Inflammatory biomarkers associated with depression, anxiety, and/or fatigue in primary Sjögren's syndrome – a systematic review

Background and objectives

Fatigue, depression, and anxiety are common burdens present in primary Sjögren's syndrome patients. Those symptoms have all been linked to inflammatory dysregulations. To explore the link between inflammatory biomarkers and fatigue, depression, and anxiety in pSS patients, we aim to do a systematic literature review.

Methods

The systematic review protocol and data extraction forms were designed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Our protocol has been registered on Prospero (ID CRD42020161952). The Cochrane Library, PubMed, Scopus, and PsycInfo were used, from inception to December 2019.

Results

The literature search initially identified 445 articles. Finally, 12 articles were included in this systematic review. The population in studies was quite similar with mainly middle-aged women. Dates of publication extended from 2008 to 2019. Different scales were used to measure fatigue, depression, and/or anxiety. Measured inflammatory biomarkers were very diverse across studies. In consequence, results in the different included studies were disparate. Only one study explored the link between depression/anxiety and inflammatory markers: patients with depression and/or anxiety were compared to pSS patients.

Conclusion

Even if the association between fatigue, depression, and/or anxiety with inflammatory markers in pSS is of interest, there are a lot of discrepancies. Sickness behavior and IFN pathways seem to be important in the inflammatory physiopathology of fatigue in pSS, and interest in depression. It also appears crucial to standardize clinical scales, inflammatory blood, and CSF tests in pSS patients to allow better generalization.