Crevicular fluid and serum IgG subclasses and corresponding mRNA expressing plasma cells in periodontitis lesions.

Recent reports suggest that specific serum IgG subclasses are a feature of several forms of periodontitis. GCF antibodies are both serum-derived and locally produced by the abundant plasma cells of the diseased periodontal tissue. Previous work has shown that crevicular fluid (GCF) levels of IgG may be reduced in active and deep periodontal pockets when compared to other sites in chronic periodontitis patients (7). These findings, and more recent findings for IgA levels in GCF (5), suggest that GCF immunoglobulins may indicate "high risk" sites for periodontitis. In these studies, the relative distribution of IgG isotypes was not investigated, nor was the relative contribution of local and serum antibodies to the GCF immunoglobulin profile. Therefore, more precise investigation of the tissue distribution of local gingival IgG subclass producing plasma cells and their protein levels in the GCF from the same sites and in serum, was undertaken.