Evidence suggests a genetic predisposition to chronic beryllium disease (CBD) and sarcoidosis, which are clinically and pathologically similar granulomatous lung diseases. TGF-β1, a cytokine involved in mediating the fibrotic/Th1 response, has several genetic variants which might predispose individuals to these lung diseases. We examined whether certain TGF-β1 variants and haplotypes are found at higher rates in CBD and sarcoidosis cases compared with controls and are associated with disease severity indicators for both diseases. Using DNA from sarcoidosis cases/controls from A Case Control Etiologic Study of Sarcoidosis Group (ACCESS) and CBD cases/controls, TGF-β1 variants were analyzed by sequence-specific primer PCR. No significant differences were found between cases and controls for either disease in the TGF-β1 variants or haplotypes. The −509C and codon 10T were significantly associated with disease severity indicators in both CBD and sarcoidosis. Haplotypes that included the −509C and codon 10T were also associated with more severe disease, whereas one or more copies of the haplotype containing the −509T and codon 10C was protective against severe disease for both sarcoidosis and CBD. These studies suggest that the −509C and codon 10T, implicated in lower levels of TGF-β1 protein production, are shared susceptibility factors associated with more severe granulomatous disease in sarcoidosis and CBD. This association may be due to lack of down-regulation by TGF-β1, although future studies will be needed to correlate TGF-β1 protein levels with known TGF-β1 genotypes and assess whether there is a shared mechanisms for TGF-β1 in these two granulomatous diseases.

Apoptosis may perpetuate some forms of inflammation. Of the apoptotic pathway proteins, Fas is particularly overexpressed in sarcoidosis. We hypothesized that Fas promoter single nucleotide polymorphisms (SNPs) contribute to the development and severity of sarcoidosis. Associations of known Fas promoter SNPs (−670, −690 and −1377) and deduced haplotypes with sarcoidosis and sarcoidosis severity were evaluated using matched case-control (n = 656 pairs) and casecomparison (n = 656) studies, respectively, using conditional logistic regression. Hardy-Weinberg equilibrium was confirmed for all three polymorphisms in African-Americans (AA), and for the −670 and −1377 in whites. Genotype and allele frequencies were significantly different between whites and AA. Race-stratified analysis revealed that a common haplotype, −1377G/−690T/ −670G, was associated with sarcoidosis [odds ratio (OR) = 1.78, P = 0.05] only in AA. The haplotype −1377G/−690C/−670A was negatively associated with sarcoidosis (OR = 0.39, P = 0.03) only in AA. In conclusion, the consistency of these findings suggests that Fas promoter genetic variants may be related to sarcoidosis disease risk in AA.