Alpha-antitrypsin genotypes in Korean patients with chronic obstructive pulmonary disease

Application of the Lancet Commission COPD classification to COPD Cohort Population in South Korea

The Lancet Commissions on COPD recommended a new classification based on five main risk factors. Patients with COPD were prospectively enrolled in a Korean COPD subgroup study cohort between April 2012 and June 2022. Patients were classified according to the etiologies (Type 1: Genetically determined (COPD-G), Type 2: Abnormal lung development (COPD-D), Type 3: Infections (COPD-I), Type 4: Cigarette smoking (COPD-C), Type 5: Biomass and pollution (COPD-P)). The database enrolled 3476 patients. Among 3392 patients, 52 (2 %), 1339 (39 %), 2930 (86 %), and 2221 (65 %) were compatible with type 2 (COPD-D), 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Most patients (71 %, 2405) had multiple risk factors contributing to their COPD. However, 93, 712, and 182 patients had only type 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Type 3 (COPD-I) only patients were significantly younger, more often female, and had lower lung function. Both the rate and frequency of severe exacerbations were significantly higher in type 3 (COPD-I) only patients (p = 0.038 and p = 0.048, respectively). Compared with type 5 (COPD-P) only, type 3 (COPD-I) only was significantly associated with the risk of severe exacerbation (Odds ratio, 5.7 [95 % CI, 1.0-32.4]; P = 0.049, incident rate ratio, 8.7 [95 % CI, 1.7-44.0]; P = 0.009). Many patients were affected by multiple factors. Therefore, it is important to consider not only smoking history, but also other potential risk factors when evaluating patients with COPD. Further research is needed to explore the implications of this new COPD classification system for clinical practice and treatment strategies.

Alpha-1 antitrypsin deficiency in Iranian patients with chronic obstructive pulmonary disease

Background

Alpha-1 antitrypsin deficiency is a genetic disease which affects both lung and liver. This disease is a recognized factor for chronic obstructive pulmonary disease (COPD). However its importance as the cause of COPD in a country such as Iran is unclear.

Objectives

This study was conducted to find out the role of α-1 antitrypsin deficiency as a cause of COPD in Iranian patients.

Materials and Methods

The serum concentration of α-1 antitrypsin was determined and the genotype of α-1 antitrypsin was also evaluated by PCR-RFLP in 130 patients with COPD and 50 normal healthy blood donors.

Results

No α-1 antitrypsin deficient case was found in normal healthy people and COPD patients.

Conclusions

Our results clarify that deficiency of α-antitrypsin is not a major cause of COPD in Iranian patients.

A rare variant of α 1 antitrypsin mutations detected in Vietnamese children with liver disease

BACKGROUND

Alpha 1 antitrypsin (A1AT) is the major plasma serine protease inhibitor that is produced in liver cells. A1AT deficiency is recognized globally as a common genetic cause of liver disease in children, which results from mutations in the SERine Protease INhibitor A1 (SERPINA1) gene. The importance of A1AT deficiency in Viet Nam is unclear. The aim of this study was to determine the A1AT variants present in paediatric patients with liver diseases in order to clarify whether A1AT deficiency is present in Viet Nam.

METHODS

A1AT studies were carried out in 130 children with liver disease of indeterminate aetiology. A1AT levels were determined by immunoturbidimetry. Phenotype analysis of A1AT was performed by isoelectric focusing (IEF) in all patients. Genotype analyses to determine A1AT mutations were performed by direct sequencing.

RESULTS

We identified a rare variant of A1AT named Zbristol. The Zbristol appeared to be deficient in the plasma to about the same degree as the PI S protein resulting in low concentration of A1AT in one of these two Vietnamese patients. No other deficient A1AT allele was detected, although 11 patients (8.5%) showed a reduced serum concentration of A1AT.

CONCLUSIONS

These are the first two cases of a rare A1AT deficiency allele to be found in Viet Nam clearly inferring that A1AT deficiency is not just a disease of Caucasians. As such, the laboratory diagnosis of A1AT deficiency including A1AT concentration determination and phenotype and genotype testing should form part of the routine differential diagnosis of paediatric liver disease of indeterminate aetiology in Vietnamese patients.

Updates on the COPD gene list

A genetic contribution to develop chronic obstructive pulmonary disease (COPD) is well established. However, the specific genes responsible for enhanced risk or host differences in susceptibility to smoke exposure remain poorly understood. The goal of this review is to provide a comprehensive literature overview on the genetics of COPD, highlight the most promising findings during the last few years, and ultimately provide an updated COPD gene list. Candidate gene studies on COPD and related phenotypes indexed in PubMed before January 5, 2012 are tabulated. An exhaustive list of publications for any given gene was looked for. This well-documented COPD candidate-gene list is expected to serve many purposes for future replication studies and meta-analyses as well as for reanalyzing collected genomic data in the field. In addition, this review summarizes recent genetic loci identified by genome-wide association studies on COPD, lung function, and related complications. Assembling resources, integrative genomic approaches, and large sample sizes of well-phenotyped subjects is part of the path forward to elucidate the genetic basis of this debilitating disease.

Combinatorial effect of TIMP-1 and α1AT gene polymorphisms on development of chronic obstructive pulmonary disease

OBJECTIVE

To study the role of α(1)AT and TIMP-1 gene polymorphisms in development of COPD.

DESIGN AND METHODS

Blood samples from total 408 subjects (217 COPD patients and 191 controls) were used for genotyping and estimating biolevels of α(1)AT, TIMP-1 and inflammatory cytokines. Data was analyzed to determine the role of interaction of TIMP-1 and α(1)AT genes; and interplay between various genotypes and biolevels of α(1)AT, TIMP-1 and inflammatory cytokines in development of COPD.

RESULTS

Significantly low levels of α(1)AT and TIMP-1 were observed in COPD patients as compared to controls (P = 0.001), where as the inflammatory cytokines were found to be increased in patients. PIM3 allele of α(1)AT gene in COPD patients was found to be associated with low levels of α(1)AT (P = 0.001), the effect being more pronounced when PIM3 combined with rs6609533 of TIMP-1 gene (P = 0.0001). Combination of genotypes rs6609533 of TIMP-1 and PIM3 of α(1)AT containing the risk alleles was over-represented in patients (P = 0.005).

CONCLUSION

The SNP rs6609533 of TIMP-1 gene interacted with PIM3 of α(1)AT to make a possible risk combination for development of COPD.

Slope of emphysema index: an objective descriptor of regional heterogeneity of emphysema and an independent determinant of pulmonary function

OBJECTIVE

The purpose of this study was to compare quantitative and visual assessments of regional heterogeneity of emphysema and to investigate the influence of regional heterogeneity on pulmonary function in smoking-related emphysema.

MATERIALS AND METHODS

We developed an automatic computerized algorithm to quantitatively assess heterogeneity in the upper-lower, anterior-posterior, and central-peripheral directions. The emphysema index was plotted with a linear function (emphysema index slopes: slope of emphysema index in upper-lower direction, slope of emphysema index in anterior-posterior direction, and slope of emphysema index in central-peripheral direction) for consecutive 1-pixel-thick slices using volumetric CT data of 59 patients (58 men and one woman; mean age, 65.7 years). Emphysema index was defined as the percentage area of lung with attenuation values below -950 HU. Visual assessment was performed using a 5-point scoring system. Quantitative and visual assessments were compared. Multiple linear regression was performed to evaluate the influence of emphysema index and emphysema index slopes on the pulmonary function test.

RESULTS

Quantitative and visual assessments were significantly correlated in both upper-lower (r(2) = 0.40 and r(2) = 0.67 for observers 1 and 2, respectively) and central-peripheral (r(2) = 0.51 and r(2) = 0.47, respectively) directions. Multiple linear regression revealed that emphysema index, slope of emphysema index in upper-lower direction, and slope of emphysema index in anterior-posterior direction were independent determinants of forced expiratory volume in 1 second (FEV(1)) (r(2) = 0.30; p < 0.001). Emphysema index and slope of emphysema index in upper-lower direction were independent determinants of the ratio of FEV(1) to forced vital capacity (FEV(1)/FVC) (r(2) = 0.32; p < 0.001). In addition to higher emphysema index, lower and posterior lung dominance was associated with a decrease in FEV(1) and FEV(1)/FVC.

CONCLUSION

Computerized, quantitative assessment using the emphysema index slope is comparable to visual assessment in the evaluation of regional heterogeneity of emphysema. In addition to the emphysema index, regional heterogeneity of smoking-related emphysema contributes to impairment of pulmonary function.

Alpha-1 antitrypsin gene polymorphism in Chronic Obstructive Pulmonary Disease (COPD)

Alpha-1-antitrypsin (AAT) plays an important role in the pathogenesis of emphysema, the pathological lesion underlying the majority of the manifestations of Chronic Obstructive Pulmonary Disease (COPD). In this study we tested the hypothesis that common AAT polymorphisms influence the risk of developing COPDs. We investigated PiM1 (Ala213Val), PiM2 (Arg101His), PiM3 (Glu376Asp), PiS (Glu264Val) and PiZ (Glu342Lys) SERPINA1 alleles in 100 COPD patients and 200 healthy controls. No significant differences were observed in allele frequencies between COPD patients and controls, neither did haplotype analysis show significant differences between the two groups. A cross-sectional study revealed no significant relationship between common SERPINA1 polymorphisms (PiM1, PiM2, PiM3) and the emphysematous type of COPD. In addition, FEV(1) annual decline, determined during a two-year follow up period, revealed no difference among carriers of the tested polymorphisms.