The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.

Large artery atherosclerotic stroke (LAS) shows substantial heritability not explained by previous genome-wide association studies. Here, we explore the role of coding variation in LAS by analyzing variants on the HumanExome BeadChip in a total of 3,127 cases and 9,778 controls from Europe, Australia, and South Asia. We report on a nonsynonymous single-nucleotide variant in serpin family A member 1 (SERPINA1) encoding alpha-1 antitrypsin [AAT; p.V213A; P = 5.99E-9, odds ratio (OR) = 1.22] and confirm histone deacetylase 9 (HDAC9) as a major risk gene for LAS with an association in the 3′-UTR (rs2023938; P = 7.76E-7, OR = 1.28). Using quantitative microscale thermophoresis, we show that M1 (A213) exhibits an almost twofold lower dissociation constant with its primary target human neutrophil elastase (NE) in lipoprotein-containing plasma, but not in lipid-free plasma. Hydrogen/deuterium exchange combined with mass spectrometry further revealed a significant difference in the global flexibility of the two variants. The observed stronger interaction with lipoproteins in plasma and reduced global flexibility of the Val-213 variant most likely improve its local availability and reduce the extent of proteolytic inactivation by other proteases in atherosclerotic plaques. Our results indicate that the interplay between AAT, NE, and lipoprotein particles is modulated by the gate region around position 213 in AAT, far away from the unaltered reactive center loop (357-360). Collectively, our findings point to a functionally relevant balance between lipoproteins, proteases, and AAT in atherosclerosis.genetics | ischemic stroke | large artery stroke | antitrypsin | variation S troke is the leading cause of long-term disability and the second most common cause of death worldwide (1, 2). About a quarter of ischemic stroke cases are caused by large artery atherosclerotic stroke (LAS) (3, 4). Atherosclerosis is a chronic inflammatory condition that involves a number of well-characterized steps. Initial stages include the deposition of lipids in vascular endothelial cells, whereas more advanced stages are characterized by fibrotic changes with formation of a fibrotic cap and, eventually, plaque rupture (5). LAS exhibits the highest heritability of all stroke subtypes, with estimates ranging from 40.3 to 66.6% (6, 7). This fact is reflected by recent genome-wide association studies that found common variants for LAS at multiple genomic loci (8-10). The lead SNPs from these regions all reside within intergenic (4, 7, 11) or SignificanceCommon single-amino acid variations of proteins are traditionally regarded as functionally neutral polymorphisms because these substitutions are mostly located outside functionally relevant surfaces. In this study, we present an example of a functionally relevant coding sequence variation, which, as we show here, confers risk for large artery atherosclerotic stroke. The singleresidue variation M1(A213V) in serpin family A member 1 (SERPINA1) [encoding alpha-1 antitrypsin (AAT)] is situated outside the...

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