Determination of IL-1B (rs16944) and IL-6 (rs1800796) genetic polymorphisms in IgA nephropathy in a northwest Chinese Han population

Interleukin Variants Are Associated with the Development and Progression of IgA Nephropathy: A Candidate-Gene Association Study and Meta-Analysis

The interleukin-1 gene cluster encodes cytokines, which modulate mesangial cell proliferation and matrix expansion, both constituting central factors in the development and progression of immunoglobulin A nephropathy (IgAN). A candidate-gene study was performed to examine the association of polymorphisms of the interleukin-1 gene cluster with the risk of progressive IgAN. To gain deeper insights into the involvement of interleukin genes in IgAN, a meta-analysis of genetic association studies (GAS) that examine the association between interleukin variants and IgAN was conducted. Association study: The case-control study consisted of 121 unrelated Caucasians with sporadic, histologically diagnosed IgAN and of 246 age- and sex-matched healthy controls. Persistent proteinuria (>2 g/24 h) and/or impaired kidney function (serum creatinine > 1.5 mg/dL) defined progressive (n = 67) vs. non-progressive (n = 54) IgAN cases. Genotypes were assessed for two promoter-region single-nucleotide polymorphisms, C-899T (rs1800587) in IL1A and C-511T (rs16944) in IL1B, and for one penta-allelic variable-length tandem repeat polymorphism (VNTR 86 bp intron 2) in IL1RN. The association of these variants with the susceptibility of IgAN and the development of progressive IgAN (healthy status, IgAN, progressive IgAN) was tested using the generalized odds ratio (ORG) metric. Linkage disequilibrium and haplotype analysis were also performed. Meta-analysis: We included in the meta-analysis 15 studies investigating association between 14 interleukin variants harbored in eight different genes and IgAN. The ORG was used to evaluate the association between interleukin variants and IgAN using random effects models. The present case-control study revealed association of IL1B C-511T (rs16944) with the progression of IgAN (p = 0.041; ORG = 2.11 (1.09-4.07)). On haplotype analysis, significant results were derived for the haplotypes C-C-1 (p = 0.005; OR = 0.456 (0.261~0.797)) and C-T-2 (p = 0.003; OR = 4.208 (1.545-11.50)). Regarding association and meta-analysis results, variants in IL1B (rs1143627 and rs16944), IL1RN (rs928940, rs439154, and rs315951) and IL10 (rs1800871) were associated with IgAN based on either genotype or allele counts. Genetic variants and haplotypes in the IL1B, IL1RN, and IL10 genes might contribute to an increased risk for development and progression of IgAN.

Expression of CCL2, FOS, and JUN May Help to Distinguish Patients With IgA Nephropathy From Healthy Controls

Background

IgA nephropathy (IgAN), the most common type of glomerulonephritis worldwide, can only be diagnosed mainly by renal biopsy owing to lack of effective biomarkers. It is urgent to explore and identify the potential diagnostic biomarkers through assessing the gene expression profiles of patients with IgAN.

Methods

Two datasets were obtained from the Gene Expression Omnibus (GEO) database, including GSE115857 (55 IgAN, 7 living healthy donors) and GSE35487 (25 IgAN, 6 living healthy donors), then underwent differentially expressed genes (DEGs) and function enrichment analyses utilizing R packages. The common gene list was screened out between DEGs and immune-associated genes by Venn diagram, then performed gene-gene interaction, protein-protein interaction (PPI) and function enrichment analyses. Top three immune-associated hub genes were selected by Maximal Clique Centrality (MCC) method, then the expression and diagnostic value of these hub genes were determined. Consensus clustering algorithm was applied to conduct the unsupervised cluster analysis of the immune-associated hub gene list in IgAN. Finally, the Nephroseq V5 tool was applied to identify the expression level of CCL2, FOS, JUN in kidney diseases, as well as the correlation between CCL2, FOS, JUN expression and renal function in the patients with IgAN.

Results

A total of 129 DEGs were obtained through comparing IgAN with healthy controls via the GSE115857 and GSE35487 datasets. Then, we screened out 24 immune-associated IgAN DEGs. CCL2, JUN, and FOS were identified as the top three hub genes, and they were all remarkably downregulated in IgAN. More importantly, CCL2, JUN, and FOS had a high accuracy [area under the curve (AUC) reached almost 1] in predicting IgAN, which could easily distinguish between IgAN patients and healthy individuals. Three distinct subgroups of IgAN were determined based on 24 immune-associated DEGs, with significant differences in the expression of CCL2, JUN, and FOS genes. Finally, CCL2, FOS, JUN were manifested a meaningful association with proteinuria, glomerular filtration rate (GFR), and serum creatinine level.

Conclusion

In summary, our study comprehensively uncovers that CCL2, JUN, and FOS may function as promising biomarkers for diagnosis of IgAN.

Pro-inflammatory and anti-inflamatory cytokine genes polymorphisms and susceptibility to Japanese encephalitis disease in the North Indian population

BACKGROUND

Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in many regions of Asia. Cytokines, including pro-inflammatory and anti-inflammatory are key regulators playing a detrimental role in the host response to JE infection, pathogenesis and disease outcome. Evidently, the host's cytokine response is genetically determined, representing the complexity of interindividual differences regarding immune response to viral infection. The current study assesses the association of single nucleotide polymorphisms of classical interleukin IL-1β and IL-10 with JEV susceptibility and disease severity in north Indian population.

METHODS

We performed a case-control study using 85 JE patients and 85 healthy controls. Polymorphisms in the IL-1β (-511 C/T) and IL-10 (-1082 A/G) genes were genotyped using PCR-RFLP. All continuous variables were expressed as mean ± standard deviation, and categorical variables were expressed in percentage.

RESULTS

The mRNA level of IL-1β and IL-10 were found significantly increased in JE patients. In severe JE patients, IL-1β mRNA level was significantly higher with heterozygous (C/T) and homozygous (C/C) genotype compared to wild (T/T) genotype and mRNA level of IL-10 was higher in heterozygous genotype (A/G) compared to wild genotype (A/A). The C/T and C/C genotypes of IL-1β were significantly associated with higher risk of JE infection (p < 0.05, OR = 7.25 and 4.40) whereas, the A/G genotype of IL-10 was associated with a reduced risk of JEV infection (p < 0.05, OR = 0.30). The C allele of IL-1β was associated with fever and neck stiffness (p < 0.05) and CT genotype was associated with disease severity and worse outcomes in JE patients. Along with this, IL-10 polymorphism was found associated with fever, and AG genotype was found to be associated with worse disease outcomes such as neurological sequelae (p < 0.05).

CONCLUSION

Mutant allele and genotype at IL-1β (-511 C/T) and IL-10 (-1082 A/G) gene polymorphism show increased expression of IL-1β and IL-10 in JE patients which contribute to disease severity as well as adverse outcomes of disease. Overall this is the first report from northern India, which shows the association of IL-1β and IL-10 polymorphisms with JEV infection.

Association of Immune and Inflammatory Gene Polymorphism With the Risk of IgA Nephropathy: A Systematic Review and Meta-Analysis of 45 Studies

IgA nephropathy is the most prevalent primary glomerulonephritis worldwide, with identical immunopathological characteristics caused by multiple etiologies as well as influenced by geographical and ethnical factors. To elucidate the role of immunologic and inflammatory mechanisms in the susceptibility to IgA nephropathy, we explored single nucleotide polymorphisms of related molecules in the immune pathways. We searched the PubMed database for studies that involved all gene variants of molecules in the 20 immunologic and inflammatory pathways selected from the Kyoto Encyclopedia of Genes and Genomes database. The odds ratios with their corresponding 95% confidence intervals in six genetic models (allele model, dominant model, homozygote model, heterozygote model, overdominant model, and recessive model) were summarized using fixed or random effect models. Subgroup analysis was conducted based on different ethnicities with generalized odds ratios. Heterogeneity was evaluated using the Q and I² tests. Begg’s funnel plot and Egger’s linear regression test were used to evaluating possible publication bias among the included studies, and sensitivity analysis was used to test the stability of the overall results. A total of 45 studies met our selection criteria and eight related genetic association studies were retrieved, including 320 single-nucleotide polymorphisms from 20 candidate pathways, ranging from 2000 to 2021. A total of 28,994 healthy people versus 20,600 IgA nephropathy patients were enrolled. Upon meta-analyzed results that TGFB1 (rs1800469, rs1982073, rs1800471), IL-1B (rs1143627), IL-18 (rs1946518), and TLR1 (rs5743557) showed effect with or without ethnicity difference. And 10 variants presented stable and robust related to IgA nephropathy. This research showed that genetic variants are related to the immunologic and inflammatory effects of IgA nephropathy pathogenesis. The meta-analysis results supported the previous researches, and may help deepen the understanding of pathogenesis and explore new targets for IgA nephropathy-specific immunotherapy.

Correlation between interleukin gene polymorphisms and current prevalence and mortality rates due to novel coronavirus disease 2019 (COVID-2019) in 23 countries

Background

The novel coronavirus disease 2019 (COVID‐19) infection may rely on a potential genetic background for the variations in the inflammatory response. We aimed to investigate the possible correlation between polymorphisms in the IL‐6 gene at rs1800796/rs1800795, in IL‐6R at rs2228145, in IL‐10 at rs1800896 and rs1800871, in IL‐17 at rs2275913 and rs763780 loci, and COVID‐19 prevalence and mortality rates among populations of 23 countries.

Methods

We searched the literature for polymorphisms in China, Japan, India, Spain, Mexico, Sweden, Turkey, Brazil, Russia, Poland, Italy, South Africa, Netherlands, Greece, Germany, UK, Iran, Finland, Czechia, Tunisia, Norway, Egypt, Croatia. We recorded the prevalence and mortality rates (per million) caused by the Coronavirus infection recorded on 7th September 2020 and 6th December 2020.

Results

There was a significant positive correlation between the frequency of AG genotype of rs1800896 and prevalence recorded on 6th December 2020 (r: 0.53, r²: 0.28, p < .05). There was a significant negative correlation between the mortality rates recorded on 7th September, and the AG genotype of rs2275913 (r: −0.51, r²: 0.26, p < .05). There was a significant positive correlation between the prevalence recorded on 6th December, and TT genotype at rs763780 (r: 0.65, r²:0.42, p < .05) while a negative correlation between prevalence and TC genotype at rs763780 (r: −0.66, r²: 0.43, p < .05). Also, a significant negative correlation was found between mortality rates recorded on 6th December 2020 and CC genotype at rs763780 (r: −0.56, r²: 0.31, p < .05).

Conclusion

The variations in prevalence of COVID‐19 and its mortality rates among countries may be explained by the polymorphisms at rs1800896 in IL‐10, rs2275913 in IL‐17A, and rs763780 loci in the IL‐17F gene.

The variations in prevalence of COVID‐19 and its mortality rates among 23 countries may be explained by the polymorphisms at rs1800896 in IL‐10, rs2275913 in IL‐17A, and rs763780 loci in the IL‐17F gene.

AG genotype frequency of rs1800896 was positively correlated with prevalence recorded on 6th December 2020.

The mortality rates recorded on 7th September was negatively correlated with AG genotype frequency of rs2275913.

The prevalence recorded on 6th December was positively correlated with frequency of TT and negatively with TC genotype at rs763780.

The mortality rates recorded on 6th December 2020 was negatively correlated with CC genotype frequency at rs763780.

Association study of genetic variations of inflammatory biomarkers with susceptibility and severity of obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) increases health risks of cardiovascular disease and stroke. Both genetic factors and environmental exposures contribute to the occurrence of OSA. The purpose of this study was to determine the role of four functional inflammatory single nucleotide polymorphisms (SNPs) (VWF rs1063856, IL-6 rs1800796, TNF rs1800629, and CRP rs2794521) in the susceptibility and severity of OSA.

METHODS

A case-control study of OSA among Chinese population was conducted. Genotyping was performed using ABI TaqMan SNP genotyping technique.

RESULTS

We found VWF rs1063856 (OR = 1.50, 95% CIs = 1.10-2.04; p = 0.010), IL-6 rs1800796 (OR = 1.32, 95% CIs = 1.11-1.56; p = 0.002), TNF rs1800629 (OR = 1.44, 95% CIs = 1.13-1.83; p = 0.003), and CRP rs2794521 (OR = 1.27, 95% CIs = 1.04-1.55; p = 0.021) were all significantly associated with increased susceptibility of OSA, while VWF rs1063856 (OR = 1.75, 95% CIs = 1.18-2.62; p = 0.006), IL-6 rs1800796 (OR = 1.39, 95% CIs = 1.10-1.76; p = 0.006) were associated with the severity of OSA.

CONCLUSIONS

Our study indicated that functional variants of inflammatory biomarkers could cause the occurrence of OSA and influence the severity of OSA. These findings further support that inflammatory cytokines were closely related to the occurrence and development of OSA.

Association of polymorphisms in inflammatory cytokines encoding genes with severe cases of influenza A/H1N1 and B in an Iranian population

Background

The increased levels of blood cytokines is the main immunopathological process that were attributed to severe clinical outcomes in cases of influenza A, influenza B and people with influenza-like illness (ILI). Functional genetic polymorphisms caused by single nucleotide polymorphisms (SNPs) in inflammatory cytokines genes can influence their functions either qualitatively or quantitatively, which is associated with the possibility of severe influenza infections. The aim of the present case-control study was to investigate the association of polymorphisms in inflammatory cytokines genes with influenza patients and ILI group in an Iranian population.

Methods

Total number of 30 influenza B, 50 influenza A (H1N1) and 96 ILI inpatient individuals were confirmed by Real-time RT-PCR and HI assays. The genotype determination was assessed for defined SNPs in IL-1β, IL-17, IL-10 and IL-28 genes.

Results

The frequencies of the IL-1β rs16944 (P = 0.007) and IL-17 rs2275913 (P = 0.006) genotypes were associated with severe influenza disease, while the frequencies of IL-10 rs1800872 and IL-28 rs8099917 were not associated with the disease (P > 0.05). Also, the absence of A allele in IL-17 rs2275913 SNP increased the risk of influenza A (H1N1) infection (P = 0.008).

Conclusions

This study demonstrated that influenza A- (H1N1) and B-infected patients and also ILI controls have different profiles of immune parameters, and individuals carrying the specific cytokine-derived polymorphisms may show different immune responses towards severe outcome.