Family based association analysis of the IL2 and IL15 genes in allergic disorders

The prognostic role of gene polymorphisms in patients with indolent non-Hodgkin lymphomas and mantle-cell lymphoma receiving bendamustine and rituximab: results of the 5-year follow-up study

The variability in disease outcome for indolent non-Hodgkin lymphomas (iNHL) and mantle-cell lymphoma (MCL) could be related to single nucleotide polymorphisms (SNPs) in genes that affect immune and inflammatory response. We investigated SNPs that could have a prognostic role for patients receiving bendamustine and rituximab (BR). All samples were genotyped for the IL-2 (rs2069762), IL-10 (rs1800890, rs10494879), VEGFA (rs3025039), IL-8 (rs4073), CFH (rs1065489) and MTHFR (rs1801131) SNPs by allelic discrimination assays using TaqMan SNP Genotyping Assays. We report a long-term follow-up analysis of 79 iNHL and MCL patients that received BR. Overall response rate was 97.5% (CR rate 70.9%). After a median follow-up of 63 months, median PFS and OS were not reached. We report a significant association between SNP in IL-2 (rs2069762) and reduced PFS and OS (p<.0001). We suggest a role for cytokine SNPs in disease outcome, while SNPs seem not related to long-term toxicity or secondary malignancies.

Cymbaria daurica L.: A Mongolian herbal medicine for treating eczema via natural killer cell-mediated cytotoxicity pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbaria daurica L. (C. daurica) is a perennial herb known commonly as "Xinba" (Chinese) and "Kanba-Arong" (Mongolian). In Mongolia, it is used as a traditional medicine to treat eczema and other skin diseases due to its anti-swelling, anti-inflammatory, anti-hemorrhagic, and anti-itching properties. However, the potential mechanism of action for eczema treatment has not been reported.

AIM OF THE STUDY

To investigate the effect of C. daurica on 1-chloro-2,4-dinitrobenzene (DNCB)-induced eczema in rats and the associated action mechanism.

MATERIALS AND METHODS

Qualitative analysis of C. daurica was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on information obtained from compound identification and relevant literature, the possible targets of C. daurica against eczema were analyzed using network pharmacology and molecular docking methods. The DNCB-induced eczema rat models were treated with different dosages of C. daurica extract (10, 50, and 250 mg/mL per day), and the therapeutic effects subsequently evaluated based on the degree of skin inflammation, spleen index, and hematoxylin and eosin staining (H&E staining). Enzyme-linked immunosorbent assay (ELISA), reverse transcription quantitative polymerase chain reaction (RT-qPCR), and western blotting were used to analyze the relevant target effects. The C. daurica mechanism of action on eczema was verified by animal experiments. High-performance liquid chromatography (HPLC) was carried out to determine the content of active ingredients in C. daurica. In addition, the physicochemical properties of the extract were evaluated.

RESULTS

Our analysis of the 173 targets included in the protein-protein interaction (PPI) network identified tumor necrosis factor (TNF) and interleukin 2 (IL-2) as key targets involved in the treatment of eczema with C. daurica extract. Furthermore, the 173 targets were associated with the natural killer cell-mediated cytotoxicity pathway. Our results showed that C. daurica significantly reduced IL-2 and TNF-α serum levels in eczema rat models (P < 0.0001); thus, playing an important role in the anti-inflammatory response. Furthermore, according to the p-value, RT-qPCR and western blotting showed that the expression of Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1), Vav guanine nucleotide exchange factor (Vav), and growth factor receptor-bound protein 2 (Grb2) changed in the skin of the eczema model rats after treatment with the C. daurica extract.

CONCLUSION

Our study confirms that C. daurica can inhibit SHP-1, Vav, and Grb2 expression; thereby, inhibiting the natural killer cell-mediated cytotoxicity pathway. These results provide insight into the mechanism of C. daurica in treating eczema.

IL-2 modulates Th2 cell responses to glucocorticosteroid: A cause of persistent type 2 inflammation?

Background

Glucocorticosteroids (GCs) are the main treatment for asthma as they reduce type 2 cytokine expression and induce apoptosis. Asthma severity is associated with type 2 inflammation, circulating Th2 cells and higher GC requirements.

Objective

The aim of this study was to assess whether ex vivo production of interleukin 2 (IL‐2), a T‐cell survival factor, associated with clinical features of asthma severity, the proportion of blood Th2 cells and Th2 cell responses to GC.

Methods

Peripheral blood from asthma patients (n = 18) was obtained and the proportion of Th2 cells determined by flow cytometry. Peripheral blood cells were activated with mitogen (24 hours) and supernatant levels of IL‐2 and IL‐13 measured by enzyme‐linked immunosorbent assay. In vitro differentiated Th2 cells were treated with dexamethasone (DEX) and IL‐2 and assessed for apoptosis by flow cytometry (annexin V). Level of messenger RNA (mRNA) for antiapoptotic (BCL‐2) and proapoptotic (BIM) genes, IL‐13, GC receptor (GR) and FKBP5 were determined by quantitative real‐time polymerase chain reaction. GR binding was assessed by chromatin immunoprecipitation.

Results

IL‐2 produced by activated peripheral blood cells correlated negatively with lung function and positively with a daily dose of inhaled GC. When patients were stratified based on IL‐2 level, high IL‐2 producers made more IL‐13 and had a higher proportion of circulating Th2 cells. In vitro, increasing the level of IL‐2 in the culture media was associated with resistance to DEX‐induced apoptosis, with more BCL‐2/less BIM mRNA. Th2 cells cultured in high IL‐2 had more IL‐13, less GR mRNA, showed reduced binding of the GR to FKBP5, a known GC‐induced gene, and required higher concentrations of DEX for cytokine suppression.

Conclusions and Clinical Relevance

IL‐2 downregulates Th2 cell responses to GC, supporting both their survival and pro‐inflammatory capacity. These results suggest that a patient's potential to produce IL‐2 may be a determinant in asthma severity.

Study of gene polymorphisms as predictors of treatment efficacy and toxicity in patients with indolent non-hodgkin lymphomas and mantle cell lymphoma receiving bendamustine and rituximab

Bendamustine is used in combination with rituximab (BR) to treat indolent non-Hodgkin lymphomas (iNHL) and mantle cell lymphoma (MCL). The variability in treatment efficacy and toxicity could be related to single nucleotide polymorphisms (SNPs) in immune response genes. We would like to show a correlation between SNPs and treatment outcome in iNHL and MCL patients receiving BR. We investigated some SNPs that had already been associated with NHL outcome. Samples were genotyped for the IL2 (rs2069762), IL10 (rs1800890, rs10494879), VEGFA (rs3025039), IL8 (rs4073), CFH (rs1065489) and MTHFR (rs1801131) SNPs by allelic discrimination assays. We enrolled 70 patients that received rituximab 375 mg/m² and bendamustine 90 mg/m² every 28 days, both as first-line treatment and ≥ second-line regimens. Overall response rate was 97·1% (complete response [CR] rate 73·9%). Treatment toxicity included grade 3-4 neutropenia (24/70 patients), infections (21/70 patients; 1/70 grade 3), skin rash (26/70 patients; 2/70 grade 3). After a median follow-up of 24 months we did find any correlation between the analysed SNPs, CR rate and PFS. However, we demonstrated an association between the SNP in IL2 (rs2069762) and the onset of skin rash (P = 0·0001). Our study suggests a role for cytokine SNPs in bendamustine-related toxicity, which could represent a promising research field.

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

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

No association of IL2, IL4, IL6, TNF, and IFNG gene polymorphisms was found with Taenia solium human infection or neurocysticercosis severity in a family-based study

Neurocysticercosis (NC) is caused by the establishment of the metacestode stage of Taenia solium in the human central nervous system. A great heterogeneity in the susceptibility to the infection and to the disease has been reported. While the factors involved in this heterogeneity are not completely understood, clearly different immune-inflammatory profiles have been associated to each condition. This study evaluated the association of cytokine single nucleotide polymorphisms (SNPs) with susceptibility to infection and disease severity in NC patients. Blood samples from 92 NC cases and their parents (trios) were genotyped for SNPs in five cytokines relevant for the immune response: IL4 (-589C/T), IL6 (-174C/G), IFNG (+874T/A), TNF (-238G/A), and IL2 (-330G/T). Specific DNA fragments were amplified by the polymerase chain reaction, using the 5'-nuclease Taqman assay on a 7500 platform, allowing the detection of the polymorphism genotypes. No association between the polymorphisms evaluated neither with susceptibility to infection nor with disease severity was found, although previous studies reported variations in the levels of these cytokines among different NC clinical pictures. These results, nevertheless, add new elements to our understanding of the complex pathogenic mechanisms involved in susceptibility to infection by T. solium cysticerci and the severity of the ensuing disease.

Association of Genetic Polymorphisms with Atopic Dermatitis, Clinical Severity and Total IgE: A Replication and Extended Study

Purpose

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease affecting up to 20% of children and 3% of adults worldwide. Although previous reports including genome-wide association study (GWAS) approaches have identified several risk factors that appear to be associated with AD development, replication studies are lacking. In our current study, we replicated the associations between candidate susceptibility loci and AD.

Methods

A total of 885 Korean subjects (425 AD patients and 460 unaffected controls) were genotyped for 17 single nucleotide polymorphisms (SNPs) from previous GWASs and meta-analyses of AD and from immune-related genes.

Results

Several SNPs showed significant associations with AD in the case-control analysis (minimum P=0.005 at rs17389644), suggesting that these polymorphisms may be related to this disease. In addition, several SNPs showed significant signals (minimum P=0.004 at rs6473227) in severe AD compared to unaffected controls. In additional linear regression analysis, a few genotypes appeared to have potential effects on the SCORing AD (SCORAD) values (minimum P=0.003 at rs13361382 on TMEM232) and immunoglobulin E (IgE) levels (minimum P<0.0001 at rs4713555 near HLA-DRB1 and HLA-DQA1) in AD patients.

Conclusions

Our replication and extended study provide additional supporting information on the genetic associations (especially, variants in TMEM232 and nearby to IL21 and HLA-DRB1/HLA-DQA1) related to AD, its clinical severity and IgE involvement.

The role of regulatory T cells and genes involved in their differentiation in pathogenesis of selected inflammatory and neoplastic skin diseases. Part III: Polymorphisms of genes involved in Tregs' activation and function

Regulatory T cells (Tregs) represent a cell type that promotes immune tolerance to autologous components and maintains immune system homeostasis. The abnormal function of Tregs is relevant to the pathogenesis of several skin diseases like psoriasis, atopic dermatitis, systemic lupus erythematosus, cutaneous T-cell lymphomas, and skin cancer and is also important in rheumatoid arthritis, diabetes and other autoimmune diseases. In this review, we will summarize the role of mutations and/or polymorphisms of genes involved in Tregs development, and functions in the pathogenesis of selected skin diseases.

Role of IL-15 in the modulation of TGF-β1-mediated inflammation in asthma

Transforming growth factor (TGF)-β1 has an essential role in bronchitis and the induction of bronchial remodelling, which are critical processes in the pathogenesis of asthma. However, the role of interleukin (IL)-15 in asthma inflammation remains unclear. The aim of the present study was to evaluate the effect of TGF-β1 mRNA expression on IL-15 mRNA expression in asthmatic patients and to assess the role of IL-15 in the clinical course of asthma. The study included 221 participants, comprising 130 patients with asthma and 91 healthy volunteers. The participants were subjected to testing using spirometry, as well as the Asthma Control Test™ and Borg Scale. The expression of TGF-β1 and IL-15 mRNA was analyzed in blood samples using reverse transcription-quantitative polymerase chain reaction. Statistical analysis indicated that IL-15 and TGF-β1 mRNA expression each differed significantly between the patient and control groups (P=0.0016 and P=0.033, respectively). A significant correlation was identified between IL-15 expression and TGF-β1 expression (R=0.41, P=0.0005). No correlation was observed between IL-15 expression and the degree of asthma severity, the results of spirometric examination or the frequency of asthma exacerbations. Further analysis revealed that IL-15 expression was elevated following the administration of inhaled glucocorticosteroids (iGCs; P=0.024), and reduced following methylxanthine treatment (P<0.001). The occurrence of dyspnoea differed between the study and control groups, and this was not found to be associated with IL-15 expression. Since IL-15 expression was correlated with TGF-β1 expression among asthmatic patients, and IL-15 expression was elevated following iGC administration, the results of the study suggest that IL-15 activity might be associated with the pathogenesis of asthma.

Association between cytokine gene polymorphisms and outcome of hepatitis B virus infection in southern Brazil

A number of studies have demonstrated associations between cytokine gene polymorphisms and outcome of hepatitis B virus (HBV) infection. However, no general consensus has been reached, possibly due to differences between ethnic groups. In this study, 345 individuals living in southern Brazil, including 196 chronic HBV carriers and 149 subjects who had spontaneously recovered from acute infection, were enrolled to evaluate the influence of cytokine gene polymorphisms on the outcome of HBV infection. Most participants were of European descent. Genotyping of IL2-330 G/T, IL4-589C/T, IL6-174 G/C, IL10-592C/A, IL10-1082 A/G, IL17A-197 G/A, IL17A-692 T/C, TNF-α-238 G/A, and TNF-α-308 G/A single nucleotide polymorphisms was performed by using the minisequencing (single base extension) method. By multivariable analysis, a statistically significant association was found between genotypic profile AA + GA in TNF-α-308 and chronic HBV infection (OR, 1.82; 95%CI, 1.01-3.27; P = 0.046). In southern Brazil, the carriers of the -308A allele in the TNF-α gene promoter have a moderately higher risk of becoming chronic carriers in case of HBV infection. In addition, patients with chronic active hepatitis B (n = 60) exhibited a decreased frequency (3.3%) of the TNF-238A allele when compared to that (14.8%) found among asymptomatic HBV carriers (n = 136), suggesting that this could be a protective factor against liver injury (OR, 0.17; 95%CI, 0.04-0.076; P = 0.023). J. Med. Virol. 88:1759-1766, 2016. © 2016 Wiley Periodicals, Inc.

New challenges and promises in solid organ transplantation pharmacogenetics: the genetic variability of proteins involved in the pharmacodynamics of immunosuppressive drugs

Interindividual variability in immunosuppressive drug responses might be partly explained by genetic variants in proteins involved in the immune response or associated with IS pharmacodynamics. On a general basis, the pharmacogenetics of drug target proteins is less known and understood than that of proteins involved in drug disposition pathways. The aim of this review is to facilitate research related to the pharmacodynamics of the main immunosuppressive drugs used in solid organ transplantation. We elaborated a quality of evidence grading system based on a literature review and identified 'highly recommended', 'recommended' or 'potential' candidates for further research. It is likely that a number of additional rare variants might further explain drug response phenotypes in transplantation, and particularly the most severe ones. The advent of next-generation sequencing will help to identify those variants.

Implications of cytokine genes in allergic asthma

Asthma is a complex disease involving numerous mediator molecules and effector cells, in combination with a range of environmental determining factors. Cytokines play a key role in the physiopathological mechanisms of asthma; the study of the structure, regulation and variations of the genes that encode for these molecules is therefore crucial. Cytokines have extremely diverse roles, and exert effects both as activators and inhibitors of the innate and adaptive immune response. Certain modifications in the expression or structure of these molecules, resulting from the presence of polymorphisms, may give rise to deregulation of the mentioned effects, and therefore to a predisposition to develop concrete asthma phenotypes.

Association of cytokines in individuals sensitive and insensitive to dust mites in a Brazilian population

Introduction

Allergic reaction to dust mites is a relatively common condition among children, triggering cutaneous and respiratory responses that have a great impact on the health of this population. Anaphylactic hypersensitivity is characterized by an exacerbated response involving the production of regulatory cytokines responsible for stimulating the production of IgE antibodies.

Objective

To investigate an association of variants in cytokine genes (IL1A⁻⁸⁸⁹, IL1B^{−511, +3962}, IL1R¹⁹⁷⁰, IL1RA¹¹¹⁰⁰, IL4RA⁺¹⁹⁰², IL12⁻¹¹⁸⁸, IFNG⁺⁸⁷⁴, TGFB1^{codon 10, codon 25}, TNFA^{−308, −238}, IL2^{−330, +166}, IL4^{−1098, −590, −33}, IL6^{−174, nt565}, and IL10^{−1082, −819, −592}) between patients sensitive to dust mites and a control group.

Methods

A total of 254 patients were grouped as atopic and non-atopic according to sensitivity as evaluated by the Prick Test and to cytokine genotyping by the polymerase chain reaction-sequence specific primers (PCR-SSP) method using the Cytokine Genotyping Kit.

Results

A comparison between individuals allergic to Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Blomia tropicalis and a non-atopic control group showed significant differences between allele and genotype frequencies in the regulatory regions of cytokine genes, with important evidence for IL4⁻⁵⁹⁰ in T/C (10.2% vs. 43.1%, odd ratio [OR] = 0.15, p = 5.2 10⁻⁸, pc = 0.0000011, and 95% confidence interval [95%CI] = 0.07–0.32) and T/T genotypes (42.9% vs. 13.8%, OR = 4.69, p = 2.5 10⁻⁶, pc = 0.000055, and 95%CI = 2.42–9.09). Other associations were observed in the pro-inflammatory cytokines IL1A⁻⁸⁸⁹ (T/T, C, and T) and IL2⁻³³⁰ (G/T and T/T) and the anti-inflammatory cytokines IL4RA⁺¹⁹⁰² (A and G), IL4⁻⁵⁹⁰ (T/C, T/T, C, and T), and IL10⁻⁵⁹² (A/A, C/A, A, and C).

Conclusion

Our results suggest a possible association between single nucleotide polymorphisms (SNPs) in cytokine genes and hypersensitivity to dust mites.

Interleukins and interleukin receptors in rheumatoid arthritis: Research, diagnostics and clinical implications

Rheumatoid arthritis (RA) is an autoimmune disease, resulting in a chronic, systemic inflammatory disorder. It may affect many tissues and organs, but it primarily affects the flexible joints. In clinical practice patient care generates many questions about diagnosis, prognosis, and treatment. It is challenging for health care specialists to keep up to date with the medical literature. This review summarizes the pathogenesis, the polymorphisms of interleukin and interleukin genes and the standard available and possible future immunologic targets for RA treatment. The identification of disease-associated interleukin and interleukin receptor genes can provide precious insight into the genetic variations prior to disease onset in order to identify the pathways important for RA pathogenesis. The knowledge of the complex genetic background may prove useful for developing novel therapies and making personalized medicine based on the individual’s genetics.

Insights into pathophysiology of dystropy through the analysis of gene networks: an example of bronchial asthma and tuberculosis

Co-existence of bronchial asthma (BA) and tuberculosis (TB) is extremely uncommon (dystropic). We assume that this is caused by the interplay between genes involved into specific pathophysiological pathways that arrest simultaneous manifestation of BA and TB. Identification of common and specific genes may be important to determine the molecular genetic mechanisms leading to rare co-occurrence of these diseases and may contribute to the identification of susceptibility genes for each of these dystropic diseases. To address the issue, we propose a new methodological strategy that is based on reconstruction of associative networks that represent molecular relationships between proteins/genes associated with BA and TB, thus facilitating a better understanding of the biological context of antagonistic relationships between the diseases. The results of our study revealed a number of proteins/genes important for the development of both BA and TB.

A promoter polymorphism (rs3806798) of interleukin-15 gene is associated with chronic hepatitis B virus infection in the Chinese Han population

This study aimed to investigate the association between the polymorphisms of IL-15 gene and susceptibility to chronic hepatitis B virus (HBV) infection in the Chinese Han population. A total of 234 patients with chronic HBV infection and 150 age- and sex-matched healthy controls in the Chinese population were enrolled in this case-control study. Genotyping of ten single nucleotide polymorphisms (SNPs) in the IL-15 gene was carried out via Sequenom MassARRAY system. The association analysis demonstrated that SNP rs3806798 (A/T) had a significant difference in the distribution between patients and healthy controls (P = 0.033). Moreover, a significantly increased risk of HBV infection was found to be associated with IL-15 rs3806798 A allele among male patients and HBeAg-negative patients, compared with IL-15 rs3806798 T allele (P = 0.003; P = 0.046, respectively). Furthermore, haplotype analysis revealed that haplotype ATAGG (rs3806798, rs12508866, rs1519551, rs6819823 and rs2857261, respectively) in block 1 was significantly associated with HBV infection (P = 0.022). In conclusion, we found an association between IL-15 rs3806798 and the risk of chronic HBV infection in a sample of Chinese Han population.

Enhanced antitumor immunity is elicited by adenovirus-mediated gene transfer of CCL21 and IL-15 in murine colon carcinomas

The chemokine CCL21 is a potent chemoattractant for T cells and dendritic cells. IL-15 elicits powerful antitumor immune responses through the stimulation of natural killer cells. We constructed a CCL21/IL-15-expressing adenovirus (Ad-CCL21-IL-15) and evaluated its antitumor effects in vitro and in vivo. We found that the intratumoral injection of Ad-CCL21-IL-15 into murine colon carcinomas significantly inhibited tumor growth. Splenocytes from mice treated with Ad-CCL21-IL-15 developed tumor-specific cytotoxic T cells and were protected from subsequent challenges with tumor cells. This study indicates that providing cancer therapy by combining CCL21 and IL-15 can induce antitumor immune responses and is an effective strategy for cancer immunotherapy.

Development of a novel severe triple allergen asthma model in mice which is resistant to dexamethasone and partially resistant to TLR7 and TLR9 agonist treatment

Severe asthma is characterised by persistent inflammation, hyperreactivity and remodeling of the airways. No efficient treatment is available, this is particularly the case for steroid resistant phenotypes. Our aim therefore was to develop a preclinical model showing characteristics of severe human asthma including steroid insensitivity. Mice were first sensitized with ovalbumin, extracts of cockroach or house dust mite followed by a challenge period of seven weeks. Further to this, an additional group of mice was sensitized with all three allergens and then challenged with allergen alternating weekly between allergens. All three allergens applied separately to the mice induced comparably strong Th2-type airway inflammation, airway hyperreactivity and airway remodeling, which was characterised by fibrosis and increased smooth muscle thickness. In contrast, application of all three allergens together resulted in a greater Th2 response and increased airway hyperreactivity and a stronger albeit not significant remodeling phenotype compared to using HDM or CRA. In this triple allergen model dexamethasone application, during the last 4 weeks of challenge, showed no suppressive effects on any of these parameters in this model. In contrast, both TLR7 agonist resiquimod and TLR9 agonist CpG-ODN reduced allergen-specific IgE, eosinophils, and collagen I in the lungs. The TLR9 agonist also reduced IL-4 and IL-5 whilst increasing IFN-γ and strongly IL-10 levels in the lungs, effects not seen with the TLR7 agonist. However, neither TLR agonist had any effect on airway hyperreactivity and airway smooth muscle mass. In conclusion we have developed a severe asthma model, which is steroid resistant and only partially sensitive to TLR7 and TLR9 agonist treatment. This model may be particular useful to test new potential therapeutics aiming at treating steroid resistant asthma in humans and investigating the underlying mechanisms responsible for steroid insensitivity.

Neonatal jaundice is a risk factor for childhood allergic rhinitis: a retrospective cohort study

BACKGROUND

This study evaluates the association between neonatal jaundice and childhood allergic rhinitis (AR).

METHODS

Eleven thousand three hundred twenty-eight children were collected from the National Health Insurance Research Database in Taiwan. Their claims data were evaluated from birth to 10 years of age, and they were assigned to either the study (with neonatal jaundice) or the control (without neonatal jaundice) group. The diagnostic criteria for AR were at least three diagnoses of AR at outpatient services, one diagnosis of AR during an admission, or one diagnosis of AR in an emergency department. Mantel-Haenszel odds ratios (ORs) were calculated after adjustment for the following confounders: preterm/low birth weight, neonatal infection, other respiratory conditions, other birth conditions, and gender. AR rate, AR onset time, the use of oral antihistamines/nasal corticosteroids, outpatient visit frequency for AR, lower respiratory infection (LRI) rates, sinusitis/otitis media/conjunctivitis rates, and the effect of phototherapy were evaluated.

RESULTS

After adjustment for the confounding factors, the rate of AR was higher in icteric children (OR, 1.46; 95% confidence interval, 1.24∼1.72). There was a higher incidence of AR in children <4 years old with icterus. The use of oral antihistamines, LRI rates, sinusitis rates, and otitis media rates were higher in the icteric children. There was no association between phototherapy and childhood AR.

CONCLUSION

Neonatal jaundice increased the rate and complications of childhood AR in subjects aged up to 10 years and may be a risk factor for childhood AR.

Polymorphic variant at the IL2 region is associated with type 1 diabetes and may affect serum levels of interleukin-2

Polymorphic variants at the interleukin-2 (IL2) locus affect the risk of several autoimmune disorders. Our aim was to evaluate the association of the four IL2 polymorphisms (rs6822844, rs6534349, rs2069762 and rs3136534) with type 1 diabetes (T1D) in the Polish population, and to correlate them with the serum interleukin-2 levels. 543 unrelated T1D patients and 706 healthy control subjects were enrolled. The minor T allele at rs6822844 was significantly less frequent in T1D compared to controls (p = 0.002; OR 0.71; 95 % CI 0.571–0.880). Likewise, the frequency of the TT genotype was decreased among the affected individuals (p = 0.007). In healthy subjects, stratification according to the rs6822844 genotype revealed significant differences in circulating interleukin-2 (p = 0.037) with the highest levels in TT protective genotypes. Three other IL2 polymorphisms did not display significant differences in allele and genotype distribution. In conclusion, the rs6822844 variant is associated with T1D and may play a functional role, or reflect the influence of another causative genetic variant in linkage disequilibrium.

Meta-analysis of genome-wide association studies identifies ten loci influencing allergic sensitization

Allergen-specific immunoglobulin E (present in allergic sensitization) has a central role in the pathogenesis of allergic disease. We performed the first large-scale genome-wide association study (GWAS) of allergic sensitization in 5,789 affected individuals and 10,056 controls and followed up the top SNP at each of 26 loci in 6,114 affected individuals and 9,920 controls. We increased the number of susceptibility loci with genome-wide significant association with allergic sensitization from three to ten, including SNPs in or near TLR6, C11orf30, STAT6, SLC25A46, HLA-DQB1, IL1RL1, LPP, MYC, IL2 and HLA-B. All the top SNPs were associated with allergic symptoms in an independent study. Risk-associated variants at these ten loci were estimated to account for at least 25% of allergic sensitization and allergic rhinitis. Understanding the molecular mechanisms underlying these associations may provide new insights into the etiology of allergic disease.

Genetic factors in the treatment of bronchial asthma

Owing to the recent vast progress in analytical tools and procedures to elucidate the relationship between genes and diseases, many candidate genes leading to the development of bronchial asthma have been reported. However, the quantitative phenotypes of asthma, such as decrease in forced expiratory volume in the first second, serum hyper-IgE, bronchial hyperresponsiveness and blood hyper-eosinophilia, do not represent this disease completely. On the other hand, eosinophilic inflammation of the bronchial mucosa represents accurately the feature of bronchial asthma, although accurate quantification of its status is difficult. While the production of interleukin (IL)-5 in peripheral CD4(+) T cells probably correlates with eosinophilic inflammation of the airway, the effectiveness of anti-IL-5 antibody for the treatment of bronchial asthma is controversial. Since intervention with asthma-causing gene products may not be sufficient for the treatment of this disease, identification of therapy-responsive genes should become more important in the near future.

Add-on montelukast to inhaled corticosteroids protects against excessive airway narrowing

RATIONALE

Excessive airway narrowing in response to broncho-active stimuli is a predictor for severe exacerbations in asthma. Leukotriene receptor antagonists (LTRAs) have complementary properties to inhaled corticosteroids (ICS) on asthma control.

OBJECTIVES

The LTRA montelukast may provide an additional protection against excessive airway narrowing. We tested the add-on effects of montelukast on the maximal response plateau and PD(20) to inhaled methacholine in asthmatics on a stable dose of ICS.

METHODS

Thirty-one patients with allergic asthma [14M/17F, 19-50 years, forced expiratory volume in 1 s (FEV(1)) >70% pred., PD(20) <3.9 micromol methacholine], with a twice documented response plateau to methacholine, were randomized in a double-blind (montelukast 10 mg or matching placebo once daily), 12-week parallel study. Bronchoprovocation tests with methacholine (0.03-256 micromol or > or =40% decline in FEV(1)) were repeated every 4 weeks and after wash-out. The main study objectives were changes from baseline in maximal FEV(1) decline at the response plateau (i.e. >2 post-dose FEV(1) values within 5%) and PD(20) to methacholine after 12 weeks' treatment.

RESULTS

Neither treatment affected baseline FEV(1) (P=0.62). Compared with placebo, montelukast significantly decreased the maximal response plateau to methacholine (mean difference 9.4%; 95% confidence interval 3.9-15.7; P<0.005), improved the FEV(1) decline (mean change in FEV(1) decline was 2.1% [montelukast] and -0.8% [placebo], respectively, P<0.05), and increased PD(20) methacholine (mean change in PD(20) of 5.3 [montelukast] and 1.4 [placebo] doubling doses, respectively, P<0.001).

CONCLUSION

Add-on montelukast to ICS has disease-modifying effects in adults with persistent asthma, and hence reduces the risk of excessive airway narrowing (NCT 00913328).

Commonly studied polymorphisms in inflammatory cytokine genes show only minor effects on mortality and related risk factors in nonagenarians

Systemic low-grade inflammation is consistently associated with functional status, cognitive functioning, multimorbidity, and survival in oldest olds. If inflammation is either a cause or a consequence of age-related pathology, genetic determinants of late-life survival can reside in cytokine genes polymorphisms, regulating inflammatory responses. The aim of this study was to test associations between commonly studied polymorphisms in interleukin (IL)6, IL10, IL15, and IL18, and tumor necrosis factor-alpha genes and late-life survival in a longitudinal cohort of nonagenarians: the Danish 1905 cohort. Additionally, associations were investigated between inflammatory markers and major predictors of mortality as cognitive and functional status. Modest sex-specific associations were found with survival, cognitive functioning, and handgrip strength. Evaluation of combined genotypes indicated that, in nonagenarian men, the balance of pro- and anti-inflammatory activity at IL18 and IL10 loci is protective against cognitive decline. In conclusion, in this large study with virtually complete follow-up, commonly studied polymorphisms in cytokine genes do not have a major impact on late-life survival or associated risk phenotypes.

Promoter polymorphisms of IL2, IL4, and risk of gastric cancer in a high-risk Chinese population

Interleukin 2 (IL2) is a typical Th1 cytokine, and interleukin 4 (IL4) is an inducible Th2 cytokine. These cytokines are critical mediators of the Th1/Th2 balance and apoptosis potential and involved in the process of inflammation-mediated carcinogenesis in human organs, including the gastrointestinal tract. Therefore, we tested the hypothesis that functional variants in IL2 and IL4 were associated with risk of gastric cancer by genotyping two promoter polymorphisms in IL2 G-330T (rs2069762) and IL4 T-168C (rs2070874) in a case-control study of 1045 patients with incident gastric cancer and 1100 cancer-free controls in a high-risk Han Chinese population. We found that, compared with the IL4 -168TT genotype, heterozygous -168TC and combined -168TC/CC genotypes were associated with a significantly decreased gastric cancer risk [adjusted odds ratio (OR) = 0.81, 95% confidence interval (CI) = 0.67-0.98 for -168TC; OR = 0.83, 95% CI = 0.69-1.00 for -168TC/CC, respectively]. Furthermore, this significant protective effect was more evident for gastric cardia cancer patients (adjusted OR = 0.73, 95% CI = 0.56-0.95 for -168TC/CC vs. -168TT). For IL2 G-330T, subjects carrying GT/TT genotypes also had a significantly reduced risk of gastric cardia cancer (adjusted OR = 0.68, 95% CI = 0.46-0.99), compared with those carrying the GG genotype. Our results indicate that IL4 T-168C and IL2 G-330T promoter polymorphisms may contribute to the etiology of gastric cardia cancer in Chinese populations.

Global expression profiling in atopic eczema reveals reciprocal expression of inflammatory and lipid genes

BACKGROUND

Atopic eczema (AE) is a common chronic inflammatory skin disorder. In order to dissect the genetic background several linkage and genetic association studies have been performed. Yet very little is known about specific genes involved in this complex skin disease, and the underlying molecular mechanisms are not fully understood.

METHODOLOGY/FINDINGS

We used human DNA microarrays to identify a molecular picture of the programmed responses of the human genome to AE. The transcriptional program was analyzed in skin biopsy samples from lesional and patch-tested skin from AE patients sensitized to Malassezia sympodialis (M. sympodialis), and corresponding biopsies from healthy individuals. The most notable feature of the global gene-expression pattern observed in AE skin was a reciprocal expression of induced inflammatory genes and repressed lipid metabolism genes. The overall transcriptional response in M. sympodialis patch-tested AE skin was similar to the gene-expression signature identified in lesional AE skin. In the constellation of genes differentially expressed in AE skin compared to healthy control skin, we have identified several potential susceptibility genes that may play a critical role in the pathological condition of AE. Many of these genes, including genes with a role in immune responses, lipid homeostasis, and epidermal differentiation, are localized on chromosomal regions previously linked to AE.

CONCLUSIONS/SIGNIFICANCE

Through genome-wide expression profiling, we were able to discover a distinct reciprocal expression pattern of induced inflammatory genes and repressed lipid metabolism genes in skin from AE patients. We found a significant enrichment of differentially expressed genes in AE with cytobands associated to the disease, and furthermore new chromosomal regions were found that could potentially guide future region-specific linkage mapping in AE. The full data set is available at http://microarray-pubs.stanford.edu/eczema.

Interleukin-15 and interleukin-15R alpha SNPs and associations with muscle, bone, and predictors of the metabolic syndrome

The aims of this study were to examine associations between two SNPs in the human IL-15 gene and three SNPs in the IL-15Ralpha gene with predictors of metabolic syndrome and phenotypes in muscle, strength, and bone at baseline and in response to resistance training (RT). Subjects were Caucasians who had not performed RT in the previous year and consisted of a strength cohort (n=748), volumetric cohort (n=722), and serum cohort (n=544). Subjects completed 12 weeks of unilateral RT of the non-dominant arm, using their dominant arm as an untrained control. ANCOVA analyses revealed gender-specific associations with: (1) IL-15 SNP (rs1589241) and cholesterol (p=0.04), LDL (p=0.02), the homeostasis model assessment (HOMA; p=0.03), and BMI (p=0.002); (2) IL-15 SNP (rs1057972) and the pre- to post-training absolute difference in 1RM strength (p=0.02), BMI (p=0.008), and fasting glucose (p=0.03); (3) IL-15Ralpha SNP (rs2296135) and baseline total bone volume (p=0.04) and the pre- to post-training absolute difference in isometric strength (p=0.01); and 4) IL-15Ralpha SNP (rs2228059) and serum triglycerides (p=0.04), baseline whole muscle volume (p=0.04), baseline cortical bone volume (p=0.04), and baseline muscle quality (p=0.04). All associations were consistent in showing a potential involvement of the IL-15 pathway with muscle and bone phenotypes and predictors of metabolic syndrome.

New drugs targeting Th2 lymphocytes in asthma

Asthma represents a profound worldwide public health problem. The most effective anti-asthmatic drugs currently available include inhaled beta2-agonists and glucocorticoids and control asthma in about 90-95% of patients. The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term therapy. Although glucocorticoids are highly effective in controlling the inflammatory process in asthma, they appear to have little effect on the lower airway remodelling processes that appear to play a role in the pathophysiology of asthma at currently prescribed doses. The development of novel drugs may allow resolution of these changes. In addition, severe glucocorticoid-dependent and resistant asthma presents a great clinical burden and reducing the side-effects of glucocorticoids using novel steroid-sparing agents is needed. Furthermore, the mechanisms involved in the persistence of inflammation are poorly understood and the reasons why some patients have severe life threatening asthma and others have very mild disease are still unknown. Drug development for asthma has been directed at improving currently available drugs and findings new compounds that usually target the Th2-driven airway inflammatory response. Considering the apparently central role of T lymphocytes in the pathogenesis of asthma, drugs targeting disease-inducing Th2 cells are promising therapeutic strategies. However, although animal models of asthma suggest that this is feasible, the translation of these types of studies for the treatment of human asthma remains poor due to the limitations of the models currently used. The myriad of new compounds that are in development directed to modulate Th2 cells recruitment and/or activation will clarify in the near future the relative importance of these cells and their mediators in the complex interactions with the other pro-inflammatory/anti-inflammatory cells and mediators responsible of the different asthmatic phenotypes. Some of these new Th2-oriented strategies may in the future not only control symptoms and modify the natural course of asthma, but also potentially prevent or cure the disease.

Molecular screening and association study of IL15 gene polymorphisms in rheumatoid arthritis

Interleukin 15 (IL-15) is a pleiotropic pro-inflammatory cytokine known to play a relevant role in rheumatoid arthritis (RA) pathogenesis. In this study we aimed to investigate for the first time the contribution of IL15 gene to RA susceptibility. We screened 13 single nucleotide polymorphisms (SNPs) localised within IL15 regulatory regions (promoter, 5' UTR region and 3' UTR region) in a total of 420 individuals, who were genotyped by direct sequencing of PCR products. In addition, an association study of these IL15 SNPs was conducted in three independent case-control cohorts of Spanish Caucasian origin, including a total of 645 RA patients and 656 healthy controls. The presence of the 13 selected IL15 SNPs in our population was confirmed and no new genetic variants were found. The distribution of the IL15 selected SNPs in RA patients and controls showed no statistically significant deviation in any of the populations studied. Additionally, we performed a haplotype analysis that revealed three IL15 haplotype blocks. None of the haplotype blocks was associated with RA susceptibility or severity in the three cohorts analysed. Our results suggest that the IL15 gene polymorphisms do not appear to play a major role in RA genetic predisposition in our population.

A functional CD86 polymorphism associated with asthma and related allergic disorders

BACKGROUND

Several studies have documented a substantial genetic component in the aetiology of allergic diseases and a number of atopy susceptibility loci have been suggested. One of these loci is 3q21, at which linkage to multiple atopy phenotypes has been reported. This region harbours the CD86 gene encoding the costimulatory B7.2 protein. The costimulatory system, consisting of receptor proteins, cytokines and associated factors, activates T cells and regulates the immune response upon allergen challenge.

METHODS

We sequenced the CD86 gene in patients with atopy from 10 families that showed evidence of linkage to 3q21. Identified polymorphisms were analysed in a subsequent family-based association study of two independent Danish samples, respectively comprising 135 and 100 trios of children with atopy and their parents. Functional analysis of the costimulatory effect on cytokine production was performed in an autologous cell-based system based on cells expressing CD86 variants.

RESULTS

Two polymorphisms were identified, encoding the amino acid changes Ile179Val and Ala304Thr, respectively. Significant associations were observed between the Ile179Val polymorphism and allergy phenotypes in both samples (eg, asthma, p = 4 x 10(-3) in the two samples combined). The undertransmitted (protective) Val179 allele was found to induce higher production of both Th1 and Th2 cytokines than the overtransmitted (risk) Ile179 allele, suggesting a functional impact of the polymorphism.

CONCLUSION

The CD86 gene, and specifically the Ile179Val polymorphism, may be a novel aetiological factor in the development of asthma and related allergic disorders.