Complement component 3 and its activation split‐products in saliva associate with periodontitis

Abstract

Background Periodontitis (PD) is classified by Grades A through C according to the risk of further progression, PD Grade C (PD‐C) being the most severe progressing form. It is a matter of controversy, whether the disease activity observed in PD‐C is due to impaired immune reactivity toward bacteria embedded in biofilms or a hyper‐reactive immune response causing tissue damage as a bystander phenomenon. Little is known about the role of complement in this respect. Methods Plasma and unstimulated saliva samples were collected from patients with PD‐B (n = 34) or ‐C (n = 27) and healthy controls (HCs) (n = 28). Salivary and plasma levels of total C3, C3c, and C3dg were quantified using sandwich enzyme‐linked immunosorbent assay (ELISA). Results Salivary levels of total C3 and C3dg were elevated in PD‐B and PD‐C patients compared to HCs (both P < 0.05), while the levels of C3c were elevated in PD‐C compared to HCs. Plasma levels of C3c were higher in PD‐B patients than in HCs (P < 0.05). Conclusion PD‐B and PD‐C patients show increased complement activation compared to HCs, but no difference was found between the two disease grades. PD‐B, but not PD‐C, is associated with increased systemic complement activation as assessed by C3c in plasma.

B‐cell cytokine responses to Porphyromonas gingivalis in patients with periodontitis and healthy controls

“…This study is part of a case‐control research project on biological material from HCs and patients with periodontitis, who were otherwise medically healthy. Participants were recruited from February 2017 to October 2018 at the Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen 14,18,19 . Of the 81 participants included in this study, 25 were HCs, 31 were patients with grade B, and 25 were patients with grade C periodontitis.…”

“…Participants were recruited from February 2017 to October 2018 at the Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen. 14,18,19 Of the 81 participants included in this study, 25 were HCs, 31 were patients with grade B, and 25 were patients with grade C periodontitis. Participants with periodontitis were diagnosed according to the 1999 criteria for periodontitis defined by the World Workshop and American Academy of Periodontology 20 and later reclassified in line with the staging and grading system for periodontitis defined in 2017 by the American Academy of Periodontology and the European Federation of Periodontology.…”

Complement components C3b and C4b as potential reliable site‐specific diagnostic biomarkers for periodontitis

“…9,[18][19][20][21][22] The progression of periodontal inflammation was associated with elevated C3 cleavage in gingival crevicular fluid (GCF), 23 whereas the increased complement activation (e.g., C3) in oral fluids was associated with the severity of periodontitis. [23][24][25][26][27][28][29] Periodontal therapy, which caused a decrease in the clinical indices of periodontal inflammation and tissue destruction, led to decreased complement activation. [27][28][29][30] Other complement components (e.g., C5) also demonstrated a correlation with the severity of periodontitis.…”

“…[23][24][25][26][27][28][29] Periodontal therapy, which caused a decrease in the clinical indices of periodontal inflammation and tissue destruction, led to decreased complement activation. [27][28][29][30] Other complement components (e.g., C5) also demonstrated a correlation with the severity of periodontitis. 30 The complement components C3b and C4b, the activation (cleavage) products of C3, were found to be positively correlated with disease severity, consequently the therapeutic effect of targeting C3b and C4b on inflammatory bone loss in experimental periodontitis models has been studied.…”

“…17 The findings indicated that complement components may be involved in the pathogenesis of periodontitis, and this association may provide a basis for the development of novel diagnostic and therapeutic strategies for periodontitis. 12,17,27,[29][30][31] However, studies on the expression levels of gingival C3b and C4b in disease progression and the correlation between the gingival C3b and C4b expression levels and clinical parameters in periodontitis are scarce.…”