Tear Proteins May Be Biomarkers of Sjögren Syndrome Keratoconjunctivitis Sicca

Tear proteins may be altered in patients with Sjögren syndrome keratoconjunctivitis sicca (SS KCS) compared with healthy individuals, according to a study published in Translational Vision Science & Technology. The differently expressed tear proteins significantly correlate with clinical parameters of this type of dry eye disease, according to the report.  

A team of researchers from the Cullen Eye Institute in Houston, Texas, enrolled 15 patients (mean age, 62 years; 100% women) with SS KCS and 21 healthy controls (mean age, 55 years; 90% women) in a study between January 2019 and January 2021. They collected tear samples with unmarked Schirmer strips from all study participants. 

The research team eluted tear proteins and measured their concentration. They assayed inflammatory mediators with a Raybiotech L-507 glass slide array and normalized via strip wetting length. All participants received an ocular surface exam to assess tear break-up time (TBUT), corneal fluorescein (CF) staining, and conjunctival (CJ) staining. The symptom assessment questionnaire in dry eye (SANDE) scores were obtained for all participants.

The researchers found that 253 of the 507 tear proteins analyzed were significantly different in patients with SS KCS compared with the healthy controls. They explain that 241 of the proteins were upregulated and 12 were downregulated.

Correlation analyses showed that 181 differentially expressed tear proteins were strongly correlated with all 4 clinical parameters: TBUT, CF staining, CJ staining, and SANDE score. 

“The results both support previous findings and provide new insights into the proteomic changes in SS KCS. Improved understanding of the pathogenesis of SS KCS will lead to better diagnostic and therapeutic modalities,” according to the researchers. “Tear proteins could serve as important biomarkers for studying pathogenesis and in clinical diagnosis and management of SS KCS.”

Study limitations include the small sample size, lack of men in the study sample, and the relatively limited number of proteins assessed in the RayBiotech L507 proteomic slide array. 

Disclosure: This research was supported by Alcon Vision, LLC. Multiple study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.