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Rationale: In the IMPACT (Informing the Pathway of Chronic Obstructive Pulmonary Disease Treatment) trial, fluticasone furoate (FF)/umeclidinium (UMEC)/vilanterol (VI) significantly reduced exacerbations compared with FF/VI or UMEC/VI in patients with symptomatic chronic obstructive pulmonary disease and a history of exacerbations. Objectives: To understand whether inhaled corticosteroid (ICS) withdrawal affected IMPACT results, given direct transition from prior maintenance medication to study medication at randomization. Methods: Exacerbations and change from baseline in trough FEV1 and St. George’s Respiratory Questionnaire results were analyzed by prior ICS use. Exacerbations were also analyzed while excluding data from the first 30 days. Measurements and Main Results: FF/UMEC/VI significantly reduced the annual moderate/severe exacerbation rate compared with UMEC/VI in prior ICS users (29% reduction; P

Rationale: Randomized data comparing triple therapy with dual inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) therapy in patients with chronic obstructive pulmonary disease (COPD) are limited.Objectives: We compared the effects of once-daily triple therapy on lung function and health-related quality of life with twice-daily ICS/LABA therapy in patients with COPD.Methods: The FULFIL (Lung Function and Quality of Life Assessment in Chronic Obstructive Pulmonary Disease with Closed Triple Therapy) trial was a randomized, double-blind, double-dummy study comparing 24 weeks of once-daily triple therapy (fluticasone furoate/umeclidinium/vilanterol 100 μg/62.5 μg/25 μg; ELLIPTA inhaler) with twice-daily ICS/LABA therapy (budesonide/formoterol 400 μg/12 μg; Turbuhaler). A patient subgroup remained on blinded treatment for up to 52 weeks. Co–primary endpoints were change from baseline in trough FEV1 and in St. George’s Respiratory Questionnaire (SGRQ) total score at Week 24.Measurements and Main Results...

Emphysema in chronic obstructive pulmonary disease (COPD) can be characterized by high-resolution chest computed tomography (HRCT); however, the repeated use of HRCT is limited because of concerns regarding radiation exposure and cost.To evaluate biomarkers associated with emphysema and COPD-related clinical characteristics, and to assess the relationships of soluble receptor for advanced glycation endproducts (sRAGE), a candidate systemic biomarker identified in this study, with single-nucleotide polymorphisms (SNPs) in the gene coding for RAGE (AGER locus) and with clinical characteristics.Circulating levels of 111 biomarkers were analyzed for association with clinical characteristics in 410 patients with COPD enrolled in the TESRA study. sRAGE was also measured in the ECLIPSE cohort in 1,847 patients with COPD, 298 smokers and 204 nonsmokers. The association between 21 SNPs in the AGER locus with sRAGE levels and clinical characteristics was also investigated.sRAGE was identified as a biomarker of diffusing capacity of carbon monoxide and lung density in the TESRA cohort. In the ECLIPSE cohort, lower sRAGE levels were associated with increased emphysema, increased Global Initiative for Chronic Obstructive Lung Disease stage, and COPD disease status. The associations with emphysema in both cohorts remained significant after covariate adjustment (P0.0001). One SNP in the AGER locus, rs2070600, was associated with circulating sRAGE levels both in TESRA (P = 0.0014) and ECLIPSE (7.07 × 10(-16)), which exceeded genome-wide significance threshold. Another SNP (rs2071288) was also associated with sRAGE levels (P = 0.01) and diffusing capacity of carbon monoxide (P = 0.01) in the TESRA study.Lower circulating sRAGE levels are associated with emphysema severity and genetic polymorphisms in the AGER locus are associated with systemic sRAGE levels. Clinical trial registered with www.clinicaltrials.gov (NCT 00413205 and NCT 00292552).

α1-Antitrypsin deficiency is one of the most common heritable human diseases, predisposing to liver and lung injury. Significant heterogeneity in phenotypic expression is well documented, but less is known of the prevalence, severity, and correlates of chronic liver disease among individuals presenting with lung disease.To determine the frequency of and risk factors for severe liver fibrosis and cirrhosis among individuals with PiZZ-related lung disease.A well-characterized cohort of 57 PiZZ adults attending a tertiary referral respiratory clinic was screened prospectively for clinical, laboratory, radiologic, and (when appropriate) histologic evidence of chronic liver disease.Thirty-six (63.2%) of 57 had a history or clinical findings suggestive of liver disease; or had one or more abnormalities of liver function, or liver ultrasound, and 24 of these underwent liver biopsy. Ten (17.5%) had evidence of severe fibrosis or cirrhosis and were more likely to have higher body mass index (P = 0.04), alanine transaminase (P = 0.0001), alkaline phosphatase (P = 0.0009), prothrombin time (P = 0.0005), and maximal vital capacity (VCmax) (P = 0.04); lower platelet count (P = 0.007); abnormal liver echogenicity (P0.001); and splenomegaly (P = 0.001) at ultrasound. Screening with liver ultrasound provided a sensitivity and negative predictive value for severe fibrosis or cirrhosis of 100%, as were the specificity and positive predictive value for platelet count less than or equal to 174,000 per mm(3) and splenomegaly. Among individuals undergoing liver biopsy, fibrosis stage correlated with increasing VCmax (P = 0.02) and % predicted VCmax (P = 0.05), and decreasing residual volume/total lung capacity (TLC) (P = 0.02) and % predicted residual volume/TLC (P = 0.05).Significant chronic liver disease is common in PiZZ individuals with lung disease and can be screened effectively by a combination of conventional tests of liver function, platelet count, and liver ultrasound.

Rationale: Chronic obstructive pulmonary disease (COPD) susceptibility is in part related to genetic variants. Most genetic studies have been focused on genome-wide common variants without a specific focus on coding variants, but common and rare coding variants may also affect COPD susceptibility. Objectives: To identify coding variants associated with COPD. Methods: We tested nonsynonymous, splice, and stop variants derived from the Illumina HumanExome array for association with COPD in five study populations enriched for COPD. We evaluated single variants with a minor allele frequency greater than 0.5% using logistic regression. Results were combined using a fixed effects meta-analysis. We replicated novel single-variant associations in three additional COPD cohorts. Measurements and Main Results: We included 6,004 control subjects and 6,161 COPD cases across five cohorts for analysis. Our top result was rs16969968 (P = 1.7 X 10(-14)) in CHRNA5, a locus previously associated with COPD susceptibility and nicotine dependence. Additional top results were found in AGER, MMP3, and SERPINA1. A nonsynonymous variant, rs181206, ina27 (P = 4.7 X 10(-6)) was just below the level of exome-wide significance but attained exome-wick significance (P = 5.7 X 10(-8)) when combined with results from other cohorts. Gene expression datasets revealed an association of rs181206 and the surrounding locus with expression of multiple genes; several were differentially expressed in COPD lung tissue, including TUFM. Conclusions: In an exome array analysis of COPD, we identified nonsynonymous variants at previously described loci and a novel exome-wide significant variant in IL27. This variant is at a locus previously described in genome-wide associations with diabetes, inflammatory bowel disease, and obesity and appears to affect genes potentially related to COPD pathogenesis.

Misfolding, polymerization, and defective secretion of functional alpha-1 antitrypsin underlies the predisposition to severe liver and lung disease in alpha-1 antitrypsin deficiency. We have identified a novel (Ala336Pro, Baghdad) deficiency variant and characterized it relative to the wild-type (M) and Glu342Lys (Z) alleles. The index case is a homozygous individual of consanguineous parentage, with levels of circulating alpha-1 antitrypsin in the moderate deficiency range, but is a biochemical phenotype that could not be classified by standard methods. The majority of the protein was present as functionally inactive polymer, and the remaining monomer was 37% active relative to the wild-type protein. These factors combined indicate an 85 to 95% functional deficiency, similar to that seen with ZZ homozygotes. Biochemical, biophysical, and computational studies further defined the molecular basis of this deficiency. These studies demonstrated that native Ala336Pro alpha-1 antitrypsin could populate the polymerogenic intermediate—and therefore polymerize—more readily than either wild-type alpha-1 antitrypsin or the Z variant. In contrast, folding was far less impaired in Ala336Pro alpha-1 antitrypsin than in the Z variant. The data are consistent with a disparate contribution by the “breach” region and “shutter” region of strand 5A to folding and polymerization mechanisms. Moreover, the findings demonstrate that, in these variants, folding efficiency does not correlate directly with the tendency to polymerize in vitro or in vivo. They therefore differentiate generalized misfolding from polymerization tendencies in missense variants of alpha-1 antitrypsin. Clinically, they further support the need to quantify loss-of-function in alpha-1 antitrypsin deficiency to individualize patient care.

Am J Respir Crit Care Med. 2012 Dec 15;186(12):1238-1247. Epub 2012 Nov 9 Rationale: A genome-wide association study (GWAS) for circulating chronic obstructive pulmonary disease (COPD) biomarkers could identify genetic determinants of biomarker levels and COPD susceptibility. Objectives: To identify genetic variants of circulating protein biomarkers and novel genetic determinants of COPD. Methods: GWAS was performed for two pneumoproteins, Clara cell secretory protein (CC16) and surfactant protein D (SP-D), and five systemic inflammatory markers (C-reactive protein, fibrinogen, IL-6, IL-8, and tumor necrosis factor-α) in 1,951 subjects with COPD. For genome-wide significant single nucleotide polymorphisms (SNPs) (P < 1 × 10(-8)), association with COPD susceptibility was tested in 2,939 cases with COPD and 1,380 smoking control subjects. The association of candidate SNPs with mRNA expression in induced sputum was also elucidated. Measurements and Main Results: Genome-wide significant susceptibility loci affecting biomarker levels were found only for the two pneumoproteins. Two discrete loci affecting CC16, one region near the CC16 coding gene (SCGB1A1) on chromosome 11 and another locus approximately 25 Mb away from SCGB1A1, were identified, whereas multiple SNPs on chromosomes 6 and 16, in addition to SNPs near SFTPD, had genome-wide significant associations with SP-D levels. Several SNPs affecting circulating CC16 levels were significantly associated with sputum mRNA expression of SCGB1A1 (P = 0.009-0.03). Several SNPs highly associated with CC16 or SP-D levels were nominally associated with COPD in a collaborative GWAS (P = 0.001-0.049), although these COPD associations were not replicated in two additional cohorts. Conclusions: Distant genetic loci and biomarker-coding genes affect circulating levels of COPD-related pneumoproteins. A subset of these protein quantitative trait loci may influence their gene expression in the lung and/or COPD susceptibility. Clinical trial registered with www.clinicaltrials.gov (NCT 00292552). PMID:23144326[PubMed - as supplied by publisher] Rationale: A genome-wide association study (GWAS) for circulating chronic obstructive pulmonary disease (COPD) biomarkers could identify genetic determinants of biomarker levels and COPD susceptibility. Objectives: To identify genetic variants of circulating protein biomarkers and novel genetic determinants of COPD. Methods: GWAS was performed for two pneumoproteins, Clara cell secretory protein (CC16) and surfactant protein D (SP-D), and five systemic inflammatory markers (C-reactive protein, fibrinogen, IL-6, IL-8, and tumor necrosis factor-α) in 1,951 subjects with COPD. For genome-wide significant single nucleotide polymorphisms (SNPs) (P

Rationale: Exacerbations of chronic obstructive pulmonary disease (COPD) are heterogeneous with respect to inflammation and etiology. Objectives: Investigate biomarker expression in COPD exacerbations to identify biologic clusters and determine biomarkers that recognize clinical COPD exacerbation phenotypes, namely those associated with bacteria, viruses, or eosinophilic airway inflammation. Methods: Patients with COPD were observed for 1 year at stable and exacerbation visits. Biomarkers were measured in sputum and serum. Viruses and selected bacteria were assessed in sputum by polymerase chain reaction and routine diagnostic bacterial culture. Biologic phenotypes were explored using unbiased cluster analysis and biomarkers that differentiated clinical exacerbation phenotypes were investigated. Measurements and Main Results: A total of 145 patients (101 men and 44 women) entered the study. A total of 182 exacerbations were captured from 86 patients. Four distinct biologic exacerbation clusters were identified. These were bacterial-, viral-, or eosinophilic-predominant, and a fourth associated with limited changes in the inflammatory profile termed "pauciinflammatory." Of all exacerbations, 55%, 29%, and 28% were associated with bacteria, virus, or a sputum eosinophilia. The biomarkers that best identified these clinical phenotypes were sputum IL-1 beta, 0.89 (area under receiver operating characteristic curve) (95% confidence interval [CI], 0.83-0.95); serum CXCL10, 0.83 (95% CI, 0.70-0.96); and percentage peripheral eosinophils, 0.85 (95% CI, 0.78-0.93), respectively. Conclusions: The heterogeneity of the biologic response of COPD exacerbations can be defined. Sputum IL-1 beta, serum CXCL10, and peripheral eosinophils are biomarkers of bacteria-, virus-, or eosinophil-associated exacerbations of COPD. Whether phenotype-specific biomarkers can be applied to direct therapy warrants further investigation.

Rationale: Chromosome 12p has been linked to chronic obstructive pulmonary disease (COPD) in the Boston Early-Onset COPD Study (BEOCOPD), but a susceptibility gene in that region has not been identified. Objectives: We used high-density single-nucleotide polymorphism (SNP) mapping to implicate a COPD susceptibility gene and an animal model to determine the potential role of SOX5 in lung development and COPD. Methods: On chromosome 12p, we genotyped 1,387 SNPs in 386 COPD cases from the National Emphysema Treatment Trial and 424 control smokers from the Normative Aging Study. SNPs with significant associations were then tested in the BEOCOPD study and the International COPD Genetics Network. Based on the human results, we assessed histology and gene expression in the lungs of Sox5−/− mice. Measurements and Main Results: In the case-control analysis, 27 SNPs were significant at P ≤ 0.01. The most significant SNP in the BEOCOPD replication was rs11046966 (National Emphysema Treatment Trial–Normative Aging Study P = 6.0 × 10−4, BEOCOPD P = 1.5 × 10−5, combined P = 1.7 × 10−7), located 3′ to the gene SOX5. Association with rs11046966 was not replicated in the International COPD Genetics Network. Sox5−/− mice showed abnormal lung development, with a delay in maturation before the saccular stage, as early as E16.5. Lung pathology in Sox5−/− lungs was associated with a decrease in fibronectin expression, an extracellular matrix component critical for branching morphogenesis. Conclusions: Genetic variation in the transcription factor SOX5 is associated with COPD susceptibility. A mouse model suggests that the effect may be due, in part, to its effects on lung development and/or repair processes.

Chronic obstructive pulmonary disease (COPD) is characterized by alveolar destruction and abnormal inflammatory responses to noxious stimuli. Surfactant protein-D (SFTPD) is immunomodulatory and essential to host defense. We hypothesized that polymorphisms in SFTPD could influence the susceptibility to COPD. We genotyped six single-nucleotide polymorphisms (SNPs) in surfactant protein D in 389 patients with COPD in the National Emphysema Treatment Trial (NETT) and 472 smoking control subjects from the Normative Aging Study (NAS). Case-control association analysis was performed using Cochran-Armitage trend tests and multivariate logistic regression. The replication of significant associations was attempted in the Boston Early-Onset COPD Study, the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) Study, and the Bergen Cohort. We also correlated SFTPD genotypes with serum concentrations of surfactant protein-D (SP-D) in the ECLIPSE Study. In the NETT-NAS case-control analysis, four SFTPD SNPs were associated with susceptibility to COPD: rs2245121 (P = 0.01), rs911887 (P = 0.006), rs6413520 (P = 0.004), and rs721917 (P = 0.006). In the family-based analysis of the Boston Early-Onset COPD Study, rs911887 was associated with prebronchodilator and postbronchodilator FEV(1) (P = 0.003 and P = 0.02, respectively). An intronic SNP in SFTPD, rs7078012, was associated with COPD in the ECLIPSE Study and the Bergen Cohort. Multiple SFTPD SNPs were associated with serum SP-D concentrations in the ECLIPSE Study. We demonstrated an association of polymorphisms in SFTPD with COPD in multiple populations. We demonstrated a correlation between SFTPD SNPs and SP-D protein concentrations. The SNPs associated with COPD and SP-D concentrations differed, suggesting distinct genetic influences on susceptibility to COPD and SP-D concentrations.

Genome-wide association studies have shown significant associations between variants near hedgehog interacting protein HHIP, FAM13A, and cholinergic nicotinic acetylcholine receptor CHRNA3/5 with increased risk of chronic obstructive pulmonary disease (COPD) in smokers; however, the disease mechanisms behind these associations are not well understood.To identify the association between replicated loci and COPD-related phenotypes in well-characterized patient populations.The relationship between these three loci and COPD-related phenotypes was assessed in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-point (ECLIPSE) cohort. The results were validated in the family-based International COPD Genetics Network (ICGN).The CHRNA3/5 locus was significantly associated with pack-years of smoking (P = 0.002 and 3 × 10⁻⁴), emphysema assessed by a radiologist using high-resolution computed tomography (P = 2 × 10⁻⁴ and 4.8 × 10⁻⁵), and airflow obstruction (P = 0.004 and 1.8 × 10⁻⁵) in the ECLIPSE and ICGN populations, respectively. However, variants in the IREB2 gene were only significantly associated with FEV₁. The HHIP locus was not associated with smoking intensity but was associated with FEV₁/FVC (P = 1.9 × 10⁻⁴ and 0.004 in the ECLIPSE and ICGN populations). The HHIP locus was also associated with fat-free body mass (P = 0.007) and with both retrospectively (P = 0.015) and prospectively (P = 0.024) collected COPD exacerbations in the ECLIPSE cohort. Single-nucleotide polymorphisms in the FAM13A locus were associated with lung function.The CHRNA3/5 locus was associated with increased smoking intensity and emphysema in individuals with COPD, whereas the HHIP and FAM13A loci were not associated with smoking intensity. The HHIP locus was associated with the systemic components of COPD and with the frequency of COPD exacerbations. FAM13A locus was associated with lung function.

The S- and Z-deficiency alleles of alpha1-antitrypsin are found in more than 20% of some white populations. This high gene frequency suggests that these mutations confer a selective advantage, but the biologic mechanism of this has remained obscure. It is now well recognized that the S and Z alleles result in a conformational transition within the alpha1-antitrypsin molecule and the formation of polymers that are retained within the endoplasmic reticulum of hepatocytes. Polymers of mutant alpha1-antitrypsin can also form within the alveoli and small airways of the lung where they may drive the inflammation that underlies emphysema in individuals with alpha1-antitrypsin deficiency. This local production of polymers by mutant S and Z alpha1-antitrypsin may have also provided protection against infectious disease in the preantibiotic era by focusing and amplifying the inflammatory response to limit invasive respiratory and gastrointestinal infection. It is only since the discovery of antibiotics, the widespread adoption of smoking, and increased longevity that these protective, proinflammatory properties of alpha1-antitrypsin mutants have become detrimental to cause the emphysema and systemic inflammatory diseases associated with alpha1-antitrypsin deficiency.

The Z variant of alpha1-antitrypsin (Z-AT) is present in 4% of Northern Europeans and is associated with liver cirrhosis and emphysema. Polymers accumulate within the hepatocyte and the subsequent plasma deficiency of AT renders the lungs susceptible to proteolysis and early onset emphysema. We have previously demonstrated that the Phe-Leu-Glu-Ala-Ile-Gly (6 mer) peptide specifically binds to Z-AT and inhibits polymerization. Here we present the first detailed biochemical study of the purified Z-AT-6 mer binary complex. Biochemical studies indicated that this complex was inactive as a proteinase inhibitor and the peptide annealed to beta-sheet A of Z-AT. Removal of the N-acetyl terminus of the 6 mer peptide did not affect the peptide's ability to prevent polymer formation. However, the nonacetylated 6 mer-Z-AT complex dissociated at a rate 2.75 x faster than the acetylated 6 mer-Z-AT complex to yield an active inhibitor; Koff 5.5 +/- 1.07 versus 2.0 +/- 0.25 10(6) s(-1), respectively. These biochemical data indicate a potential therapeutic approach whereby polymerization is prevented in the liver, with the gradual release of the peptide from the binary complex restoring proteinase inhibitory function within the tissues. Thus, it raises the novel prospect of ameliorating both the cirrhosis and the emphysema associated with Z-AT.

Plasma deficiency of alpha(1)-antitrypsin is most commonly due to the Z mutation ((342)Glu--> Lys) and is associated with early-onset panlobular emphysema. The lung disease in these patients is attributed to the relative deficiency of circulating alpha(1)-antitrypsin resulting in uncontrolled neutrophil-derived proteolytic activity. We have previously demonstrated that the local deficiency of Z alpha(1)-antitrypsin is exacerbated by the formation of polymers within the lung and now show that this polymerization not only inactivates alpha(1)-antitrypsin but also converts the molecule to a chemoattractant for human neutrophils. The chemotactic action of polymeric alpha(1)-antitrypsin was substantially greater than that seen with other conformers, was of similar magnitude to C5a, and was apparent over a range of physiologically relevant concentrations (EC(50) 0.0045 +/- 0.002 mg/ml). The biologic activity of polymeric alpha(1)-antitrypsin was confirmed by the demonstration that polymers, but not native alpha(1)-antitrypsin, induced neutrophil shape change and stimulated myeloperoxidase release and neutrophil adhesion. Polymeric alpha(1)-antitrypsin had no effect on basal or N-formyl-Met-Leu-Phe- stimulated superoxide anion release or constitutive apoptosis. The chemotactic properties of polymeric alpha(1)-antitrypsin may provide an explanation for the excessive neutrophils found in the lungs of Z alpha(1)-antitrypsin homozygotes and suggests a new paradigm for the pathogenesis of emphysema in these patients.

alpha1-Antitrypsin (alpha1-AT) is the most abundant circulating proteinase inhibitor. The Z variant results in profound plasma deficiency as the mutant polymerizes within hepatocytes. The retained polymers are associated with cirrhosis, and the lack of circulating protein predisposes to early onset emphysema. We have investigated the role of the naturally occurring solute trimethylamine N-oxide (TMAO) in modulating the polymerization of normal M and disease-associated Z alpha1-AT. TMAO stabilized both M and Z alpha1-AT in an active conformation against heat-induced polymerization. Spectroscopic analysis demonstrated that this was due to inhibition of the conversion of the native state to a polymerogenic intermediate. However, TMAO did not aid the refolding of denatured alpha1-AT to a native conformation; instead, it enhanced polymerization. These data show that TMAO can be used to control the conformational transitions of folded alpha1-AT but that it is ineffective in promoting folding of the polypeptide chain within the secretory pathway.

Patients with alpha1-antitrypsin (alpha1-AT) deficiency are at risk of developing early-onset panlobular basal emphysema, which has been attributed to uncontrolled proteolytic activity within the lung. Severe genetic deficiency of alpha1-AT is most commonly due to the Z mutation (342Glu--> Lys), which results in a block in alpha1-AT processing within the endoplasmic reticulum of hepatocytes. The retained alpha1-AT forms inclusions, which are associated with neonatal hepatitis, juvenile cirrhosis, and hepatocellular carcinoma. Our recent studies have shown that the accumulation of alpha1-AT is due to the Z mutation perturbing the structure of alpha1-AT to allow polymer formation, with a unique linkage between the reactive center loop of one alpha1-AT molecule and the A beta-pleated sheet of a second. The detection of loop-sheet polymers and other conformations of alpha1-AT in the lungs of patients with emphysema has been technically difficult. We show here that transverse urea-gradient-gel (TUG) electrophoresis and Western blot analysis may be used to characterize conformations of alpha1-AT in dilute samples of bronchoalveolar lavage fluid (BALF). This technique was used to demonstrate loop-sheet polymers in the lungs of patients with Z alpha1-AT-deficiency-related emphysema. Polymers were the predominant conformational form of alpha1-AT in BALF from the lungs of two of five Z homozygotes with emphysema, but were not detectable in any of 13 MM, MS, or MZ alpha1-AT controls. Because alpha1-AT loop-sheet polymers are inactive as proteinase inhibitors, this novel conformational transition will further reduce the levels of functional proteinase inhibitor in the lungs of the Z alpha1-AT homozygote, and so exacerbate tissue damage.

alpha(1)-Antitrypsin deficiency is the only genetic factor that is widely recognized to predispose smokers to chronic obstructive pulmonary disease. We have shown that the plasma deficiency results from point mutations perturbing the structure of the protein to favor sequential linkage between the reactive center loop of one molecule and beta-sheet A of another. These polymers are retained within the liver to form the periodic acid-Schiff-positive inclusions that are characteristic of the disease. Intracellular polymerization also explains the retention of mutants of other members of the serine proteinase inhibitor (or serpin) superfamily to cause diseases as diverse as thrombosis, angio-edema, and dementia. In view of the common mechanism, we have grouped these conditions together as the serpinopathies. Intrapulmonary Z alpha(1)-antitrypsin similarly forms polymers within the alveolar space. These polymers are inactive as a proteinase inhibitor and act as a chemoattractant for neutrophils. This conformational transition may explain the excessive inflammation that underlies the progressive emphysema associated with Z alpha(1)-antitrypsin deficiency.

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with local (lung) and systemic (blood) inflammation and manifestations. DNA methylation is an important regulator of gene transcription, and global and specific gene methylation marks may vary with cigarette smoke exposure. Objectives: To perform a comprehensive assessment of methylation marks in DNA from subjects well phenotyped for nonneoplastic lung disease. Methods: We conducted array-based methylation screens, using a test-replication approach, in two family-based cohorts (n = 1,085 and 369 subjects). Measurements and Main Results: We observed 349 CpG sites significantly associated with the presence and severity of COPD in both cohorts. Seventy percent of the associated CpG sites were outside of CpG islands, with the majority of CpG sites relatively hypomethylated. Gene ontology analysis based on these 349 CpGs (330 genes) suggested the involvement of a number of genes responsible for immune and inflammatory system pathways, responses to stress and external stimuli, as well as wound healing and coagulation cascades. Interestingly, our observations include significant, replicable associations between SERPINA1 hypomethylation and COPD and lower average lung function phenotypes (combined P values: COPD, 1.5 × 10−23; FEV1/FVC, 1.5 × 10−35; FEV1, 2.2 × 10−40). Conclusions: Genetic and epigenetic pathways may both contribute to COPD. Many of the top associations between COPD and DNA methylation occur in biologically plausible pathways. This large-scale analysis suggests that DNA methylation may be a biomarker of COPD and may highlight new pathways of COPD pathogenesis.

alpha 1-Antitrypsin is a member of the serine proteinase inhibitor, serpin, family of protease inhibitors, which have their reactive centers situated on a mobile peptide loop. This reactive loop can adopt varied conformations and perturbations of molecular structure to allow the pathological linking of the loop of one molecule to a beta-pleated sheet of another. This linkage has been shown to be the cause of the polymerization and aggregation within the hepatocyte of the common Z mutant of antitrypsin. The occurrence of loop-sheet polymerization has been confirmed with other deficiency variants of antitrypsin that accumulate in the liver (Mmalton, Siiyama) and also shown to occur in pathological mutants of C1-inhibitor and antithrombin. Deductive evidence indicates that the loop is inserted into the A-sheet of the next molecule, but recent structural findings raise the possibility of insertion into the C-sheet. This detail of loop-sheet polymerization is important for the design of strategies to interfere with insertion and hence lesson the accumulation of Z antitrypsin that is responsible for associated liver damage.