Analysis of gene polymorphisms in interleukin-10 and transforming growth factor-beta 1 in sarcoidosis

Interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-beta 1) are anti-inflammatory cytokines that play important roles in the immunoregulatory processes of numerous granulomatous diseases. In sarcoidosis polymorphisms (PMs) within these cytokine genes are suspected of modifing the course of the disorder. Therefore, we were interested in whether the genotype frequencies for a PM at position -1082 of the IL-10 or in codon 25 of the TGF-beta 1 gene differ in sarcoidosis or its distinct phenotypes in comparison with healthy individuals.

In 51 sarcoidosis patients and 72 healthy blood donors, genotyping for the named PMs was performed by PCR methodology and restriction enzyme digestion. Patients were retrospectively classified according to their course of disease, namely spontaneous remission, regressive under therapy, or chronic-progressive.

For TGF-beta 1 PM the genotype frequencies ranged between 81.8-90.5, 9.6-13.9 and 0-5.3 percent for genotype GG, CG and CC respectively. For IL-10 PM the values ranged between 17.7-23.2, 54.4-68.4 and 21.1-26.4 percent for AA, AG and GG. Statistical comparisons of the allele and genotype frequencies between the clinical defined sarcoidosis groups and the healthy blood donors revealed no significant differences.