As widely demonstrated, autoimmune diseases are characterized by a multifactorial pathogenesis, in which genetic and environmental factors interact in determining disease development. Data identifying a higher concordance ratio between monozygotic twins compared to dizygotic twins or siblings have confirmed the role of genetic factors in patients affected by autoimmune diseases. To date, thanks to genomewide association studies, several genetic loci have been identified as associated with disease susceptibility. The identification of the same genetic modifications in different autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis, suggests a shared immune pathogenesis. The genetic polymorphisms could influence not only the susceptibility, but also the disease phenotype, as demonstrated by the association of different loci with specific clinical manifestations or outcomes, such as response to treatment.

The proteins encoded by the genes associated with autoimmune diseases development are involved in several mechanisms participating to inflammatory process, such as antigen presentation, type I interferon, Toll-like receptor and NF-κB signaling, B- and T-cell function, apoptosis, and clearance of cellular debris and immune complexes. The genetic polymorphisms could determine modifications of these proteins, in terms of production rate and function, with possible changes in the related processes.

To date, more than 200 genetic loci have been associated with one or more disorders. Further studies are needed to better understand the implications of these associations in the susceptibility and phenotype of autoimmune diseases.

We invite investigators to contribute with original research articles as well as review articles that will stimulate the continuing efforts to better understand the genetic factors involved in the autoimmune diseases.

Potential topics include, but are not limited to:

• Role of genetic factors in determining disease susceptibility
• Role of genetic factors as markers of disease outcome in terms of chronic damage development and response to treatment