Our study highlights the significance of epigenetic marks in lung immune response in granulomatous lung disease.

Background-Most diseases, including asthma, result from the interaction between environmental exposures and genetic variants. Functional variants of CD14 negatively affect lung function in farm workers and children exposed to animal allergens and endotoxin.

Sarcoidosis is a complex systemic disease. Our study aimed to 1) identify novel alleles associated with sarcoidosis susceptibility; 2) provide an in-depth evaluation of HLA alleles and sarcoidosis susceptibility; 3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1,335 sarcoidosis cases and 1,264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1,487 cases and 1,504 controls). The EA cohort was recruited from National Jewish Health, Cleveland Clinic, University of California San Francisco, and Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis. The AA cohort was from a previous study with subjects enrolled from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. 49 SNPs in HLA-DRA, -DRB9, -DRB5, -DQA1, and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA. Among them, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101, and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage. In summary, we identified several novel SNPs and three HLA alleles associated with sarcoidosis susceptibility in the largest EA population evaluated to date using an integrative analysis of genetics and transcriptomics. We also replicated our findings in an AA population.

Previously we showed that alveolar macrophages(AMs) from patients with chronic beryllium disease(CBD) and beryllium sensitization(BeS) demonstrated significantly greater cell surface CD16(encoded by the FCGR3A gene) than controls. We hypothesized that these differences were related to polymorphisms in the FCGR3A gene. This study was to determine the association between FCGR3A polymorphisms in CBD, BeS versus controls as well as clinical data, providing potential information about disease pathogenesis, risk and activity. 189 CBD/154 BeS /150 controls (92 Be-exposed-non-diseased and 58 healthy controls) were included in this study. Sequence specific primers polymerase chain reaction(PCR-SSP) was used to determine FCGR3A 158V/F polymorphisms. We found significantly higher frequencies of the 158V allele (OR:1.60 (CI: 1.17-2.19),p=0.004) and 158VV homozygotes (OR:2.97 (CI:1.48-5.97) p=0.007) in CBD versus controls. No differences were found in the frequencies of FCGR3A alleles or genotypes between BeS versus controls and CBD versus BeS. Average changes in exercise testing maximum workload(Wlm),maximum oxygen consumption(VO2m) and diffusion capacity of carbon monoxide(DLCO) demonstrated greater decline over time in those CBD cases with the 158VV gene, modelled between 10 and 40 years from first beryllium exposure. The FCGR3A V158F polymorphism is associated with CBD compared to BeS and controls and may impact lung function in CBD.

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