Genetics, Genomics, Gene Expression Profiling, and Epigenetics in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a chronic, immune-mediated condition of unknown etiology characterized by focal lymphocytic infiltration of exocrine glands associated with dry mouth and eyes. There is a strong female bias. pSS typically affects women in the middle years with an estimated prevalence from studies in different countries of 0.04% to 0.6%. 75% of patients have anti-Ro and/or anti-La antibodies, often with raised immunoglobulin levels (hypergammaglobulinemia). There is a 44-times increased risk of mucosa-associated lymphoid tissue (MALT) B-cell lymphoma in pSS, typically affecting the salivary glands. Anti-Ro/La antibodies are typically associated with the HLA-DR3-DQ2 haplotype. Genome-wide screening has identified interferon-related and B-cell-related genes linked to the development of pSS.There is less data in pSS from genomics, proteomics, metabolomics, and epigenetics, but these are active areas of research. Understanding the clinical relevance of these studies will be important if they are to translate into new therapeutic approaches.