IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms in patients with chronic rhinosinusitis with sinonasal polyposis

Background/aim: Sinonasal polyposis is a complex chronic disease displaying contributions from multiple genetic and environmental factors. In this study, we analyzed possible genetic factors that increase susceptibility to this widespread inflammatory disease. Materials and methods: A total of 176 adult patients, including 78 patients with sinonasal polyposis and 98 healthy controls, were analyzed for IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms using polymerase chain reaction and enzyme restriction. Results: IL-1RN and IL-4 VNTR polymorphisms were notably associated with sinonasal polyposis (P = 0.0001 and P = 0.036, respectively); however, regarding the IL-2(-330) gene polymorphism, no significant difference was shown between the patient and control groups (P = 0.235). Conclusions: Our study indicates that the RN2 allele of IL-1RN and the RP1 allele of IL-4 might be risk factors for developing sinonasal polyposis.

IL-1 Polymorphism and Helicobacter pylori Infection Features: Highlighting VNTR's Potential in Predicting the Susceptibility to Infection-Associated Disease Development.

Genetic polymorphisms at the IL-1 cluster are associated with increased Helicobacter pylori (H. pylori)-associated disease risk in an ethnically dependent manner. Due to the corroborated role of IL-1ß in H. pylori infection progression, our aim is to depict the impact of IL1B rs1143627 and rs16944 as well as the IL1RN variable number of identical tandem repeats (VNTR) on the clinical and biological features of Moroccan H. pylori-infected patients. A total of 58 patients with epigastralgic pain were referred to the gastroenterology department for histopathological and clinical analysis. DNA extraction from antrum and fundus biopsies and PCR-RFLP were performed to detect polymorphisms. As a result, VNTR was significantly associated with IL-1ß antrum levels (p-value = 0.029), where the *1/*4 genotype showed a positive association with upregulated cytokine levels in the antrum and was clustered with H. pylori-infected patients' features and higher levels of IL-1ß in the antrum and fundus. Likewise, *1/*1 genotype carriers clustered with severe gastritis activity and H. pylori density scores along with low levels of IL-1ß in the antrum and fundus, while the *1/*2 genotype was clustered with non-infected-patient features and normal IL-1ß levels. In conclusion, VNTR might be an interesting predictor to identify patients at risk of developing H. pylori-associated pathologies.

Association between IL-1B (-511)/IL-1RN (VNTR) polymorphisms and type 2 diabetes: a systematic review and meta-analysis.

Interleukin-1 (IL-1) plays an essential role in the immune pro-inflammatory process, which is regarded as one of many factors in the development of type 2 diabetes mellitus (T2DM). Several case-control studies have illustrated the association of the IL-1B (-511) (rs16944, Chr 2:112,837,290, C/T Intragenic, Transition Substitution) and IL-1RN (VNTR) (gene for IL-1 receptor antagonist, IL-1RA, 86 bp tandem repeats in intron 2) polymorphisms with T2DM risk. However, the results were inconsistent and inconclusive. We performed a meta-analysis (registry number: CRD42021268494) to assess the association of the IL-1B (-511) and IL-1RN (VNTR) polymorphisms with T2DM risk. Random-effects models were applied to calculate the pooled ORs (odds ratios) and 95% CIs (confidence intervals) to test the strength of the association in the overall group and subgroups stratified by ethnicity, respectively. Between-study heterogeneity and publication bias were evaluated by the Q-test, I2 statistic, Harbord test, and Peters test accordingly. Sensitivity analyses were also performed. A total of 12 publications evaluating the association of IL-1B (-511) and IL-1RN (VNTR) polymorphisms with the risk of T2DM development were included. The meta-analysis showed that IL-1RN (VNTR) was related to the increasing development of T2DM risk in the recessive model (OR = 1.62, 95% CI [1.09-2.42], Phet = 0.377, Pz = 0.018) and in the homozygous model (OR = 2.02, 95% CI [1.07-3.83], Phet = 0.085, Pz = 0.031), and the IL-1RN 2* allele was found a significant association with evaluated T2DM risk in all ethnicities (OR = 2.08, 95% CI [1.43-3.02], Phet < 0.001, Pz < 0.001) and in EA (OR = 2.01, 95% CI [1.53-2.66], Phet = 0.541, Pz < 0.001). Moreover, stratification by ethnicity revealed that IL-1B (-511) was associated with a decreased risk of T2DM in the dominant model (OR=0.76, 95% CI [0.59-0.97], Phet = 0.218, P z = 0.027) and codominant model (OR = 0.73, 95% CI [0.54-0.99], Phet = 0.141, Pz = 0.040) in the East Asian (EA) subgroup. Our results suggest that the IL-1RN 2* allele and 2*2* homozygous polymorphism are strongly associated with increasing T2DM risk and that the IL-1B (-511) T allele polymorphism is associated with decreasing T2DM risk in the EA subgroup.

High expression of interleukine-1 receptor antagonist in rheumatoid arthritis: Association with IL1RN*2/2 genotype.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and pro-inflammatory cytokines production. IL-1Ra is an anti-inflammatory cytokine codified by IL1RN gene that blocks IL-1 signalling. A VNTR polymorphism of 86 bp in IL1RN gene has been associated with RA risk and regulation of IL-1Ra expression. In this study, we determined mRNA and protein expression of IL-1Ra in RA patients and control subjects (CS). This study included 85 RA patients classified according to the ACR/EULAR 2010 criteria and 67 CS. Polymerase chain reaction was used to identify IL1RN VNTR polymorphism, the expression of sIL-1Ra (secreted isoform) mRNA was determined by SYBR Green-based real time quantitave-PCR assay, and IL-1Ra soluble levels quantification was evaluated by ELISA test. RA patients had higher soluble levels of IL-1Ra than CS (p < .01), sIL-1Ra mRNA expression was higher in RA patients compared to CS (p < .01). Carriers of IL1RN*2/2 homozygous genotype show increased IL-1Ra soluble levels compared to IL1RN*long/long and IL1RN*2/long genotypes (p < .05) in the CS group, whereas mRNA expression in carriers of IL1RN*2/2 genotype was 1.2 times higher compared to IL1RN*long/long genotypes in the same group. Regarding RA patients, high expression of sIL-1Ra mRNA on carriers of IL1RN*long/long genotype was observed. Nevertheless, in RA patients IL-1Ra soluble levels among genotypes did not show significant differences. High expression of IL-1Ra in RA patients under treatment or not with antirheumatic drugs was detected. Additionally, carriers of IL1RN*2/2 genotype had higher IL-1Ra expression than carriers of other genotypes.