Background: As reported recently, some gene polymorphisms are suspected to determine susceptibility to sarcoidosis and are held responsible for the extent and progression of the disease. Polymorphism at -857 locus of tumor necrosis factor (TNF)-alpha gene is considered to be a predisposition factor in sarcoidosis and held responsible for pathogenesis of the disease. We compared these polymorphisms in healthy Turkish control subjects and Turkish patients with sarcoidosis.
Methods: We examined gene polymorphisms in 90 cases which were histopathologically diagnosed as sarcoidosis and 110 healthy subjects without any history of a chronic disease. TNF-alpha-857 gene polymorphisms were determined using a polymerase chain reaction (PCR)-based method after DNA isolation. Genotype distributions of the groups were evaluated by the Hardy-Weinberg equilibrium test.
Results: Genotype distributions were in agreement with the Hardy-Weinberg equilibrium both in sarcoidosis patients and healthy subjects. TNF-alpha gene (C/T) polymorphism, at position -857, revealed no differences in genotype and allele frequency between patients and control subjects but more relapses and more frequently involvement of three or more organs were found in sarcoidosis patients who have this polymorphism (p<0.05, p<0.01 respectively).
Conclusion: T allele at -857 locus of TNF gene is a marker for more extensive disease in Turkish sarcoidosis patients.