C‐reactive protein levels in blood and saliva show no correlation in young, healthy adults

Abstract

C‐Reactive Protein (CRP) is found at elevated levels in the serum of patients with inflammation and cardiovascular disease. Recent studies have shown that CRP can also be detected in saliva and its use as a non‐invasive biomarker of myocardial infarction has been proposed. However, the relationship between CRP levels in saliva and blood has not been investigated. The objective of this study was to determine if salivary levels of CRP correlate to blood levels in healthy adults. After IRB approval, saliva and blood samples were collected from 69 medical students. All samples were tested for CRP levels using ELISA assays. Salivary CRP concentration ranged from 0.05 to 64.3 ng/mL (median = 1.2 ng/mL). Plasma CRP concentration ranged from 0.14 to 31.1 μg/mL (median = 2.0 μg/mL). Generalized linear modeling was used to investigate the relationship between salivary and plasma CRP levels. None of the models passed lack of fit testing even when variables such as salivary flow rate and time since eating were included. Therefore, a relationship between CRP concentration in saliva and blood could not be established in this group of subjects. This work was funded by a WVSOM intramural grant.