Genetic polymorphisms of IL6 gene -174G > C and -597G > A are associated with the risk of COVID-19 severity

Association between polymorphisms in TLR3, TICAM1 and IFNA1 genes and covid-19 severity in Southern Brazil

BACKGROUND

A distinct phenotype in Coronavirus disease 2019 (Covid-19) was observed in severe patients, consisting of a highly impaired interferon (IFN) type I response, an exacerbated inflammatory response.

OBJECTIVE

The aim of the present study was to investigate a possible association of single nucleotide polymorphisms (SNPs), in five genes related to the immune response, rs3775291 in TLR3; rs2292151 in TICAM1; rs1758566 in IFNA1; rs1800629 in TNF, and rs1800795 in IL6 with the severity of Covid-19.

METHODS

A cross-sectional study was performed, with non-severe and severe/critical patients diagnosed with Covid-19, by two public hospitals in Brazil. In total, 300 patients were genotyped for the SNPs, 150 with the non-severe form of the disease and 150 with severe/critical form.

RESULTS

The T/T genotype of TLR3 in recessive model shows 58% of protection against severe/critical Covid-19; as well as the genotypes G/A+A/A of TICAM1 in dominant model with 60% of protection, and in a codominant model G/A with 57% and A/A with 71% of protection against severe/critical Covid-19. Comparing severe and critical cases, the T/C genotype of IFNA1 in the codominant model and TC+C/C in the dominant model showed twice the risk of critical Covid-19.

CONCLUSION

We can conclude that rs3775291, rs2292151 and rs1758566 can influence the COVID-19 severity.

The Interleukin-6 gene variants may protect against SARS-CoV-2 infection and the severity of COVID-19: a case-control study in a Moroccan population

The symptoms of SARS-CoV-2 infection vary widely, ranging from asymptomatic cases to severe forms marked by acute respiratory distress syndrome, multi-organ damage, and fatalities. Studies indicate a correlation between specific genes and susceptibility to SARS-CoV-2 infection and disease severity, particularly involving variants in genes linked to inflammation and immune responses. The objective of this study is to investigate the association between rs1800795 (- 174 G > C) and rs1800797 (- 597 A > G) variants in the interleukin-6 (IL-6) promoter region and susceptibility to SARS-CoV-2 infection. Additionally, we aim to explore their correlation with COVID-19 severity in a Moroccan population. In this case-control study, we enrolled 270 unvaccinated COVID-19 patients, consisting of 132 with severe COVID-19 and 138 with asymptomatic-moderate COVID-19. Additionally, we included 339 SARS-CoV-2-negative group. Genotyping of rs1800795 and rs1800797 polymorphisms of the IL-6 gene was performed using predesigned TaqMan SNP genotyping. The median age of SARS-CoV-2-negative controls was 50 years, while severe COVID-19 cases exhibited a median age of 61 years. Additionally, individuals with asymptomatic to moderate COVID-19 had a median age of 36 years. We observed a significant age difference between severe and mild COVID-19 patients (p < 0.0001), and an association was noted between gender and the severity of COVID-19 (p = 0.011). The allele and genotype frequencies of the IL-6 - 597G > A and - 174G > C variants did not show significant associations with susceptibility to SARS-CoV-2 infection (p > 0.05). However, further analysis revealed that the linkage disequilibrium between rs1800797 and rs1800795 indicated that individuals with the GC* haplotype (OR = 0.04, 95% CI 0.01-0.30, p = 0.001) and AG* haplotype (OR = 0.11, 95% CI 0.03-0.46, p = 0.002) were significantly associated with protection against SARS-CoV-2 infection. Moreover, in the overdominant model, the IL-6 - 174 G/C genotype was found to be protective against the development of severe disease compared to those with the G/G-C/C genotypes (p = 0.03; OR = 0.41, 95% CI 0.18-0.96). However, correlations between complete blood count markers, hematological markers, D-dimer, C-reactive protein, and ferritin levels according to - 597 A > G and - 174G > C genotypes showed no significant differences (all p > 0.05). Our findings provide valuable insights into the pathogenesis of COVID-19, suggesting that genetic variations at the IL-6 gene may contribute to the susceptibility to severe SARS-CoV-2 infection within the Moroccan population.

Association of genetic polymorphisms with COVID-19 infection and outcomes: An updated meta-analysis based on 62 studies

Background

The relationship between genetic polymorphisms and coronavirus disease 2019 (COVID-19) remains to be inconsistent. This meta-analysis aimed to provide an updated evaluation of the role of genetic polymorphisms in the infection, severity and mortality of COVID-19 based on all available published studies.

Methods

A systematic search was performed using six databases: PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang. Summary odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to calculate the genotypic comparison. All statistical analyses were conducted in Stata 12.0.

Results

A total of 62 studies with 19600 cases and 28899 controls was included in this meta-analysis. For COVID-19 infection, ACE Ins/Del polymorphism might be related with significantly decreased risk of COVID-19 infection under dominant, homozygote and allelic models. Meanwhile, the IFITM3 rs12252 and TMPRSS2 rs12329760 polymorphisms were significantly associated with the increased risk of COVID-19 infection under one or more models. Regarding COVID-19 severity, ACE2 rs2074192, ACE2 rs2106809, IFITM3 rs12252 and VDR rs1544410 polymorphisms might be related with significantly increased risk of COVID-19 severity in one or more models. Moreover, the analysis of TMPRSS2 rs2070788 indicated that a variant A allele decreased the risk of COVID-19 severity in recessive model. For COVID-19 mortality, the variant C allele of IFITM3 rs12252 polymorphism might be related with significantly increased risk of COVID-19 mortality under all genetic models.

Conclusions

This meta-analysis indicated that he infection, severity or mortality of COVID-19 were related to the above genetic polymorphisms, which might provide an important theoretical basis for understanding the clinical feature of COVID-19 disease.

Influence of polymorphic variations of IFNL, HLA, and IL-6 genes in severe cases of COVID-19

The administration of vaccination doses to the global population has led to a decrease in the incidence of COVID-19. However, the clinical picture developed by infected individuals remains extremely concerning due to the great variability in the severity of cases even in vaccinated individuals. The clinical progression of the pathology is characterized by various influential factors such as sex, age group, comorbidities, and the genetics of the individual. The immune response to viral infections can be strongly influenced by the genetics of individuals; nucleotide variations called single-nucleotide polymorphisms (SNPs) in structures involved in the innate and adaptive immune response such as interferon (IFN)-λ, human leukocyte antigen (HLA), and interleukin (IL)-6 are frequently associated with pathological progression. In this study, we conducted a review of the main SNPs of these structures that are associated with severity in COVID-19. Searches were conducted on some platforms of the National Center for Biotechnology and Information (NCBI), and 102 studies were selected for full reading according to the inclusion criteria. IFNs showed a strong association with antiviral function, specifically, IFN-λ3 (IL-28B) demonstrated genetic variants commonly related to clinical progression in various pathologies. For COVID-19, rs12979860 and rs1298275 presented frequently described unfavorable genotypes for pathological conditions of hepatitis C and hepatocellular carcinoma. The high genetic variability of HLA was reported in the studies as a crucial factor relevant to the late immune response, mainly due to its ability to recognize antigens, with the HLA-B*46:01 SNP being associated with susceptibility to COVID-19. For IL-6, rs1554606 showed a strong relationship with the clinical progression of COVID-19. In addition, rs2069837 was identified with possible host protection relationships when linked to this infection.

Evaluation of IL-6 and IL-17A gene polymorphisms in Iraqi patients infected with COVID-19 and type 2 diabetes mellitus

BACKGROUND

In patients with COVID-19, diabetes mellitus type 2 (T2DM) increases the risk of hospitalization and death. Patients who have IL-6 and IL-17A single nucleotide polymorphisms (SNPs) are more likely to have severe COVID-19. This study aims to determine whether SNPs of the IL-6 gene at rs1800795 (G > C) and the IL-17A gene at rs2275913 (G > A) are associated with COVID-19 and T2DM in the Iraqi population.

PATIENTS AND METHODS

Twenty-four people were divided into 4 groups as follows: six patients with severe COVID-19 and T2DM were placed in Group 1 as "G1", six patients with COVID-19 but no T2DM were placed in Group 2 as "G2", and six patients with T2DM were placed in Group 3 as "G3". There were also six healthy controls included in each group. Polymerase chain reaction (PCR) was used to amplify the target genes after genomic DNA from the blood samples was extracted. Sanger sequencing was used to find the SNPs in both the forward and reverse directions for each sample.

RESULTS

In the case of IL-6 SNP at rs1800795, the GG genotype was more common in "G3", the CC genotype was less common in all patient groups than in controls, and the GC allele was more common in "G2" than in the control group. In comparison to the controls, the three patient groups showed lower frequencies of the C allele and higher frequencies of the G allele. Regarding IL-17A gene polymorphism, the AA and GA genotypes were more prevalent in "G2" and "G3", respectively. The GG genotype and G allele frequency dropped in all patient groups compared to the control group, whereas the A allele frequency increased in all patient groups.

CONCLUSIONS

The IL-6 gene at rs1800795 (G/C) and the IL-17A gene at rs2275913 (G/A) loci were associated with COVID-19 and T2DM in Iraqi population.