Overlap of genetic risk between interstitial lung abnormalities and idiopathic pulmonary fibrosis

Rationale Interstitial lung abnormalities (ILA) are associated with the highest genetic risk locus for IPF; however, the extent to which there is additional overlap with IPF, or unique associations among those with ILA is not known. Objectives To perform a genome-wide association study (GWAS) of ILA. Methods: ILA and the subpleural-predominant subtype were assessed on chest computed tomography (CT) scans in the AGES, COPDGene, Framingham Heart, ECLIPSE, MESA, and SPIROMICS studies. We performed a GWAS of ILA in each cohort and combined the results using a meta-analysis. We assessed for overlapping associations in independent GWASs of IPF. Measurements and Main Results Genome-wide genotyping data were available in 1,699 ILA cases and 10,274 controls. The MUC5B promoter variant rs35705950 was significantly associated with both ILA (p=2.6x10-27) and subpleural ILA (p=1.6x10-29). We discovered novel genome-wide associations near IPO11 (rs6886640, p=3.8x10-8 ) and FCF1P3 (rs73199442, p=4.8x10-8 ) with ILA, and HTRE1 (rs7744971, p=4.2x10-8 ) with subpleural-predominant ILA. These novel associations were not associated with IPF. Of 12 previously reported IPF GWAS loci, 5 (DPP9, DSP, FAM13A, IVD, and MUC5B) were significantly associated (p<0.05/12) with ILA. Conclusions In a GWAS of ILA in six studies, we confirmed the association with a MUC5B promoter variant and found strong evidence for an effect of previously described IPF loci; however, novel ILA associations were not associated with IPF. These findings highlight common and suggest distinct genetically-driven biologic pathways between ILA and IPF

Genetic loci associated with chronic obstructive pulmonary disease overlap with loci for lung function and pulmonary fibrosis

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality worldwide1. We performed a genetic association in 15,256 cases and 47,936 controls, with replication of select top results (P < 5x10-6) in 9,498 cases and 9,748 controls. In the combined meta-analysis, we identified 22 loci at genome-wide significance, including 13 new associations with COPD. Nine of these 13 loci have been associated with lung function in general population samples2-7; however, 4 (EEFSEC, DSP, MTCL1, and SFTPD) are novel. We noted 2 loci shared with pulmonary fibrosis8,9 (FAM13A and DSP) but with opposite risk alleles for COPD. None of our loci overlapped with genome-wide associations for asthma; however, one locus has been implicated in the joint susceptibility to asthma and obesity10. We also identified genetic correlation between COPD and asthma. Our findings highlight novel loci, demonstrate the importance of specific lung function loci to COPD, and identify potential regions of genetic overlap between COPD and other respiratory diseases