Levels of Common Salivary Protein 1 (CSP1) in Healthy Subjects and Periodontal Patients

Objectives: Human saliva, as a vital part of the immune defense system, contains a number of distinct proteins and peptides. Recently human common salivary protein 1 (CSP1) has been identified as a one of abundant salivary proteins and may play a role in promoting the binding cariogenic bacteria to salivary pellicle. However, other functional information on CSP1 regarding periodontal aspects of dentistry is still unknown. The aim of this study was to quantify and compare CSP1 level between healthy subjects and periodontal patients.
Methods: The controlled clinical study was conducted for periodontally healthy individuals and patients with chronic periodontitis in Chonbuk National University Dental Hospital. The whole saliva from 36 healthy subjects and 33 chronic periodontitis patients were collected under Institutional Review Board. SDS-PAGE and immune blotting were conducted to ensure that anti-CSP1 monoclonal antibody (mAb) binds to CSP1 in human saliva. The sandwich ELISA system was house-fabricated using mAb-hCSP1#14 and mAb-hCSP1#4 as a capture and a detector mAb, respectively. The CSP1 concentrations in saliva from 36 healthy subjects and 33 periodontal patients were quantified by the CSP1 sandwich ELISA system, and the results were analyzed by Student’s t-test.
Results: Immunoblot analysis using mAb-hCSP1 as a probe confirmed that CSP1 in human saliva existed as a single band with molecular weight of approximately 27-kDa. Quantification of CSP1 concentration by CSP1 ELISA showed that the median values (25^th to 75^th percentile) of periodontal patients group and healthy subjects group were 9474 ng/mL (8434 – 10139) and 8588 ng/mL (7421 – 9877), respectively. Student’s t-test results indicated that there was a statistically difference between the two groups (P < 0.024).
Conclusions: The significant difference of CSP1 levels between healthy subjects group and periodontal patients group indicated that CSP1 may be a potential marker for detection or screening of periodontitis patients.