Association of single nucleotide polymorphisms of IL23R and IL17 with ulcerative colitis risk in a Chinese Han population. PLoS One. 2012;7:e44380. [PMID: 22984500 PMCID: PMC3439435 DOI: 10.1371/journal.pone.0044380]

Intestinal flora alterations in patients with ulcerative colitis and their association with inflammation

Ulcerative colitis (UC), which is a type of inflammatory bowel disease, is a chronic intestinal disorder of multifactorial etiology. Numerous studies have indicated an association between UC and intestinal bacteria. However, a limited number of studies regarding the expression of interleukin-17 (IL-17) and interleukin-23 (IL-23) in association with intestinal bacteria have been performed. The aim of the current study was to investigate the gut microbiota alterations in patients with UC, at a number of taxonomic levels, and their relationship with intestinal inflammation by analyzing the protein expression of IL-17 and IL-23. Specimens were collected from 10 healthy controls and 16 patients with UC. A histological examination was performed in colonic tissues, IL-17 and IL-23 protein expression was detected by immunohistochemistry, fecal samples were sequenced using 16S rDNA sequencing and bioinformatics analysis was performed. The UC group exhibited an increased histological score (P<0.01) and upregulated IL-17 and IL-23 expression (P<0.01). At the order level, the bacterial diversity of the UC group was decreased. β-diversity analyses, including principal component analysis, principal coordinate analysis and non-metric multidimensional scaling, demonstrated that the two groups of samples were separated into two taxonomic categories, as distinct variations were observed in the analysis of group differences (P=0.001). Regarding the differences in species composition between the groups, Enterococcus was indicated to be the species with the greatest difference in abundance compared with the healthy control group (P<0.01), followed by Lactobacillus (P<0.05), Escherichia-Shigella (P<0.05), Bifidobacterium and Bacteroides. In addition, the average optical density of IL-17 was positively correlated with the histological score (ρ=0.669; P=0.035), Enterococcus (r=0.843; P<0.001), Lactobacillus (r=0.737; P=0.001), Bifidobacterium (r=0.773; P<0.001) and Escherichia-Shigella (r=0.663; P=0.005), and the average optical density of IL-23 was positively correlated with the histological score (ρ=0.733; P=0.016), Enterococcus (r=0.771; P<0.001), Lactobacillus (r=0.566; P=0.022), Bifidobacterium (r=0.517; P=0.041) and Escherichia-Shigella (r=0.613; P=0.012). The results of the present study indicated that the intestinal microbiota of patients with UC differed from that of healthy controls at multiple taxonomic levels. The alterations of the intestinal microflora were closely associated with the degree of inflammation. The IL-23/IL-17 axis, as a key factor in the development of UC, maybe associated with the alterations of intestinal microflora. The interaction between intestinal microflora and the IL-23/IL-17 axis may serve an important role in the pathogenesis of UC.

The Association Study of IL-23R Polymorphisms With Cerebral Palsy in Chinese Population

Background: Cerebral palsy (CP) is a syndrome of non-progressive motor dysfunction caused by early brain development injury. Recent evidence has shown that immunological abnormalities are associated with an increased risk of CP.

Methods: We recruited 782 children with CP as the case group and 770 healthy children as the control group. The association between IL-23R single nucleotide polymorphisms (SNPs; namely, rs10889657, rs6682925, rs1884444, rs17375018, rs1004819, rs11805303, and rs10889677) and CP was studied by using a case–control method and SHEsis online software. Subgroup analysis based on complications and clinical subtypes was also carried out.

Results: There were differences in the allele and genotype frequencies between CP cases and controls at the rs11805303 and rs10889677 SNPs (Pallele = 0.014 and 0.048, respectively; Pgenotype = 0.023 and 0.008, respectively), and the difference in genotype frequency of rs10889677 remained significant after Bonferroni correction (Pgenotype = 0.048). Subgroup analysis revealed a more significant association of rs10889677 with CP accompanied by global developmental delay (Pgenotype = 0.024 after correction) and neonatal encephalopathy (Pgenotype = 0.024 after correction).

Conclusion: The present results showed a significant association between IL-23R and CP, suggesting that IL-23R may play a potential role in CP pathogenesis.

Association of single-nucleotide polymorphisms in the IL27 gene with autoimmune thyroid diseases

Background Accumulating data have shown that interleukin-27 (IL27) polymorphisms are linked to the susceptibility of some autoimmune diseases. We assessed whether there was an association between three single-nucleotide polymorphisms (SNPs) of IL27 gene and autoimmune thyroid diseases (AITDs). Methods Three SNPs (rs153109, rs17855750 and rs181206) of IL27 gene were genotyped by Hi-SNP high-throughput genotyping in 843 patients with AITDs (516 Graves' disease (GD) and 327 Hashimoto's thyroiditis (HT)) and 677 healthy controls in Chinese Han population. Results Compared with controls, rs153109 displayed significant associations with GD in allele and genotype frequencies (P = 0.002 and P = 0.008, respectively) and rs17855750 displayed significant associations with HT in allele frequencies (P = 0.02), whereas no differences in genotype or allele frequencies were found between AITD patients and controls at rs181206. Conclusion Our study, for the first time, showed the significant association of the IL27 gene SNPs with AITD.

Genetic associations of inflammatory bowel disease in a South Asian population

AIM

To estimate prevalence and phenotypic associations of selected inflammatory bowel disease (IBD)-associated genetic variants among Sri Lankan patients.

METHODS

A case study of histologically confirmed ulcerative colitis (UC) or Crohn’s disease (CD) patients with ≥ 1 year disease duration, who were compared to unrelated, gender-matched, healthy individuals as controls, was conducted at four major centers in Sri Lanka. Phenotypic data of the cases were obtained and all participants were genotyped for 16 selected genetic variants: IL12B:rs1045431, IL23R:rs11805303, ARPC2:rs12612347, IRGM:rs13361189, IL26/IL22:rs1558744, CDH1:rs1728785, IL10:rs3024505, FCGR2A:rs3737240, PTGER4:rs4613763, IL17REL/PIM3:rs5771069, HNF4a:rs6017342, STAT3:rs744166, SMURF1:rs7809799, LAMB1:rs886774, HLA-DRB5, DQA1, DRB1, DRA:rs9268853, MST1, UBA7, and APEH:rs9822268. The genotypes of all variants were in Hardy-Weinberg Equilibrium (P > 10⁻³). To account for multiple hypothesis testing, P-values < 0.003 were considered significant.

RESULTS

A total of 415 patients and 465 controls were recruited. Out of the single nucleotide polymorphisms (SNPs) tested, the majority were not associated with IBD in Sri Lankans. Significant positive associations were noted between rs886774 (LAMB1-gene) and UC (odds ratio (OR) = 1.42, P = 0.001). UC patients with rs886774 had mild disease (OR = 1.66, P < 0.001) and remained in remission (OR = 1.48, P < 0.001). A positive association was noted between rs10045431 (IL 12B gene) and upper gastrointestinal involvement in CD (OR = 4.76, P = 0.002).

CONCLUSION

This confirms the heterogeneity of allelic mutations in South Asians compared to Caucasians. Most SNPs and disease associations reported here have not been described in South Asians.

新疆维吾尔族和汉族溃疡性结肠炎患者IL-23R基因多态性的初步研究

目的

初步探讨新疆维汉民族溃疡性结肠炎(ulcerative colitis, UC)患者及正常对照人群中白介素23受体(interleukin-23 receptor, IL-23R)基因中9个单核苷酸多态性(single nucleotide polymorphism, SNP)位点的基因型, 以探究IL-23R基因的UC易感位点.

方法

采用SNaPshot SNP分型技术对263个样本进行9个SNP位点基因分型, 分析上述位点基因型, 对比维汉民族、维吾尔族UC组与对照组, 汉族UC组与对照组上述位点基因型频率、等位基因频率, 探索IL-23R基因的UC易感位点及其在维汉民族间有无差异.

结果

与维吾尔族对照组相比, 维吾尔族UC组在rs11805303、rs17375018基因型上差异有统计学意义(P<0.05). 与汉族对照组相比, 汉族UC组在rs1495965、rs11805303、rs17375018基因型上差异有统计学意义(P<0.05). 维吾尔族UC组与汉族UC组在上述9个SNP位点的基因型差异无统计学意义(P>0.05).

结论

IL-23R基因的rs1495965、rs11805303、rs17375018可能是影响UC发病的易感位点, 但本研究涉及IL-23R基因9个SNP位点基因型在维汉民族间无明显差异, 考虑上述位点可能不是民族易感性位点.

Association of single nucleotide polymorphisms of IL23R and IL17 with necrotizing enterocolitis in premature infants

Necrotizing enterocolitis (NEC) is a severe gastrointestinal inflammatory disease in neonates, particularly in preterm infants. The interleukin (IL) 23/IL17 axis has been shown to play an important role in the gastrointestinal inflammation. However, the association of gene polymorphisms in the IL23/IL17 axis and the development of NEC remains unknown. In this study, we aimed to explore a possible genetic role of IL23R and IL17 in the development of NEC. We identified single nucleotide polymorphisms (SNPs) in IL23R (rs10889677), IL17A (rs2275913), and IL17F (rs763780) by polymerase chain reaction and Sanger sequencing. A total of 102 NEC patients (stage II, n = 75; and stage III, n = 27) and 120 control subjects were recruited for the study. All of the participants were premature (gestational age < 37 weeks). Our results revealed that the combination of the IL17F rs763780 (TC + CC) genotype and the C allele both significantly increased the risk of NEC [odds ratio (OR) 1.89, 95% confidence interval (CI) 1.04-3.43, P = 0.035; OR 1.82, 95% CI 1.06-3.13, P = 0.028, respectively]. Furthermore, the rs763780 (TC + CC) genotype was associated with increased severity of NEC and the incidence of NEC-related perforation [OR 2.80, 95% CI 1.10-7.12, P = 0.031; OR 3.86, 95% CI 1.10-13.53, P = 0.035, respectively]. However, IL23R rs10889677 and IL17A rs2275913 were not associated with the susceptibility to NEC. In conclusion, our data suggest that a variant of IL17F (rs763780) may contribute to the development of NEC.

IL23R single nucleotide polymorphisms could be either beneficial or harmful in ulcerative colitis

AIM

To investigate the association of seven single nucleotide polymorphisms (SNPs) of the IL23R gene with the clinical picture of ulcerative colitis (UC).

METHODS

Genomic DNA samples of 131 patients (66 males, 65 females, mean age 55.4 ± 15.8 years) with Caucasian origin, diagnosed with UC were investigated. The diagnosis of UC was based on the established clinical, endoscopic, radiological, and histopathological guidelines. DNA was extracted from peripheral blood leukocytes by routine salting out method. Polymerase chain reaction and restriction fragment length polymorphism were used to identify the alleles of seven SNPs of IL23R gene (rs11209026, rs10889677, rs1004819, rs2201841, rs7517847, rs10489629, rs7530511).

RESULTS

Four out of seven analyzed SNPs had statistically significant influence on the clinical picture of UC. Two SNPs were associated with greater colonic extension (rs2201841 P = 0.0084; rs10489629 P = 0.0405). For two of the SNPs, there was more frequently need for operations (rs2201841 P = 0.0348, OR = 8.0; rs10889677 P = 0.0347, OR = 8.0). The rs2201841 showed to be a risk factor for the development of iron deficiency (P = 0.0388, OR = 6.1837). For patients with the rs10889677, a therapy with azathioprine was more frequently necessary (P = 0.0116, OR = 6.1707). Patients with rs10489629 SNP had a lower risk for weight loss (P = 0.0169, OR = 0.3394). Carriers of the heterozygous variant had a higher risk for an extended disease (P = 0.0284). The rs7517847 showed a protective character leading to mild bowel movements. Three SNPs demonstrated no statistically significant influence on any examined clinical features of UC.

CONCLUSION

We demonstrated susceptible or protective character of the investigated IL23R SNPs on the phenotype of UC, confirming the genetic association.

IL-23R mutation is associated with ulcerative colitis: A systemic review and meta-analysis

OBJECTIVES

Since a genome-wide association study revealed that Interleukin-23 receptor (IL-23R) gene is a candidate gene for Ulcerative Colitis (UC), many studies have investigated the association between the IL-23R polymorphisms and UC. However, the results were controversial. The aim of the study was to determine whether the IL-23R polymorphisms confer susceptibility to UC.

METHODS

A systematic literature search was carried out to identify all potentially relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of association.

RESULTS

A total of 33 studies in 32 articles, including 10,527 UC cases and 15,142 healthy controls, were finally involved in the meta-analysis. Overall, a significant association was found between all UC cases and the rs11209026A allele (OR = 0.665, 95% CI = 0.604~0.733, P < 0.001). Similarly, meta-analyses of the rs7517847, rs1004819, rs10889677, rs2201841, rs11209032, rs1495965, rs1343151 and rs11465804 polymorphisms also indicated significant association with all UC (all P < 0.05). Stratification by ethnicity revealed that the rs11209026, rs7517847, rs10889677, rs2201841 andrs11465804 polymorphisms were associated with UC in the Caucasian group, but not in Asians, while the rs1004819 and rs11209032 polymorphisms were found to be related to UC for both Caucasian and Asian groups. However, subgroup analysis failed to unveil any association between the rs1495965 and rs1343151 polymorphisms and UC in Caucasians or Asians.

CONCLUSIONS

The meta-analysis suggests significant association between IL-23R polymorphisms and UC, especially in Caucasians.

Associations of genotypes and haplotypes of IL-17 with risk of gastric cancer in an eastern Chinese population

Interleukin-17 plays a crucial role in inflammation-related carcinogenesis. We hypothesize that genetic variants in IL-17 are associated with gastric cancer (GCa) risk, and we genotyped five potentially functional single nucleotide polymorphisms (SNPs) (rs1974226 G > A, rs2275913 A > G, rs3819024 A > G, rs4711998 A > G, and rs8193036 C > T) of IL-17 in 1121 GCa patients and 1216 cancer-free controls in an eastern Chinese population. Logistic regression analysis was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Meta-analysis and genotype-mRNA expression correlation were performed to further validate positive associations. We found that an increased GCa risk was independently associated with rs1974226 (adjusted OR = 2.60, 95% CI = 1.27-5.32 for AA vs. GG + GA) and rs2275913 (adjusted OR = 1.33, 95% CI = 1.03-1.72 for GA + AA vs. GG), while a decreased GCa risk was independently associated with rs3819024 (adjusted OR = 0.72, 95% CI = 0.54-0.96 for GG vs. AA + AG). Additional meta-analyses confirmed the observed risk association with rs2275913. We also found that two IL-17 haplotypes (G-G-G-A-C) and (A-G-G-A-C) (in the order of rs1974226, rs2275913, rs3819024, rs4711998 and rs8193036) were associated with a reduced GCa risk (adjusted OR = 0.64, 95% CI = 0.46-0.89 and adjusted OR = 0.38, 95% CI = 0.17-0.81, respectively). However, the expression Quantitative Trait Locus (eQTL) analysis for the genotype-phenotype correlation did not find mRNA expression changes associated with either the genotypes. In conclusions, genetic variants of IL-17 are likely to be associated with risk of GCa, and additional larger studies with functional validation are needed to explore the molecular mechanisms underlying the observed associations.

Faecalibacterium prausnitzii supernatant ameliorates dextran sulfate sodium induced colitis by regulating Th17 cell differentiation

AIM: To explore the preventive and therapeutic effects of Faecalibacterium prausnitzii (F. prausnitzii) supernatant on dextran sulfate sodium (DSS) induced colitis in mice.

METHODS: Forty C57BL/6J male mice were randomly divided into four groups: control group, model group, treatment group, and prevention group. Mice were weighed daily. On day 10, the colon length was measured, the colorectal histopathologic damage score (HDS) was assessed, and plasma interleukin (IL)-17A, IL-6, and IL-4 levels were detected by enzyme-linked immunosorbent assay. The expression of transcription factor retinoic acid-related orphan receptor-γt (RORγt) and IL-17A in colon inflammatory mucosa tissue were determined by immunohistochemical assay, and the expression levels of RORγt mRNA, IL-17A mRNA, and IL-6 mRNA were detected by real-time quantitative polymerase chain reaction (PCR). The proportion of Th17 in mononuclear cells in spleen was assayed by fluorescence activated cell sorter.

RESULTS: When compared with the model group, the colon length (P < 0.05) and body weight (P < 0.01) in the treatment and prevention groups were significantly increased, and the colon HDS was decreased (P < 0.05 and P < 0.01). There was no statistical difference between the treatment group and prevention group. After treatment with F. prausnitzii supernatant, the plasma levels of IL-17A and IL-6 (P < 0.05), the protein and mRNA expression of IL-17A and RORγt, and the Th17 cell ratio of spleen cells (P < 0.01) were significantly decreased compared to the model group. Plasma IL-4 level in the prevention group was significantly higher than that in the model group (P < 0.05), but there was no significant difference between these two groups in the expression of IL-6 in both the plasma and colon mucosa tissues.

CONCLUSION: F. prausnitzii supernatant exerts protective and therapeutic effects on DSS-induced colitis in mice, probably via inhibition of Th17 differentiation and IL-17A secretion in the plasma and colon mucosa tissues. It can also improve colitis in mice by downregulating IL-6 and prevent colitis by upregulating IL-4.

Protective role of R381Q (rs11209026) polymorphism in IL-23R gene in immune-mediated diseases: A comprehensive review

Interleukin-23 (IL-23) is a regulator of cellular immune responses involved in controlling infection and autoimmune diseases. Strong evidence has shown that IL-23 plays a role in the maintenance of immune responses by influencing the proliferation and survival of IL-17-producing T-helper (TH)-17 cells. The critical role of the IL-23/TH17 axis in immune-mediated diseases has emerged from different studies. It has also been seen that polymorphisms in the IL-23 receptor (IL-23R) gene might influence IL-23 responses. Interestingly, a functional single nucleotide polymorphism (SNP) in the IL-23 receptor gene (IL-23R; rs11209026, 1142 G wild-type A reduced function, Arg381Gln, R381Q) seems to confer a measure of protection against development of inflammatory bowel disease (IBD; Crohn's disease, ulcerative colitis), ankylosing spondylitis, rheumatoid arthritis, psoriasis, thyroiditis, recurrent spontaneous abortion and asthma, suggesting that a perturbation in the IL-23 signaling pathway is likely to be relevant to the pathophysiology of these diseases. The aim of this review was to provide an evaluation of what is currently known about the protective role of R381Q variant in IL-23R gene in immune-based diseases.

Interleukin-23 receptor genetic polymorphisms and ulcerative colitis susceptibility: A meta-analysis

OBJECTIVE

The interleukin-23 receptor (IL-23R) polymorphism has been implicated in susceptibility to ulcerative colitis (UC), but the results remain inconclusive. This study was designed to evaluate whether IL-23R polymorphisms were associated with UC susceptibility.

METHODS

CNKI, WanFang Data, PubMed, MEDLINE, Web of Science, Google Scholar, EBSCO, CBM database and EMBASE were searched until 31 June 2014 for eligible studies on eight IL-23R polymorphisms: rs11209026, rs7517847, rs1209032, rs2201841, rs1343151, rs1088967, rs1495965 and rs1004819. Meta-analysis from all eligible case-control studies was performed to assess the purported associations. Meta-analysis was performed by using the RevMan 5.2 software and STATA package version 12.0.

RESULTS

Sixteen studies with 5438 cases and 7380 controls were included. Overall, our analysis found that variant minor alleles for single nucleotide polymorphisms (SNPs) rs11209026 (Arg381Gln) (dominant model: GG+TG vs. TT, P=0.02, OR=0.71, 95%CI: 0.53-0.94); rs7517847 (recessive model: GG vs. TT, P=0.04, OR=0.80, 95%CI: 0.65-0.99) and rs11209032 [dominant model: GA+AA vs. GG (P=0.04, OR=1.31, 95% CI: 1.01-1.26); AA vs. GG: (P=0.04, OR=1.21, 95% CI: 1.01-1.45)] of IL-23R were associated with UC risk. In stratification analysis by ethnicity, we observed that the rs11209026 and rs7517847 polymorphism of IL-23R could protect against development of UC among Caucasian populations [rs11209026: dominant model (P=0.01, OR=0.69, 95%CI: 0.52-0.92); rs7517847: GG vs. TT (P=0.002, OR=0.69, 95%CI: 0.54-0.87); recessive model (P=0.004, OR=0.73, 95% CI: 0.59-0.90)]; the rs11209032 were associated with a greater risk for UC in Caucasian populations [dominant model (P=0.04, OR=1.13, 95%CI: 1.00-1.26)]; the rs1088967 were associated with a lower risk for UC among Asian populations [dominant model (P=0.04, OR=0.73, 95%CI: 0.54-0.99)]. Moreover, meta-analysis revealed no association between the four alleles of the rs2201841, rs1004819, rs1495965 and rs1343151 polymorphisms and the risk of developing UC in Caucasian and Asian populations.

CONCLUSION

Our meta-analysis supports that two polymorphisms (rs11209026 and rs7517847) in the IL-23 gene may be considered to be protective factors against developing UC among Caucasian populations; while the rs11209032 polymorphisms may increase the risk of UC among Caucasian populations; furthermore, the rs1088967 polymorphisms in the IL-23 gene may be considered to be protective factors against developing UC among Asian populations. Further large case-control studies especially concerning ethnicity differences and genotype-phenotype interaction should be performed to clarify possible roles of IL-23R in UC.

Involvement of IL17A, IL17F and IL23R Polymorphisms in Colorectal Cancer Therapy

IL23/IL17 pathway plays an important role in the development of inflammatory bowel diseases (IBD). In general, the genes encoding the cytokines are genetically polymorphic and polymorphisms in genes IL23R and IL17 have been proved to be associated with its susceptibility to inflammatory diseases as well as cancer including colorectal cancer. Moreover, it has been shown that these interleukins are involved in anti-tumor or pro-tumor effects of various cancers. Previously, we showed that there is a significant association between IL17A, IL17F and IL23R polymorphisms as well as the occurrence of colorectal cancer and the clinical features of the disease. The purpose of the present work is to investigate an association between IL17A, IL17F and IL23R polymorphisms in 102 Tunisian patients with colorectal cancer treatment. The association was analyzed by statistical tools. We found that patients with mutated genotypes of IL17A G197A SNP could be a risk factor for the inefficiency of chemotherapy and radiotherapy. Unlike IL17F variant, patients with wild type genotypes require surgery and adjuvant chemotherapy. On the one hand, we found no evidence that supports a significant association between IL23R polymorphism and the combined genotypes of these three genes and the colorectal cancer treatment. On the other hand, we showed that there is an important interaction between IL17A/IL17F polymorphisms and the stage of the disease as well as its treatment. Finally, patients with IL17F wild type genotype highlighted that there is a valid longer OS without all treatments and with radiotherapy and a neoadjuvant chemotherapy. In contrast, we observed that there are no relationships between IL17A, IL23R and the survival of these patients neither with nor without the treatment. Our results suggest that polymorphisms in IL17A and IL17F genes may be a predictive source of colorectal cancer therapy type. Therefore, IL17F may serve as an independent prognostic factor for overall survival in patients with colorectal cancer.

Correlation of IL-17 Level in Synovia and Severity of Knee Osteoarthritis

Background

The aim of this study was to evaluate the role of interleukin-17 (IL-17) level in synovia and its relationship with the severity of knee osteoarthritis (OA).

Material/Methods

We enrolled 226 OA patients and 106 controls in this study. The symptomatic/radiation severity of OA was assessed by the Western Ontario McMaster University Osteoarthritis Index (WOMAC) pain score/Kellgren-Lawrence (KL) grading system. Serum IL-17 levels were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Synovia IL-17 levels were significantly higher in OA patients compared with controls (P<0.01), and were negatively correlated with OA severity. IL-17 level gradually decreased among different phases but lacked statistical significance.

Conclusions

IL-17 might play a crucial role in the pathogenesis of OA and is closely related to pain. Blocking the IL-17 signaling pathway may delay pain related to OA.

Interleukin-17 SNPs and serum levels increase ulcerative colitis risk: A meta-analysis

AIM: To investigate the associations of interleukin-17 (IL-17) genetic polymorphisms and serum levels with ulcerative colitis (UC) risk.

METHODS: Relevant articles were identified through a search of the following electronic databases, excluding language restriction: (1) the Cochrane Library Database (Issue 12, 2013); (2) Web of Science (1945-2013); (3) PubMed (1966-2013); (4) CINAHL (1982-2013); (5) EMBASE (1980-2013); and (6) the Chinese Biomedical Database (1982-2013). Meta-analysis was conducted using STATA 12.0 software. Crude odds ratios and standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated. All of the included studies met all of the following five criteria: (1) the study design must be a clinical cohort or a case-control study; (2) the study must relate to the relationship between IL-17A/F genetic polymorphisms or serum IL-17 levels and the risk of UC; (3) all patients must meet the diagnostic criteria for UC; (4) the study must provide sufficient information about single nucleotide polymorphism frequencies or serum IL-17 levels; and (5) the genotype distribution of healthy controls must conform to the Hardy-Weinberg equilibrium (HWE). The Newcastle-Ottawa Scale (NOS) criteria were used to assess the methodological quality of the studies. The NOS criteria included three aspects: (1) subject selection: 0-4; (2) comparability of subjects: 0-2; and (3) clinical outcome: 0-3. NOS scores ranged from 0 to 9, with a score ≥ 7 indicating good quality.

RESULTS: Of the initial 177 articles, only 16 case-control studies met all of the inclusion criteria. A total of 1614 UC patients and 2863 healthy controls were included in this study. Fourteen studies were performed on Asian populations, and two studies on Caucasian populations. Results of the meta-analysis revealed that IL-17A and IL-17F genetic polymorphisms potentially increased UC risk under both allele and dominant models (P < 0.001 for all). The results also showed that UC patients had higher serum IL-17 levels than healthy controls (SMD = 5.95, 95%CI: 4.25-7.65, P < 0.001). Furthermore, serum IL-17 levels significantly correlated with the severity of UC (moderate vs mild: SMD = 2.59, 95%CI: 0.03-5.16, P < 0.05; severe vs mild: SMD = 7.09, 95%CI: 3.96-10.23, P < 0.001; severe vs moderate: SMD = 5.84, 95%CI: 5.09-6.59, P < 0.001). The NOS score was ≥ 5 for all of the included studies. Based on the sensitivity analysis, no single study influenced the overall pooled estimates. Neither the Begger’s funnel plots nor Egger’s test displayed strong statistical evidence for publication bias (IL-17A/F genetic polymorphisms: t = -2.60, P = 0.019; serum IL-17 levels: t = -1.54, P = 0.141).

CONCLUSION: The findings strongly suggest that IL-17A/F genetic polymorphisms and serum IL-17 levels contribute to the development and progression of UC.

Genetic update on inflammatory factors in ulcerative colitis: Review of the current literature

Ulcerative colitis (UC) is one of the main types of inflammatory bowel disease, which is caused by dysregulated immune responses in genetically predisposed individuals. Several genetic factors, including interleukin and interleukin receptor gene polymorphisms and other inflammation-related genes play central role in mediating and modulating the inflammation in the human body, thereby these can be the main cause of development of the disease. It is clear these data are very important for understanding the base of the disease, especially in terms of clinical utility and validity, but summarized literature is exiguous for challenge health specialist that can used in the clinical practice nowadays. This review summarizes the current literature on inflammation-related genetic polymorphisms which are associated with UC. We performed an electronic search of Pubmed Database among publications of the last 10 years, using the following medical subject heading terms: UC, ulcerative colitis, inflammation, genes, polymorphisms, and susceptibility.

Interleukin and interleukin receptor gene polymorphisms in inflammatory bowel diseases susceptibility

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), represents a group of chronic inflammatory disorders caused by dysregulated immune responses in genetically predisposed individuals. Genetic markers are associated with disease phenotype and long-term evolution, but their value in everyday clinical practice is limited at the moment. IBD has a clear immunological background and interleukins play key role in the process. Almost 130 original papers were revised including meta-analysis. It is clear these data are very important for understanding the base of the disease, especially in terms of clinical utility and validity, but text often do not available for the doctors use these in the clinical practice nowadays. We conducted a systematic review of the current literature on interleukin and interleukin receptor gene polymorphisms associated with IBD, performing an electronic search of PubMed Database from publications of the last 10 years, and used the following medical subject heading terms and/or text words: IBD, CD, UC, interleukins and polymorphisms.

Significant association between IL23R and IL17F polymorphisms and clinical features of colorectal cancer

Th17cells are involved in inflammatory and autoimmune diseases. These cells may be involved in pathological processes mainly producing pro-inflammatory cytokines. Recently, it was shown that the IL23/IL17 pathway plays an important role in the development of inflammatory bowel disease. In general, genes encoding cytokines are genetically polymorphic and polymorphisms in genes IL23R el IL17F were shown associated with susceptibility to Crohn's disease and ulcerative colitis which in their turn are considered as risk factors for developing colorectal cancer (CRC). Our approach is to study IL17F and IL23R polymorphisms as risk factor associated with CRC in the Tunisian population in patients and healthy controls. Interesting, we noted a significant association between IL17F and IL23R polymorphisms and tumor location (p=0.0001 and p=0.049, respectively), tumor histology (p=0.007 and p=0.049, respectively) and tumor architecture (p=0.0000000001 and p=0.07, respectively) in CRC patients. We also showed a significant association of IL17F variant with an increased risk of TNM stage III/IV (p=0.007), showing an increased risk of advanced stage. Finally, we observed a positive link between IL17F polymorphism and CRC patients with lymph nodes (p=0.0000000001) and metastasis (p=0.00000009). However, we found no evidence to support a significant association between IL17F and IL23R polymorphisms and colorectal cancer susceptibility. Our findings suggest that IL17F and IL23R polymorphisms were significantly associated with clinical features variables. The IL17F cytokine appear to be involved in the control of tumor growth and invasion of gastrointestinal tumors. IL17 and IL23 polymorphisms or those of their receptors as important determinants of susceptibility to colorectal cancer are still subject to questioning.

Marked differences of haplotype tagging SNP distribution, linkage, and haplotype profile of IL23 receptor gene in Roma and Hungarian population samples

Polymorphisms of the interleukin-23 receptor (IL23R) gene have been found to play an important role in the development of several autoimmune diseases. We examined five susceptible (rs10889677, rs1004819, rs2201841, rs11805303, rs11209032), one protective (rs7517847) and two neutral variants (rs7530511, rs1884444) of the IL23R gene in pooled DNA of healthy Roma (Gipsy) and Hungarian population samples. Our aim was to determine the genetic variability of the major haplotype tagging polymorphisms, and the haplotype profile of IL23R between the two groups. We analyzed 273 healthy Roma and 253 Hungarian DNA samples using PCR/RFLP assay. Comparing the five susceptible conferring alleles, there were significant increase (p<0.05), while in the protective alleles, there were decrease in the allele frequencies in Roma population (p<0.05). One of the neutral alleles showed increase, the another one did not differ between the two groups. The haplotype analysis of the SNPs revealed fundamentally different association types of SNPs in the two groups; moreover, the frequencies of the various haplotypes also exhibited strong differences, as of ht4 and ht5 haplotypes were significantly higher, whereas the frequencies of ht2 and ht3 haplotypes were significantly lower in the Roma population than in Hungarians (p<0.05). The data presented here show profound differences in the IL23R genetic profiles in the Roma population, that likely has also clinical implications in respect their possible role in the development of certain immunological diseases.