Saliva has been increasingly used as a diagnostic medium for disease detection and monitoring. The aim of this observational, prospective, pilot study was to investigate whether salivary concentrations of CRP and IL-6 correlate with those in serum and with the clinical course of a rheumatic disease.
Nineteen patients with rheumatic disease newly scheduled for anti-TNFα therapy were included. Patients received anti-TNFα treatment (adalimumab, certolizumab, golimumab or infliximab) as per standard protocols. CRP and IL-6 were measured with high-sensitivity immunoassays before and after 12 weeks of therapy, according to standard regimens. The data were analyzed with nonparametric statistics.
Concentrations of CRP in saliva correlated significantly with those in serum (R = 0.62; p < 0.0001) and decreased markedly after successful response to treatment. In patients with a limited response to treatment salivary CRP levels increased. In contrast to CRP, the salivary concentrations of IL-6 did not change significantly over the course of therapy and they did not correlate with serum IL-6 concentrations. Salivary levels of neither CRP nor IL-6 corresponded to parameters of oral health and hygiene.
Salivary CRP but not IL-6 could be of potential use for monitoring the rheumatic disease activity.