Pronounced Diurnal Pattern of Salivary C-Reactive Protein (CRP) With Modest Associations to Circulating CRP Levels.

Autor: Wetterö J; Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden., von Löhneysen S; Faculty of Mathematics and Computer Science, University of Leipzig, Leipzig, Germany., Cobar F; Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Rheumatology, Karolinska University Hospital, Stockholm, Sweden., Kristenson M; Division of Society and Health, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden., Garvin P; Research and Development Unit in Region Östergötland, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden., Sjöwall C; Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Jazyk: angličtina
Zdroj: Frontiers in immunology [Front Immunol] 2021 Jan 08; Vol. 11, pp. 607166. Date of Electronic Publication: 2021 Jan 08 (Print Publication: 2020).
DOI: 10.3389/fimmu.2020.607166
Abstrakt: C-reactive protein (CRP), a humoral component of the innate immune system with important functions in host-defense, is extensively used as a sensitive biomarker of systemic inflammation. During inflammation, hepatocyte-derived CRP rises dramatically in the blood due to increased interleukin-6 (IL-6) levels. Reliable detection of CRP in saliva, instead of blood, would offer advantages regarding sampling procedure and availability but using saliva as a diagnostic body fluid comes with challenges. The aims of this study were to evaluate associations between salivary CRP, total protein levels in saliva and serum CRP. Furthermore, we examined associations with plasma IL-6, body mass index (BMI), tobacco smoking and age. Salivary CRP was investigated by ELISA in 107 middle-aged participants from the general population. We employed spectrophotometric determination of total protein levels. Correlation analyses were used for associations of salivary CRP with serum CRP (turbidimetry), plasma IL-6 (Luminex ® ), BMI and smoking habits. Salivary median CRP was 68% higher ( p =0.009), and total protein levels were 167% higher ( p <0.0001), in morning compared to evening saliva. The correlation coefficients between serum and salivary CRP were low to moderate, but stronger for evening than morning saliva. Plasma IL-6 correlated significantly with serum CRP ( r s =0.41, p <0.01), but not with morning or evening salivary CRP. Non-smokers showed 103% higher salivary CRP levels ( p =0.015), whereas serum CRP was independent of smoking status. As opposed to CRP in serum, salivary CRP was not associated with BMI. Salivary CRP was 90% higher among the age interval 60-69 years compared to subjects aged 45-59 ( p =0.02) while serum CRP levels did not differ between the age groups. In conclusion, CRP in saliva did not straightforwardly reflect serum concentrations. This raises questions regarding adequate reflection of biological events. The pronounced diurnal salivary CRP pattern accentuates the importance of standardizing the time-point of sampling.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2021 Wetterö, von Löhneysen, Cobar, Kristenson, Garvin and Sjöwall.)
Databáze: MEDLINE
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