Alpha-1 Antitrypsin-Deficient Macrophages Have Increased Matriptase-Mediated Proteolytic Activity.

Alpha-1 antitrypsin (AAT) deficiency-associated emphysema is largely attributed to insufficient inhibition of neutrophil elastase released from neutrophils. Correcting AAT levels using augmentation therapy only slows disease progression, and that suggests a more complex process of lung destruction. Because alveolar macrophages (Mɸ) express AAT, we propose that the expression and intracellular accumulation of mutated Z-AAT (the most common mutation) compromises Mɸ function and contributes to emphysema development. Extracellular matrix (ECM) degradation is a hallmark of emphysema pathology. In this study, Mɸ from individuals with Z-AAT (Z-Mɸ) have greater proteolytic activity on ECM than do normal Mɸ. This abnormal Z-Mɸ activity is not abrogated by supplementation with exogenous AAT and is likely the result of cellular dysfunction induced by intracellular accumulation of Z-AAT. Using pharmacologic inhibitors, we show that several classes of proteases are involved in matrix degradation by Z-Mɸ. Importantly, compared with normal Mɸ, the membrane-bound serine protease, matriptase, is present in Z-Mɸ at higher levels and contributes to their proteolytic activity on ECM. In addition, we identified matrix metalloproteinase (MMP)-14, a membrane-anchored metalloproteinase, as a novel substrate for matriptase, and showed that matriptase regulates the levels of MMP-14 on the cell surface. Thus, high levels of matriptase may contribute to increased ECM degradation by Z-Mɸ, both directly and through MMP-14 activation. In summary, the expression of Z-AAT in Mɸ confers increased proteolytic activity on ECM. This proteolytic activity is not rescued by exogenous AAT supplementation and could thus contribute to augmentation resistance in AAT deficiency-associated emphysema.

5 Year Expression and Neutrophil Defect Repair after Gene Therapy in Alpha-1 Antitrypsin Deficiency.

Alpha-1 antitrypsin deficiency is a monogenic disorder resulting in emphysema due principally to the unopposed effects of neutrophil elastase. We previously reported achieving plasma wild-type alpha-1 antitrypsin concentrations at 2.5%-3.8% of the purported therapeutic level at 1 year after a single intramuscular administration of recombinant adeno-associated virus serotype 1 alpha-1 antitrypsin vector in alpha-1 antitrypsin deficient patients. We analyzed blood and muscle for alpha-1 antitrypsin expression and immune cell response. We also assayed previously reported markers of neutrophil function known to be altered in alpha-1 antitrypsin deficient patients. Here, we report sustained expression at 2.0%-2.5% of the target level from years 1-5 in these same patients without any additional recombinant adeno-associated virus serotype-1 alpha-1 antitrypsin vector administration. In addition, we observed partial correction of disease-associated neutrophil defects, including neutrophil elastase inhibition, markers of degranulation, and membrane-bound anti-neutrophil antibodies. There was also evidence of an active T regulatory cell response (similar to the 1 year data) and an exhausted cytotoxic T cell response to adeno-associated virus serotype-1 capsid. These findings suggest that muscle-based alpha-1 antitrypsin gene replacement is tolerogenic and that stable levels of M-AAT may exert beneficial neutrophil effects at lower concentrations than previously anticipated.

Alpha-1 Antitrypsin PiMZ Genotype Is Associated with Chronic Obstructive Pulmonary Disease in Two Racial Groups.

RATIONALE: Alpha-1 antitrypsin deficiency, caused primarily by homozygosity for the Z allele of the SERPINA1 gene, is a well-established genetic cause of chronic obstructive pulmonary disease (COPD). Whether the heterozygous PiMZ genotype for alpha-1 antitrypsin confers increased risk for COPD has been debated. OBJECTIVES: We analyzed 8,271 subjects in the Genetic Epidemiology of COPD (COPDGene) Study, hypothesizing that PiMZ would independently associate with COPD and COPD-related phenotypes. METHODS: The COPDGene Study comprises a multiethnic, cross-sectional, observational cohort of non-Hispanic white and African American current and former smokers with at least 10 pack-years of smoking who were enrolled for detailed clinical and genetic studies of COPD and COPD-related traits. We performed multivariate logistic regression analysis for moderate to severe COPD and assessed Pi genotype with other relevant covariates in models stratified by race. We analyzed quantitative characteristics on the basis of volumetric computed tomography with generalized linear models controlling for genotype, scanner type, and similar covariates. RESULTS: White PiMZ COPDGene subjects had significantly lower lung function, FEV1 percent predicted (68 ± 28 vs. 75 ± 27; P = 0.0005), and FEV1/FVC ratio (0.59 ± 0.18 vs. 0.63 ± 0.17; P = 0.0008), as well as more radiographic emphysema (P = 0.001), than subjects without alpha-1 antitrypsin Z risk alleles. Similarly, African American PiMZ subjects had lower lung function, FEV1 percent predicted (65 ± 33 vs. 84 ± 25; P = 0.009) and FEV1/FVC (0.61 ± 0.21 vs. 0.71 ± 0.15; P = 0.03). CONCLUSIONS: In the COPDGene Study, we demonstrate that PiMZ heterozygous individuals who smoke are at increased risk for COPD and obstructive lung function impairment compared with Z-allele noncarriers, regardless of race. Although severe alpha-1 antitrypsin deficiency is uncommon in African Americans, our study adds further support for initial targeted detection of all subjects with COPD for alpha-1 antitrypsin deficiency, including African Americans. Clinical trial registered with www.clinicaltrials.gov (NCT00608784).

SVIP regulates Z variant alpha-1 antitrypsin retro-translocation by inhibiting ubiquitin ligase gp78.

Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by early-onset emphysema and liver disease. The most common disease-causing mutation is a single amino acid substitution (Glu/Lys) at amino acid 342 of the mature protein, resulting in disruption of the 290-342 salt bridge (an electrophoretic abnormality defining the mutation [Z allele, or ZAAT]), protein misfolding, polymerization, and accumulation in the endoplasmic reticulum of hepatocytes and monocytes. The Z allele causes a toxic gain of function, and the E3 ubiquitin ligase gp78 promotes degradation and increased solubility of endogenous ZAAT. We hypothesized that the accumulation of ZAAT is influenced by modulation of gp78 E3 ligase and SVIP (small VCP-interacting protein) interaction with p97/VCP in ZAAT-expressing hepatocytes. We showed that the SVIP inhibitory effect on ERAD due to overexpression causes the accumulation of ZAAT in a human Z hepatocyte-like cell line (AT01). Overexpression of gp78, as well as SVIP suppression, induces gp78-VCP/p97 interaction in AT01 cells. This interaction leads to retro-translocation of ZAAT and reduction of the SVIP inhibitory role in ERAD. In this context, overexpression of gp78 or SVIP suppression may eliminate the toxic gain of function associated with polymerization of ZAAT, thus providing a potential new therapeutic approach to the treatment of AATD.

Characterising the association of latency with α(1)-antitrypsin polymerisation using a novel monoclonal antibody.

α1-Antitrypsin is primarily synthesised in the liver, circulates to the lung and protects pulmonary tissues from proteolytic damage. The Z mutant (Glu342Lys) undergoes inactivating conformational change and polymerises. Polymers are retained within the hepatocyte endoplasmic reticulum (ER) in homozygous (PiZZ) individuals, predisposing the individuals to hepatic cirrhosis and emphysema. Latency is an analogous process of inactivating, intra-molecular conformational change and may co-occur with polymerisation. However, the relationship between latency and polymerisation remained unexplored in the absence of a suitable probe. We have developed a novel monoclonal antibody specific for latent α1-antitrypsin and used it in combination with a polymer-specific antibody, to assess the association of both conformers in vitro, in disease and during augmentation therapy. In vitro kinetics analysis showed polymerisation dominated the pathway but latency could be promoted by stabilising monomeric α1-antitrypsin. Polymers were extensively produced in hepatocytes and a cell line expressing Z α1-antitrypsin but the latent protein was not detected despite manipulation of the secretory pathway. However, α1-antitrypsin augmentation therapy contains latent α1-antitrypsin, as did the plasma of 63/274 PiZZ individuals treated with augmentation therapy but 0/264 who were not receiving this medication (p<10(-14)). We conclude that latent α1-antitrypsin is a by-product of the polymerisation pathway, that the intracellular folding environment is resistant to formation of the latent conformer but that augmentation therapy introduces latent α1-antitrypsin into the circulation. A suite of monoclonal antibodies and methodologies developed in this study can characterise α1-antitrypsin folding and conformational transitions, and screen methods to improve augmentation therapy.

Longer telomere length in COPD patients with α1-antitrypsin deficiency independent of lung function.

Oxidative stress is involved in the pathogenesis of airway obstruction in α1-antitrypsin deficient patients. This may result in a shortening of telomere length, resulting in cellular senescence. To test whether telomere length differs in α1-antitrypsin deficient patients compared with controls, we measured telomere length in DNA from peripheral blood cells of 217 α1-antitrypsin deficient patients and 217 control COPD patients. We also tested for differences in telomere length between DNA from blood and DNA from lung tissue in a subset of 51 controls. We found that telomere length in the blood was significantly longer in α1-antitrypsin deficient COPD patients compared with control COPD patients (p = 1×10(-29)). Telomere length was not related to lung function in α1-antitrypsin deficient patients (p = 0.3122) or in COPD controls (p = 0.1430). Although mean telomere length was significantly shorter in the blood when compared with the lungs (p = 0.0078), telomere length was correlated between the two tissue types (p = 0.0122). Our results indicate that telomere length is better preserved in α1-antitrypsin deficient COPD patients than in non-deficient patients. In addition, measurement of telomere length in the blood may be a suitable surrogate for measurement in the lung.

Genome-wide study of percent emphysema on computed tomography in the general population. The Multi-Ethnic Study of Atherosclerosis Lung/SNP Health Association Resource Study.

RATIONALE: Pulmonary emphysema overlaps partially with spirometrically defined chronic obstructive pulmonary disease and is heritable, with moderately high familial clustering. OBJECTIVES: To complete a genome-wide association study (GWAS) for the percentage of emphysema-like lung on computed tomography in the Multi-Ethnic Study of Atherosclerosis (MESA) Lung/SNP Health Association Resource (SHARe) Study, a large, population-based cohort in the United States. METHODS: We determined percent emphysema and upper-lower lobe ratio in emphysema defined by lung regions less than -950 HU on cardiac scans. Genetic analyses were reported combined across four race/ethnic groups: non-Hispanic white (n = 2,587), African American (n = 2,510), Hispanic (n = 2,113), and Chinese (n = 704) and stratified by race and ethnicity. MEASUREMENTS AND MAIN RESULTS: Among 7,914 participants, we identified regions at genome-wide significance for percent emphysema in or near SNRPF (rs7957346; P = 2.2 × 10(-8)) and PPT2 (rs10947233; P = 3.2 × 10(-8)), both of which replicated in an additional 6,023 individuals of European ancestry. Both single-nucleotide polymorphisms were previously implicated as genes influencing lung function, and analyses including lung function revealed independent associations for percent emphysema. Among Hispanics, we identified a genetic locus for upper-lower lobe ratio near the α-mannosidase-related gene MAN2B1 (rs10411619; P = 1.1 × 10(-9); minor allele frequency [MAF], 4.4%). Among Chinese, we identified single-nucleotide polymorphisms associated with upper-lower lobe ratio near DHX15 (rs7698250; P = 1.8 × 10(-10); MAF, 2.7%) and MGAT5B (rs7221059; P = 2.7 × 10(-8); MAF, 2.6%), which acts on α-linked mannose. Among African Americans, a locus near a third α-mannosidase-related gene, MAN1C1 (rs12130495; P = 9.9 × 10(-6); MAF, 13.3%) was associated with percent emphysema. CONCLUSIONS: Our results suggest that some genes previously identified as influencing lung function are independently associated with emphysema rather than lung function, and that genes related to α-mannosidase may influence risk of emphysema.

Biochemical efficacy and safety of a new, ready-to-use, liquid alpha-1-proteinase inhibitor, GLASSIA (alpha1-proteinase inhibitor (human), intravenous).

Maintaining serum levels of alpha-1-proteinase inhibitor (A1PI) >11 µM by augmentation with plasma-derived human A1PI is currently the only specific therapy available to treat patients with the genetic deficiency of A1PI. In this study, a new, high-purity (≥90% A1PI in monomeric form), ready-to-use, liquid formulation of A1PI-GLASSIA (Kamada, Ness Ziona, Israel) was compared to PROLASTINÆ (Talecris, Research Triangle Park, NC, now Grifols), both commercially available, FDA-approved products. This multicenter, double-blind, randomized controlled trial with partial cross-over was designed to test the non-inferiority and safety of GLASSIA compared to PROLASTIN, assessing both antigenic and functional A1PI trough levels in subject serum. Non-inferiority of GLASSIA to PROLASTIN was demonstrated by remaining within the lower bounds of the confidence intervals (≤3 µM) for both antigenic and functional A1PI. The study concluded that GLASSIA, a new liquid, ready to use, formulation of A1PI, was not inferior to PROLASTIN and it was well tolerated with a safety profile comparable to PROLASTIN.

Human Treg responses allow sustained recombinant adeno-associated virus-mediated transgene expression.

Recombinant adeno-associated virus (rAAV) vectors have shown promise for the treatment of several diseases; however, immune-mediated elimination of transduced cells has been suggested to limit and account for a loss of efficacy. To determine whether rAAV vector expression can persist long term, we administered rAAV vectors expressing normal, M-type α-1 antitrypsin (M-AAT) to AAT-deficient subjects at various doses by multiple i.m. injections. M-specific AAT expression was observed in all subjects in a dose-dependent manner and was sustained for more than 1 year in the absence of immune suppression. Muscle biopsies at 1 year had sustained AAT expression and a reduction of inflammatory cells compared with 3 month biopsies. Deep sequencing of the TCR Vß region from muscle biopsies demonstrated a limited number of T cell clones that emerged at 3 months after vector administration and persisted for 1 year. In situ immunophenotyping revealed a substantial Treg population in muscle biopsy samples containing AAT-expressing myofibers. Approximately 10% of all T cells in muscle were natural Tregs, which were activated in response to AAV capsid. These results suggest that i.m. delivery of rAAV type 1-AAT (rAAV1-AAT) induces a T regulatory response that allows ongoing transgene expression and indicates that immunomodulatory treatments may not be necessary for rAAV-mediated gene therapy.

Alpha-1 antitrypsin augmentation therapy and biomarkers of elastin degradation.

BACKGROUND: Intravenous alpha-1 antitrypsin protein (AAT) augmentation is a prescribed therapy for severe, genetically determined, alpha-1 antitrypsin deficiency (AATD), a genetic basis for pulmonary emphysema. AAT, a predominant systemic inhibitor of neutrophil elastase thus far has not been shown to decrease elastin degradation in a significant number of patients on this therapy. The objective of this study was to compare levels of biomarkers of elastin degradation in plasma, bronchoalveolar lavage (BALF) fluid and urine before and after beginning AAT augmentation therapy in patients with AATD. METHODS: Desmosine and isodesmosine (DI), which occur only in elastin, are amino acid cross-links in mature elastin. Levels of DI in body fluids measure degradation of elastin and can be measured more specifically by mass spectrometry. This method was used to measure DI levels in plasma, bronchoalveolar lavage fluid and urine in cohorts of severe AATD patients on augmentation, not on augmentation and before and after the initiation of augmentation therapy. RESULTS: Statistically significant reductions in plasma DI and in BALF DI were demonstrated in AATD patients receiving intravenous (IV) augmentation therapy as compared with those not receiving it. Administration by aerosol also produced statistically significant reductions in levels of DI in BALF. CONCLUSIONS: Results indicate that the currently prescribed doses of AAT augmentation inhibit neutrophil elastase adequately to reduce elastin degradation, both systemically and in the lung per se. The currently prescribed doses did not reduce elastin degradation to control levels, which may be possible with higher doses.

Development, validation and use of ELISA for antibodies to human alpha-1 antitrypsin.

Evaluation of human antibody responses to alpha-1 antitrypsin (AAT) in clinical trials and clinical practice has been limited by the lack of a validated assay. Here we describe the development and validation of an ELISA method for quantification of human and nonhuman primate antibody responses to human AAT. A reference anti-human AAT serum standard was generated using sera from a cynomolgus macaque injected with a recombinant adeno-associated virus vector expressing human AAT. The ELISA was validated for use with human serum dilutions as low as 1:10 and was able to distinguish between specific responses in cynomolgus serum and non-specific increases in apparent antibody titer in serum from subjects in a clinical trial of an AAT gene therapy vector.

Cytosolic, autocrine alpha-1 proteinase inhibitor (A1PI) inhibits caspase-1 and blocks IL-1ß dependent cytokine release in monocytes.

RATIONALE: Activation state-dependent secretion of alpha-1 proteinase inhibitor (A1PI) by monocytes and macrophages was first reported in 1985. Since then, monocytes and tissue macrophages have emerged as key sentinels of infection and tissue damage via activation of self-assembling pattern recognition receptors (inflammasomes), which trigger inflammation and cell death in a caspase-1 dependent process. These studies examine the relationship between A1PI expression in primary monocytes and monocytic cell lines, and inflammatory cytokine expression in response to inflammasome directed stimuli. METHODS: IL-1 ß expression was examined in lung macrophages expressing wild type A1PI (A1PI-M) or disease-associated Z isoform A1PI (A1PI-Z). Inflammatory cytokine release was evaluated in THP-1 monocytic cells or THP-1 cells lacking the inflammasome adaptor ASC, transfected with expression vectors encoding A1PI-M or A1PI-Z. A1PI-M was localized within monocytes by immunoprecipitation in hypotonic cell fractions. Cell-free titration of A1PI-M was performed against recombinant active caspase-1 in vitro. RESULTS: IL-1 ß expression was elevated in lung macrophages expressing A1PI-Z. Overexpression of A1PI-M in THP-1 monocytes reduced secretion of IL-1ß and TNF-α. In contrast, overexpression of A1PI-Z enhanced IL-1ß and TNF- α secretion in an ASC dependent manner. A1PI-Z-enhanced cytokine release was inhibited by a small molecule caspase-1 inhibitor but not by high levels of exogenous wtA1PI. Cytosolic localization of A1PI-M in monocytes was not diminished with microtubule-inhibiting agents. A1PI-M co-localized with caspase-1 in gel-filtered cytoplasmic THP-1 preparations, and was co-immunoprecipitated with caspase 1 from nigericin-stimulated THP-1 cell lysate. Plasma-derived A1PI inhibited recombinant caspase-1 mediated conversion of a peptide substrate in a dose dependent manner. CONCLUSIONS: Our results suggest that monocyte/macrophage-expressed A1PI-M antagonizes IL-1ß secretion possibly via caspase-1 inhibition, a function which disease-associated A1PI-Z may lack. Therapeutic approaches which limit inflammasome responses in patients with A1PI deficiency, in combination with A1PI augmentation, may provide additional respiratory tissue-sparing benefits.

Liver test results do not identify liver disease in adults with α(1)-antitrypsin deficiency.

BACKGROUND & AIMS: Liver disease is a significant cause of death among adults with α(1)-antitrypsin (A-AT) deficiency. Age and male sex are reported risk factors for liver disease. In the absence of adequate risk stratification, current recommendations are to intermittently test A-AT-deficient adults for liver function. We evaluated this recommendation in a large group of adults with A-AT deficiency to determine the prevalence of increased levels of alanine aminotransferase (ALT) and identify risk factors for liver disease. METHODS: We used the Alpha-1 Foundation DNA and Tissue Bank to identify a cross section of A-AT-deficient adults (n = 647) with and without liver disease; individuals without A-AT deficiency were used as controls (n = 152). Results from ALT tests were compared between groups. RESULTS: The prevalence of liver disease among individuals with A-AT deficiency was 7.9%; an increased level of ALT was observed in 7.8% of A-AT-deficient individuals, which did not differ significantly from controls. Mean levels of ALT fell within normal range for all groups. An increased level of ALT identified patients with liver disease with 11.9% sensitivity. The level of only γ-glutamyl transpeptidase was significantly higher in the A-AT-deficient group than in controls (43 vs 30 IU/mL; P < .003). A childhood history of liver disease and male sex were risk factors for adult liver disease in the multivariate analysis. CONCLUSIONS: An increased level of ALT does not identify adults with A-AT deficiency who have liver disease. Male sex and liver disease during childhood might help identify those at risk.

The prevalence of alpha-1 antitrypsin deficiency among patients found to have airflow obstruction.

INTRODUCTION: Alpha-1 antitrypsin deficiency (AATD) is a genetic disease that may be manifested by chronic obstructive pulmonary disease. Despite professional society guidelines that recommend broad testing of at-risk individuals, fewer than 10% of affected individuals have been identified. The goals of this study were to estimate the frequency of abnormal AAT genotypes among patients found to have fixed airflow obstruction and to assess the feasibility of having Pulmonary Function Laboratory personnel administer the study. METHODS: Nineteen medical centers in the United States participated in the study. Eligible patients (> GOLD II, FEV(1)/FVC ratio < 0.7, with post-bronchodilator FEV(1)<80% predicted) were offered testing for AATD by the Pulmonary Function Laboratory personnel at the time of pulmonary function testing. RESULTS: A total of 3,457 patients were tested, of whom 3152 were eligible. Deficient patients (ZZ, SZ) constituted 0.63% of subjects, while 10.88% were carriers (MS, MZ). Neither demographic (except African-American race) nor post-bronchodilator pulmonary function variables (FEV(1), FVC, FEV(1)/FVC ratio, TLC, and FEV(1)/FVC) allowed us to predict AAT heterozygote or deficiency status. CONCLUSIONS: The prevalence of AATD among patients undergoing pulmonary function tests with fixed airflow obstruction was 0.63%. Pulmonary Function Laboratory personnel effectively conducted the study.

Phase 2 clinical trial of a recombinant adeno-associated viral vector expressing α1-antitrypsin: interim results.

Recombinant adeno-associated virus (rAAV) vectors offer promise for the gene therapy of α(1)-antitrypsin (AAT) deficiency. In our prior trial, an rAAV vector expressing human AAT (rAAV1-CB-hAAT) provided sustained, vector-derived AAT expression for >1 year. In the current phase 2 clinical trial, this same vector, produced by a herpes simplex virus complementation method, was administered to nine AAT-deficient individuals by intramuscular injection at doses of 6.0×10(11), 1.9×10(12), and 6.0×10(12) vector genomes/kg (n=3 subjects/dose). Vector-derived expression of normal (M-type) AAT in serum was dose dependent, peaked on day 30, and persisted for at least 90 days. Vector administration was well tolerated, with only mild injection site reactions and no serious adverse events. Serum creatine kinase was transiently elevated on day 30 in five of six subjects in the two higher dose groups and normalized by day 45. As expected, all subjects developed anti-AAV antibodies and interferon-γ enzyme-linked immunospot responses to AAV peptides, and no subjects developed antibodies to AAT. One subject in the mid-dose group developed T cell responses to a single AAT peptide unassociated with any clinical effects. Muscle biopsies obtained on day 90 showed strong immunostaining for AAT and moderate to marked inflammatory cell infiltrates composed primarily of CD3-reactive T lymphocytes that were primarily of the CD8(+) subtype. These results support the feasibility and safety of AAV gene therapy for AAT deficiency, and indicate that serum levels of vector-derived normal human AAT >20 µg/ml can be achieved. However, further improvements in the design or delivery of rAAV-AAT vectors will be required to achieve therapeutic target serum AAT concentrations.

Alpha1-antitrypsin deficiency-related alleles Z and S and the risk of Wegener's granulomatosis.

OBJECTIVE: Deficiency of α(1) -antitrypsin (α(1) AT) may be a determinant of susceptibility to Wegener's granulomatosis (WG). Several previous, mainly small, case-control studies have shown that 5-27% of patients with WG carried the α(1) AT deficiency Z allele. It is not clear whether the S allele, the other major α(1) AT deficiency variant, is associated with WG. This study investigated the relationship of the α(1) AT deficiency Z and S alleles with the risk of developing WG in a large cohort. METHODS: We studied the distribution of the α(1) AT deficiency alleles Z and S in 433 unrelated Caucasian patients with WG and 421 ethnically matched controls. Genotyping was performed using an allele discrimination assay. Results were compared between cases and controls using exact statistical methods. RESULTS: Among the patients with WG, the allele carriage frequencies of Z and S were 7.4% and 11.5%, respectively. The frequencies of the 6 possible genotypes differed in a statistically significant manner between cases and controls (P = 0.01). The general genetic 2-parameter codominant model provided the best fit to the data. Compared with the normal MM genotype, the odds ratio (OR) for MZ or MS genotypes was 1.47 (95% confidence interval [95% CI] 0.98-2.22), and the OR for ZZ, SS, or SZ genotypes was 14.58 (95% CI 2.33-∞). ORs of similar direction and magnitude were observed within the restricted cohorts that excluded cases and controls carrying ≥1 Z or ≥1 S allele. CONCLUSION: Both Z and S alleles display associations with risk of WG in a codominant genetic pattern. These findings strengthen the evidence of a causal link between α(1) AT deficiency and susceptibility to WG.

Is PiSS Alpha-1 Antitrypsin Deficiency Associated with Disease?

Background. Alpha-1 antitrypsin deficiency (AAT) is an inherited condition that predisposes to lung and/or liver disease. Objective. The current study examined the clinical features of the PiSS genotype. Methods. Nineteen study participants (PiSS) and 29 matched control participants (PiMM) were telephone interviewed using a standardized questionnaire. Demographic features, cigarette smoking, vocation, medication history, and clinical diagnoses were compared. Statistical analysis was performed. Finally, a comprehensive literature review was performed by two investigators. Results. 12/19 (63.2%) study participants reported the presence of lung and/or liver disease compared to 12/29 (41.4%) control participants. There trended toward having a higher frequency of medication allergies in the study population (42.11% versus 20.69%). Conclusions. The PiSS genotype was associated with a similar incidence of obstructive lung disease to controls. Selective bias intrinsic in testing for AAT deficiency and the rarity of the PiSS genotype will make future study of this association dependent on population-based tests.

Alveolar macrophage dysregulation in Hermansky-Pudlak syndrome type 1.

RATIONALE: Individuals with Hermansky-Pudlak syndrome type 1 (HPS-1), an autosomal recessive disorder characterized by defective biogenesis of lysosome-related organelles, develop an accelerated form of progressive fibrotic lung disease. The etiology of pulmonary fibrosis associated with HPS-1 is unknown. OBJECTIVES: To investigate the potential pathogenesis of pulmonary fibrosis in HPS-1, lung cells and proteins from individuals with HPS-1 were studied. METHODS: Forty-one subjects with HPS-1 with and without pulmonary fibrosis were evaluated with pulmonary function tests, high-resolution computed tomography scan, and bronchoscopy. Bronchoalveolar lavage cells and analytes were analyzed. MEASUREMENTS AND MAIN RESULTS: Concentrations of total bronchoalveolar lavage cells and alveolar macrophages were significantly higher in epithelial lining fluid from subjects with HPS-1 with and without pulmonary fibrosis compared with healthy research volunteers. Concentrations of cytokines and chemokines (i.e., monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, and granulocyte-macrophage colony-stimulating factor) in alveolar epithelial lining fluid were significantly higher in subjects with HPS-1 with and without pulmonary fibrosis compared with healthy research volunteers (P < 0.001). In vitro, HPS-1 pulmonary fibrosis alveolar macrophages, which did not express HPS1 mRNA, secreted significantly higher concentrations of monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, and regulated upon activation, normal T cell expressed and secreted (RANTES) protein compared with normal cells (P = 0.001, P = 0.014, and P = 0.011, respectively). Pirfenidone suppressed HPS-1 alveolar macrophage cytokine and chemokine secretion in vitro in a dose-dependent manner. CONCLUSIONS: In HPS-1, alveolar inflammation predominantly involves macrophages and is associated with high lung concentrations of cytokines and chemokines. HPS-1 alveolar macrophages provide a model system in which to study the pathogenesis and treatment of HPS pulmonary fibrosis.

Sustained transgene expression despite T lymphocyte responses in a clinical trial of rAAV1-AAT gene therapy.

Alpha-1 antitrypsin (AAT) deficiency is well-suited as a target for human gene transfer. We performed a phase 1, open-label, dose-escalation clinical trial of a recombinant adeno-associated virus (rAAV) vector expressing normal (M) AAT packaged into serotype 1 AAV capsids delivered by i.m. injection. Nine AAT-deficient subjects were enrolled sequentially in cohorts of 3 each at doses of 6.9 x 10(12), 2.2 x 10(13), and 6.0 x 10(13) vector genome particles per patient. Four subjects receiving AAT protein augmentation discontinued therapy 28 or 56 days before vector administration. Vector administration was well tolerated, with only mild local reactions and 1 unrelated serious adverse event (bacterial epididymitis). There were no changes in hematology or clinical chemistry parameters. M-specific AAT was expressed above background in all subjects in cohorts 2 and 3 and was sustained at levels 0.1% of normal for at least 1 year in the highest dosage level cohort, despite development of neutralizing antibody and IFN-gamma enzyme-linked immunospot responses to AAV1 capsid at day 14 in all subjects. These findings suggest that immune responses to AAV capsid that develop after i.m. injection of a serotype 1 rAAV vector expressing AAT do not completely eliminate transduced cells in this context.