Gene Expression Signature Shared in Autoimmune Diseases Not in Unaffected Family Members

Even though autoimmune diseases are heterogeneous, believed to result from the interaction between genetic and environmental components, patients with these disorders exhibit reproducible patterns of gene expression in their peripheral blood mononuclear cells. A portion of this gene expression profile reflects family resemblance rather than the actual presence of an autoimmune disease. Here we wanted to identify that portion of this gene expression pattern that is independent of family resemblance and determine if it is a product of disease duration, disease onset, or other factors. By increasing the number of autoimmune samples in our analysis and employing supervised clustering algorithms, we identified 100 genes whose expression profiles are shared in individuals with various autoimmune diseases but are not shared by first-degree relatives of individuals with autoimmune disease or by controls. Individuals with early disease (1 yr after onset) and established disease (10 yr after onset) exhibit a near identical expression pattern suggesting that this unique profile reflects disease onset rather than disease duration. Keywords: gene expression signatures supervised gene expression profiling were performed to a cohort sample pool: control individuals(8), unaffected family members of autoimmune diseases patients (8), and individuals with autoimmune diseases (54). we try to identify a gene expression signatures that were exclusively associated with autoimmune diseases but not infulenced by genetic components