An IL-13 promoter polymorphism associated with increased risk of allergic asthma

Association of IL13 polymorphisms with susceptibility to myocardial infarction: A case-control study in Chinese population

BACKGROUND

Inflammatory cytokines play a major role in the pathogenesis of myocardial infarction (MI). Although information on the importance of interleukin 13 (IL13) in human MI is limited, it has been well documented in the mouse model. Genetic variation in the IL13 gene has been associated with the structure and expression of the IL13. In the present study, we hypothesized that IL13 common genetic variants would be associated with a predisposition to the development of MI.

MATERIALS AND METHODS

The present study enrolled 305 MI patients and 310 matched healthy controls. Common genetic polymorphisms in the IL13 gene (rs20541, rs1881457, and rs1800925) were genotyped using the TaqMan SNP genotyping method. Plasma levels of IL13 were measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

In MI patients, minor alleles of the IL13 rs1881457 and rs1800925 polymorphisms were less common than in healthy controls [rs1881457: AC (P = 0.004, OR = 0.61), C (P = 0.001, OR = 0.66); rs1800925: CT (P = 0.006, OR = 0.59)]. Further haplotype analysis of three studied SNPs revealed a significant association with predisposition to MI. Interestingly, IL13 rs1881457 and rs1800925 were linked to plasma levels of IL13: the reference genotype had higher levels, heterozygotes were intermediate, and the alternate genotype had the lowest levels.

CONCLUSIONS

In the Chinese population, IL13 (rs1881457 and rs180092) variants are associated with different plasma IL13 levels and offer protection against MI development. However, additional research is required to validate our findings in different populations, including descent samples.

Association of interleukin-4, interleukin-13 gene polymorphisms, HLA-DQ and DR genotypes with genetic susceptibility of type-1 Diabetes Mellitus in Kuwaiti children

Background

Type-1 diabetes mellitus (T1DM) is a complex multifactorial disease with an autoimmune etiology and is thought to result from an interaction between genetic and non-genetic factors. Cytokines play a crucial role in the pathogenesis of autoimmune diseases due to their effector and regulatory functions in immune responses. Interleukin-4 (IL4) and Interleukin-13 (IL13) are anti-inflammatory cytokines and are considered as important mediators in pathology of the autoimmune diseases.

Methods

We have determined the genotype frequency of IL4 gene promoter polymorphism (-590C/T, rs2243250), IL13 gene polymorphism p.(Arg130Glu, rs20541) and human leukocyte antigen, HLA-DQ and DR genotypes in Kuwaiti children with T1DM to investigate their role in genetic susceptibility. This study included 261 Kuwaiti children with T1DM and 214 healthy controls. The genotypes for IL4 (-590C/T) and IL13 p.(Arg130Glu) gene polymorphisms were detected by PCR-RFLP methods. HLA-DQ and DR genotypes were determined by sequence-specific PCR methods.

Results

The CC genotype of IL4 gene polymorphism (-590C/T) was significantly related to the risk for T1DM in Kuwaiti patients (OR 1.64). The homozygous AA (QQ) and heterozygous AG (RQ) genotypes of IL13 gene polymorphism p.(Arg130Glu), also manifested a statistically significant association with T1DM (OR 2.92 and 4.79). In 55% T1DM patients, the HLA genotype was either DQ2/DQ2 or in combination with a DQ8 allele. Collectively, 91% Kuwaiti T1DM patients had either DQ2 or DQ8 alleles in different combinations highlighting them as the high risk-genotypes in comparison to the controls. In the case of HLA-DR, the genotypes DR3/DRB5, DR3/DR4, DR3/DR7 and DR4/DR4 showed highest frequency amongst the Kuwaiti T1DM patients and thus can be considered as high-risk genotypes when compared to the controls. A high degree of co-inheritance (>80%) was detected between IL4 and IL13 gene polymorphism genotypes (CC and QQ) and the high-risk HLA-DQ and DR genotypes amongst the Kuwaiti T1DM patients.

Conclusions

We have identified the association of IL4 and IL13 gene polymorphisms with susceptibility to T1DM in Kuwaiti children and the co-inheritance of these polymorphisms with high-risk HLA genotypes. The findings may contribute to early identification of childhood diabetes.

Potential Metabolic Biomarkers in Adult Asthmatics

Asthma is the most common chronic airway inflammation, with multiple phenotypes caused by complicated interactions of genetic, epigenetic, and environmental factors. To date, various determinants have been suggested for asthma pathogenesis by a new technology termed omics, including genomics, transcriptomics, proteomics, and metabolomics. In particular, the systematic analysis of all metabolites in a biological system, such as carbohydrates, amino acids, and lipids, has helped identify a novel pathway related to complex diseases. These metabolites are involved in the regulation of hypermethylation, response to hypoxia, and immune reactions in the pathogenesis of asthma. Among them, lipid metabolism has been suggested to be related to lung dysfunction in mild-to-moderate asthma. Sphingolipid metabolites are an important mediator contributing to airway inflammation in obese asthma and aspirin-exacerbated respiratory disease. Although how these molecular variants impact the disease has not been completely determined, identification of new causative factors may possibly lead to more-personalized and precise pathway-specific approaches for better diagnosis and treatment of asthma. In this review, perspectives of metabolites related to asthma and clinical implications have been highlighted according to various phenotypes.

Interleukin-13 rs1800925/-1112C/T promoter single nucleotide polymorphism variant linked to anti-schistosomiasis in adult males in Murehwa District, Zimbabwe

Background

Chronic schistosomiasis is predominantly induced through up-regulation of inflammatory cytokines such as interleukin (IL)-13. IL-13 may contribute to the disease outcomes by increasing eosinophil infiltration thereby promoting fibrosis. IL-13 may act as an immunosuppressive inflammatory cytokine that may promote carcinogenesis and also may offer protection against schistosomiasis thereby reducing risk of schistosome infections. Our study evaluated the frequency of the IL-13 rs1800925/-1112 C/ T promoter single nucleotide polymorphisms (SNPs) among schistosomiasis infected individuals and assessed the association of the variants on IL-13 cytokine levels. We also investigated IL-13 rs1800925 polymorphisms on prostate-specific antigen levels as an indicator for risk of prostate cancer development.

Methodology

The study was cross-sectional and included 50 schistosomiasis infected and 316 uninfected male participants residing in Murehwa District, Zimbabwe. IL-13 rs1800925 SNPs were genotyped by allele amplification refractory mutation system-polymerase chain reaction. Concentrations of serum prostate-specific antigens and plasma IL-13 were measured using enzyme-linked immunosorbent assay.

Results

Frequencies of the genotypes CC, CT and TT, were 20%, 58% and 22% in schistosomiasis infected, and 18.3%, 62.1% and 19.6% in uninfected participants with no statistical differences. There were significantly (p<0.05) higher IL-13 cytokine levels among both infected and uninfected participants with the genotypes CC and CT; median 92.25 pg/mL and 106.5 pg/mL, respectively, compared to TT variant individuals; 44.78 pg/mL. Within the schistosomiasis uninfected group, CC and CT variants had significantly (p<0.05) higher IL-13 levels; median 135.0 pg/mL and 113.6 pg/mL, respectively compared to TT variant individuals; 47.15 pg/mL. Within the schistosomiasis infected group, CC, CT and TT variant individuals had insignificant differences of IL-13 level. Using logistic regression, no association was observed between prostate-specific antigen levels, IL-13 cytokine levels and IL-13 rs1800925 variants (p>0.05).

Conclusion

IL-13 rs1800925 C variant individuals had the highest IL-13 cytokine levels among the schistosomiasis uninfected suggesting that they may be protective against Schistosoma infections. There was no association between IL-13 concentrations or IL-13 rs1800925 variants and risk of prostate cancer indicating that IL-13 levels and IL-13 rs10800925 may not be utilised as biomarker for risk of prostate cancer in schistosome infections.

The Genetics of Human Schistosomiasis Infection Intensity and Liver Disease: A Review

Schistosomiasis remains the fourth most prevalent parasitic disease affecting over 200 million people worldwide. Control efforts have focussed on the disruption of the life cycle targeting the parasite, vector and human host. Parasite burdens are highly skewed, and the majority of eggs are shed into the environment by a minority of the infected population. Most morbidity results from hepatic fibrosis leading to portal hypertension and is not well-correlated with worm burden. Genetics as well as environmental factors may play a role in these skewed distributions and understanding the genetic risk factors for intensity of infection and morbidity may help improve control measures. In this review, we focus on how genetic factors may influence parasite load, hepatic fibrosis and portal hypertension. We found 28 studies on the genetics of human infection and 20 studies on the genetics of pathology in humans. S. mansoni and S. haematobium infection intensity have been showed to be controlled by a major quantitative trait locus SM1, on chromosome 5q31-q33 containing several genes involved in the Th2 immune response, and three other loci of smaller effect on chromosomes 1, 6, and 7. The most common pathology associated with schistosomiasis is hepatic and portal vein fibroses and the SM2 quantitative trait locus on chromosome six has been linked to intensity of fibrosis. Although there has been an emphasis on Th2 cytokines in candidate gene studies, we found that four of the five QTL regions contain Th17 pathway genes that have been included in schistosomiasis studies: IL17B and IL12B in SM1, IL17A and IL17F in 6p21-q2, IL6R in 1p21-q23 and IL22RA2 in SM2. The Th17 pathway is known to be involved in response to schistosome infection and hepatic fibrosis but variants in this pathway have not been tested for any effect on the regulation of these phenotypes. These should be priorities for future studies.

Genetic polymorphism patterns suggest a genetic driven inflammatory response as pathogenesis in appendicitis

PURPOSE

The pathogenesis of appendicitis is not well understood. Environmental factors are regarded most important, but epidemiologic findings suggest a role of inflammatory and genetic mechanisms. This study determines the association of single nucleotide polymorphisms (SNPs) of inflammatory genes with appendicitis.

METHODS

As part of a larger prospective study on the diagnostic value of inflammatory variables in appendicitis, the genotype frequency of 28 polymorphisms in 26 inflammatory response genes from the appendicitis and control patients was analyzed in blood samples from 343 patients, 100 with appendicitis, and 243 with non-specific abdominal pain, using TaqMan SNP genotyping assays.

RESULTS

Associations with appendicitis were found for SNPs IL-13 rs1800925 with odds ratio (OR) 6.02 (95% CI 1.52-23.78) for T/T versus C/C + T/T, for IL-17 rs2275913 with OR 2.38 (CI 1.24-4.57) for A/A vs G/G + GA, for CCL22 rs223888 with OR 0.12 (0.02-0.90), and for A/A vs G/G + GA. Signs of effect modification of age for the association with appendicitis were found for IL-13 rs1800925 and CTLA4 rs3087243. Stratified analysis showed difference in association with severity of disease for IL-17 rs2275913 and CD44 rs187115.

CONCLUSIONS

The association of gene variants on risk of appendicitis and its severity suggest an etiologic role of genetically regulated inflammatory response. This may have implications for understanding the prognosis of untreated appendicitis as a possible self-limiting disorder and for understanding the inverse association of appendicitis with ulcerative colitis.

Association of cytokine Th2 gene polymorphisms with autoimmune thyroid diseases in Tunisian population

Autoimmune thyroid diseases (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT) are complex genetic diseases. Th2 cytokines act on the development of AITD. This study was conducted on Tunisian patients with AITD to investigate the association of Th2 cytokine gene polymorphisms and haplotype combination with GD or HT risk. A total of 156 controls, 160 patients with HT and 88 patients with GD were genotyped for IL-4 rs2243250, IL-5 rs2069812, IL-6 rs1800796 and IL-13 rs1800925 polymorphisms by PCR-RFLP. The AITD risk was assessed by a logistic regression analysis using the SNP stats statistical program. False-positive report probability (FPRP) was estimated to evaluate significant findings. IL-13 rs1800925 was associated with GD, after adjustment for age and gender, in codominant, dominant and allele genetic models (p = .0072; p = .0018; p = .012, respectively). Significant association of the IL-6 rs1800796C/G genotype with GD was also detected (p = .025). Furthermore, increased risk of HT was still found for IL-13 rs1800925T allele (p = .039, OR = 1.39) and for IL-4 rs2243250T/T genotype both in codominant (p = .033, OR = 2.59) and recessive (p = .011, OR = 2.73) models after adjustment for age and gender. Interestingly, haplotype analysis performed on the IL-4, IL-5 and IL-13 genes revealed a high risk of HT with CTT haplotype (p = .008, OR = 2.12). However, the CCT haplotype is a protective factor (OR = 0.36). Patients carrying the CT haplotype with only one minor allele had a moderate risk of HT (OR = 1.56). The FPRP analysis showed that the association of IL-13 rs1800925 polymorphism with GD and HT and the association of CTT haplotype with HT were noteworthy. In conclusion, the IL-4, IL-5, IL-6 and IL-13 polymorphism may play a role in susceptibility to GD and HT in the Tunisian population. Furthermore, gene-gene interaction between the IL-4, IL-5 and IL-13 significantly increases the risk of AITD. Further studies with larger numbers of individuals are needed to confirm the results.

Relationship between various cytokines implicated in asthma

Asthma is a complex disorder involving immunologic, environmental, genetic and other factors. Today, asthma is the most common disease encountered in clinical medicine in both children and adults worldwide. Asthma is characterized by increased responsiveness of the tracheobronchial tree resulting in chronic swelling and inflammation of the airways recognized to be controlled by the T-helper 2 (Th2) lymphocytes, which secrete cytokines to increase the production of IgE by B cells. There are many cytokines implicated in the development of the chronic inflammatory processes that are often observed in asthma. Ultimately, these cytokines cause the release of mediators such as histamine and leukotrienes (LT), which in turn promote airway remodeling, bronchial hyperresponsiveness and bronchoconstriction. The CD4⁺ T-lymphocytes from the airways of asthmatics express a panel of cytokines that represent the Th2 cells. The knowledge derived from numerous experimental and clinical studies have allowed physicians and scientists to understand the normal functions of these cytokines and their roles in the pathogenesis of asthma. The main focus of this review is to accentuate the relationship between various cytokines implicated in human asthma. However, some key findings from animal models will be highlighted to support the discoveries from clinical studies.

Association of Imatinib Plasma Concentration and Single-nucleotide Polymorphisms with Adverse Drug Reactions in Patients with Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GIST) are the most prevalent mesenchymal tumors of the digestive tract. To investigate the association of imatinib mesylate plasma concentration with adverse drug reactions (ADRs) and influences of genetic polymorphisms on ADRs in GIST patients taking imatinib, a cohort of GIST patients consecutively treated with imatinib were included in the observational study. Clinical, pathologic and genotype information was recorded at enrollment and blood samples were collected at time as design. The plasma concentration of the imatinib was detected by LC-MS/MS. A questionnaire was used to evaluate the ADRs at each visit. SNPs in 13 genes were analyzed for a possible association with ADRs. The mean plasma trough concentration of 129 patients taking imatinib was 1.45 ± 0.79 μg/ml, average peak concentration was 2.63 ± 1.07 μg/ml. The imatinib concentration in patients treated with 600 mg/day was significantly higher than other dosage groups (P < 0.05). The ADRs were mostly mild. Edema, vomiting, and fatigue were significantly correlated with imatinib concentration (P < 0.05). Mutations of IL13 rs1800925 and CXCL14 rs7716492 were related with the incidence of leukopenia and rash in our research, separately (P < 0.05). We confirmed that with the increase of imatinib concentration, the incidence of edema, vomiting, and fatigue rises as well. Mutations of IL13 rs1800925 and CXCL14 rs7716492 may be the promising biomarkers to predict the ADRs of imatinib. The results of the study are of guiding significance for the use of imatinib in patients with GIST.

The Initiation of Th2 Immunity Towards Food Allergens

In contrast with Th1 immune responses against pathogenic viruses and bacteria, the incipient events that generate Th2 responses remain less understood. One difficulty in the identification of universal operating principles stems from the diversity of entities against which cellular and molecular Th2 responses are produced. Such responses are launched against harmful macroscopic parasites and noxious substances, such as venoms, but also against largely innocuous allergens. This suggests that the established understanding about sense and recognition applied to Th1 responses may not be translatable to Th2 responses. This review will discuss processes and signals known to occur in Th2 responses, particularly in the context of food allergy. We propose that perturbations of homeostasis at barrier sites induced by external or internal subverters, which can activate or lower the threshold activation of the immune system, are the major requirement for allergic sensitization. Innate signals produced in the tissue under these conditions equip dendritic cells with a program that forms an adaptive Th2 response.

Global issues in allergy and immunology: Parasitic infections and allergy

Allergic diseases are on the increase globally in parallel with a decrease in parasitic infection. The inverse association between parasitic infections and allergy at an ecological level suggests a causal association. Studies in human subjects have generated a large knowledge base on the complexity of the interrelationship between parasitic infection and allergy. There is evidence for causal links, but the data from animal models are the most compelling: despite the strong type 2 immune responses they induce, helminth infections can suppress allergy through regulatory pathways. Conversely, many helminths can cause allergic-type inflammation, including symptoms of "classical" allergic disease. From an evolutionary perspective, subjects with an effective immune response against helminths can be more susceptible to allergy. This narrative review aims to inform readers of the most relevant up-to-date evidence on the relationship between parasites and allergy. Experiments in animal models have demonstrated the potential benefits of helminth infection or administration of helminth-derived molecules on chronic inflammatory diseases, but thus far, clinical trials in human subjects have not demonstrated unequivocal clinical benefits. Nevertheless, there is sufficiently strong evidence to support continued investigation of the potential benefits of helminth-derived therapies for the prevention or treatment of allergic and other inflammatory diseases.

Genetic variation at the Th2 immune gene IL13 is associated with IgE-mediated paediatric food allergy

BACKGROUND

Food allergies pose a considerable world-wide public health burden with incidence as high as one in ten in 12-month-old infants. Few food allergy genetic risk variants have yet been identified. The Th2 immune gene IL13 is a highly plausible genetic candidate as it is central to the initiation of IgE class switching in B cells.

OBJECTIVE

Here, we sought to investigate whether genetic polymorphisms at IL13 are associated with the development of challenge-proven IgE-mediated food allergy.

METHOD

We genotyped nine IL13 "tag" single nucleotide polymorphisms (tag SNPs) in 367 challenge-proven food allergic cases, 199 food-sensitized tolerant cases and 156 non-food allergic controls from the HealthNuts study. 12-month-old infants were phenotyped using open oral food challenges. SNPs were tested using Cochran-Mantel-Haenszel test adjusted for ancestry strata. A replication study was conducted in an independent, co-located sample of four paediatric cohorts consisting of 203 food allergic cases and 330 non-food allergic controls. Replication sample phenotypes were defined by clinical history of reactivity, 95% PPV or challenge, and IL13 genotyping was performed.

RESULTS

IL13 rs1295686 was associated with challenge-proven food allergy in the discovery sample (P=.003; OR=1.75; CI=1.20-2.53). This association was also detected in the replication sample (P=.03, OR=1.37, CI=1.03-1.82) and further supported by a meta-analysis (P=.0006, OR=1.50). However, we cannot rule out an association with food sensitization. Carriage of the rs1295686 variant A allele was also associated with elevated total plasma IgE.

CONCLUSIONS AND CLINICAL RELAVANCE

We show for the first time, in two independent cohorts, that IL13 polymorphism rs1295686 (in complete linkage disequilibrium with functional variant rs20541) is associated with challenge-proven food allergy.

Role of IL-13 Genetic Variants in Signalling of Asthma

Asthma is a chronic inflammatory disease of the lower airways characterised by intermittent airway narrowing and airflow obstruction. The aim of this study was to examine the association of IL-13 Arg 130 Gln (A/G) and -1112C/T cytokine gene polymorphisms and to know the secretion of IL-13 cytokine levels and the interactions between the IL-13 130A/G and IL-13Rα1/IL-4Rα complex cytokine genes. The study population comprised of atopic and non-atopic asthma patients and healthy controls (HC) (N = 120). Single nucleotide polymorphisms (SNPs) were determined by restriction fragment length polymorphism (RFLP). IL-13 cytokine serum levels were measured by enzyme-linked immunosorbent assay (ELISA), and homology modelling of IL-13 A/G cytokine gene was performed through in silico analysis. In IL-13 130A/G cytokine gene AG, GG genotypes (p < 0.0042, OR = 2.87, CI 1.46-5.65; OR = 1.92, CI 1.06-3.48) were found to be significant in atopic asthma patients vs HC. The mean IL-13 serum cytokine levels were found to be significantly high in atopic (38.48 ± 36.54) and non-atopic (36.05 ± 34.54) asthma patients whereas total serum IgE levels were significantly high at p < 0.0001 in atopic and low in non-atopic asthma patients at p < 0.003 compared to HC. In silico analysis indicated that residue IL-13 130 with charge modifying variants was crucial in ligand-receptor interactions. IL-13 cytokine serum levels were significantly high in atopic and non-atopic asthma patients compared to HC. The GG genotype of IL-13 130A/G cytokine gene might be involved in the induced production of total IgE and IL-13 cytokine serum levels suggesting IL-13 may be important in the signalling of asthma.

Strategies targeting the IL-4/IL-13 axes in disease

IL-4 and IL-13 are pleiotropic Th2 cytokines produced by a wide variety of different cell types and responsible for a broad range of biology and functions. Physiologically, Th2 cytokines are known to mediate host defense against parasites but they can also trigger disease if their activities are dysregulated. In this review we discuss the rationale for targeting the IL-4/IL-13 axes in asthma, atopic dermatitis, allergic rhinitis, COPD, cancer, inflammatory bowel disease, autoimmune disease and fibrotic disease as well as evaluating the associated clinical data derived from blocking IL-4, IL-13 or IL-4 and IL-13 together.

A Mutation in IL4RA Is Associated with the Degree of Pathology in Human TB Patients

The contribution of interleukin- (IL-) 4 receptor-alpha- (Rα-) dependent events in the pathogenesis of tuberculosis (TB) is controversial. We have recently shown IL-13 overexpression in mice to cause recrudescent Mtb replication and centrally necrotizing granulomas strongly resembling pathology of human TB. A deletion of IL-4Rα completely abrogates TB tissue pathology in these mice. To validate our results in human TB patients, we here determined the association of distinct variants of the IL4, IL13, IL4RA, IL13RA1, and IL13RA2 genes with cavity formation in a large Ghanaian cohort of HIV-negative individuals with newly diagnosed pulmonary TB. In fact, the structural variant of the IL4RA I50V, previously shown to result in enhanced signal transduction, was significantly associated with greater cavity size, and a variant of IL13RA2 was associated with disease in females. To evaluate whether the human-like TB pathology in IL-13-overexpressing mice is specifically mediated through the IL-4Rα subunit, we analyzed IL-13 transgenic mice with a genetic ablation of the IL-4Rα. In these mice, the IL-13-mediated increased susceptibility, human-like pathology of collagen deposition around centrally necrotizing granulomas, and alternative macrophage activation were abolished. Together, our genetic association study in human TB patients further supports the assumption that IL-13/IL-4Rα-dependent mechanisms are involved in mediating tissue pathology of human TB.

Polymorphisms in Host Immunity-Modulating Genes and Risk of Invasive Aspergillosis: Results from the AspBIOmics Consortium

Recent studies suggest that immune-modulating single-nucleotide polymorphisms (SNPs) influence the risk of developing cancer-related infections. Here, we evaluated whether 36 SNPs within 14 immune-related genes are associated with the risk of invasive aspergillosis (IA) and whether genotyping of these variants might improve disease risk prediction. We conducted a case-control association study of 781 immunocompromised patients, 149 of whom were diagnosed with IA. Association analysis showed that the IL4Rrs2107356 and IL8rs2227307 SNPs (using dbSNP numbering) were associated with an increased risk of IA (IL4Rrs2107356 odds ratio [OR], 1.92; 95% confidence interval [CI], 1.20 to 3.09; IL8rs2227307 OR, 1.73; 95% CI, 1.06 to 2.81), whereas the IL12Brs3212227 and IFNγrs2069705 variants were significantly associated with a decreased risk of developing the infection (IL12Brs3212227 OR, 0.60; 95% CI, 0.38 to 0.96; IFNγrs2069705 OR, 0.63; 95% CI, 0.41 to 0.97). An allogeneic hematopoietic stem cell transplantation (allo-HSCT)-stratified analysis revealed that the effect observed for the IL4Rrs2107356 and IFNγrs2069705 SNPs was stronger in allo-HSCT (IL4Rrs2107356 OR, 5.63; 95% CI, 1.20 to 3.09; IFNγrs2069705 OR, 0.24; 95% CI, 0.10 to 0.59) than in non-HSCT patients, suggesting that the presence of these SNPs renders patients more vulnerable to infection, especially under severe and prolonged immunosuppressive conditions. Importantly, in vitro studies revealed that carriers of the IFNγrs2069705C allele showed a significantly increased macrophage-mediated neutralization of fungal conidia (P = 0.0003) and, under stimulation conditions, produced higher levels of gamma interferon (IFNγ) mRNA (P = 0.049) and IFNγ and tumor necrosis factor alpha (TNF-α) cytokines (P value for 96 h of treatment with lipopolysaccharide [PLPS-96 h], 0.057; P value for 96 h of treatment with phytohemagglutinin [PPHA-96 h], 0.036; PLPS+PHA-96 h = 0.030; PPHA-72 h = 0.045; PLPS+PHA-72 h = 0.018; PLPS-96 h = 0.058; PLPS+PHA-96 h = 0.0058). Finally, we also observed that the addition of SNPs significantly associated with IA to a model including clinical variables led to a substantial improvement in the discriminatory ability to predict disease (area under the concentration-time curve [AUC] of 0.659 versus AUC of 0.564; P-2 log likehood ratio test = 5.2 · 10(-4) and P50.000 permutation test = 9.34 · 10(-5)). These findings suggest that the IFNγrs2069705 SNP influences the risk of IA and that predictive models built with IFNγ, IL8, IL12p70, and VEGFA variants can used to predict disease risk and to implement risk-adapted prophylaxis or diagnostic strategies.

Pleiotropic Effects of Immune Responses Explain Variation in the Prevalence of Fibroproliferative Diseases

Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to helminthic infections, and concurrently increases susceptibility to fibrosis due to the profibrotic action of Th2 cytokines. Many studies on selection of Th2-related genes for host resistance to helminths have been reported, but the pleiotropic impact of this selection on the distribution of fibrotic disorders has not been explicitly investigated. We discuss the disproportionate occurrence of fibroproliferative diseases in individuals of African ancestry and provide evidence that adaptation of the immune system has shaped the genetic structure of these human populations in ways that alter the distribution of multiple fibroproliferative diseases.

Association of single nucleotide polymorphisms in IL8 and IL13 with sunitinib-induced toxicity in patients with metastatic renal cell carcinoma

Purpose

Earlier, the association of single nucleotide polymorphisms (SNPs) with toxicity and efficacy of sunitinib has been explored in patients with metastatic renal cell carcinoma (mRCC). Recently, additional SNPs have been suggested as potential biomarkers. We investigated these novel SNPs for association with sunitinib treatment outcome in mRCC patients.

Methods

In this exploratory study, we selected SNPs in genes CYP3A4, NR1I2, POR, IL8, IL13, IL4-R, HIF1A and MET that might possibly be associated with sunitinib treatment outcome. Each SNP was tested for association with progression-free survival (PFS) and overall survival (OS) by Cox-regression analysis and for clinical response and toxicity using logistic regression.

Results

We included 374 patients for toxicity analyses, of which 38 patients with non-clear cell renal cell cancer were excluded from efficacy analyses. The risk for hypertension was increased in the presence of the T allele in IL8 rs1126647 (OR = 1.69, 95 % CI = 1.07–2.67, P = 0.024). The T allele in IL13 rs1800925 was associated with an increase in the risk of leukopenia (OR = 6.76, 95 % CI = 1.35–33.9, P = 0.020) and increased prevalence of any toxicity > grade 2 (OR = 1.75, 95 % CI = 1.06–2.88, P = 0.028). No significant associations were found with PFS, OS or clinical response.

Conclusions

We show that polymorphisms in IL8 rs1126647 and IL13 rs1800925 are associated with sunitinib-induced toxicities. Validation in an independent cohort is required.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-015-1935-7) contains supplementary material, which is available to authorized users.

An IL-13 promoter polymorphism associated with liver fibrosis in patients with Schistosoma japonicum

The aim of this study was to determine whether two polymorphisms in the gene encoding IL13 previously associated with Schistosoma hematobium (S. hematobium) and S. mansoni infection are associated with S. japonicum infection. Single nucleotide polymorphisms (SNPs) rs1800925 (IL13/-1112C>T) and rs20541 (IL13R130Q) were genotyped in 947 unrelated individuals (307 chronically infected, 339 late-stage with liver fibrosis, 301 uninfected controls) from a schistosomiasis-endemic area of Hubei province in China. Regression models were used to evaluate allelic and haplotypic associations with chronic and late-stage schistosomiasis adjusted for non-genetic covariates. Expression of IL-13 was measured in S. japonicun-infected liver fibrosis tissue and normal liver tissue from uninfected controls by immunohistochemistry (IHC). The role of rs1800925 in IL-13 transcription was further determined by Luciferase report assay using the recombinant PGL4.17-rs180092 plasmid. We found SNP rs1800925T was associated with late-stage schistosomiasis caused by S. japonicum but not chronic schistosomiasis (OR = 1.39, 95%CI = 1.02-1.91, p = 0.03) and uninfected controls (OR = 1.49, 95%CI = 1.03-2.13, p = 0.03). Moreover, the haplotype rs1800925T-rs20541C increased the risk of disease progression to late-stage schistosomiasis (OR = 1.46, p = 0.035), whereas haplotype rs1800925C-rs20541A showed a protective role against development of late-stage schistosomiasis (F = 0.188, OR = 0.61, p = 0.002). Furthermore, S. japonicum-induced fibrotic liver tissue had higher IL13 expression than normal liver tissue. Plasmid PGL4.17-rs1800925T showed a stronger relative luciferase activity than Plasmid PGL4.17-rs1800925C in 293FT, QSG-7701 and HL-7702 cell lines. In conclusion, the functional IL13 polymorphism, rs1800925T, previously associated with risk of schistosomiasis, also contributes to risk of late-stage schistosomiasis caused by S. japonicum.

Identification and practical management of latex allergy in occupational settings

Allergy to natural rubber latex (NRL) from Hevea brasiliensis is a relevant occupational health hazard. The use of gloves and products manufactured with latex and environmental allergen exposure in the work environment are risks factors for the development of occupational allergy among different job categories. Healthcare workers have been the most commonly affected, but other professions with exposure to latex products such as hairdressers, cleaners, food handlers and those making natural rubber latex (NRL) products are also at risk of developing occupational allergy. Clinical manifestations of IgE-mediated latex allergy can range from troublesome skin disorders to life-threatening systemic reactions. It is very important to identify the occupational allergic diseases in their early stages in order to implement avoidance strategies. For this purpose, the interventions for prevention should emphasize the importance of latex allergy awareness and surveillance among exposed workforces.

Clinical associations of host genetic variations in the genes of cytokines in critically ill patients

Host genetic variations may influence a changing profile of biochemical markers and outcome in patients with trauma/injury. The objective of this study was to assess clinical associations of single nucleotide polymorphisms (SNPs) in the genes of cytokines in critically ill patients. A total of 430 patients were genotyped for SNPs in the genes of pro- (IL1B, IL6, IL8) and anti-inflammatory (IL4, IL10, IL13) cytokines. The main end-points were sepsis, mortality and adult respiratory distress syndrome (ARDS). We evaluated the dynamic levels of bilirubin, blood urea nitrogen, creatine kinase, creatinine and lactate dehydrogenase in five points of measurements (between 1 and 14 days after admission) and correlated them with SNPs. High-producing alleles of proinflammatory cytokines protected patients against sepsis (IL1B -511A and IL8 -251A) and mortality (IL1B -511A). High-producing alleles of anti-inflammatory cytokines IL4 -589T and IL13 431A (144Gln) were less frequent in ARDS patients. The carriers of IL6 -174C/C genotypes were prone to the increased levels of biochemical markers and acute kidney and liver insufficiency. Genotype-dependent differences in the levels of biochemical indicators gradually increased to a maximal value on the 14th day after admission. These findings suggest that genetic variability in pro- and anti-inflammatory cytokines may contribute to different clinical phenotypes in patients at high risk of critical illness.

Phenome-wide association study (PheWAS) in EMR-linked pediatric cohorts, genetically links PLCL1 to speech language development and IL5-IL13 to Eosinophilic Esophagitis

Objective: We report the first pediatric specific Phenome-Wide Association Study (PheWAS) using electronic medical records (EMRs). Given the early success of PheWAS in adult populations, we investigated the feasibility of this approach in pediatric cohorts in which associations between a previously known genetic variant and a wide range of clinical or physiological traits were evaluated. Although computationally intensive, this approach has potential to reveal disease mechanistic relationships between a variant and a network of phenotypes.

Method: Data on 5049 samples of European ancestry were obtained from the EMRs of two large academic centers in five different genotyped cohorts. Recently, these samples have undergone whole genome imputation. After standard quality controls, removing missing data and outliers based on principal components analyses (PCA), 4268 samples were used for the PheWAS study. We scanned for associations between 2476 single-nucleotide polymorphisms (SNP) with available genotyping data from previously published GWAS studies and 539 EMR-derived phenotypes. The false discovery rate was calculated and, for any new PheWAS findings, a permutation approach (with up to 1,000,000 trials) was implemented.

Results: This PheWAS found a variety of common variants (MAF > 10%) with prior GWAS associations in our pediatric cohorts including Juvenile Rheumatoid Arthritis (JRA), Asthma, Autism and Pervasive Developmental Disorder (PDD) and Type 1 Diabetes with a false discovery rate < 0.05 and power of study above 80%. In addition, several new PheWAS findings were identified including a cluster of association near the NDFIP1 gene for mental retardation (best SNP rs10057309, p = 4.33 × 10⁻⁷, OR = 1.70, 95%CI = 1.38 − 2.09); association near PLCL1 gene for developmental delays and speech disorder [best SNP rs1595825, p = 1.13 × 10⁻⁸, OR = 0.65(0.57 − 0.76)]; a cluster of associations in the IL5-IL13 region with Eosinophilic Esophagitis (EoE) [best at rs12653750, p = 3.03 × 10⁻⁹, OR = 1.73 95%CI = (1.44 − 2.07)], previously implicated in asthma, allergy, and eosinophilia; and association of variants in GCKR and JAZF1 with allergic rhinitis in our pediatric cohorts [best SNP rs780093, p = 2.18 × 10⁻⁵, OR = 1.39, 95%CI = (1.19 − 1.61)], previously demonstrated in metabolic disease and diabetes in adults.

Conclusion: The PheWAS approach with re-mapping ICD-9 structured codes for our European-origin pediatric cohorts, as with the previous adult studies, finds many previously reported associations as well as presents the discovery of associations with potentially important clinical implications.

Association of interleukin genes polymorphism with asthma susceptibility in Indian children: a case-control study

BACKGROUND

Interleukins (IL) 4 and 13 genes and their receptors (R) are the key cytokines which amplify inflammatory reactions in asthma.

OBJECTIVE

This study aimed to investigate the association of IL 4, 4 R, 13 and 13 R genes polymorphism with asthma in Indian children.

METHODS

In this hospital-based case-control study, included were children aged 1-15 years recruited as diagnosed cases of bronchial asthma, according to EPR 2007 and excluded were subjects with other respiratory diseases. Children with no present or past history of asthma were enrolled as controls. Spirometry was done in cases age ≥ 6 years. Gene-gene interaction was evaluated using binary logistic regression.

RESULTS

From October 2010 to July 2013, 275 cases and 275 controls were recruited. Gene-gene interactions between C1112T in IL 13 and Ile50Val in IL 4 R gene polymorphisms were found to be statistically significant (OR = 2.37, 95% CI = 1.04-5.42, p = 0.040). Individuals with CT and GG genotype of C1112T in IL 13 and Ile50Val in IL 4 R were at twice the risk for the development of asthma compared to individuals with both non-risk genotypes.

CONCLUSION

The data suggests that gene-gene interactions between IL 13 and IL 4 R genes may play an important role in asthma among Indian children.

Genetic determinants of chronic obstructive pulmonary disease in South Indian male smokers

The development of chronic obstructive pulmonary disease, upon exposure to tobacco smoke, is the cumulative effect of defects in several genes. With the aim of understanding the genetic structure that is characteristic of our patient population, we selected forty two single nucleotide polymorphisms of twenty genes based on previous studies and genotyped a total of 382 samples, which included 236 patients and 146 controls using Sequenom MassARRAY system. Allele frequencies of rs2276109 (MMP12) and rs1800925 (IL13) differed significantly between patients and controls (p = 0.013 and 0.044 respectively). Genotype analysis showed association of rs2276109 (MMP12) under additive and dominant models (p = 0.017, p = 0.012 respectively), rs1800925 (IL13) under additive model (p = 0.047) and under recessive model, rs1695 (GSTP1; p = 0.034), rs729631, rs975278, rs7583463 (SERPINE2; p = 0.024, 0.024 and 0.012 respectively), rs2568494, rs10851906 (IREB2; p = 0.026 and 0.041 respectively) and rs7671167 (FAM13A; p = 0.029). The minor alleles of rs1695 (G), rs7671167 (T), rs729631 (G), rs975278 (A) and rs7583463 (A) showed significant negative association whereas those of rs2276109 (G), rs2568494 (A), rs10851906 (G) and rs1800469 (T; TGF-β) showed significant positive association with lung function under different genetic models. Haplotypes carrying A allele of rs2276109, G allele of rs1695 showed negative correlation with lung function. Haplotypes carrying major alleles of rs7671167 (C) of FAM13A and rs729631 (C), rs975278 (G), rs7583463 (C) of SERPINE2 had protective effect on lung function. Haplotypes of IREB2 carrying major alleles of rs2568494 (G), rs2656069 (A), rs10851906 (A), rs965604 (C) and minor alleles of rs1964678 (T), rs12593229 (T) showed negative correlation with lung function. In conclusion, our study replicated the results of most of the previous studies. However, the positive correlation between the minor alleles of rs2568494 (A) and rs10851906 (G) of IREB2 and lung function needs further investigation.

Respiratory syncytial virus--a comprehensive review

Respiratory syncytial virus (RSV) is amongst the most important pathogenic infections of childhood and is associated with significant morbidity and mortality. Although there have been extensive studies of epidemiology, clinical manifestations, diagnostic techniques, animal models and the immunobiology of infection, there is not yet a convincing and safe vaccine available. The major histopathologic characteristics of RSV infection are acute bronchiolitis, mucosal and submucosal edema, and luminal occlusion by cellular debris of sloughed epithelial cells mixed with macrophages, strands of fibrin, and some mucin. There is a single RSV serotype with two major antigenic subgroups, A and B. Strains of both subtypes often co-circulate, but usually one subtype predominates. In temperate climates, RSV infections reflect a distinct seasonality with onset in late fall or early winter. It is believed that most children will experience at least one RSV infection by the age of 2 years. There are several key animal models of RSV. These include a model in mice and, more importantly, a bovine model; the latter reflects distinct similarity to the human disease. Importantly, the prevalence of asthma is significantly higher amongst children who are hospitalized with RSV in infancy or early childhood. However, there have been only limited investigations of candidate genes that have the potential to explain this increase in susceptibility. An atopic predisposition appears to predispose to subsequent development of asthma and it is likely that subsequent development of asthma is secondary to the pathogenic inflammatory response involving cytokines, chemokines and their cognate receptors. Numerous approaches to the development of RSV vaccines are being evaluated, as are the use of newer antiviral agents to mitigate disease. There is also significant attention being placed on the potential impact of co-infection and defining the natural history of RSV. Clearly, more research is required to define the relationships between RSV bronchiolitis, other viral induced inflammatory responses, and asthma.

Association of cytokine and Toll-like receptor gene polymorphisms with severe malaria in three regions of Cameroon

P. falciparum malaria is one of the most widespread and deadliest infectious diseases in children under five years in endemic areas. The disease has been a strong force for evolutionary selection in the human genome, and uncovering the critical human genetic factors that confer resistance to the disease would provide clues to the molecular basis of protective immunity that would be invaluable for vaccine development. We investigated the effect of single nucleotide polymorphisms (SNPs) on malaria pathology in a case- control study of 1862 individuals from two major ethnic groups in three regions with intense perennial P. falciparum transmission in Cameroon. Twenty nine polymorphisms in cytokine and toll-like receptor (TLR) genes as well as the sickle cell trait (HbS) were assayed on the Sequenom iPLEX platform. Our results confirm the known protective effect of HbS against severe malaria and also reveal a protective effect of SNPs in interleukin-10 (IL10) cerebral malaria and hyperpyrexia. Furthermore, IL17RE rs708567 GA and hHbS rs334 AT individuals were associated with protection from uncomplicated malaria and anaemia respectively in this study. Meanwhile, individuals with the hHbS rs334 TT, IL10 rs3024500 AA, and IL17RD rs6780995 GA genotypes were more susceptible to severe malarial anaemia, cerebral malaria, and hyperpyrexia respectively. Taken together, our results suggest that polymorphisms in some immune response genes may have important implications for the susceptibility to severe malaria in Cameroonians. Moreover using uncomplicated malaria may allow us to identify novel pathways in the early development of the disease.

IL-4 Receptor α Polymorphisms May Be a Susceptible Factor for Work-Related Respiratory Symptoms in Bakery Workers

Purpose

The IL-4 and IL-4 receptor α (IL-4Rα) genes are the key candidate genes for atopy and asthma susceptibility. Exposure to wheat flour can cause IgE sensitization and respiratory symptoms in bakery workers. Therefore, we hypothesized that IL-4 and IL-4Rα single nucleotide polymorphisms (SNPs) may be involved in the pathogenic mechanism of baker's asthma.

Methods

Clinical and genetic data from 373 bakery workers were analyzed. A survey questionnaire, spirometry, and skin prick tests with wheat flour were performed. Serum-specific IgE, IgG1, and IgG4 to wheat flour were determined using ELISA. Five candidate IL-4 (-729 T>G, 589 T>C, and 33 T>C) and IL-4Rα (Ile75Val A>G and Gln576Arg A>G) SNPs were genotyped and analyzed.

Results

Workers with the G allele of IL-4Rα Ile75Val A>G had a significantly higher prevalence of work-related lower respiratory symptoms than those with the AA genotype (P=0.004, 16.0% vs. 2.9%). In the skin prick test, workers with the AA genotype of IL-4Rα Gln576Arg A>G had a significantly higher positive rate to wheat flour (P=0.015, 8.2% vs. 1.1%) than those with AG/GG genotype. No significant associations were found in the three genetic polymorphisms of IL-4. For the predicted probabilities, workers with the AA genotype of Gln576Arg A>G had a higher prevalence of IgG1 and IgG4 in response to wheat flour, according to increased exposure intensity (P=0.001 for IgG1 and P=0.003 for IgG4).

Conclusions

These findings suggest that the IL-4Rα Ile75Val and Gln576Arg polymorphisms may be associated with work-related respiratory symptom development.

Single nucleotide polymorphism in the promoter of the human interleukin-13 gene is associated with asthma in Malaysian adults

Asthma susceptibility genes are mapped to a region on human chromosome 5q31-q33, which contains a cluster of proinflammatory cytokine genes such as interleukin-13 (IL-13), which is associated with asthma. This study investigated the allele frequencies of two single nucleotide polymorphisms (SNPs) (−1111C>T and 4257C>A) in the IL-13 gene between asthmatics and healthy volunteers as well as the relationship between these SNPs and IL-13 production. DNA extracted from buffy coat of asthmatic and control subjects was genotyped using the PCR-RFLP method. Amount of IL-13 produced by mitogen-stimulated peripheral blood leucocytes PBLs (PBLs) was determined by ELISA. The frequencies of the −1111C and 4257G wild-type alleles were 0.52 and 0.55 in asthmatics and were 0.67 and 0.56 in controls. A significant (P < 0.05) association was found between genotype and allele frequencies of SNP at position −1111C>T between asthmatic and control groups (OR, 1.810; 95% CI = 1.184 to 2.767; P < 0.05). The mitogen-stimulated PBLs from asthmatics produced higher amounts of IL-13 production (P < 0.001). The 4257GA heterozygous and 4257AA homozygous mutant alleles were associated with higher IL-13 production in asthmatics (P < 0.05). Our results show that the −1111T mutant allele are associated with asthma and the 4257A mutant alleles are associated with elevated IL-13 production.

Effects of polymorphisms -1112C/T and +2044A/G in interleukin-13 gene on asthma risk: a meta-analysis

Background

Associations between interleukin-13 (IL-13) polymorphisms and asthma risk remained controversial and ambiguous. Therefore, we performed a meta-analysis to assess the associations between IL-13 polymorphisms and asthma susceptibility.

Methods

Pubmed, EMBASE, Chinese National Knowledge Infrastructure (CNKI) and Wangfang databases were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the strength of association in the random-effects model.

Results

Thirty-four studies were included in this meta-analysis. The results indicated that IL13 -1112C/T polymorphism was significantly associated with asthma risk (OR = 1.20, 95% CI 1.08–1.34, P = 0.0009) in a dominant genetic model. When stratifying for race, IL13 -1112C/T polymorphism exhibited increased asthma risk in Caucasians (OR = 1.30, 95% CI 1.09–1.55, P = 0.003), while no significant association was found in Asians and African Americans. In the subgroup analysis based on atopic status, significant association was observed in atopic patients (OR = 1.25, 95% CI 1.07–1.45, P = 0.004) but not in the non-atopic patients. In addition, a significant association between IL13+2044A/G polymorphism and asthma risk was observed (OR = 1.18, 95% CI 1.08–1.28, P = 0.0002). In the subgroup analysis by ethnicity, there were significant associations between IL13+2044A/G polymorphism and asthma risk in Asians (OR = 1.19, 95% CI 1.04–1.36, P = 0.01) and Caucasians (OR = 1.22, 95% CI 1.06–1.40, P = 0.005) but not in African Americans. In the subgroup analysis stratified by atopic status, a marginal significant association was found in atopic patients (OR = 1.12, 95% CI 1.00–1.26, P = 0.05).

Conclusions

This meta-analysis suggested that the IL13 -1112C/T and +2044A/G polymorphisms were risk factors for asthma.

Interleukin-13 genetic variants, household carpet use and childhood asthma

Interleukin (IL)-13 genetic polymorphisms have shown adverse effects on respiratory health. However, few studies have explored the interactive effects between IL-13 haplotypes and environmental exposures on childhood asthma. The aims of our study are to evaluate the effects of IL-13 genetic variants on asthma phenotypes, and explore the potential interaction between IL-13 and household environmental exposures among Taiwanese children. We investigated 3,577 children in the Taiwan Children Health Study from 14 Taiwanese communities. Data regarding children's exposure and disease status were obtained from parents using a structured questionnaire. Four SNPs were tagged accounting for 100% of the variations in IL-13. Multiple logistic regression models with false-discovery rate (FDR) adjustments were fitted to estimate the effects of IL-13 variants on asthma phenotypes. SNP rs1800925, SNP rs20541 and SNP rs848 were significantly associated with increased risks on childhood wheeze with FDR of 0.03, 0.04 and 0.04, respectively. Children carrying two copies of h1011 haplotype showed increased susceptibility to wheeze. Compared to those without carpet use and h1011 haplotype, children carrying h1011 haplotype and using carpet at home had significantly synergistic risks of wheeze (OR, 2.5; 95% CI, 1.4–4.4; p for interaction, 0.01) and late-onset asthma (OR, 4.7; 95% CI, 2.0–10.9; p for interaction, 0.02). In conclusions, IL-13 genetic variants showed significant adverse effects on asthma phenotypes among children. The results also suggested that asthma pathogenesis might be mediated by household carpet use.

Structural basis of signaling blockade by anti-IL-13 antibody Lebrikizumab

The cytokine interleukin 13 (IL-13) is a major effector molecule for T-helper type 2 inflammation and is pathogenic in allergic diseases such as asthma. The effects of IL-13 are mediated via a pathway that is initiated by binding to a heterodimeric receptor consisting of IL-13Rα1 and IL-4Rα. Antibodies raised against IL-13 can block its inflammatory effects by interfering with binding to either of the two receptor polypeptides. Lebrikizumab is a monoclonal anti-IL-13 antibody that has shown clinical benefit in a phase II study for the treatment of moderate-to-severe uncontrolled asthma. Here we report the molecular structure of IL-13 in complex with the Fab from lebrikizumab by X-ray crystallography at 1.9Å resolution. We show that lebrikizumab inhibits IL-13 signaling by binding to IL-13 with very high affinity and blocking IL-13 binding to IL-4Rα. In addition, we use site-directed mutations to identify the most important antibody contributors to binding. Our studies define key features of lebrikizumab binding and its mechanism of action that may contribute to its clinical effects.

Association between IL13 gene polymorphisms and susceptibility to cancer: a meta-analysis

BACKGROUND/AIMS

Interleukin-13 (IL13) is an immunoregulatory cytokine which plays an important role in carcinogenesis through affecting tumor immunosurveillance. Many studies had reported the influence of IL13 rs1800925 and rs20541 polymorphisms on cancer risk, however, with inconclusive results. The aim of the present study was to conduct a meta-analysis to clarify the relationship.

METHODS

Twenty studies including a total of 6713 cancer cases and 8693 controls for IL13 rs20541 polymorphism and 4081 cancer cases and 6202 controls for IL13 rs1800925 polymorphism were included in the meta-analysis. Data were extracted from these studies and odds ratios with corresponding 95% confidence intervals were computed to estimate the strength of the association.

RESULTS

Overall, the IL13 rs20541 polymorphism were associated with significantly decreased cancer risk in all genetic models (AA vs. GG: OR=0.82, 95%CI=0.71-0.95; GA vs. GG: OR=0.92, 95%CI=0.85-0.99; GA/AA vs. GG: OR=0.90, 95%CI=0.85-0.97; AA vs. GG/GA: OR=0.85, 95CI%=0.74-0.98). In the stratified analyses, significant effects were found among European populations, studies with population-based controls and studies of glioma. No influence of the IL13 rs1800925 polymorphism on the overall cancer risk was observed. However, in the stratified analyses, we found the IL13 rs1800925 polymorphism was significantly associated with decreased risk for glioma (CT vs. TT: OR=0.72, 95%CI=0.55-0.93; CT/TT vs. TT: OR=0.76, 95%CI=0.62-0.89).

CONCLUSION

Our meta-analysis suggests that the IL13 rs20541 polymorphism contributes to susceptibility to cancer, especially for glioma; and the IL13 rs1800925 polymorphism may be associated with glioma risk.

Association between the interleukin-4, interleukin-13 polymorphisms and asthma: a meta-analysis

A numbers studies had been reported that the polymorphisms in the Interleukin 4 (IL-4) and Interleukin 13 (IL-13) genes were associated with susceptibility to asthma. However, the results were inconsistent and inconclusive. We carried out a meta-analysis of case-control genetic association studies to assess whether the combined data showed this association by using a genetic model-free approach. Thirty studies (total 12,781 asthma and 11,500 controls) for the IL-4 C-33T and C-589T, IL-13 C-1112T and G+2044A with asthma were included in the meta-analysis. The results indicated that there were an association between the IL-4 C-33T (P = 0.006) and C-589T (P = 0.04), IL-13 C-1112T (P = 0.002) and G+2044A (P = 0.04) and susceptibility to asthma. And the definition of asthma subgroup meta-analysis demonstrates that the IL-4 C-33T is not associated with nonatopic or atopic, and IL-4 C-589T and IL-13 C-1112T polymorphisms are not associated with atopic. In the ethnicity subgroup meta-analysis, the IL-4 -589T (P = 0.003) and the IL-13 -1112T (P < 0.00001) alleles are associated with asthma among Caucasian, but not on the IL-13 +2044A allele. In conclusion, IL-4 C-33T and C-589T, IL-13 C-1112T and G+2044A could be proposed as asthma susceptible SNPs. Further investigation in larger studies and meta-analysis is required.

Cytokine gene polymorphisms: methods of detection and biological significance

In recent years, several functional polymorphisms, particularly, SNPs have been identified in cytokines and their receptor genes that regulate levels of cytokine expression. These have been implicated as immune prognostic markers in diseases, including differential response to therapy and as biomarkers of graft outcome following organ and stem cell transplantation. Population distribution of cytokine gene polymorphisms (CGPs) reveals significant variations in allele frequencies in different ethnic groups and this might explain, to some extent, the observed differences in SNP associations with various diseases and immune-pathologies. A number of molecular methods are available for defining CGPs. These include PCR-SSP, AFLP, Taqman probe assays as well as sequencing based typing. Of these, the PCR-based sequence-specific primer based test is the most widely accepted technique. This chapter describes steps involved in this procedure along with sources for procuring essential reagents. An important aspect of CGP analyses is the correct interpretation of results particularly determination of their multilocus haplotypes.

Cytokines and cytokine-specific therapy in asthma

Asthma is increasing in prevalence worldwide. It is characterized by typical symptoms and variable airway obstruction punctuated with episodes of worsening symptoms known as exacerbations. Underlying this clinical expression of disease is airway inflammation and remodeling. Cytokines and their networks are implicated in the innate and adaptive immune responses driving airway inflammation in asthma and are modulated by host-environment interactions. Asthma is a complex heterogeneous disease, and the paradigm of Th2 cytokine-mediated eosinophilic inflammation as a consequence of allergic sensitization has been challenged and probably represents a subgroup of asthma. Indeed, as attention has switched to the importance of severe asthma, which represents the highest burden both to the patient and health care provider, there is an increasing recognition of inflammatory subphenotypes that are likely to be driven by different cytokine networks. Interestingly, these networks may be specific to aspects of clinical expression as well as inflammatory cell profiles and therefore present novel phenotype-specific therapeutic strategies. Here, we review the breadth of cytokines implicated in the pathogenesis of asthma and focus upon the outcomes of early clinical trials conducted using cytokines or cytokine-blocking therapies.

Preclinical development of CAT-354, an IL-13 neutralizing antibody, for the treatment of severe uncontrolled asthma

BACKGROUND AND PURPOSE

IL-13 is a pleiotropic Th2 cytokine considered likely to play a pivotal role in asthma. Here we describe the preclinical in vitro and in vivo characterization of CAT-354, an IL-13-neutralizing IgG4 monoclonal antibody (mAb), currently in clinical development.

EXPERIMENTAL APPROACH

In vitro the potency, specificity and species selectivity of CAT-354 was assayed in TF-1 cells, human umbilical vein endothelial cells and HDLM-2 cells. The ability of CAT-354 to modulate disease-relevant mechanisms was tested in human cells measuring bronchial smooth muscle calcium flux induced by histamine, eotaxin generation by normal lung fibroblasts, CD23 upregulation in peripheral blood mononuclear cells and IgE production by B cells. In vivo CAT-354 was tested on human IL-13-induced air pouch inflammation in mice, ovalbumin-sensitization and challenge in IL-13 humanized mice and antigen challenge in cynomolgus monkeys.

KEY RESULTS

CAT-354 has a 165 pM affinity for human IL-13 and functionally neutralized human, human variant associated with asthma and atopy (R130Q) and cynomolgus monkey, but not mouse, IL-13. CAT-354 did not neutralize human IL-4. In vitro CAT-354 functionally inhibited IL-13-induced eotaxin production, an analogue of smooth muscle airways hyperresponsiveness, CD23 upregulation and IgE production. In vivo in humanized mouse and cynomolgus monkey antigen challenge models CAT-354 inhibited airways hyperresponsiveness and bronchoalveolar lavage eosinophilia.

CONCLUSIONS AND IMPLICATIONS

CAT-354 is a potent and selective IL-13-neutralizing IgG4 mAb. The preclinical data presented here support the trialling of this mAb in patients with moderate to severe uncontrolled asthma.

Association of interleukin-13 SNP rs1800925 with allergic rhinitis risk: a meta-analysis based on 1,411 cases and 3169 controls

Studies investigating the association between interleukin-13 (IL-13) single nucleotide polymorphism (SNP) rs1800925 and allergic rhinitis risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of IL-13 SNP rs1800925 with allergic rhinitis risk. The relevant studies were identified through a search of PubMed, Embase, ISI Web of Knowledge and Chinese National Knowledge Infrastructure until December 2011 and selected on the basis of the established inclusion criteria for publications. Five studies were included in the present meta-analysis (1411 cases and 3169 controls). The combined results based on all studies showed that IL-13 SNP rs1800925 was not associated with increased allergic rhinitis risk (T versus C: odds ratio (OR)=1.06, 95% confidence interval (CI)=0.94-1.20; C/T versus C/C: OR=1.12, 95% CI=0.97-1.29; T/T versus C/C: OR=1.00, 95% CI=0.69-1.44; C/T+T/T versus CC: OR=1.10, 95% CI=0.96-1.27; T/T versus C/C+C/T: OR=0.91, 95% CI=0.64-1.31). This meta-analysis supported that IL-13 SNP rs1800925 was not associated with allergic rhinitis.

Functional polymorphisms in IL13 are protective against high Schistosoma mansoni infection intensity in a Brazilian population

Background

IL-13 is a signature cytokine of the helper T cell type 2 (TH2) pathway which underlies host defense to helminthic infection and activates production of IgE in both parasitized populations and in urban settings after allergen exposure.

Methodology/Principal Findings

Two functional polymorphisms in IL13, rs1800925 (or c.1-1111C>T) and rs20541 (or R130Q) were previously found to be associated with Schistosoma hematobium infection intensity. They have not been thoroughly explored in S. mansoni-endemic populations, however, and were selected along with 5 tagging SNPs for genotyping in 812 individuals in 318 nuclear families from a schistosomiasis-endemic area of Conde, Bahia, in Brazil. Regression models using GEE to account for family membership and family-based quantitative transmission disequilibrium tests (QTDT) were used to evaluate associations with total serum IgE (tIgE) levels and S. mansoni fecal egg counts adjusted for non-genetic covariates. We identified a protective effect for the T allele at rs20541 (P = 0.005) against high S. mansoni egg counts, corroborated by QTDT (P = 0.014). Our findings also suggested evidence for protective effects for the T allele at rs1800925 and A allele at rs2066960 after GEE analysis only (P = 0.050, 0.0002).

Conclusions/Significance

The two functional variants in IL13 are protective against high S. mansoni egg counts. These markers showed no evidence of association with tIgE levels, unlike tIgE levels previously studied in non-parasitized or atopic study populations.

Association of interleukin-13 C-1112T and G+2044A polymorphisms with asthma: a meta-analysis

BACKGROUND AND OBJECTIVE

Polymorphisms in the IL13 gene have been reported to be associated with susceptibility to asthma. However, a number of studies have shown inconsistent results. A meta-analysis was performed to investigate whether polymorphisms in the IL13 gene were associated with the risk of asthma.

METHODS

Searches were performed of the Medline and Chinese National Knowledge Infrastructure (CNKI) databases, covering all papers published up to 31 August 2010. A recently proposed logistic regression-based method for meta-analysis of case-control genetic association studies was used to analyse pooled data. All statistical analyses were performed using stata version 10.0 software.

RESULTS

The IL13 C-1112T and G+2044A polymorphisms were investigated in 10 and 14 studies, respectively. The summary estimates suggested that both these polymorphisms were associated with susceptibility to asthma. Carriers of the IL13 -1112T allele had a 38.9% increased risk of asthma compared with homozygotes (-1112CC) (odds ratio (OR) 1.389, 95% confidence interval (CI): 1.103-1.749). Carriers of the IL13+2044A allele had a 40.0% increased risk of asthma compared with homozygotes (+2044GG) (OR 1.400, 95% CI: 1.137-1.724). In a subgroup analysis by ethnicity, the IL13 -1112T allele was associated with an increased risk of asthma among Caucasians (OR 1.629, 95% CI: 1.255-2.113) but not among Asians, and the IL13+2044A allele was associated with an increased risk of asthma among Asians (OR 1.436, 95% CI: 1.101-1.873) but not among Caucasians.

CONCLUSIONS

This meta-analysis indicated that the IL13 C-1112T and G+2044A polymorphisms predispose to asthma. Further studies, including pooling of individual data to facilitate evaluation of gene-gene and gene-environment interactions between these IL13 gene polymorphisms and asthma susceptibility, are recommended.

Impact of interleukin-13 and -18 promoter polymorphisms in health care workers with natural rubber latex allergy

It is a matter of debate whether single nucleotide polymorphisms (SNP) in the promoter region of interleukin (IL)-13, an IgE regulator, and IL-18, an inducer of immune responses, modulating the respective protein expression, are accompanied by an increased risk of atopy, allergic asthma, and total IgE levels. The suspected associations were noted in health care workers (HCW) with and without latex allergy. IL-13 (-1055C>T) and three IL-18 (-656T>G, -607C>A, -137G>C) SNP were studied in 523 HCW with natural rubber latex (NRL) exposure and diagnosis in the late 1990s. Three hundred and thirty-four HCW displayed NRL sensitization and allergic symptoms, 93 with latex-allergic asthma, and 189 HCW with neither symptoms nor NRL sensitization. SNP analyses were performed by real-time polymerase chain reaction (PCR) using newly developed LightCycler assays. Analysis of IL-13 -1055C>T by analysis of variance (ANOVA) revealed significantly elevated total IgE levels in HCW carrying the CT or TT variant compared with the CC variant. None of the studied SNP showed an association with NRL-specific IgE. The IL-18 variants -656GG and -607CC displayed 99.5% linkage disequilibrium. Frequencies of alleles -656GG and -607CC were elevated in HCW with NRL asthma (48.4%) compared with HCW without symptoms (37.6%). In contrast, IL-18 -137G>C variants displayed an overall homogenous distribution. The association between the IL-13 -1055T allele and elevated total IgE levels confirms the role of a genetic background for total IgE regulation. The studied IL-18 SNP demonstrated no significant association with the clinical outcome, total IgE, or specific IgE in HCW with natural rubber latex allergy.

IL-13 polymorphisms contribute to the risk of asthma: a meta-analysis

OBJECTIVES

The purpose of this study was to evaluate the effects of interleukin-13 (IL-13) polymorphisms on the risk of asthma using a meta-analysis.

DESIGN AND METHODS

Fifteen publications were identified by searching Pubmed, Embase, ISI, OVID, and EBSCO databases. Odds ratios with corresponding 95% confidence intervals were computed to estimate the association between IL-13 polymorphisms and risk of asthma.

RESULTS

The polymorphisms of R130Q (rs20541) and -1112C/T (rs1800925) in IL-13 gene were associated with significantly increased risks of asthma in overall analyses. Subgroup analyses showed that the elevated risks occurred in adult-onset asthma, Caucasians, and high quality studies.

CONCLUSIONS

This meta-analysis provides evidence that the R130Q and -1112C/T polymorphisms in IL-13 are risk factors for asthma.

Case-control study of IL13 polymorphisms, smoking, and rhinoconjunctivitis in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Six previous studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the IL13 gene and allergic rhinitis, but the results have been inconsistent. However, a recent meta-analysis using data from these 6 studies has shown that the A allele of IL13 SNP rs20541 was associated with an increased risk of allergic rhinitis, whereas no such relationship existed between IL13 SNP rs1800925 and allergic rhinitis. We investigated the associations between IL13 SNPs rs1800925 and rs20541 and the risk of rhinoconjunctivitis in Japanese women.

METHODS

Included were 393 cases who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Control subjects were 767 women without rhinoconjunctivitis according to the ISAAC criteria, who had also not been diagnosed with allergic rhinitis by a doctor. Adjustment was made for age, region of residence, presence of older siblings, smoking, family history of allergic rhinitis, and education.

RESULTS

Compared with the GG genotype of IL13 SNP rs20541, the AA genotype, occurring in 7.1% of control subjects, was significantly positively related to the risk of rhinoconjunctivitis: the adjusted odds ratio was 1.65 (95% confidence interval: 1.05 - 2.60). SNP rs1800925 was not associated with rhinoconjunctivitis. The haplotype comprising the rs1800925 C allele and the rs20541 A allele was significantly positively related to rhinoconjunctivitis. The multiplicative interactions between the two SNPs under study and smoking on the risk of rhinoconjunctivitis were not statistically significant. Based on the recessive model, however, the additive interaction between SNP rs1800925, but not rs20541, and smoking was significant.

CONCLUSIONS

This study suggests that the minor genotype of IL13 SNP rs20541 and the CA haplotype are significantly positively associated with the risk of rhinoconjunctivitis. In addition, a new pattern of biological interaction that affects the risk of rhinoconjunctivitis is described between SNP rs1800925 and smoking.

IL13 genetic polymorphisms, smoking, and eczema in women: a case-control study in Japan

Background

Several genetic association studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the IL13 gene and eczema, and have provided contradictory results. We investigated the relationship between the IL13 SNPs rs1800925 and rs20541 and the risk of eczema in Japanese young adult women.

Methods

Included were 188 cases who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for eczema. Control subjects were 1,082 women without eczema according to the ISAAC criteria, who had not been diagnosed with atopic eczema by a doctor and who had no current asthma as defined by the European Community Respiratory Health Survey criteria. Adjustment was made for age, region of residence, number of children, smoking, and education.

Results

The minor TT genotype of SNP rs1800925 was significantly associated with an increased risk of eczema in the co-dominant model: the adjusted odds ratio was 2.19 (95% confidence interval: 1.03-4.67). SNP rs20541 was not related to eczema. None of the haplotypes were significantly associated with eczema. Compared with women with the CC or CT genotype of SNP rs1800925 who had never smoked, those with the TT genotype who had ever smoked had a 2.85-fold increased risk of eczema, though the adjusted odds ratio was not statistically significant, and neither multiplicative nor additive interaction was statistically significant.

Conclusions

Our findings suggest that the IL13 SNP rs1800925 is significantly associated with eczema in Japanese young adult women. We could not find evidence for an interaction between SNP rs1800925 and smoking with regard to eczema.

Role of IL-13 in systemic sclerosis

Systemic sclerosis (SSc) has the highest fatality rate among connective tissue diseases and is characterized by vascular damage, inflammation and fibrosis. Currently, no therapy has proven effective in modifying the course of SSc, a reflection of its complex pathogenesis. T cell-derived cytokines have been implicated in the induction of fibrosis. The role of the pro-fibrotic type 2 cytokine IL-13 and its regulation appear to be important in the pathogenesis of SSc and other fibrotic disorders. Recent work has shown that dysregulated production of IL-13 by effector CD8+ T cells is critical for predisposing patients to more severe forms of cutaneous disease and that this dysregulation is associated with defects in the molecular control of IL-13 production, such as increased expression of the transcription factor GATA-3. Silencing of GATA-3 with siRNA significantly reduces IL-13 production by CD8+ T cells from patients. We review these new insights into SSc pathogenesis that will enable establishment of highly relevant biomarkers of immune dysfunction in patients predisposed to develop SSc and open new possibilities for development of more specific diagnosis and treatment.

Association of polymorphisms in genes encoding IL-4, IL-13 and their receptors with atopic dermatitis in a Korean population

Th2-dominated immune responses are believed to contribute to the pathogenesis of atopic dermatitis (AD). IL-4 and IL-13 are typical pleiotropic Th2 cytokines that play a central role in IgE-dependent inflammatory reactions. Single-nucleotide polymorphisms (SNPs) in IL-4 and IL-13 have been reported in patients with allergic disease from numerous countries. Gene-gene interactions among genes have been identified in patients with asthma, although negative results have been reported. To investigate the associations of SNPs in these genes and the interactions between these genes in AD, we genotyped 23 SNPs of the IL-4, IL-13, IL-4R, IL-13Rα1 and IL-13Rα2 genes for 1089 case-control samples (631 AD patients and 458 controls) and analysed the SNPs and haplotypes in these genes. We also searched for gene-gene interactions among these five genes. Our data identified an association between rs3091307 and rs20541 in the IL-13 gene and between rs2265753 and rs2254672 in the IL-13Rα1 gene and the AD phenotype. In particular, three of the four SNPs were especially predictive of the allergic type of AD (ADe), and the haplotype TCGG in the IL-13Rα1 gene showed significant association with AD, especially ADe. Furthermore, the combination of rs3091307 GG/ rs2265753 GG (IL-13/IL-13Rα1) conveyed a significantly higher risk for developing ADe. However, we did not identify any SNPs in the IL-4, IL-4R and IL-13Rα2 genes that were associated with AD. As IL-13Rα1 is most likely expressed in Th17 cells rather than in Th2 cells, these data suggest diversity in the classification of Th cells that needs to be verified in future studies.

The impact of cis-acting polymorphisms on the human phenotype

Cis-acting polymorphisms that affect gene expression are now known to be frequent, although the extent and mechanisms by which such variation affects the human phenotype are, as yet, only poorly understood. Key signatures of cis-acting variation are differences in gene expression that are tightly associated with regulatory SNPs or expression Quantitative Trait Loci (eQTL) and an imbalance of allelic expression (AEI) in heterozygous samples. Such cis-acting sequence differences appear often to have been under selection within and between populations and are also thought to be important in speciation. Here we describe the example of lactase persistence. In medical research, variants that affect regulation in cis have been implicated in both monogenic and polygenic disorders, and in the metabolism of drugs. In this review we suggest that by further understanding common regulatory variations and how they interact with other genetic and environmental variables it will be possible to gain insight into important mechanisms behind complex disease, with the potential to lead to new methods of diagnosis and treatments.

Recent advances in the characterization of genetic factors involved in human susceptibility to infection by schistosomiasis

Human resistance to infection by schistosomes is associated to a strong Th2 immune. However a persistent Th2 response can cause severe kidney and liver disease in human. In this review, we mainly focused on the control of infection levels caused by schistosomes. Several experimental models allowed us to better understand the immunological mechanisms of the host against schistosome infection. High IgE and eosinophil levels are associated with resistance to infection by schistosomes and this effect is counterbalanced by IgG4. IgE and eosinophils are highly dependent on IL-4, IL-13, and Il-5, which are three main Th2 cytokines. We also examined the genetic factors involved in human susceptibility to infection by schistosomiasis. Infection levels are mainly regulated by a major locus SM1, in 5q31-q33 region, which contains the genes encoding for the IL-4, IL-13, and Il-5 cytokines. An association between an IL13 polymorphism, rs1800925, and infection levels has been shown. This polymorphism synergistically acts with another polymorphism (rs324013) in the STAT6 gene, encoding for the signal transducer of the IL13 pathway. This pathway has also been involved in atopic disorders. As helminthiasis, atopy is the result of aberrant Th2 cytokine response to allergens, with an increased production of IL-4, IL-13, Il-9 and Il-5, with high amounts of allergen-specific and total IgE and eosinophilia. However, the Th2 immune response is protective in helminthiasis but aggravating in atopic disorders. Several studies reported interplay between helminthic infections and allergic reactions. The different results are discussed here.

A meta-analysis of Th2 pathway genetic variants and risk for allergic rhinitis

There is a significant genetic contribution to allergic rhinitis (AR). Genetic association studies for AR have been performed, but varying results make it challenging to decipher the overall potential effect of specific variants. The Th2 pathway plays an important role in the immunological development of AR. We performed meta-analyses of genetic association studies of variants in Th2 pathway genes and AR. PubMed and Phenopedia were searched by double extraction for original studies on Th2 pathway-related genetic polymorphisms and their associations with AR. A meta-analysis was conducted on each genetic polymorphism with data meeting our predetermined selection criteria. Analyses were performed using both fixed and random effects models, with stratification by age group, ethnicity, and AR definition where appropriate. Heterogeneity and publication bias were assessed. Six independent studies analyzing three candidate polymorphisms and involving a total of 1596 cases and 2892 controls met our inclusion criteria. Overall, the A allele of IL13 single nucleotide polymorphism (SNP) rs20541 was associated with increased odds of AR (estimated OR=1.2; 95% CI 1.1-1.3, p-value 0.004 in fixed effects model, 95% CI 1.0-1.5, p-value 0.056 in random effects model). The A allele of rs20541 was associated with increased odds of AR in mixed age groups using both fixed effects and random effects modeling. IL13 SNP rs1800925 and IL4R SNP 1801275 did not demonstrate overall associations with AR. We conclude that there is evidence for an overall association between IL13 SNP rs20541 and increased risk of AR, especially in mixed-age populations.