IL-17 polymorphisms and asthma risk: a meta-analysis of 11 single nucleotide polymorphisms

Autophagy related gene 5 polymorphism rs17587319 (C/G) in asthmatic patients in North Indian population

Objective: Genetic background and environmental stimuli play an important role in asthma, which is an individual's hyper-responsiveness to these stimuli leading to airway inflammation. Autophagy Related Gene 5 (ATG5) plays a critical role in the autophagy pathway and has been shown to be involved in asthma. The genetic polymorphisms in the ATG5 have been reported to predispose individuals to asthma. The role of single nucleotide polymorphism rs17587319 (C/G) of ATG5 in asthma has not been studied so far. Materials and methods: In this study, we in silico analysed rs17587319 (C/G) using web-based tools Human Splice Finder (HSF) and RegulomeDB and further a case-control study was conducted that included 187 blood samples (94 asthmatic and 93 healthy controls). Results: In silico analysis suggested alteration of splicing signals by this intronic variant. The samples were genotyped by applying the PCR-RFLP method. The MAF obtained was 0.022 and 0.043 in healthy controls and asthmatic individuals, respectively. The statistical analysis revealed no association (allelic model, OR = 2.02, 95%CI = 0.59-6.83, p = 0.25; co-dominant model, OR = 2.06, 95%CI = 0.6-7.12, p = 0.24) of rs17587319 (C/G) with the susceptibility to asthma in the north Indian population. Conclusions: In conclusion, rs17587319 (C/G) of ATG5 does not predispose individuals to asthma in our part of the world. Further studies are needed including more number of samples to ascertain the role of this polymorphism in asthma.

Association of rs4711998 of IL-17A, rs2275913 of IL-17A and rs763780 IL-17F gene polymorphisms with non-segmental vitiligo in a Mexican population

Vitiligo is the most common depigmenting disease characterized by achromic macules due to selective loss of melanocytes. The pathogenesis remains poorly elucidated, and multiple hypotheses exist regarding its pathogenesis. Evidence suggests that stress on melanocytes can result in activation of the immune system, and involvement of both activated cluster of differentiation (CD8+) cytotoxic and CD4+ T cells in the dysfunction, depigmentation, and apoptosis of melanocytes. Recent studies show that the interleukin 17 (IL-17) axis plays a central role in the pathogenesis of the disease. IL-17 is an important regulatory effector cytokine in this pathway. The aim of this study was to evaluate the association of IL-17A rs4711998 (-832A/G), IL-17A rs2275913 (-197G/A), and IL-17F rs763780 (7488A/G) with vitiligo in a Northeastern Mexican population. This was a case-control study and included 116 patients with vitiligo and 116 control subjects. Genotype characterization of IL-17A rs4711998 (-832A/G), IL-17A rs2275913 (-197G/A), and IL-17F rs763780 (7488A/G) was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. A p ≤ 0.05 was considered significant. It was observed that the combination of the genotypes GG/GA for IL-17F rs763780 (7488A/G) was associated with an increased risk for the development of vitiligo (OR 2.0943, 95% Cl 1.2375-3.5445, p = 0.0056). Regarding IL-17A rs4711998 (-832A/G) and IL-17A rs2275913 (-197G/A) genotyping, no association with vitiligo development was found. In conclusion, the SNP rs763780 in the IL-17F gene appears to be a risk factor for vitiligo development in this Mexican population and it may be useful in future studies, especially for the development of new therapies.

Associations between interleukin 17A and 17F polymorphisms and asthma susceptibility: A meta-analysis

Owing to their role in inflammatory reactions and immunological responses as well as their chromosomal location, interleukin (IL) 17A and 17F are regarded as candidate causal genes associated with asthma. The aim of this study was to determine whether IL17 polymorphisms are associated with susceptibility to asthma. We used the PubMed/Medline and Embase databases to search for studies reporting IL17 polymorphisms in patients with asthma and healthy controls. Meta-analyses were conducted to determine the associations between IL17A rs8193036 (-737C/T), rs2275913 (-197G/A), rs3819024 (A/G), rs3748067 (C/T), and rs4711998 (A/G) and IL17F rs763780 (7488A/G), rs2397084 (T/C), rs1889570 (C/T), rs11465553 (G/A), and rs1266828 (T/C) polymorphisms and asthma susceptibility. A total of 20 studies were included in this meta-analysis. Our results revealed the IL17A rs8193036 CC genotype was associated with asthma susceptibility (odds ratio [OR] = 1.490, 95% confidence interval [CI] = 1.027-2.161, p = .036). However, stratification by ethnicity indicated no association between this polymorphism and asthma in European and Asian subjects. Furthermore, no association was found between this polymorphism and asthma using the allele contrast, dominant or homozygous contrast models. No evidence of an association was found between any of the other IL17A and IL17F polymorphisms and asthma susceptibility in this meta-analysis. This meta-analysis showed that, among the studied polymorphisms, only the CC genotype of IL17A rs8193036 is associated with asthma susceptibility.

Relationship between asthma and IL-17 gene polymorphism in a Turkish population

BACKGROUND

Asthma is a prevalent chronic obstructive disease of the airways.

AIMS

The aim of our study was to investigate the relationship between asthma and IL-17F gene 74488 T > C, IL-17A gene -197G > A, and IL17A gene -737C > T polymorphisms in Turkish population.

METHODS

In our study, peripheral blood samples collected from a total of 127 subjects, with 65 in the patient group and 62 in the control group, were analyzed for IL-17F gene 74488 T > C, IL-17A gene -197G > A, and IL17A gene -737C > T polymorphisms using next-generation sequencing.

RESULTS

There was no statistically significant relationship between IL-17A gene -197G > A and IL-17A gene -737C > T polymorphisms and the risk of developing asthma. It was found that the risk of developing asthma was 2.9-fold higher in individuals with a C allele in the IL-17F gene 7488 T > C polymorphic site than the individuals with a T allele. It was shown that ATT and GCT haplotype carriers had a greater disease risk compared with the GTT haplotype carriers.

CONCLUSIONS

In conclusion, IL-17F gene 7488 T > C polymorphism was found to be associated with asthma in the Turkish population. The IL-17 gene should be further investigated as a potential candidate gene in predicting asthma susceptibility and in the treatment of asthma.

A pathogenic integrated view explaining the different endotypes of asthma and allergic disorders

The inflammation of allergic diseases is characterized by a complex interaction between type 2 and type 3 immune responses, explaining clinical symptoms and histopathological patterns. Airborne stimuli activate the mucosal epithelium to release a number of molecules impacting the activity of resident immune and environmental cells. Signals from the mucosal barrier, regulatory cells, and the inflamed tissue are crucial conditions able to modify innate and adaptive effector cells providing the selective homing of eosinophils or neutrophils. The high plasticity of resident T- and innate lymphoid cells responding to external signals is the prerequisite to explain the multiplicity of endotypes of allergic diseases. This notion paved the way for the huge use of specific biologic drugs interfering with pathogenic mechanisms of inflammation. Based on the response of the epithelial barrier, the activity of resident regulatory cells, and functions of structural non-lymphoid environmental cells, this review proposes some immunopathogenic scenarios characterizing the principal endotypes which can be associated with a precise phenotype of asthma. Recent literature indicates that similar concepts can also be applied to the inflammation of other non-respiratory allergic disorders. The next challenges will consist in defining specific biomarker(s) of each endotype allowing for a quick diagnosis and the most effective personalized therapy.

Gene polymorphisms in asthma: a narrative review

Background and Objective

Asthma is a heterogeneous disease caused by interactions between genetic and environmental factors. Genome-wide association studies (GWAS) have revealed that genetic variation plays a crucial role in the occurrence and development of asthma. The objective is to systematically review the existing literature on the association between gene polymorphisms and asthma to better understand the relationship between genetic factors and the occurrence and development of asthma.

Methods

We used keywords "asthma" and "gene polymorphism" with their combinations to search for relevant literature published from 2000 to 2021 in the PubMed database and the foreign medical literature retrieval service (FMRS). All articles included in the review are English. Then, we summarized the information pertaining to the genetic factors related to asthma susceptibility.

Key Content and Findings

This study summarized the information on 10 gene variants related to the risk of asthma published over the past 20 years, which will assist in further understanding the role of genetic variants in the risk of asthma.

Conclusion

Dozens of candidate genes have been identified that were associated with asthma risk. Asthmatics existed specific gene variation performed different response to therapy. Personalized therapy based on genotypic profiling would be an important direction in the future. However, it remains a great challenge for us to explore the relationship between gene polymorphisms and pathophysiological mechanism of asthma.

G Protein-Coupled Receptor Kinase 2 (GRK2) Regulates T Cell Response in a Murine Model of House Dust Mite-Induced Asthma

G protein-coupled receptor kinase 2 (GRK2) is an adapter protein that modulates G protein-coupled receptor (GPCR) signaling. It also regulates the functions and activity of other intracellular proteins in many cell types. Accordingly, GRK2 is thought to contribute to disease progression by a variety of mechanisms related to its multifunctional roles. Indeed, GRK2 levels are enhanced in patient samples as well as in preclinical models of several diseases. We have previously shown that GRK2 regulates mast cell functions, and thereby contributes to exacerbated inflammation during allergic reactions. In the current study, we observed that GRK2 levels are enhanced in the lungs of human asthma patients and in mice sensitized to house dust mite extract (HDME) allergen. Consistent with these findings, interleukin (IL)-4 and IL-13 levels were reduced in the lungs of GRK2+/- mice in a HMDE mouse model of asthma. Because Th2 cells are the major source of these cytokines during asthma, we determined the role of GRK2 in regulating T cell-specific responses in our HMDE mouse model. We observed a significant reduction of airway hyperresponsiveness (AHR), lung eosinophil and lymphocyte counts, serum IgE, Th2 cytokines (IL-4 and IL-13), goblet cell hyperplasia and mucus production in mice that had reduced GRK2 expression specifically in T cells. Collectively, our studies reveal an important role for GRK2 in regulating T cell response during asthma pathogenesis and further elucidation of the mechanisms through which GRK2 modulates airway inflammation will lead to the development of new therapeutic strategies for asthma.

IL17RA variations showed no associations with post-bronchiolitis asthma or lung function

BACKGROUND

Interleukin-17A (IL-17A) and IL-17F are involved in the pathogenesis of asthma and allergy. Interleukin-17 receptor A (IL-17RA), encoded by the IL17RA gene, is a common receptor for IL-17A and IL-17F. The aim of the present study was to evaluate the association of IL17RA gene variations with asthma, allergy, and lung function at school age in children prospectively followed up after hospitalization for bronchiolitis in early infancy.

METHODS

Data on IL17RA rs4819553, rs4819554, and rs4819558 polymorphisms and clinical outcomes, including asthma and allergic rhinitis, were available for 145 former bronchiolitis patients at 5-7 years and for 125 at 11-13 years of age. One hundred children underwent impulse oscillometry at 5-7 years and 84 underwent flow-volume spirometry at 11-13 years of age. The IL17RA rs4819553, rs4819554 and rs4819558 were completely co-segregating in Finnish children in our previous studies.

RESULTS

The distributions of the studied IL17RA wild versus variant genotypes and major versus minor allele frequencies did not differ between bronchiolitis cases and population controls. These variations showed no significant association with asthma or allergic rhinitis nor with lung function reduction at 5-7 or 11-13 years of ages. Only 5.6% to 6.4% of the variations were homozygous.

CONCLUSIONS

The IL17RA gene variations that were studied showed no association with susceptibility to severe bronchiolitis in infancy, nor with post-bronchiolitis asthma or lung function at school age. Future studies should evaluate other IL17RA polymorphisms and include more cases, and especially cases with homozygous variations.

Macrophage Receptor With Collagenous Structure Polymorphism and Recurrent Respiratory Infections and Wheezing During Infancy: A 5-Years Follow-Up Study

Background: Recurrent wheezing is a common clinical manifestation in childhood, and respiratory syncytial virus infection is a well-known risk factor. However, the genetic background favoring the development of recurrent wheezing is not fully understood. A possible role of macrophage receptor with collagenous gene (MARCO) polymorphism has been recently proposed. Objective: To investigate a correlation between MARCO rs1318645 polymorphisms and susceptibility to recurrent wheezing during childhood. Methods: We prospectively recruited 116 infants, of which 58 with respiratory syncytial virus bronchiolitis and 58 controls hospitalized at Regina Margherita Children's Hospital, Turin, Italy, between November 2014 and April 2015. All subjects were investigated for MARCO rs1318645 polymorphisms in the first period of life. Genotyping of rs1318645 was carried out by TaqMan mismatch amplification mutation assay real-time polymerase chain reaction procedure. Subjects were then enrolled in a 5-year follow-up study to monitor the occurrence of wheezing and respiratory infections. Results: The analysis of MARCO rs1318645 of allelic frequencies shows an increasingly significant risk to develop recurrent infection (p = 0.00065) and recurrent wheezing (p = 0.000084) with a wild-type C allele compared with a G allele. No correlation was found between wheezing and past respiratory syncytial virus infection (p = 0.057) and for a history of atopy in the family (p = 0.859). Conclusion: Our finding showed that subjects with C allelic MARCO rs1318645 polymorphism are at higher risk for recurrent infection and wheezing episodes during the first 5 years of life. Future studies of genetic associations should also consider other types of polymorphisms.

Association between IL-17 gene polymorphisms and circulating IL-17 levels in osteoarthritis: a meta-analysis

OBJECTIVE

This study systemically reviewed the evidence regarding associations between polymorphisms in interleukin-17 (IL-17) genes and osteoarthritis (OA) susceptibility, and the relationship between circulating IL-17 levels and OA.

METHODS

We performed a meta-analysis of the associations between the IL-17A rs2275913 and IL-17F rs763780 polymorphisms and risk for OA and serum/plasma IL-17 levels in OA patients and controls.

RESULTS

Eight studies including 2214 OA patients and 2474 controls were included. Our meta-analysis identified a significant association between OA and the AA genotype of the IL-17A rs2275913 polymorphism in a pooled cohort of affected individuals, compared to the case in a pooled cohort of control participants (OR = 1.516, 95% CI = 1.260-1.825, P < 0.001), and a significant association between OA and the CC genotype of the IL-17F rs763780 polymorphism (OR = 2.257, 95% CI = 1.376-3.704, p = 0.001). OA site-based stratification identified an association between the AA genotype of the IL-17A rs2275913 polymorphism and the CC genotype of the IL-17F rs763780 polymorphism and knee OA, but not hip OA. Furthermore, the same patterns of significant associations between OA and the IL-17A rs2275913 and IL-17F rs763780 polymorphisms were identified based on homozygote contrasts. The OA patients showed significantly higher IL-17 levels than the control subjects (SMD = 1.830, 95% CI = 1.184-2.477, P < 0.001).

CONCLUSION

Our meta-analysis revealed associations between the IL-17A rs2275913 and IL-17F rs763780 polymorphisms and OA susceptibility, and the presence of significantly higher circulating IL-17 levels in OA patients.

Association between IL-17A and IL-17F gene polymorphism and susceptibility in inflammatory arthritis: A meta-analysis

OBJECTIVES

The association between Interleukin (IL)-17A and IL-17F gene polymorphism with inflammatory arthritis were inconsistent among previous studies. This meta-analysis aimed to determine the association between IL-17A and IL-17F gene polymorphism with ankylosing spondylitis (AS), osteoarthritis (OA) and rheumatoid arthritis (RA).

METHODS

We searched Medline up to August 2019. The summary Odds Ratio (OR) with corresponding 95% confidence intervals (CIs) was calculated to evaluate the relationship between IL-17A and IL-17F gene polymorphism with genetic susceptibility of AS, OA and RA.

RESULTS

A total of 19 studies with 5298 cases and 5675 healthy controls were included. There were significant associations between rs2275913 G allele with OA, RA susceptibility (P < .05) but not AS. Subgroup analysis by ethnicity indicated that rs763780 C allele was closely related to AS and OA in Caucasian populations (P < .001) but not Mongolians. A significant association between rs763780 and RA susceptibility was detected in Caucasian populations (P < .05).

CONCLUSION

IL-17F gene rs763780 C allele confers increased risk of inflammatory arthritis in Caucasians; IL-17A gene rs2275913 G allele are protective for OA susceptibility in Mongolians. More well-designed studies with larger sample size are needed to elucidate the role of IL-17A gene rs2275913 G allele in inflammatory arthritis, especially AS.

Elevated circulating IL-17 level is associated with inflammatory arthritis and disease activity: A meta-analysis

OBJECTIVES

Previous studies found that the interleukin (IL)-17 level was elevated in inflammatory arthritis, but results were inconsistent. This meta-analysis aimed to investigate the association of IL-17 cytokine with osteoarthritis (OA), rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA).

METHODS

Relevant studies were searched using databases. Standardized mean difference (SMD) was calculated. Correlation coefficient was utilized to evaluate the relationship between IL-17 and disease activity of AS and RA. Subgroup analysis, sensitivity analysis and meta-regression were applied to explore the sources of heterogeneity.

RESULTS

83 records were enrolled. The IL-17 level was elevated in AS (SMD = 2.348, P < .001), RA (SMD = 1.502, P < .001), PsA (SMD = 1.710, P < .001) and OA (SMD = 1.192, P = .016), and similar results occurred in subgroup analysis. Furthermore, the IL-17 level was positively associated with disease activity of AS and RA.

CONCLUSION

Circulating IL-17 level is significantly elevated in inflammatory arthritis and is related to the disease activity of AS and RA, suggesting that it plays an important role in the pathogenesis and progression of inflammatory arthritis (especially in AS and RA).

A novel predictive approach for GVHD after allogeneic SCT based on clinical variables and cytokine gene polymorphisms

Despite considerable advances in our understanding of the pathophysiology of graft-versus-host disease (GVHD), its prediction remains unresolved and depends mainly on clinical data. The aim of this study is to build a predictive model based on clinical variables and cytokine gene polymorphism for predicting acute GVHD (aGVHD) and chronic GVHD (cGVHD) from the analysis of a large cohort of HLA-identical sibling donor allogeneic stem cell transplant (allo-SCT) patients. A total of 25 SNPs in 12 cytokine genes were evaluated in 509 patients. Data were analyzed using a linear regression model and the least absolute shrinkage and selection operator (LASSO). The statistical model was constructed by randomly selecting 85% of cases (training set), and the predictive ability was confirmed based on the remaining 15% of cases (test set). Models including clinical and genetic variables (CG-M) predicted severe aGVHD significantly better than models including only clinical variables (C-M) or only genetic variables (G-M). For grades 3-4 aGVHD, the correct classification rates (CCR1) were: 100% for CG-M, 88% for G-M, and 50% for C-M. On the other hand, CG-M and G-M predicted extensive cGVHD better than C-M (CCR1: 80% vs. 66.7%, respectively). A risk score was calculated based on LASSO multivariate analyses. It was able to correctly stratify patients who developed grades 3-4 aGVHD (P < .001) and extensive cGVHD (P < .001). The novel predictive models proposed here improve the prediction of severe GVHD after allo-SCT. This approach could facilitate personalized risk-adapted clinical management of patients undergoing allo-SCT.

Bcl11b Regulates IL-17 Through the TGF-β/Smad Pathway in HDM-Induced Asthma

PURPOSE

T helper (Th) 17 cells play a critical role in the development of asthma, but the underlying mechanism of how interleukin (IL)-17 is regulated in allergic airway inflammation is poorly understood. In this study, we investigated the impact of Bcl11b on Th17 response in asthma.

METHODS

Blood samples from patients with mild asthma (MA) and severe asthma (SA) were collected. Expression of Bcl11b, IL-4, IL-5, IL-13, IL-17A and transforming growth factor (TGF)-β1 were determined in CD4⁺ T cells and plasma by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Relative mRNA and protein levels of Bcl11b, IL-17A and genes involved in the TGF/Smad signaling pathway were examined by PCR, ELISA and western blot analysis in house dust mite (HDM)-challenged mice. Ectopic expression of Bcl11b in HDM-stimulated primary mouse splenocytes was achieved by nucleofection of Bcl11b expression plasmid.

RESULTS

We found significantly decreased Bcl11b but increased IL-17A and TGF-β1 expression in patients with asthma and a strongly negative correlation between Bcl11b and these 2 cytokines in SA patients. Similar expression patterns of Bcl11b, IL-17A and TGF-β1 were also found in mice with HDM-induced allergic airway inflammation. We demonstrated further that Smad2/3 phosphorylation was increased in HDM-challenged mice and that ectopic expression of Bcl11b in HDM-stimulated primary mouse splenocytes reduced Smad2 phosphorylation and IL-17 expression.

CONCLUSIONS

Our findings demonstrate a potential effect of Bc111b in controlling IL-17-mediated inflammation in asthma and suggest that Bc111b may be a useful therapeutic target for asthma.

Association of Interleukin-17F gene polymorphisms with susceptibility to severe enterovirus 71 infection in Chinese children

Enterovirus 71 (EV71) is a single-strand RNA virus that causes hand, foot and mouth disease (HFMD) in infants and young children, leading to neurological complications with significant morbidity and mortality. Unfortunately, the pathogenesis of EV71 infection is not well understood. In this study, we investigated the IL-17F rs1889570 and rs4715290 gene polymorphisms in a Chinese Han population. Severe cases and cases with EV71 encephalitis had a significantly higher frequency of the rs1889570 T/T genotype and T allele. The serum IL-17F levels in rs1889570 T/T and C/T genotypes were also significantly elevated when compared to C/C genotypes. However, there was no significant difference observed in rs4715290 genotype distribution and allele frequency. These findings suggest that IL-17F rs1889570 gene polymorphisms are significantly associated with the susceptibility to severe EV71 infection in Chinese Han children.

Role of gene polymorphisms/haplotypes and serum levels of interleukin-17A in susceptibility to viral myocarditis

Interleukin-17A (IL-17A) has been implicated in the pathogenesis of viral myocarditis (VMC). However, the role of IL-17A polymorphisms in susceptibility to VMC has not been reported to date. The aim of this study was to explore the association between IL-17A variants as well as serum IL-17 levels with VMC. Three single-nucleotide polymorphisms (SNPs) (rs2275913, rs3819025, and rs3748067) were analyzed by the polymerase chain reaction-restriction fragment length polymorphism method in 236 VMC patients and 259 controls from China. Serum IL-17A levels were measured by enzyme-linked immunosorbent assay kits. Multivariable logistic regression analysis that the rs2275913 AA genotype and the haplotype -197A/+45G/+1249G (AGG) were associated with an increased risk of VMC (all P < 0.05). Consistent with these findings, the rs2275913 AA genotype was linked to higher serum IL-17A compared to GG/AG genotype (all P < 0.001). We observed no associations between the other two SNPs and risk of VMC. Serum IL-17A levels were significantly higher in the VMC group than controls (P < 0.001) and gradually increased with the increase of New York Heart Association grade in VMC patients (P < 0.05). Spearman correlation test revealed that the serum IL-17A level was correlated with the cardiac damage and left ventricular systolic functions among VMC patients (all P < 0.05). Our study reveals that IL-17A expression may contribute to the development and severity of VMC. The SNP rs2275913 in the IL-17A gene might exert influence on susceptibility to VMC via linking with the serum IL-17A level.

Haplotype of the Interleukin 17A gene is associated with osteitis after Bacillus Calmette-Guerin vaccination

Bacillus Calmette-Guerin (BCG) osteitis was more common in Finland than elsewhere at the time when universal BCG vaccinations were given to Finnish newborns. There is evidence that IL-17 plays a role in the defense against tuberculosis. The aim of this study was to evaluate the associations of IL17A rs4711998, IL17A rs8193036 and IL17A rs2275913 single-nucleotide polymorphisms (SNPs) with the risk of BCG osteitis after newborn vaccination. IL17A rs4711998, rs8193036 and rs2275913 SNPs were determined in 131 adults had presented with BCG osteitis after newborn BCG vaccination. We analyzed, using the HaploView and PLINK programs, whether allele or haplotype frequencies of these SNPs differ between the former BCG osteitis patients and Finnish population controls. Of the three IL17A SNPs studied, rs4711998 associated nominally with BCG osteitis; minor allele frequency was 0.215 in 130 BCG osteitis cases and 0.298 in 99 controls (p = 0.034). Frequency of the second common haplotype (GTA) differed significantly between BCG osteitis cases and controls (0.296 vs. 0.184, p = 0.040 after multi-testing correction). The GTA haplotype of the IL17A SNPs rs4711998, rs8193036 and rs2275913 was associated with osteitis after BCG vaccination.

Susceptibility to chronic inflammation: an update

Chronic inflammation is defined by the persistence of inflammatory processes beyond their physiological function, resulting in tissue destruction. Chronic inflammation is implicated in the progression of many chronic diseases and plays a central role in chronic inflammatory and autoimmune disease. As such, this review aims to collate some of the latest research in relation to genetic and environmental susceptibilities to chronic inflammation. In the genetic section, we discuss some of the updates in cytokine research and current treatments that are being developed. We also discuss newly identified canonical and non-canonical genes associated with chronic inflammation. In the environmental section, we highlight some of the latest updates and evidence in relation to the role that infection, diet and stress play in promoting inflammation. The aim of this review is to provide an overview of the latest research to build on our current understanding of chronic inflammation. It highlights the complexity associated with chronic inflammation, as well as provides insights into potential new targets for therapies that could be used to treat chronic inflammation and consequently prevent disease progression.

Asthma and rhinitis have different genetic profiles for IL13, IL17A and GSTP1 polymorphisms

BACKGROUND

Asthma and rhinitis have a complex etiology, depending on multiple genetic and environmental risk factors. An increasing number of susceptibility genes are currently being identified, but the majority of reported associations have not been consistently replicated across populations of different genetic backgrounds.

PURPOSE

To evaluate whether polymorphisms of IL4R (rs1805015), IL13 (rs20541), IL17A (rs2275913) and GSTP1 (rs1695) genes are associated with rhinitis and/or asthma in adults of Portuguese ancestry.

METHODS

192 unrelated healthy individuals and 232 patients, 83 with rhinitis and 149 with asthma, were studied. All polymorphisms were detected by real time polymerase chain reaction (PCR) using TaqMan assays.

RESULTS

Comparing to controls, significant association with asthma was observed for GSTP1 rs1695 AA genotype (odds ratio (OR) - 1.96; 95% CI - 1.18 to 3.25; p=0.010). The association sustains for allergic asthma (OR - 2.17; 95% CI - 1.23 to 3.80; p=0.007). IL13 rs20541 GG genotype was associated with less susceptibility to asthma (OR - 0.55, 95% CI - 0.33 to 0.94, p=0.028). Among patients, IL17A rs2275913 AA genotype was less associated with asthma than with rhinitis (OR - 0.20; 95% CI of 0.07 to 0.56; p=0.002). A similar association was found for IL13 rs20541 GG genotype (OR - 0.48; 95% CI of 0.25 to 0.93; p=0.031). There were no significant differences in the distribution of allelic and genotypic frequencies between patients and controls for the IL4R polymorphism' analyzed.

CONCLUSION

These results support the existence of a significant association between GSTP1 rs1695 and IL13 rs20541 SNPs, with susceptibility to asthma, in the population studied. Different genotype profiles of IL17A and IL13 genes seem to influence the clinical pattern of disease expression mainly confined to the upper airways, as rhinitis, or including the lower airways, as asthma.