Identification of autoantibody biomarkers for primary Sjögren's syndrome using protein microarrays

Abstract

Sjögren's syndrome (SS) is a chronic, progressive autoimmune disease primarily affecting women. Diagnosis of SS requires an invasive salivary gland tissue biopsy and a long delay from the start of the symptoms to final diagnosis has been frequently observed. In this study, we aim to identify salivary autoantibody biomarkers for primary SS (pSS) using a protein microarray approach. Immune‐response protoarrays were used to profile saliva autoantibodies from patients with pSS (n=14), patients with systemic lupus erythematosus (SLE, n=13), and healthy control subjects (n=13). We identified 24 potential autoantibody biomarkers that can discriminate patients with pSS from both patients with SLE and healthy individuals. Four saliva autoantibody biomarkers, anti‐transglutaminase, anti‐histone, anti‐SSA, and anti‐SSB, were further tested in independent pSS (n=34), SLE (n=34), and healthy control (n=34) subjects and all were successfully validated with ELISA. This study has demonstrated the potential of a high‐throughput protein microarray approach for the discovery of autoantibody biomarkers. The identified saliva autoantibody biomarkers may lead to a clinical tool for simple, noninvasive detection of pSS at low cost.