Genetics of sarcoidosis

Sarcoidosis is a multisystem inflammatory disease of unknown etiology. Clinical course of the disease varies considerably, from a mild, acute form of the disease, with spontaneous resolution, to a chronic progressive disease. Factors that determinate the susceptibility and clinical course of the disease are still unknown. The more frequent occurrence of the disease within certain races and ethnic groups, as well as the described cases of family sarcoidosis support the belief that sarcoidosis occurs in genetically susceptible hosts. Previous genetic studies were based on immunopathogenic mechanisms in the development of sarcoidosis. The strongest association was found between human leukocyte antigen and disease susceptibility. Many studies on different ethnic groups have shown that tumor necrosis factor α-308 A allele has been associated with good prognosis and non-progressive disease. Association studies of the vascular endothelial growth factor, interleukin-1, interleukin- 18, Toll-like receptors polymorphisms and sarcoidosis have yielded controversial results. Recent studies, using genome scan techniques, have led to the discovery of new disease susceptibility genes, such as annexin A11 and Butyrophilin-like protein -2. Further genetic tests will allow better understanding of etiopathogenesis of the disease, as well as new clinical classifications of the disease and administration of new therapeutic modalities for the treatment of chronic and progressive form of this disease.