest that CIC plays only a secondary role in the pathogenesis of ROU.