Novel Cytokine Multiplex Assay for Tear Fluid Analysis in Sjogren’s Syndrome

Abstract

<b>Purpose</b>: Sjögren's syndrome (SS) is an autoimmune disease associated with ocular surface inflammation. The goals of this study were to establish a novel bead-based protein microarray for simultaneous analysis of 11 cytokines from tear fluid collected with Schirmer strips from patients with SS.<b>Methods</b>: Three to ten microliter of tear fluid was collected with Schirmer strips from both eyes of 13 healthy controls and 12 SS patients. Tear fluid was eluted from the Schirmer strips, total protein and concentrations of 11 different cytokines were analyzed.<b>Results</b>: The multiplex assay demonstrated high assay sensitivity with LoDs between 1.4 and 55.3 pg/µl with mean CVs between 3.7% and 9.7%. Statistically significant upregulation (<i>p</i> < .005) of eight cytokines was observed in SS patients compared to controls. Additionally, four patient cytokine values showed a significant inverse correlation (r<-0.7) with Schirmer strip readings.<b>Conclusion</b>: The assay offers analytical reliability for quantification of biomarkers in small amounts of tear fluid with potential utility for treatment monitoring of SS and other types of Dry Eye Disease.