Deposits of immunoglobulins, complement, and immune complexes in inflamed human gingiva.
Gingival biopsy specimens from 20 patients with moderate to advanced periodontitis were obtained from inflamed sites with pockets of 5 mm or more. Sections were studied by an immunofluorescence technique, using polyclonal rabbit or goat anti-IgG, anti-IgM, anti-C1q, anti-C3a, and anti-C3c and mouse monoclonal anti-C9. Prewashed ethanol-fixed and nonwashed ethanol-fixed or frozen specimens showed many plasma cells staining for IgG or C3a, suggesting the possible occurrence of a receptor for C3a in plasma cells. Plasma cells containing IgM were also seen. Deposits of IgG and IgM with C1q, C3a, and C3c, suggesting immune complexes, were demonstrated by a double staining technique, combining fluorescein (FITC) or rhodamine (TRITC)-labeled anti-immunoglobulins with TRITC- or FITC-conjugated antibody to C3a, C3c, and C1q. The complexes were located mainly within or around vessel walls. Deposits of C3a and C1q were found in vessel walls, in the basement membrane zone of oral gingival epithelium, or diffusely distributed in the tissues. Deposits of C3c were found to a lesser extent and only in vessel walls. Mouse monoclonal anti-C9, visualized with FITC-labeled rabbit anti-mouse and swine anti-rabbit antiserum, showed granular deposits of C9, mainly in the basement membrane zone of oral gingival epithelium. The study indicates the involvement of immune complex vasculitis in inflammatory periodontal lesions. Also, our observations of the occurrence of deposits of complement factors support the hypothesis that complement factors play an important role in the immunopathology of the periodontal lesion.
D000936:Antigen-Antibody Complex / Q000032:analysis*; D003166:Complement Activating Enzymes / Q000032:analysis; D003172:Complement C1 / Q000032:analysis; D015922:Complement C1q; D003176:Complement C3 / Q000032:analysis; D015926:Complement C3a; D015932:Complement C3c; D003186:Complement C9 / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis*; D005891:Gingivitis / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis*; D010518:Periodontitis / Q000276:immunology
D000936:Antigen-Antibody Complex; D003172:Complement C1; D003176:Complement C3; D003186:Complement C9; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D015922:Complement C1q; D015926:Complement C3a; D015932:Complement C3c; D003165:Complement System Proteins; D003166:Complement Activating Enzymes