The presence of C-reactive protein, salivary agglutinin and complement protein C4 in the oral cavity

Periodontitis is an inflammatory disease of the supporting tissues of the teeth. It is caused by an excessive immune response in which the complement system plays a key role. Both C-reactive protein (CRP) and salivary agglutinin (SAG) can activate the complement system, but it is unknown if CRP and SAG play a role in the etiology of periodontitis and in which areas of the oral cavity these proteins may be found. In a first attempt to clarify the role of CRP and SAG in the etiology of periodontitis we investigated the presence of CRP, SAG and complement protein C4 in serum and in various oral fractions, including supragingival and subgingival plaque, saliva, and salivary cell fraction of healthy subjects and periodontitis patients. In addition , serum and saliva of edentulous subjects were tested for the presence of these proteins. Samples were screened by immunoblotting. CRP concentrations in serum and saliva were measured by ELISA. CRP was detected in supra-and subgingival plaque samples of healthy subjects and periodontitis patients. CRP was present in all salivary cell fractions. No significant differences in the serum or salivary CRP concentrations were found between the three patient groups. A positive correlation was found between CRP concentrations in serum and in saliva (p<0.05) in healthy subjects. SAG was detected in all saliva samples and salivary cell fractions, in supra-and subgingival plaque of both peri-odontitis patients (7/10) and controls (7/10). C4 was found in cell fractions, plaque samples, and saliva of healthy controls (5/10) and periodontitis patients (3/10), but not in saliva of edentulous subjects. CRP, SAG, and C4 are detectable in dental plaque and saliva, both in healthy and inflammatory conditions. This suggests that these proteins play a role in processes in the vicinity of the gingival crevice. 61 crp, SaG and c4 In the oral cavIty