sRAGE levels are decreased in plasma and sputum of COPD secondary to biomass-burning smoke and tobacco smoking: Differences according to the rs3134940 AGER variant.

The receptor for advanced glycation end products (RAGE) and its gene (AGER) have been related to lung injury and inflammatory diseases, including chronic obstructive pulmonary disease (COPD). We aimed to evaluate the association of rs2071288, rs3134940, rs184003, and rs2070600 AGER single-nucleotide variants and the soluble-RAGE plasma and sputum levels with COPD secondary to biomass-burning smoke (BBS) and tobacco smoking. Four groups, including 2189 subjects, were analyzed: COPD secondary to BBS exposure (COPD-BBS, n = 342), BBS-exposed subjects without COPD (BBES, n = 774), tobacco smoking-induced COPD (COPD-TS, n = 434), and smokers without COPD (SWOC, n = 639). Allelic discrimination assays determined the AGER variants. The sRAGE was quantified in plasma (n = 240) and induced-sputum (n = 72) samples from a subgroup of patients using the ELISA technique. In addition, a meta-analysis was performed for the association of rs2070600 with COPD susceptibility. None of the studied genetic variants were found to be associated with COPD-BBS or COPD-TS. A marginal association was observed for the rs3134940 with COPD-BBS (p = 0.066). The results from the meta-analysis, including six case-control studies (n = 4149 subjects), showed a lack of association of rs2070600 with COPD susceptibility (p = 0.681), probably due to interethnic differences. The sRAGE plasma levels were lower in COPD-BBS compared to BBS and in COPD-TS compared to SWOC. The sRAGE levels were also lower in sputum samples from COPD-BBS than BBES. Subjects with rs3134940-TC genotypes exhibit lower sRAGE plasma levels than TT subjects, mainly from the COPD-BBS and SWOC groups. The AGER variants were not associated with COPD-BBS nor COPD-TS, but the sRAGE plasma and sputum levels are related to both COPD-BBS and COPD-TS and are influenced by the rs3134940 variant.

The rs16969968 Tobacco Smoking-Related Single-Nucleotide Variant Is Associated with Clinical Markers in Patients with Severe COVID-19.

Tobacco smoking is the leading risk factor for many respiratory diseases. Several genes are associated with nicotine addiction, such as CHRNA5 and ADAM33. This research aims to evaluate the association of the polymorphisms rs16969968 (CHRNA5) and rs3918396 (ADAM33) in patients who developed severe COVID-19. We included 917 COVID-19 patients hospitalized with critical disease and oxygenation impairment. They were divided into two groups, tobacco-smoking (n = 257) and non-smoker (n = 660) patients. The genotype and allele frequencies of two single nucleotide variants, the rs16969968 (CHRNA5) and rs3918396 (ADAM33), were evaluated. The rs3918396 in ADAM33 does not show a significative association. We analyzed the study population according to the rs16969968 genotype (GA + AA, n = 180, and GG, n = 737). The erythrocyte sedimentation rate (ESR) shows statistical differences; the GA + AA group had higher values than the GG group (p = 0.038, 32 vs. 26 mm/h, respectively). The smoking patients and GA or AA genotype carriers had a high positive correlation (p < 0.001, rho = 0.753) between fibrinogen and C-reactive protein. COVID-19 patients and smokers carriers of one or two copies of the risk allele (rs16969968/A) have high ESR and a positive correlation between fibrinogen and C-reactive protein.

The ACE rs1799752 Variant Is Associated with COVID-19 Severity but Is Independent of Serum ACE Activity in Hospitalized and Recovered Patients.

This paper assesses the association of the insertion/deletion ACE (angiotensin-converting enzyme) variant (rs1799752 I/D) and the serum ACE activity with the severity of COVID-19 as well as its impact on post-COVID-19, and we compare these associations with those for patients with non-COVID-19 respiratory disorders. We studied 1252 patients with COVID-19, 104 subjects recovered from COVID-19, and 74 patients hospitalized with a respiratory disease different from COVID-19. The rs1799752 ACE variant was assessed using TaqMan® Assays. The serum ACE activity was determined using a colorimetric assay. The DD genotype was related to risk for invasive mechanical ventilation (IMV) requirement as an indicator of COVID-19 severity when compared to the frequencies of II + ID genotypes (p = 0.025, OR = 1.428, 95% CI = 1.046-1.949). In addition, this genotype was significantly higher in COVID-19 and post-COVID-19 groups than in the non-COVID-19 subjects. The serum ACE activity levels were lower in the COVID-19 group (22.30 U/L (13.84-32.23 U/L)), which was followed by the non-COVID-19 (27.94 U/L (20.32-53.36 U/L)) and post-COVID-19 subjects (50.00 U/L (42.16-62.25 U/L)). The DD genotype of the rs1799752 ACE variant was associated with the IMV requirement in patients with COVID-19, and low serum ACE activity levels could be related to patients with severe disease.

COVID-19 Survivor Patients Carrying the Rs35705950 Risk Allele in MUC5B Have Higher Plasma Levels of Mucin 5B.

BACKGROUND: Genetic susceptibility to infectious diseases is partly due to the variation in the human genome, and COVID-19 is not the exception. This study aimed to identify whether risk alleles of known genes linked with emphysema (SERPINA1) and pulmonary fibrosis (MUC5B) are associated with severe COVID-19, and whether plasma mucin 5B differs according to patients' outcomes. MATERIALS AND METHODS: We included 1258 Mexican subjects diagnosed with COVID-19. We genotyped rs2892474 and rs17580 of the SERPINA1 gene and rs35705950 of MUC5B. Based on the rs35705950 genotypes, mucin 5B plasma protein levels were quantified. RESULTS: Homozygous for the risk alleles of the three polymorphisms were found in less than 5% of the study population, but no statistically significant difference in the genotype or allele association analysis. At the protein level, non-survivors carrying one or two copies of the risk allele rs35705950 in MUC5B (GT + TT) had lower levels of mucin 5B compared to the survivors (0.0 vs. 0.17 ng/mL, p = 0.0013). CONCLUSION: The polymorphisms rs28929474 and rs17580 of SERPINA1 and rs35705950 of MUC5B are not associated with the risk of severe COVID-19 in the Mexican population. COVID-19 survivor patients bearing one or two copies of the rs35705950 risk allele have higher plasma levels of mucin 5B.