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

Area of Science:

• Immunology
• Oral Health
• Biochemistry

Background:

• Periodontitis (PD) is graded A-C based on progression risk, with Grade C being the most severe.
• The immune response in severe periodontitis is debated: impaired reactivity or bystander damage.
• The role of the complement system in periodontitis pathogenesis is poorly understood.

Purpose of the Study:

• To investigate the role of complement activation in different grades of periodontitis.
• To compare salivary and plasma complement levels between periodontitis patients and healthy controls.

Main Methods:

• Collected plasma and unstimulated saliva from patients with PD-B (n=34), PD-C (n=27), and healthy controls (HCs, n=28).
• Quantified salivary and plasma levels of total C3, C3c, and C3dg using sandwich ELISA.

Main Results:

• Salivary total C3 and C3dg were elevated in PD-B and PD-C patients versus HCs (P<0.05).
• Salivary C3c levels were higher in PD-C patients compared to HCs.
• Plasma C3c levels were elevated in PD-B patients versus HCs (P<0.05).

Conclusions:

• Both PD-B and PD-C show increased complement activation in saliva compared to HCs, with no significant difference between PD grades.
• PD-B, unlike PD-C, is associated with increased systemic complement activation, as indicated by plasma C3c levels.