Abstract
Sjögren's syndrome (SS) is a unique autoimmune disease that shows dry mouth (xerostomia) and dry eye (xerophthalmia). Some SS patients develop visceral involvement, including malignant lymphoma. However, the molecular markers for disease activity or disease progression of SS have not been established. Therefore, the gene expression pattern in SS peripheral blood was examined by DNA microarray analysis. The gene expression patterns of primary and secondary SS were similar, but different from that of rheumatoid arthritis. Interferon (IFN)-inducible genes were upregulated in primary and secondary SS. The interferon gene signature was more prominent in primary SS compared to secondary SS. Primary and secondary SS were distinguishable based on the gene expression pattern of peripheral blood. The most upregulated gene, IFNα-inducible protein 27, showed a significant positive correlation with serum IgG level in SS. IFN-inducible genes could be markers for disease activity. The expression of ribosomal protein S27 and S29 genes was upregulated in peripheral blood from SS patients with marginal zone B cell lymphoma. The levels of ribosomal protein S27 and S29 expression were decreased after chemotherapy against lymphoma. The ribosomal protein S27 and S29 genes could be molecular markers for lymphoma development in SS.
