Association of angiotensin-converting enzyme gene I/D polymorphism with chronic obstructive pulmonary disease: a meta-analysis

Angiotensin-converting enzyme 1 gene polymorphisms in patients with systemic sclerosis-associated interstitial lung disease: a single centre retrospective observational study

Angiotensin-converting enzyme (ACE) 1 gene polymorphisms have been associated with vascular permeability, alveolar endothelial dysfunction and fibroblast proliferation and have been studied in pulmonary diseases such as COPD and idiopathic pulmonary fibrosis. Similar mechanisms of ACE 1 polymorphisms have been seen in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD). We are presenting a retrospective observational study in patients with SSc-ILD and analysing the association of ACE 1 gene polymorphisms (DD, II and ID) with the features of SSc, changes in pulmonary function tests (PFTs) and lung HRCT over three different periods of time (at the time of the diagnosis, 5 and 10 years after the diagnosis). The aim of the study was to determine whether ACE 1 gene polymorphisms have an effect on the severity of SSc-ILD. We found no statistically significant differences in the development and severity of SSc-ILD and changes in PFTs between subgroups of ACE 1 gene polymorphism over the analysed periods (at the time of diagnosis HRCT changes p = 0.270, FEV1 p = 0.483, FVC p = 0.497, DLco p = 0.807, after 5 years HRCT changes p = 0.163, FEV1 p = 0.551, FVC p = 0.362, DLco p = 0.620 and 10 years of follow-up HRCT changes p = 0.853, FEV1 p = 0.589, FVC p = 0.328, DLco p = 0.992). However, patients with the ID genotype showed a significant reduction in FEV1 after 10 years of follow-up in comparison to baseline levels (91.0 (IR 80.0-105.0) at the time of diagnosis and 84.0 (IR 69.0-99.0) after 10 years, p = 0.014). Our study suggests that ACE 1 gene polymorphisms do not have a role in the severity of SSc-ILD. Further studies are needed to explain the exact role of ACE 1 gene polymorphisms in SSc-ILD and SSc in general.

Association of RAGE gene multiple variants with the risk for COPD and asthma in northern Han Chinese

Clinical and experimental data have shown that the receptor for advanced glycation end products (RAGE) is implicated in the pathogenesis of respiratory disorders. In this study, we genotyped five widely-evaluated variants in RAGE gene, aiming to assess their association with the risk for chronic obstructive pulmonary disease (COPD) and asthma in northern Han Chinese. Genotypes were determined in 105 COPD patients, 242 asthma patients and 527 controls. In single-locus analysis, there was significant difference in the genotype distributions of rs1800624 between COPD patients and controls (p=0.022), and the genotype and allele distributions of rs1800625 differed significantly (p=0.040 and 0.016) between asthma patients and controls. Haplotype analysis revealed that haplotype T-A-G-T (allele order: rs1800625, rs1800624, rs2070600, rs184003) was significantly associated with a reduced COPD risk (OR=0.32, 95% CI: 0.06-0.60), and haplotype T-A-A-G was significantly associated with a reduced asthma risk (OR=0.19, 95% CI: 0.04-0.96). Further haplotype-phenotype analysis showed that high- and low-density lipoprotein cholesterol and blood urea nitrogen were significant mediators for COPD (p_sim=0.041, 0.043 and 0.030, respectively), and total cholesterol was a significant mediator for asthma (p_sim=0.009). Taken together, our findings indicate that RAGE gene is a promising candidate for COPD and asthma, and importantly both disorders are genetically heterogeneous.

Analysis of Angiotensin Converting Enzyme, Endothelial Nitric Oxide Synthase & Serotonin Gene Polymorphisms among Atrial Septal Defect Subjects with and without Pulmonary Arterial Hypertension

Genetic polymorphisms are variations in DNA sequences which can influence either disease susceptibility, severity, or prognosis. Pulmonary arterial hypertension (PAH) is one of the complications that occurs in certain patients who have atrial septal defect (ASD). This study seeks to determine the association of gene polymorphisms with the pathogenesis of PAH in ASD patients. This study was conducted on 30 ASD patients with PAH, and 50 ASD patients who were not diagnosed with PAH. All respondents were Malay. Patients were selected based on stringent inclusion and exclusion criteria. Molecular analyses were done to detect the genetic polymorphisms of angiotensin converting enzyme (ACE I/D), serotonin transporter (5-HTTLPR), endothelial nitric oxide synthase (eNOS) G894T, and eNOS 4b/4a. The genotypes of these genetic polymorphisms were determined using conventional PCR and PCR-RFLP methods. The PCR products were analysed using agarose gel electrophoresis. Statistical analysis was done using SPSS Version 22. Clinical characteristics, such as the diameter of ASD, mean arterial pressure (MAP), and mean pulmonary artery pressure (mPAP) differed significantly (p < 0.05). Based on the statistical analysis, ACE I/D, eNOS G894T, and eNOS 4b/4a do not contribute to the progression of PAH amongst ASD patients (p > 0.05). However, the L allele of the 5-HTTLPR gene polymorphism may have an affect on the development of PAH in ASD patients (p < 0.05).