Interleukin 3 (IL3) polymorphisms associated with decreased risk of asthma and atopy

IL-3: key orchestrator of inflammation

Interleukin (IL)-3 has long been known for its hematopoietic properties. However, recent evidence has expanded our understanding of IL-3 function by identifying IL-3 as a critical orchestrator of inflammation in a wide array of diseases. Depending on the type of disease, the course of inflammation, the cell or the tissue involved, IL-3 promotes either pathologic inflammation or its resolution. Here, we describe the cell-specific functions of IL-3 and summarize its role in diseases. We discuss the current treatments targeting IL-3 or its receptor, and highlight the potential and the limitations of targeting IL-3 in clinics.

Pulmonary Eosinophils at the Center of the Allergic Space-Time Continuum

Eosinophils are typically a minority population of circulating granulocytes being released from the bone-marrow as terminally differentiated cells. Besides their function in the defense against parasites and in promoting allergic airway inflammation, regulatory functions have now been attributed to eosinophils in various organs. Although eosinophils are involved in the inflammatory response to allergens, it remains unclear whether they are drivers of the asthma pathology or merely recruited effector cells. Recent findings highlight the homeostatic and pro-resolving capacity of eosinophils and raise the question at what point in time their function is regulated. Similarly, eosinophils from different physical locations display phenotypic and functional diversity. However, it remains unclear whether eosinophil plasticity remains as they develop and travel from the bone marrow to the tissue, in homeostasis or during inflammation. In the tissue, eosinophils of different ages and origin along the inflammatory trajectory may exhibit functional diversity as circumstances change. Herein, we outline the inflammatory time line of allergic airway inflammation from acute, late, adaptive to chronic processes. We summarize the function of the eosinophils in regards to their resident localization and time of recruitment to the lung, in all stages of the inflammatory response. In all, we argue that immunological differences in eosinophils are a function of time and space as the allergic inflammatory response is initiated and resolved.

IL-3 in the development and function of basophils

The β common chain (βc) cytokine family includes granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) and IL-5, all of which use βc as key signaling receptor subunit. GM-CSF, IL-3 and IL-5 have specific roles as hematopoietic growth factors. IL-3 binds with high affinity to the IL-3 receptor α (IL-3Rα/CD123) and then associates with the βc subunit. IL-3 is mainly synthesized by different subsets of T cells, but is also produced by several other immune [basophils, dendritic cells (DCs), mast cells, etc.] and non-immune cells (microglia and astrocytes). The IL-3Rα is also expressed by immune (basophils, eosinophils, mast cells, DCs, monocytes, and megacaryocytes) and non-immune cells (endothelial cells and neuronal cells). IL-3 is the most important growth and activating factor for human and mouse basophils, primary effector cells of allergic disorders. IL-3-activated basophils and mast cells are also involved in different chronic inflammatory disorders, infections, and several types of cancer. IL-3 induces the release of cytokines (i.e., IL-4, IL-13, CXCL8) from human basophils and preincubation of basophils with IL-3 potentiates the release of proinflammatory mediators and cytokines from IgE- and C5a-activated basophils. IL-3 synergistically potentiates IL-33-induced mediator release from human basophils. IL-3 plays a pathogenic role in several hematologic cancers and may contribute to autoimmune and cardiac disorders. Several IL-3Rα/CD123 targeting molecules have shown some efficacy in the treatment of hematologic malignancies.

Interleukin-10 Gene Promoter Polymorphisms and Susceptibility to Asthma: Systematic Review and Meta-analysis

Several studies have previously assessed the association between interleukin (IL)-10 gene polymorphisms and the risk of asthma, leading to conflicting results. To resolve the incongruent outcomes yielded from different single studies, we conducted the most up-to-date meta-analysis of the IL-10 gene rs1800896, rs1800871, and rs1800872 single-nucleotide polymorphisms (SNPs) and susceptibility to asthma. A systematic literature search performed until April 2020, and the pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were calculated to determine the association strength. Thirty articles comprising 5678 asthmatic patients and 6079 controls met the inclusion criteria. No significant association was found between rs1800872 SNP and susceptibility to asthma across all genetic models in the overall and subgroup analyses. The rs1800871 SNP had only significant association with a decreased risk of asthma in Europeans (OR 0.66, CI 0.53-0.82, P < 0.001). However, rs1800896 SNP was significantly associated with a decreased risk of asthma by dominant (OR 0.67, CI 0.50-0.90, P < 0.001) and heterozygote (OR 0.66, CI 0.49-0.88, P < 0.001) models in the overall analysis. Subgroup analyses indicated significant association of rs1800896 SNP by dominant (OR 0.45, CI 0.28-0.72, P < 0.001) and heterozygote (OR 0.43, CI 0.26-0.70, P < 0.001) models in the African population. The IL-10 rs1800896 SNP confers protection against the risk of asthma, especially in Africans. Additionally, rs1800871 SNP has a protective role against asthma in Europeans.

Interleukin-4 gene polymorphism (C33T) and the risk of the asthma: a meta-analysis based on 24 publications

Background

Previous studies evaluated the association of IL-4 C33T polymorphism and risk of bronchial asthma but failed to establish a consistent conclusive association. In the present meta-analysis, we intend to define a more reliable estimate of the association in the presence of filling published literature.

Methods

An exhaustive search in Web of Science, Scopus, and PubMed databases was performed to identify all relevant publications before September 2020, and 24 publications (28 studies) with 6587 cases and 8408 controls were included in final analysis. The association between polymorphism and risk of asthma were measured by Odd ratios (ORs) and 95% confidence intervals (CIs). Moreover, Cochran’s Q and the I² statistics were used to evaluate the degree of heterogeneity between studies.

Results

In the overall study populations, a significant positive association was detected under all genotype models and announced the IL-4 C33T polymorphism as a potential risk factor in the pathogenesis of asthma. In the subgroup analysis by age, a significant association between IL-4 C33T polymorphism and risk of asthma in different age groups was identified in allelic model, which highlighted the predisposing role of the T allele for the asthma risk in all three age groups. Furthermore, the results of subgroup analysis by continent were heterogenous. Accordingly, IL-4 C33T polymorphism was a risk factor in Europeans (all models except heterozygote comparison), Americans (all models except recessive and homozygote comparison) and Asians (just recessive and allelic model). Finally, the ethnicity-specific analysis disclosed a significant association between IL-4 C33T polymorphism and asthma risk in Caucasians (all genotype models except heterozygote comparison), while this association was not significant in African-Americans.

Conclusions

This study suggests that IL-4 C33T polymorphism potentially acts as a risk factor for asthma in different ethnicities and age groups.

Interleukin 4 gene polymorphism (-589C/T) and the risk of asthma: a meta-analysis and met-regression based on 55 studies

BACKGROUND

Numerous investigations have previously evaluated the association of interleukin (IL) 4 gene polymorphisms and the risk of asthma, conferring inconsistent results. To resolve the incongruent outcomes yielded from different single studies, we conducted the most up-to-date meta-analysis of IL4 gene -589C/T (rs2243250) polymorphism and susceptibility to asthma.

METHODS

A systematic literature search was performed in ISI web of science, Scopus, Medline/PubMed databases prior to September 2020, and the pooled odds ratio (OR) and their corresponding 95% CI were calculated to determine the association strength.

RESULTS

Literature search led to retrieving of 49 publications (55 case-control studies) containing 9572 cases and 9881 controls. It was revealed that IL4 gene -589C/T polymorphism increased the risk of asthma across all genetic models, including dominant model (OR = 1.22), recessive model (OR = 1.17), allelic model (OR = 1.21), and TT vs. CC model (OR = 1.34), but not the CT vs. TT model. The subgroup analysis by age indicated that IL4 gene -589C/T polymorphism was significantly associated with asthma risk in both pediatrics and adults. Additionally, the subgroup analysis by ethnicity revealed significant association in Asian, American, and Europeans. Finally, subgroup analysis by East Asian and non-East Asian populations indicated significant associations.

CONCLUSIONS

The current meta-analysis revealed that IL4 gene -589C/T polymorphism was a susceptibility risk in both pediatrics and adults in the whole and different ethnic groups.

Genetic variation in interleukin-7 is associated with a reduced erythropoietic response in Kenyan children infected with Plasmodium falciparum

BACKGROUND

Severe malarial anemia (SMA) is a leading cause of malaria-related morbidity and mortality in children. The genetic factors that influence development of SMA and inefficient erythropoiesis, a central pathogenic feature of SMA, are only partially understood.

METHODS

We performed a pilot Genome-wide Association Study (GWAS) on children with Plasmodium falciparum. The GWAS was performed using the Illumina® Infinium® HD Super Assay in conjunction with Illumina's® Human Omni2.5-8v1 BeadChip (with > 2.45 M markers). Data were analyzed using single SNP logistic regression analysis with an additive model of inheritance controlling for covariates. Results from our pilot global genomics study identified that variation in interleukin (IL)-7 was associated with enhanced risk of SMA. To validate this finding, we investigated the relationship between genotypes and/or haplotypes of two single nucleotide polymorphisms (SNPs) in IL7 [72194 T/C and - 2440 A/G] and susceptibility to both SMA and inefficient erythropoiesis [i.e., reticulocyte production index (RPI) < 2.0 in anemic children (Hb < 11.0 g/dL). Children presenting with P. falciparum malaria (< 3 years, n = 883) were stratified into two groups: Uncomplicated malaria (UM, n = 718) and SMA (n = 165).

RESULTS

Regression modeling, controlling for anemia-related confounders, revealed that carriage of the TC genotype at position 72194 T/C was associated with enhanced susceptibility to inefficient erythropoiesis (OR = 1.90; 95% CI 1.09-3.30; P = 0.02) as was homozygous CC (OR 5.14; 95% CI = 1.20-21.99; P = 0.03). Consistent with this finding, individuals with the CA (72194C/-2440A) haplotype had an increased risk of inefficient erythropoiesis (OR = 1.90; 95% CI = 1.10-3.30; P = 0.02), whereas TA haplotype carriers had marginal protection against inefficient erythropoiesis (OR = 0.24; 95% CI = 0.06-1.21; P = 0.05). These observations were supported by Cochran-Armitage trend test for inefficient erythropoiesis (CA > TA > CG; P < 0.01). Although none of the genotype and/or haplotypic variants were significantly associated with SMA, the direction of the risk profiles were consistent with the erythropoiesis results.

CONCLUSION

Taken together, variation in IL7 is associated with erythropoietic responses in children with falciparum malaria, a central physiological feature contributing to development of SMA.

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.

Interleukin-7 gene polymorphism rs766736182 associates with the risk of asthma in children

BACKGROUND

Recently studies uncovered associations between polymorphisms of interleukin genes and the risk of asthma. However, the relationship between polymorphisms of interleukin-7 gene and the risk of children asthma has not been discovered yet. This study aims to investigate the relationship between single nucleotide polymorphisms (SNPs) on interleukin-7 gene and the risk of children asthma.

METHODS

We genotyped eight SNPs of interleukin-7 gene in blood samples from 437 asthma patients and 489 healthy controls to analyze potential associations of these SNPs with the risk of asthma in children.

RESULTS

A missense SNP rs766736182 (odds ratio (OR) = 2.185, 95% confidence interval (CI) = 1.561-2.252, P-value = 8.69468E-19) of the interleukin-7 gene is associated with the risk of children asthma.

CONCLUSIONS

This study reveals that SNP rs766736182 of interleukin-7 is the risk factor for children asthma and implies potential role of immune system in the pathogenesis of children asthma.

Differences in Genetic Variations Between Treatable and Recalcitrant Atopic Dermatitis in Korean

Purpose

Variations in barrier- or immune response-related genes are closely related to the development of atopic dermatitis (AD). This study was designed to identify genetic variations and clinical features to predict ‘recalcitrant AD.’

Methods

AD patients were classified as treatable and recalcitrant. Treatable AD patients showed satisfactory clinical improvement with basic and topical treatments. Recalcitrant AD patients used systemic immune-suppressants for over 4 weeks as they had not shown clinical improvement with basic and topical treatments. The frequency of gene variations in barrier- (FLG 3321delA, FLG K4022X, KLK7, SPINK 1156, SPINK 1188, SPINK 2475) and immune response- (DEFB1, KDR, IL-5RA, IL-9, and IL-12RB1a, b) related genes were compared between each AD group and the controls.

Results

Of all, 249 treatable AD and 32 recalcitrant AD were identified. Heterozygous mutations (Hetero) in KLK7 was more frequent in recalcitrant AD patients than treatable AD, without statistical significance. Hetero in DEFB1 was more frequent in treatable AD patients. However, no other significant genetic differences between treatable and recalcitrant AD was observed. Instead, higher initial Eczema Area Severity Index (EASI) score, serum immunoglobulin E (IgE) level, allergen specific IgE for house dust mites, and family history of atopic diseases were associated with recalcitrant AD with statistical significance.

Conclusions

According to our study, no genetic variation to predict recalcitrant AD was identified, suggesting that clinical manifestation, rather than genetic variations of AD patients is more likely to be an important factor in predicting the prognosis of AD. Further large-scale studies on the correlation between genetic variation and recalcitrant AD are needed.

IL-3 up-regulates and activates human eosinophil CD32 and αMβ2 integrin causing degranulation

BACKGROUND

Eosinophils contribute to the pathogenesis of multiple diseases, including asthma. Treatment with antibodies targeting IL-5 or IL-5 receptor α reduces the frequency of asthma exacerbations. Eosinophil receptors for IL-5 share a common ß-chain with IL-3 and GM-CSF receptors. We recently reported that IL-3 is more potent than IL-5 or GM-CSF in maintaining the ERK/p90S6K/RPS6 ribosome-directed signaling pathway, leading to increased protein translation.

OBJECTIVE

We aimed to determine disease-relevant consequences of prolonged eosinophil stimulation with IL-3.

RESULTS

Human blood eosinophils were used to establish the impact of activation with IL-3 on IgG-driven eosinophil degranulation. When compared to IL-5, continuing exposure to IL-3 further induced degranulation of eosinophils on aggregated IgG via increased production and activation of both CD32 (low affinity IgG receptor) and αMß2 integrin. In addition, unlike IL-5 or GM-CSF, IL-3 induced expression of CD32B/C (FCGRIIB/C) subtype proteins, without changing CD32A (FCGRIIA) protein and CD32B/C mRNA expression levels. Importantly, these in vitro IL-3-induced modifications were recapitulated in vivo on airway eosinophils.

CONCLUSIONS AND CLINICAL RELEVANCE

We observed for the first time upregulation of CD32B/C on eosinophils, and identified IL-3 as a potent inducer of CD32- and αMß2-mediated eosinophil degranulation.

Predictive genetic markers of coagulation, inflammation and apoptosis in Perthes disease—Serbian experience

Perthes disease is one of the most common forms of pediatric femoral head osteonecrosis with an unknown etiology. Coagulation factors were the first genetic factors suspected to have a role in the pathogenesis of this disease, but studies showed inconsistent results. It is described that inflammation is present during early stages of Perthes disease, but its genetic aspect has not been studied extensively. Little is known regarding the status of apoptotic factors during the repair process that leads to the occurrence of hip deformity in patients. Therefore, the aim of this study was to analyze major mediators involved in coagulation, inflammation, and apoptotic processes as possible causative factors of Perthes disease. The study cohort consisted of 37 patients. Gene variants of TNF-α, FV, FII, and MTHFR genes were determined by PCR-RFLP, while IL-3 and PAI-1 were genotyped by direct sequencing. The expression level of Bax, Bcl-2, Bcl2L12, Fas and FasL was analyzed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) technique. Our results showed a significantly increased level of expression of pro-apoptotic factor Bax along with significantly higher Bax/Bcl-2 ratio in the patient group.

CONCLUSION

The results presented indicate that apoptosis could be one of the factors contributing to the lack of balanced bone remodeling process in Perthes patients.

IL-10 and IL-17F Promoter Single Nucleotide Polymorphism and Asthma: A Case-Control Study in South India

BACKGROUND

Several studies have assessed the association between IL-17F and IL-10 promoter polymorphisms and asthma, but the results were conflicting. Furthermore, few studies have evaluated the association of cytokine polymorphisms with asthma and its clinical phenotypes.

OBJECTIVE

This study was conducted to evaluate the association of IL-10 (interleukin 10) and IL-17F (interleukin 17F) promoter polymorphisms (rs1800871, rs1800896 and rs1889570) with asthma and its clinical phenotypes including severity, atopic status, spirometric parameters, and response to treatment in south Indian population. A sub-study was conducted to assess cytokine levels in subjects with different gene variants.

METHODS

IL-10 and IL-17F polymorphisms were genotyped in 419 asthmatic patients and 393 controls using Mass ARRAY.

RESULTS

Our results showed an association between IL-10 SNPs and mild asthma. No association was found with any of three SNPs in moderate to severe asthma. Comparison of genotype distribution of IL-17F rs1887570 AA variant among atopic and non-atopic patients showed significant difference (p = 0.024). Correlation analysis of IL-10 and IL-17F SNPs to clinical variables showed a positive correlation between IL-17F rs1887570 AA and number of allergen sensitized (rs = 0.142, p = 0.004). Significant improvement in lung function was observed after 2 months of ICS (Inhaled corticosteroids) and LABA (long acting β2 agonist) treatment in all subjects with no statistically significant difference among SNPs variants. Cytokines levels were similar in different SNP variants.

CONCLUSION

We observed an association between IL-10 rs1800871 and rs1800896 SNPs and mild asthma, as well as IL-17F rs1887570 AA variant and number of allergens sensitized.

IL5RA polymorphisms, smoking and eczema in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

The present case-control study examined the relationship between IL5RA SNPs and eczema in young adult Japanese women. Cases and control subjects were selected from pregnant women who participated in the baseline survey of the Kyushu Okinawa Maternal and Child Health Study, which is an ongoing prebirth cohort study. Cases comprised 188 women with eczema in the previous 12 months as defined according to the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC), regardless of the presence of a doctor's diagnosis of atopic eczema. Control subjects comprised 1130 women without eczema as defined according to the ISAAC criteria who also had not been diagnosed with atopic eczema by a doctor. Compared with the AA genotype of IL5RA SNP rs17881144, the AT genotype, but not the TT genotype, was significantly associated with a decreased risk of eczema. The ATTAGA haplotype and the GTAGCA haplotype of rs17882210, rs3804797, rs334809, rs9831572, rs6771148 and rs17881144 were significantly associated with an increased risk of eczema. In contrast, the GCTGCA haplotype was significantly related to a decreased risk of eczema. Multiplicative interactions between IL5RA SNPs rs334809 and rs17881144 and smoking with respect to eczema were marginally significant (P = 0.07 and 0.07, respectively). This is the first study to show significant associations between IL5RA SNP rs17881144, the ATTAGA haplotype, the GTAGCA haplotype, and the GCTGCA haplotype and eczema. Smoking may modify the relationships between SNPs rs334809 and rs17881144 and eczema.

IL3 rs40401 polymorphism and interaction with smoking in risk of asthma in Japanese women: the Kyushu Okinawa Maternal and Child Health study

Three previous genetic association studies conducted in Korea and China investigated the relationship between IL3 single nucleotide polymorphism (SNP) rs40401 and asthma, but their results were inconsistent. We examined this relationship and the possibility of an interaction between IL3 SNP rs40401 and smoking in young adult Japanese women. Included were 89 women who met the criteria of the European Community Respiratory Health Survey (ECRHS) for asthma. Control subjects were 700 women without asthma according to the ECRHS criteria who had not been diagnosed with asthma and/or allergic rhinitis by a doctor and/or who had not met the criteria of the International Study of Asthma and Allergies in Childhood for rhinoconjunctivitis. A significant positive association was found between SNP rs40401 and the risk of asthma, with the TT genotype as the reference under the additive model: the adjusted odds ratio was 1.39 (95% CI: 1.004-1.93). The positive association was not statistically significant in any other genetic model. Compared with subjects with the TT or TC genotype of SNP rs40401 who had never smoked, those with the CC genotype who had ever smoked had a significantly increased risk of asthma: the adjusted OR was 2.67 (95% CI: 1.23-5.79); the additive interaction, but not the multiplicative interaction, was significant. This study suggests that IL3 SNP rs40401 is significantly associated with the risk of asthma in young adult Japanese women and reveals that the combination of ever smoking and having the CC genotype of IL3 SNP rs40401 is significantly positively associated with asthma.

Association of matrix metalloproteinase 8 genetic polymorphisms with bronchial asthma in a Japanese population

Asthma has a strong genetic component. The final disease phenotype results from complex interactions between environment and multiple genes of small-to-modest effects. We investigated whether the polymorphism in genes encoding inflammatory mediators and cytokines is important for solving the onset and progression of asthma. We investigated whether 31 single nucleotide polymorphisms (SNPs) in genes encoding cytokines or monokines (interleukin [IL]-5R, matrix metalloproteinase [MMP] 8, beta2 adrenergic receptor, cytotoxic T-lymphocyte–associated antigen 4, IL-3, C-reactive protein, cytochrome P450 (CYP) 2C9, CYP3A4, a disintegrin and metalloproteinase [ADAM] 33, cysteinyl leukotriene receptor [CysLTR] 1, CysLTR2, eosinophilic cationic protein, glucocorticoid receptor, and leukotriene A 4 hydrolase) are related to asthma development in 206 Japanese bronchial asthma patients and 127 healthy controls. Using multifactor dimensionality reduction (MDR), we identified rs17099451 in MMP8, using a single locus model, with a mean cross-validation of 87.0%. Using a two-locus model, combinations of MMP8 and rs44707 in ADAM33, and MMP8 and rs40401 in IL-3, were identified, with mean cross-validation consistencies reaching 45.0%. Of the SNPs selected by the MDR method, rs17099451 in MMP8 and rs40401 in IL-3 were regarded as the most significant results in a 2 × 2 dominant model analysis. The finding that an MMP8 allele was most strongly related to asthma development indicates that metalloproteinase function is crucial to the airflow limitation process involved in this disease.

Case-control study of rhinoconjunctivitis associated with IL5RA polymorphisms in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Epidemiological research on the relationship between single nucleotide polymorphisms (SNPs) in the IL5RA gene and allergic disorders is limited. We examined the relationship between IL5RA SNPs and risk of rhinoconjunctivitis in young adult Japanese women.

METHODS

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

RESULTS

Compared with the CC genotype of SNP rs6771148, the CG genotype, but not the GG genotype, was significantly associated with a reduced risk of rhinoconjunctivitis: the adjusted OR for the CG genotype was 0.76 (95% CI: 0.58-0.99). No evident associations were found between SNPs rs17882210, rs3804797, rs334809, rs9831572, or rs17881144 and rhinoconjunctivitis. The ACTAGA haplotype of rs17882210, rs3804797, rs334809, rs9831572, rs6771148, and rs17881144 was significantly inversely associated with rhinoconjunctivitis (crude OR=0.58, 95% CI: 0.37-0.88) while the GTAGCA haplotype was significantly positively related to rhinoconjunctivitis (crude OR=1.74, 95% CI: 1.14-2.65). No significant interactions affecting rhinoconjunctivitis were observed between any of the six SNPs and smoking.

CONCLUSION

This is the first study to show significant associations between IL5RA SNP rs6771148, the ACTAGA haplotype, and the GTAGCA haplotype and the risk of rhinoconjunctivitis. We did not find evidence for interactions affecting rhinoconjunctivitis between any of the IL5RA SNPs and smoking.

Interleukin-10 promoter 1082/-819/-592 polymorphisms are associated with asthma susceptibility in Asians and atopic asthma: a meta-analysis

BACKGROUND

Although interleukin-10 (IL-10) is a potent inhibitor of allergic diseases, the association between promoter -1082/-819/-592 polymorphisms and asthma susceptibility remains inconclusive. We sought to determine if IL-10 promoter -1082/-819/-592 polymorphisms contribute to asthma susceptibility and are associated with phenotypes of atopic asthma.

METHODS

Systematic computerized searches were performed. Pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated by using random-effect and fixed-effect models, based on between-study heterogeneity. Subgroup analyses were performed according to age, ethnicity, and atopy. Publication bias was detected by funnel plot using Egger's test.

RESULTS

A total of 4,716 asthmatic patients and 5,093 controls were included. The asthma susceptibility correlated significantly with IL-10 promoter gene -1082 polymorphism [OR (95 % CI) 1.26 (1.02, 1.55) for AA vs. AG + GG] and -592 polymorphism [OR (95 % CI) 1.12 (1.07, 1.34) for AC + AA vs. CC] (both P < 0.05), but not with -819 polymorphism (P > 0.05). Subgroup analyzes suggested that the AA versus AG + GG genotype of -1082A/G polymorphism and AC + AA versus CC genotype of -592A/C polymorphism contributed significantly to increased asthma susceptibility in adults [OR (95 % CI) 1.39 (1.03, 1.87) for -1082A/G and 1.53 (1.25, 1.87) for -592A/C polymorphism]. The Asian population [OR (95 % CI) 1.35 (1.1, 1.7) for -1082A/G and 1.4 (1.12, 1.64) for -592A/C polymorphism] and subjects with atopic asthma [OR (95 % CI) 1.49 (1.18, 1.88) for -1082A/G and 1.23 (1.01, 1.48) for -592A/C polymorphism] also had an increased susceptibility of asthma. No publication bias was detected.

CONCLUSIONS

IL-10 promoter -1028A/G, -592A/C polymorphisms and their haplotypes, but not -819T/C polymorphism, correlate with asthma susceptibility.

IL3 SNP rs40401 variant is a risk factor for rhinoconjunctivitis in Japanese women: the Kyushu Okinawa maternal and child health study

BACKGROUND

No studies have investigated the relationship between IL3 single nucleotide polymorphism (SNP) rs40401 and allergic rhinitis. We performed a case-control study to examine this issue and to assess interactions between the SNP and smoking or older siblings in young adult Japanese women.

METHODS

Included were 393 women who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Controls were 767 women without rhinoconjunctivitis according to the ISAAC criteria who had not been diagnosed with allergic rhinitis by a doctor.

RESULTS

Compared with women with the TT genotype of SNP rs40401, those with the CC genotype had a significantly increased risk of rhinoconjunctivitis: the adjusted OR was 1.52 (95% CI: 1.05-2.19). This positive relationship was significant under the additive model: the adjusted OR was 1.23 (95% CI: 1.02-1.47). The positive association fell just short of the significance level under the dominant or recessive model. There was no significant interaction between SNP rs40401 and smoking with respect to rhinoconjunctivitis. Compared with subjects with the TT or TC genotype of IL3 SNP rs40401 who had one or more older siblings, those with the CC genotype who had no older siblings had a 2.33-fold increased risk of rhinoconjunctivitis; nevertheless, the interaction was not significant.

CONCLUSION

This is the first study to show a significant positive association between IL3 SNP rs40401 variant and the risk of rhinoconjunctivitis. We could not find evidence for interactions between SNP rs40401 and smoking or older siblings affecting rhinoconjunctivitis.

The interleukin-4 -589C/T polymorphism and the risk of asthma: a meta-analysis including 7,345 cases and 7,819 controls

BACKGROUND

A number of studies assessed the association of -589C/T polymorphism in the promoter region of interleukin-4 (IL-4) with asthma in different populations. However, the results were contradictory. A meta-analysis was conducted to investigate the association between polymorphism in the IL-4 and asthma susceptibility.

METHODS

Databases including Pubmed, EMBASE, Wanfang Database, China National Knowledge Infrastructure (CNKI) and Weipu Database were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

RESULTS

Thirty-four studies involving 7345 cases and 7819 controls were included. Overall, significant association between -589C/T polymorphism and asthma was observed for TT+CT vs. CC (OR=1.26; 95% CI 1.12-1.42; P=0.0001; I(2)=26%). In the subgroup analysis by ethnicity, significant associations were found among Asians (OR=1.36; 95% CI 1.07-1.73; P=0.01; I(2)=0%) and Caucasians (OR=1.30; 95% CI 1.09-1.54; P=0.004; I(2)=53%) but not among African Americans (OR=1.20; 95% CI 0.72-2.00; P=0.48; I(2)=48%). In the subgroup analysis by atopic status, no significant association was found among atopic asthma patients (OR=1.20; 95% CI 0.92-1.34; P=0.27; I(2)=6%) and non-atopic asthma patients (OR=0.97; 95% CI 0.73-1.28; P=0.81; I(2)=0%).

CONCLUSIONS

This meta-analysis suggested that the IL-4 -589C/T polymorphism was a risk factor of asthma.

Respiratory syncytial virus infection and recurrent wheezing in Chilean infants: a genetic background?

Respiratory syncytial virus (RSV) infection has been associated to recurrent wheezing, but pathogenic mechanisms are unclear. Interleukin-4/Interleukin-13 (IL-4/IL-13) pathway is involved in both conditions. A common host genetic susceptibility may exist in patients whom RSV will trigger severe illness and those who develop recurrent wheezing.

OBJECTIVE

To assess, by a candidate-gene approach, whether genetic polymorphisms in IL-4/IL-13 pathway are associated with RSV infection severity and its outcome in Chilean children. A cohort of 118 RSV-infected infants was analyzed and followed for one year. Severity of acute infection and later recurrent wheezing were characterized. Alleles and genotypes frequencies were determined for two SNP in each of the genes IL-4, IL-13 and IL-4Rα. Association tests and interaction analyses were performed. Enrollment included 60 moderate and 58 severe cases. Two SNP were found associated to severity during acute infection in IL-4Rα gene (Gln551Arg, Ile50Val). The follow up was completed in 71% of patients (84/118). Later recurrent wheezing was 54% in severe group, versus 31% in moderate cases (p=0.035). In relation to outcome, allele Ile50 in IL-4Rα was more frequent in patients with moderate disease and no wheezing outcome. A common protector genotype is proposed for Chilean children: IL-4Rα Ile/Ile.

CONCLUSION

Genetic variations in the host are associated to infection severity and outcome. A common genetic background might be influencing both pathologies.

Interleukin-10 promoter gene polymorphisms and susceptibility to asthma: a meta-analysis

Objective

The aim of this study was to explore whether the interleukin (IL)-10 polymorphisms and their haplotypes contribute to asthma susceptibility.

Methods

MEDLINE, EMBASE and the COCHRANE library databases were utilized to identify available articles. A meta-analysis was conducted on IL-10 -1082 G/A, -819 C/T, -592 C/A polymorphisms, and their haplotypes and asthma.

Results

Eleven studies involving 2,215 asthma patients and 2,170 controls were considered in the meta-analysis. The meta-analysis revealed no association between asthma and the IL-10 -1082 G allele [Odds ratio (OR) = 0.87, 95% Confidence interval (CI) = 0.68–1.12, p = 0.28]. However, meta-analysis of the five studies in Hardy-Weinburg equilibrium produced the relationship between the IL-10 -1082 G allele and asthma (OR = 0.71, 95% CI = 0.60–0.83, p<0.0001). Stratification by ethnicity indicated an association between the IL-10 -1082 G allele and asthma in East Asians (OR = 0.74, 95% CI = 0.57–0.96, p = 0.02), but not in West Asians. Furthermore, stratification by age indicated an association between the IL-10 -1082 G allele and asthma in adults and mixed groups (OR = 0.77, 95% CI = 0.62–0.96, p = 0.02; OR = 0.67, 95% CI = 0.49–0.92, p = 0.01). No association was found between asthma and IL-10 -819 C/T and IL-10 -592 C/A polymorphisms and their haplotypes.

Conclusion

The IL-10 -1082 G/A polymorphism confers susceptibility to asthma in East Asians and in adults. However, the IL-10 -819 C/T, -592 C/A polymorphisms and their haplotypes are not associated with asthma.

Interleukin-10 promoter polymorphisms and asthma risk: a meta-analysis

Several studies assessed the associations of interleukin-10 (IL-10) polymorphisms with asthma in different populations. However, the results were inconclusive. The aim of the present study was to further assess the associations by the method of meta-analysis. Pubmed, EMBASE, Wanfang Database, China National Knowledge Infrastructure (CNKI) and Weipu Database were searched. Data were extracted independently by two authors. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Seventeen potentially eligible articles were identified (4478 cases and 4803 controls). Significant associations between -1082A/G and -592A/C polymorphisms and asthma were observed. However, there was no significant association between -819T/C polymorphism and asthma risk. In addition, there were significant associations of the IL-10 haplotypes with asthma. In summary, this meta-analysis suggested that IL-10 promoter polymorphisms were associated with asthma risk.

Genetic polymorphism studies in periodontitis and Fcγ receptors

Periodontitis is a complex chronic subgingival plaque-induced inflammatory disease influenced by multiple factors, including genetics, behavior and the environment. Many genetic association studies have been conducted in periodontology. One of the most extensively investigated gene families is the Fcγ receptor gene family, which plays a key role in regulating host immune responses to bacteria. Unlike other genetic polymorphisms reported in periodontology, most Fcγ receptor polymorphisms reported not only have established biological functions but are reported to associate with other autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. There are, however, few recent reviews summarizing the association of this gene family with periodontitis. This article critically reviews the current understanding of genetic polymorphism studies in periodontitis, then summarizes the research status of Fcγ receptor polymorphisms and periodontitis and also of other genes involved in the regulatory network of Fcγ receptors, with special reference to their anticipated biological roles. Moreover, some possible future research directions in the related area are discussed.

Relationship between group-specific component protein and the development of asthma

RATIONALE

Airway inflammation and remodeling during asthma are attributed to the altered expression of biologically relevant proteins.

OBJECTIVES

To search for asthma-specific proteins in bronchoalveolar lavage fluid (BAL) from individuals with asthma and to validate the identified proteins in an experimental model of asthma.

METHODS

Liquid chromatography-tandem mass spectrometry was performed to identify proteins in BAL fluid found by two dimensional electrophoresis (2DE) to be differentially expressed in subjects with asthma versus control subjects. Group-specific component (Gc) and mRNA levels were measured using an ELISA, Western blots, and PCR. A neutralization study using an antibody against Gc protein was performed in an experimental asthma model.

MEASUREMENTS AND MAIN RESULTS

Based on 2DE, 15 proteins were significantly up-regulated or down-regulated in eight subjects with asthma compared with eight control subjects. The protein levels of Gc, hemopexin, and haptoglobin-b were increased, whereas the a1- antitrypsin and glutathione S-transferase levels were decreased in subjects with asthma. The Gc concentration in BAL fluid was significantly elevated in 67 subjects with asthma compared with that in 22 control subjects (P < 0.009). The Gc was significantly correlated with the neutrophil percentage in BAL fluid of subjects with asthma (P = 0.001). Gc mRNA and protein levels were higher in ovalbumin-sensitized/ challenged asthma mice than in sham-treated mice. Gc protein were expressed on alveolar macrophages and on epithelial cells. Treatment with an anti-Gc antibody dose-dependently reduced the ovalbumin sensitization/challenge-induced enhancement of airway hyperreactivity, airway inflammation, goblet cell hyperplasia,and levels of eotaxin, interleukin-4, -5, and -13, and interferon-g.

CONCLUSIONS

Gc may be involved in the development of asthma, and the neutralization of Gc protein could be a therapeutic strategy for asthma.

The IL1B-511 Polymorphism (rs16944 AA Genotype) Is Increased in Aspirin-Exacerbated Respiratory Disease in Mexican Population

Aspirin exacerbated respiratory disease (AERD) is characterized by chronic hyperplastic rhinosinusitis, nasal polyposis, asthma, and aspirin sensitivity. The mechanisms which produce these manifestations of intolerance are not fully defined, current research focuses on cyclooxygenase 1 (COX-1) inhibition, metabolism of arachidonic acid, and the COX pathway to the lipoxygenase (LO) route, inducing increased synthesis of leukotrienes (LT). The biological plausibility of this model has led to the search for polymorphisms in genes responsible for proinflammatory cytokines synthesis, such as IL1B and IL8. We performed a genetic association study between IL8-251 (rs4073) and IL1B-511 (rs16944) polymorphisms in AERD, aspirin-tolerant asthma (ATA), and healthy control subjects. Using allelic discrimination by real-time PCR, we found statistically nonsignificant associations between AERD, ATA, and healthy control subjects for the GG and GA genotypes of IL1B (rs16944). Interestingly, the AA genotype showed an increased frequency in the AERD patients versus the ATA group (GF = 0.19 versus 0.07, p = 0.018, OR 2.98, and 95% CI 1.17–7.82). This is the first observation that IL1B polymorphisms are involved in AERD. Thus, future studies must investigate whether interleukin-1β is released in the airways of AERD patients and whether it relates to genetic polymorphisms in the IL1B gene.

Genetic effect of single-nucleotide polymorphisms in the PPARGC1B gene on airway hyperreactivity in asthmatic patients

BACKGROUND

Peroxisome proliferator-activated receptor gamma coactivator 1 beta (PPARGC1B) is a co-activator for intracellular receptors such as the estrogen receptor, PPAR, and glucocorticoid receptor, which are involved in asthma development.

OBJECTIVES

Genetic association of single-nucleotide polymorphisms (SNPs) in the PPARGC1B gene with the risk of asthma and airway hyperreactivity (AHR) was investigated, as well as the functional effects of these SNPs on PPARGC1B gene and protein expression.

METHODS

Direct sequencing of DNA from 24 Korean was performed to identify PPARGC1B SNPs. Genotyping was done in 264 controls and 949 asthmatics using single-base extension methods. PPARGC1B mRNA levels were measured using real-time PCR methodology. Luciferase and electrophoretic mobility shift assays (EMSA) were performed to functionally analyse PPARGC1B SNPs on promoter.

RESULTS

Eighteen SNPs and one insertion/deletion polymorphism were identified, and seven SNPs were genotyped. No significant difference existed in the distribution of SNPs and haplotypes between the asthmatics and controls. However, the allele frequency of -427C>T and +102525G>A;R265Q showed a significant association with log-transformed PC(20) methacholine values in the asthmatics (P=0.005-0.0004). Real-time PCR demonstrated higher PPARGC1B mRNA levels in asthmatics having -427CC allele than in those having -427TT or CT alleles (P=0.048). The ratio of the mRNA expression for each PPARGC1B exon4-mRNA compared with the wild type was similar in peripheral blood mononuclear cells carrying the +102525G>A allele. Luciferase reporter assays revealed that -427C allele caused higher promoter activity than -427T allele. EMSA demonstrated that -427C allele exhibited stronger binding activity to a nuclear protein in 293T cells than did the -427T allele.

CONCLUSIONS AND CLINICAL RELEVANCE

Polymorphisms of -427C>T on the promoter and those of +102525G>A on exon 5 of the PPARGC1B gene may affect the development of AHR through the modulation of PPARGC1B gene products. The PPARGC1B genotypes may serve as genetic markers for AHR.

Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.

Association between interleukin-3 gene polymorphism and acute rejection after kidney transplantation

BACKGROUND

Acute rejection (AR) after kidney transplantation resulting from alloimmune responses has a negative effect on graft survival. AR is mainly caused by T-cell immune responses activated by cytokines, including interleukin (IL)-2, -4, and -7. Many reports have shown that single nucleotide polymorphisms (SNPs) of these cytokines can affect the occurrence of AR. IL-3, which is secreted by activated T cells, can mediate AR. Our study sought to investigate the association between SNPs of the IL3 gene and the occurrence of an AR episode (ARE).

METHODS

We analyzed 3 SNPs of IL3 (rs181781, rs2073506, and rs40401) among 330 renal recipients, 60 of whom had developed an ARE. SNPs of the IL3 gene, including 1 exonic SNP (rs40401) and 2 regulatory thought to be promoter SNPs (rs181781 and rs2073506).

RESULTS

The genotypes of 60 ARE subjects and the 270 patients without AR demonstrated a significant relationship between genotype frequencies and the SNPs. The occurrence of an ARE was associated with rs181781 (P = .041, dominant model), rs2073506 (P = .009, codominant 1 model; P = .003, dominant model), and rs40401 (P = .014, recessive model). Among haplotypes, AAT showed a significant association with ARE. (P = .0033).

CONCLUSION

Our results suggest that IL3 gene polymorphisms were associated with this event.

Haplotypes in the interleukin 8 gene and their association with chronic periodontitis susceptibility

Interleukin-8 (IL-8), which is responsible for the migration and activation of neutrophils, is an important inflammatory mediator involved in the initiation and amplification of acute inflammatory reactions and chronic inflammatory processes. IL-8 plays an important role in periodontitis, an inflammatory disease characterized by the loss of connective tissue and alveolar bone. The aim of this study was to investigate whether the SNPs rs2227307 (+396) and rs2227306 (+781), and the haplotypes they formed together with the previously investigated rs4073 (-251), were associated with chronic periodontitis susceptibility. Clinical periodontal exams were performed and DNA samples were collected from 493 individuals (223 with periodontitis and 270 controls). Associations between SNPs, haplotypes, and subject phenotypes were analyzed using the χ(2) test followed by multivariate logistic regression modeling. We conclude that the +396TT genotype and the haplotypes ATC/TTC and AGT/TGC were significantly associated with chronic periodontitis susceptibility in Brazilians.

Association analysis of polymorphisms in IL-3, IL-4, IL-5, IL-9, and IL-13 with Graves' disease

BACKGROUND

Graves' disease (GD) is a common autoimmune disorder with genetic predisposition. There is strong evidence that the Chr.5q31-33 region, which contains the immune response cytokine genes [interleukin (IL)-3, IL-4, IL-5, IL-9, and IL-13], is linked to autoimmune thyroid disorders in Chinese and Japanese populations. The aim of the present study is to elucidate whether the single nucleotide polymorphisms (SNP) and the interaction of variants in the 5 genes are associated with the development of GD and Graves' ophthalmopathy (GO).

MATERIALS AND METHODS

GD patients (no.=751), with 190 of GO patients and healthy control subjects (no.=748) were included in this study. Six SNP [rs40401 (IL-3), rs2070874 (IL-4), rs2069812 (IL-5), rs1859430 (IL-9), rs2069868 (IL-9), and rs20541 (IL-13)] were genotyped by SNPstream Genotyping System.

RESULTS

There was a significant increase of C allele of rs40401 in GD [odds ratio (OR)=1.18 [95% confidence interval (CI): 1.02-1.36], pallele=0.028] and GO [OR=1.30 (95%CI: 1.04-1.63), pallele=0.022] patients compared with those in the controls. The C allele of the rs2069812 was also significantly associated with GD [OR=1.22 (95%CI: 1.04-1.44), pallele=0.015] and GO [OR=1.45 (95%CI: 1.13-1.86), pallele=0.003] patients. Haplotype analysis showed a predominant increase of the 2 SNP (rs40401-rs2069812, CC) and all the 6 SNP (CCCCCC) haplotype in GD (OR=1.70, OR=3.70, respectively) and even stronger in GO (OR=2.18, OR=7.01, respectively) patients.

CONCLUSIONS

The results suggested that the polymorphism of IL-3 (rs40401) and IL-5 (rs2069812) were associated with GD and GO susceptibility in Chinese population. The interaction of 6-locus from the 5 genes might confer higher risk for GD and GO than single risk allele.

Basophil CD203c levels are increased at baseline and can be used to monitor omalizumab treatment in subjects with nut allergy

RATIONALE

Basophils contribute to anaphylaxis and allergies. We examined the utility of assessing basophil-associated surface antigens (CD11b/CD63/CD123/CD203c/CD294) in characterizing and monitoring subjects with nut allergy.

METHODS

We used flow cytometry to analyze basophils at baseline (without any activation) and after ex vivo stimulation of whole blood by addition of nut or other allergens for 2, 10, and 30 min. We also evaluated whether basophil expression of CD11b/CD63/CD123/CD203c/CD294 was altered in subjects treated with anti-IgE monoclonal antibody (omalizumab) to reduce plasma levels of IgE.

RESULTS

We demonstrate that basophil CD203c levels are increased at baseline in subjects with nut allergy compared to healthy controls (13 subjects in each group, p < 0.0001). Furthermore, we confirm that significantly increased expression of CD203c occurs on subject basophils when stimulated with the allergen to which the subject is sensitive and can be detected rapidly (10 min of stimulation, n = 11, p < 0.0008). In 5 subjects with severe peanut allergy, basophil CD203c expression following stimulation with peanut allergen was significantly decreased (p < 0.05) after 4 and 8 weeks of omalizumab treatment but returned toward pretreatment levels after treatment cessation.

CONCLUSIONS

Subjects with nut allergy show an increase of basophil CD203c levels at baseline and following rapid ex vivo stimulation with nut allergen. Both can be reduced by omalizumab therapy. These results highlight the potential of using basophil CD203c levels for baseline diagnosis and therapeutic monitoring in subjects with nut allergy.

Past, present, and future of allergy in Korea

Korean allergology has made great progress in keeping pace with global scientific advances in spite of a short history. Outstanding academic and scientific researches have been performed in a variety of allergy fields in Korea. Epidemiologic studies revealed increasing prevalence of asthma and allergic diseases and considerable morbidity and mortality in Korea. Novel inhalant allergens such as citrus red mite and two-spotted spider mite as causes of asthma and allergic rhinitis have been discovered and reported in Korea. Bidirectional translational researches have been performed and are underway to elucidate the pathogenesis of asthma and allergy, mechanisms of airway inflammation and remodeling, and new therapeutic modalities for asthma and allergic diseases. Experimental asthma models of different phenotypes according to exposed levels of lipopolysaccharide or double-stranded RNA suggested the crucial role of the innate immunity in the development of allergic airway inflammation and a new insight for asthma pathogenesis, in which both Th1 and Th2 inflammation are involved. In the field of genetic researches, numerous genetic associations with asthma and asthma-related phenotypes, such as atopy, IgE production, and airway hyperresponsiveness, have been demonstrated in Korean population. The Easy Asthma Management (EAM) program, a computer-assisted asthma management program, is anticipated to facilitate the achievement of more successful clinical outcomes by filling the gaps between guidelines and actual practices. The Integration of these multi-disciplinary allergy research resources and translation of scientific achievements to the bedside and society will lead to better allergy and asthma control in Korea.

Polymorphisms in the interleukin 3 gene show strong association with susceptibility to Graves' disease in Chinese population

Graves' disease (GD) is a common organ-specific autoimmune disorder, which is multifactorial and develops in genetically susceptible individuals. We had earlier mapped a susceptibility locus for GD to chromosome 5q31-33 in a linkage study. Here we used tag single-nucleotide polymorphisms (SNPs) to search for genetic variants associated with GD, and examined 19 functional candidate genes in this chromosomal region. We identified 192 polymorphisms by re-sequencing the candidate genes, and selected 51 tagSNPs to genotype in a case-control collection of 1118 south Han Chinese subjects (428 cases and 690 controls). Initial analysis suggested that a non-synonymous SNP rs40401 (P27S) of interleukin 3 (IL3) was associated with GD, and further fine-mapping showed that rs40401, or its perfect proxy SNP rs31480 in the 5' flanking region of IL3, fully accounted for the association signal at this locus. We replicated significant association of rs40401 with GD in an independent sample collection of 839 north Han Chinese subjects. A combined analysis revealed strong validation of this association (odds ratio (OR(common))=1.63, combined P (P(comb))=4 x 10(-6) in the Recessive disease model). This study provides convincing evidence that the IL3 gene is a susceptibility locus for GD in the Chinese population.

Study of gene-gene interactions for endophenotypic quantitative traits in Chinese asthmatic children

BACKGROUND

Asthma is a complex disease resulting from interactions between multiple genes and environmental factors. Study of gene-gene interactions could provide insight into the pathophysiology of asthma.

METHODS

We investigated the interactions among 18 single-nucleotide polymorphisms in eight candidate genes for plasma total immunoglobulin E (IgE) concentration and peripheral blood (PB) eosinophil count in 298 Chinese asthmatic children and 175 controls. Generalized multifactor dimensionality reduction and generalized linear model were used to analyze gene-gene interactions for the quantitative traits.

RESULTS

A significant interaction was found between R130Q in IL13 and I50V in IL4RA for plasma total IgE concentration, with a cross-validation (CV) consistency of nine of 10 and a prediction error of 41.1% (P = 0.013). Plasma total IgE concentration was significantly higher in the high-risk than the low-risk groups (P < 0.0001). For PB eosinophil count, significant interaction was found between C-431T in TARC and RsaI_in2 in FCERIB, with a CV consistency of nine of 10 and a prediction error of 40.2% (P = 0.009). PB eosinophil count was significantly higher in the high-risk group than the low-risk groups (P < 0.0001). Generalized linear model also revealed significant gene-gene interaction for the above two endophenotypes with P = 0.013 for plasma total IgE concentration and P = 0.029 for PB eosinophil count respectively.

CONCLUSIONS

Our data suggest significant interactions between IL13 and IL4RA for plasma total IgE concentration, and this is the first report to show significant interaction between TARC and FCERIB for PB eosinophil count in Chinese asthmatic children.

A report of cytokine polymorphisms and COPD risk in Xuan Wei, China

Indoor air pollution has been documented as an important risk factor for chronic obstructive pulmonary disease (COPD), and inflammation is central to the development and progression of COPD. Single nucleotide polymorphisms (SNP) in some cytokine genes have been reported to be associated with COPD. We examined the association between 18 SNPs in 10 cytokine genes and COPD risk in a case-control study conducted in a population with high exposure to indoor smoky coal emissions. The study included 53 COPD cases and 122 healthy community controls. Carriers of the CSF2 117Ile allele had a 2.4-fold higher risk of COPD than the wild type (Thr/Thr) carriers (OR: 2.44; 95% CI: 1.10-5.41), and the AA genotype at IL8 -351 was associated with an increased risk of COPD (OR: 2.71; 95% CI: 1.04-7.04). When the combined effects of CSF2 117Ile and IL8 -351A were examined, individuals carrying at least one variant in both genes had a five-fold increased risk of COPD (OR: 5.14, 95% CI: 1.32-29.86). This study suggests that polymorphisms in both CSF2 and IL8 may play a role in the pathogenesis of COPD, at least in highly exposed populations. However, in view of our relatively small sample size, this study should be replicated in other populations with substantial exposure to indoor air pollutants such as polycyclic aromatic hydrocarbons (PAH) and particulate matter.

Polymorphisms in eosinophil pathway genes, asthma and atopy

BACKGROUND

Eosinophilic inflammation is considered to play an important role in the development as well as in the perpetuation of asthma. As eosinophil production and survival is under genetic control we investigated whether polymorphisms in eosinophil regulation pathway genes (IL-3, IL-5, GM-CSF and their respective enhancers and receptors) may influence the development of atopic diseases.

METHODS

In two large study populations of children, the German part of the International Study of Asthma and Allergy in Childhood (ISAAC II) and the German Multicentre Atopy Study (MAS), 3099 and 824 children, seven polymorphisms previously associated with the development of atopic diseases were genotyped: two in and around the GM-CSF gene (Ile117Thr and T3085G), one in IL-3 (Pro27Ser), in IL-5 (C-746T), and in the IL-5 high affinity receptor chain IL-5R (G-80A) and two in the common receptor chain CSFR2b for IL-3, IL-5, and GM-CSF (Asp312Asn and Glu249Gln). Statistical analyses were performed using chi-squared tests and variance analyses. Gene by gene interactions were evaluated in logistic regression models.

RESULTS

The T allele at position -746 in the IL-5 gene was significantly protective for atopy in the ISAAC II population (P = 0.006). Furthermore, the risk for atopic asthma was decreased in carriers of the T allele (P = 0.036) and evidence for interaction with the enhancer polymorphism 3085 bp 3' of GM-CSF was detected.

CONCLUSIONS

IL-5 C-746T influenced atopic outcomes and showed evidence for gene by gene interaction. No significant associations were found with all other tested polymorphisms in the eosinophil regulation pathway after correction for multiple testing.

Histamine releasibility and expression of Lyn and Syk kinases in Indian subjects and role of less potent IL-3 in non-releaser basophils

BACKGROUND

Allergen-mediated activation of the IgE signal pathway in basophils and mast cells leads to release of mediators in-vitro and in-vivo systems. However, basophils from 10% to 20% of the population do not release histamine and other mediators on activation of the IgE signal transduction pathway and this has been attributed to the absence of tyrosine kinases Lyn and Syk. Interestingly, when these non-releaser basophils are incubated with the IL-3, it leads to the recovery of the histamine releasibility.

OBJECTIVE

To investigate histamine releasibility in the Indian population and to evaluate the role of IL-3 with reference to non-releaser phenotypes.

METHODS

Peripheral blood basophils from healthy adults were purified by density gradient centrifugation and negative immuno-selection. Histamine release assay was performed fluorometrically. Assessment of Lyn and Syk expression were carried out by flow-cytometry. SNP analysis in the IL-3 gene was carried by sequencing analysis.

RESULTS

Histamine release after ConA challenge varied greatly from 0% to 100% in Indian subjects. Eighteen percent subjects showed less than 5% histamine release (non-releasers). Flow-cytometric analysis revealed a significantly reduced expression of Lyn and Syk kinases in basophils (p<0.05). Histamine release also significantly correlated with expression of Lyn and Syk kinase (p<0.05). Non-releasers showed the presence of SNP at +79 (T-C), which leads to the one amino acid change at 8th position in the mature IL-3 from serine to proline.

CONCLUSIONS

About 18% of the Indian subjects studied showed non-releaser phenotype and also had reduced Lyn and Syk kinase expression. Non-releasers have also shown the presence of less potent isoform of IL-3/P8, which is suspected to be responsible for the non-releaser phenotype. This needs to be extended to a larger sample size and could be a potential target for the development of therapeutics for allergic patients.

Ethnicity-specific gene-gene interaction between IL-13 and IL-4Ralpha among African Americans with asthma

RATIONALE

Genes in the interleukin (IL)-4/IL-13/IL-4Ralpha pathway have been shown to be associated with asthma and related phenotypes in some populations, but not in others. Furthermore, interaction between these genes has been shown to affect asthma in white and Chinese populations.

OBJECTIVES

To determine whether there are IL-4/IL-13 and IL-4Ralpha gene-gene interactions that are associated with asthma in African Americans.

METHODS

Eighteen single-nucleotide polymorphisms (SNPs) in IL-4, IL-13, and IL-4Ralpha genes were genotyped in 264 African Americans with asthma and 176 healthy control subjects. We tested the SNPs for genetic associations and gene-gene interactions with asthma, baseline lung function, bronchodilator drug response, and total serum IgE levels.

MEASUREMENTS AND MAIN RESULTS

We identified 94 SNPs in IL-4, IL-13, and IL-4Ralpha genes by directly sequencing these genes in 24 African-American subjects with asthma. Seventeen SNPs were analyzed for association with asthma and related phenotypes. We found no evidence of association in the IL-4 gene. One SNP in the IL-13 gene (A-646G, rs2069743) and two SNPs in the IL-4Ralpha gene (A+4679G, rs1805010, and C+22656T, rs1805015) showed association with lung function (both baseline and post-bronchodilator). Although the association between individual SNPs and asthma-related phenotypes differed from previous studies performed in white and Chinese populations, significant gene-gene interaction was found between the IL-13 (A-646G) and IL-4Ralpha (A+4679G) SNPs for baseline lung function among African-American subjects with asthma.

CONCLUSIONS

Gene-gene interaction between the IL-13 and IL-4Ralpha genes may play an important role in asthma among African Americans.

Risk factors of allergic rhinitis: genetic or environmental?

Allergic diseases such as allergic rhinitis represent a global health problem, affecting 10%-25% of the world population. There is clear evidence to support the concept that allergic diseases are influenced by genetic predisposition and environmental exposure. Polymorphisms of candidate genes have been associated with clinical expression of these diseases. However, characterization of these susceptibility markers in discriminating an "allergic individual" from the general population has not yet been achieved, and the value of how this genetic insight leading to recognition of specific subtypes of these disorders still needs to be confirmed. Environmental factors (eg, air pollution and bacterial/viral infection) also play an important role in the development of the diseases. A number of epidemiologic studies have supported the "hygiene hypothesis", which is based on the observations that Th1 responses induced by microbial stimulation can counterbalance allergen-induced Th2 responses. Future studies are needed to identify the key genes or their haplotypes for atopic phenotypes and to investigate the interactions between genetic and environmental factors that influence the complex trait of allergic diseases. This will help us to further understand the etiology of the diseases and develop new avenues for genetically oriented diagnosis and more effective measures of prevention and intervention.

Diversity of theCYP21P-Like Gene inCYP21Deficiency

More than 90% of cases of congenital adrenal hyperplasia (CAH) are caused by mutations of the CYP21 gene. The occurrence of defective CYP21 genes, including 15 mutations, has been attributed to intergenic recombination of DNA sequences from CYP21P, and shows no influence on the RP1-C4A-CYP21P-XA-RP2-C4BCYP21- TNXB gene locus on chromosome 6p21.3. However, multiple gene deletions in this region produce at least three categories of gene arrangements: (a) C4A-CYP21P/CYP21-TNXB, in which there is a CYP21P/CYP21 fusion gene; (b) C4A-XCYP21-TNXB, where XCYP21 indicates that the CYP21 gene contains mutations of IVS2 (-12A/C>G and 707-714delGAGACTAC); and (c) C4A-CYP21P-TNXA/TNXB, in which the TNX A and B genes are fused. Among them, seven different structures of the CYP21 haplotype were found at these three loci. Formation of the C4A-CYP21P/CYP21-TNXB locus produced four distinct CYP21P/CYP21 chimeras. The C4A-XCYP21-TNXB locus contained the IVS2 mutation -12A/C>G and 707-714delGAGACTAC from the XCYP21 gene; and two kinds of TNXA/TNXB hybrids were found in the C4A-CYP21P-TNXA/TNXB locus. The seven different CYP21 alleles produced 3.2 kb Taq I fragments caused by deletion of the RP2-XA-C4B locus. Therefore, production of a 3.2-kb CYP21 allele shows diversity, but is not a unique feature of the CYP21P gene. Most of these gene arrangements probably exist in the C4A-XCYP21-TNXB and C4A-CYP21P/CYP21-TNXB gene loci. The existence of the C4A-CYP21P-TNXA/TNXB locus might not be common in CAH patients with 21-hydroxylase deficiency.