Interleukin-10 gene promoter region polymorphism is associated with eosinophil count and circulating immunoglobulin E in adult asthma

Regulation of inflammation by Interleukin-10 in the intestinal and respiratory mucosa

Intricate immune regulation is required at mucosal surfaces to allow tolerance to microbiota and harmless allergens and to prevent overexuberant inflammatory responses to pathogens. The cytokine Interleukin-10 (IL-10) is a key mediator of mucosal immune regulation. While IL-10 can be produced by virtually all cells of the immune system, many of its in vivo functions depend upon its production by regulatory or effector T cell populations and its signalling to macrophages, dendritic cells and specific T cell subsets. In this review, we discuss our current understanding of the role of IL-10 in regulation of immune responses, with a focus on its context-specific roles in intestinal homeostasis, respiratory infection and asthma. We highlight the importance of appropriate production and function of IL-10 for balancing pathogen clearance, control of microbiota and host tissue damage, and that precise modulation of IL-10 functions in vivo could present therapeutic opportunities.

Resolvin and lipoxin metabolism network regulated by Hyssopus Cuspidatus Boriss extract in asthmatic mice

Resolvin (Rv) and lipoxin (Lx) play important regulative roles in the development of several inflammation-related diseases. The dysregulation of their metabolic network is believed to be closely related to the occurrence and development of asthma. The Hyssopus Cuspidatus Boriss extract (SXCF) has long been used as a treatment for asthma, while the mechanism of anti-inflammatory and anti-asthma action targeting Rv and Lx has not been thoroughly investigated. In this study, we aimed to investigate the effects of SXCF on Rv, Lx in ovalbumin (OVA)-sensitized asthmatic mice. The changes of Rv, Lx before and after drug administration were analyzed based on high sensitivity chromatography-multiple response monitoring (UHPLC-MRM) analysis and multivariate statistics. The pathology exploration included behavioral changes of mice, IgE in serum, cytokines in BALF, and lung tissue sections stained with H&E. It was found that SXCF significantly modulated the metabolic disturbance of Rv, Lx due to asthma. Its modulation effect was significantly better than that of dexamethasone and rosmarinic acid which is the first-line clinical medicine and the main component of Hyssopus Cuspidatus Boriss, respectively. SXCF is demonstrated to be a potential anti-asthmatic drug with significant disease-modifying effects on OVA-induced asthma. The modulation of Rv and Lx is a possible underlying mechanism of the SXCF effects.

Exploring the Links between Personality and Immune Function

Decades of research finds associations between personality traits and health. In recent years, it has become clear that the activities of the immune system play a key role in linking these variables. In the current work, we add to this research by exploring the relationship between Big Five personality traits and (Study 1) polymorphisms known to impact cytokine release and (Study 2) immunological parameters measured in vivo (differential white blood cell counts, plasma proinflammatory cytokine levels) and in vitro (proinflammatory cytokine release by peripheral blood mononuclear cells, Staphylococcus aureus growth in plasma). Results provide insights into potential mechanistic drivers of the link between personality and immune function and the possibility that, in some cases, relationships between personality and immune function may be sex differentiated.

Interleukin 10 -1082 G/A Gene Polymorphism and Susceptibility to Bronchial Asthma in Children: A Single-Center Study

Interleukin-10 (IL-10) is the key regulator of immune responses preventing the undesirable exaggerated ones. Genetic variation in the promoter region of IL-10 may influence its serum level and contribute to susceptibility to bronchial asthma in children. This is a case-control study including 100 patients and 100 healthy control children who had undergone skin prick test, estimation of total IgE and serum level of IL-10 by enzyme-linked immunosorbent assay, and polymerase chain reaction-restriction fragment length polymorphism for IL-10 gene polymorphism. A significant association between IL-10 polymorphism and susceptibility to pediatric asthma was found. AA genotype represented (66%) of the patient group compared to (6%) only of the control group, while AG genotype was detected in 20% of patients and 4% of control. In contrast, wild genotype GG was found in 14% of patients and 90% of control with a highly statistically significant difference among both groups (P < 0.001). The serum level of IL-10 was significantly elevated in the GG genotype in comparison to other genotypes (P < 0.001), and it was negatively correlated with the severity of asthma among the studied pediatric asthmatic group (P < 0.001). In conclusion, IL-10 polymorphism may play an important role in the development of bronchial asthma in children.

Potential Metabolic Biomarkers in Adult Asthmatics

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

Interleukin-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.

Analysis of associations of polymorphisms in the genes coding for L4, IL10, IL13 with the development of atopic bronchial asthma and its remission

Bronchial asthma is a multifactorial disease underpinned by chronic inflammation. The atopic phenotype of BA implies the presence of similar molecular mechanisms of pathogenesis between the patients. The aim of this study was to analyze the associations between the development of atopic BA/its remission and the following polymorphisms of interleukin genes: IL4 (rs2243250; C-589T), IL10 (rs1800896; G-1082A; rs1800872; C-592A), and IL13 (rs20541; Arg130Gln). Using allele-specific polymerase chain reaction (PCR), we studied the listed SNPs in the mixed urban sample of patients with BA (n = 53) and the controls (n = 30) residing in South Ural. The analysis revealed that genotype АА of IL10 (rs1800872) occurred more frequently in the control group (23.3%) than in the patients with atopic BA (5.7%) (OR = 0.197; 95% CI [0.047–0.832]; р = 0.031). No differences in genotype frequencies were observed between the patients with atopic BA and the controls for other studied polymorphisms. Our study failed to demonstrate the association of the listed polymorphisms and BA remission.

[Association of interleukin-10 gene polymorphism with enterovirus 71 infection in children]

OBJECTIVE

To study the association of interleukin-10 (IL-10) -1082A/G, -819C/T, and -592C/A polymorphisms with IL-10 level and the severity of enterovirus 71 (EV71) infection in children.

METHODS

A total of 137 children with hand-foot-mouth disease due to EV71 infection were enrolled as EV71 infection group, which was further divided into mild group with 91 children and severe group with 46 children, and 122 healthy children who underwent physical examination were enrolled as healthy control group. Related clinical data were collected. ELISA was used to measure the serum level of IL-10, and polymerase chain reaction-restriction fragment length polymorphism was used to analyze IL-10 -1082A/G, -819C/T and -592C/A polymorphisms.

RESULTS

Compared with the healthy control group, the children with EV71 infection had significantly higher frequency of -1082 AA genotype and A allele (P<0.05). Among the children with EV71 infection, the severe group had significantly higher frequency of -1082 AA genotype and A allele than the mild group (P<0.05), while there was no significant difference in the distribution of IL-10 -819C/T and IL-10 -592C/A polymorphisms between the two groups (P>0.05). The severe group had a significantly higher serum level of IL-10 than the mild group and the healthy control group. IL-10 -1082 AA genotype, -819 TT genotype, and -592 AA genotype were associated with the low expression of IL-10 (P<0.05). As for haplotype, the EV71 infection group had a significantly lower frequency of GCC haplotype than the healthy control group (P<0.05). In the severe group, the children with ATA haplotype had a significantly lower IL-10 level than those with other haplotypes, and the children with GCC haplotype had a significantly higher IL-10 level than those with other haplotypes (P<0.05). There was no significant difference in IL-10 level between children with different haplotypes in the mild group and the healthy control group (P>0.05).

CONCLUSIONS

IL-10 gene polymorphisms are associated with IL-10 expression and the severity of EV71 infection in children.

Immunological Factors Associated with Adult Asthma in the Aseer Region, Southwestern Saudi Arabia

Background: The prevalence of asthma is on the rise in Saudi Arabia. Data regarding the immunological profile of asthma in adults in the Aseer region, in southwestern Saudi Arabia, have not been well studied. Objectives: Our aim was to study the immunological factors associated with sensitization to asthma among adults in the Aseer region. Methods: A cross-sectional study with a nested case control design in a 1:1 ratio was conducted on a sample of adults attending primary health care centers in the Aseer region. The study used a validated Arabic version of the International study of asthma and allergies in childhood (ISAAC) questionnaire. The presence of wheezing in the past 12 months was used as a proxy for bronchial asthma. Matched age and sex controls were selected. Both groups were tested for complete blood count (CBC), total and differential white blood cell (WBC) count including eosinophils, total immunoglobulin E (IgE) measurement, allergen-specific immunoglobulin E (IgE), and cytokine levels. Results: The present study included 110 cases and 157 age- and sex-matched controls. Rye wheat was found to be a significant outdoor sensitizing agent ((odds ratio) OR = 5.23, 95% CI: 1.06–25.69). Indoors, house dust mites Dermatophagoides petronyssinus (OR = 2.04, 95% CI: 1.04–3.99) and Dermatophagoides farinae (OR = 2.50, 95% CI: 1.09–5.75) were significant. Higher total IgE (OR = 1.84, 95% CI: 1.10–3.06) and eosinophil levels (OR = 2.85, 95% CI: 1.14–7.15) were significantly associated with adult bronchial asthma in Aseer. On the other hand, the role of cytokines was not significant. Conclusions: In the present study, certain environmental agents were found to be important with regards to sensitization to bronchial asthma in adults. Knowledge about these sensitization agents should be disseminated to health providers and treating physicians in order to enhance preventive environmental control measures and asthma management. Asthma-treating physicians in the region should be alerted to the use of targeted biological therapies in selected asthmatics with difficult-to-control courses.

Polymorphisms in the promoter region of IL10 gene are associated with virus etiology of infant bronchiolitis

BACKGROUND

Bronchiolitis is the most common infection leading to hospitalization in infancy. Interleukin-10 (IL-10) is an anti-inflammatory cytokine, and in our previous study, IL10 gene rs1800896 (- 1082A/G) polymorphism was associated with viral etiology of infant bronchiolitis. The objective of this study was to evaluate the associations between IL10 single nucleotide polymorphisms (SNPs) at rs1800890 (- 3575A/T), rs1800871 (- 819C/T) or rs1800872 (- 592C/A) either alone or combined with the SNP at rs1800896 (- 1082G/A), and the etiology and severity of infant bronchiolitis.

METHODS

Data on four IL10 SNPs were available from 135 full-term infants, hospitalized for bronchiolitis at age less than 6 months, and from 378 to 400 controls. Viral etiology was studied, and oxygen support, feeding support and the length of stay in hospital were recorded during bronchiolitis hospitalization.

RESULTS

Infants with rhinovirus bronchiolitis had the IL10 rs1800890 variant AT or TT genotype less often (18.2%) than controls (63.3%, P = 0.03), and likewise, had the IL10 rs1800896 variant AG or GG genotype less often (27.3%) than controls (65.5%, P = 0.009). Twenty-eight infants with bronchiolitis had the variant-variant G_rs1800896T_rs1800890 haplotype, and none of them had rhinovirus infection. The IL10 rs1800871 or rs1800872 genotypes showed no associations with viruses. No association was found between any genotypes and bronchiolitis severity measures.

CONCLUSION

IL10 rs1800890 and rs1800896 polymorphisms differed between infants with rhinovirus bronchiolitis and controls, but not between infants with respiratory syncytial virus bronchiolitis and controls.

Single nucleotide polymorphisms of the genes encoding IL-10 and TGF-β1 in Iranian children with atopic dermatitis

BACKGROUND

Atopic dermatitis is an inflammatory skin disease in which both genetic and environmental factors interact to determine the susceptibility and severity of the disease.

OBJECTIVE

The aim of this study was to determine the association between atopic dermatitis and IL-10 and TGF-β1 gene polymorphisms.

METHODS

The allele and genotype frequencies of genes encoding for IL-10 and TGF-β1 were investigated in 89 patients with atopic dermatitis in comparison with 138 in the control group using the PCR-SSP method.

RESULTS

A significant increase was found in the frequency of the TGF-β1 codon 10/C allele among patients (p<0.001, OR=6.77), whereas a significant decrease was observed in the frequency of the T allele at the same position (p<0.001, OR=0.14). The frequency of the TGF-β1 codon 25/G allele in the control group was significantly higher than among patients (p<0.001, OR=0.08). A significant positive correlation was seen between CC (p<0.001, OR=15.10) and CG (p<0.001) genotypes and AD at codons 10 and 25, respectively. The most frequent haplotypes among patients was TGF-β1 CG which was significantly higher than in the control subjects (50% in patients vs. 39.9% in controls, p=0.042). A significant increase was found in the frequency of TGF-β CC (36% in patients vs. 7.6% in controls, p<0.001) and TC (14% in patients vs. 0% in controls, p<0.001) haplotypes among patients compared to controls. By contrast, the TGF-β1 TG haplotype was significantly lower in patients than controls (0% in patients vs. 52.5% in controls, p<0.001). There were no significant differences in the frequency of alleles, genotypes and haplotypes of the IL-10 gene.

CONCLUSIONS

We found a strong association between the polymorphisms of the TGF-β1 gene at codon 10 and codon 25 positions and atopic dermatitis.

Dendritic cell phenotype in severe asthma reflects clinical responsiveness to glucocorticoids

Background

Subsets of patients with severe asthma remain symptomatic despite prolonged, high‐dose glucocorticoid therapy. We hypothesized that the clinical glucocorticoid sensitivity of these asthmatics is reflected in differences in peripheral blood dendritic cell subsets.

Objective

To compare peripheral blood leucocyte populations using flow cytometry at baseline and after 2 weeks of systemic glucocorticoid (steroid) treatment to identify immunological differences between steroid‐sensitive (SS) and steroid‐resistant (SR) asthmatics.

Methods

Adult severe asthmatics (SS n = 12; SR n = 23) were assessed for their response to 2 weeks of therapy with oral prednisolone. Peripheral blood was obtained before and after therapy and stained for lymphocyte (CD3, CD19, CD4, CD8 and Foxp3) and dendritic cell markers (Lineage negative [CD3, CD14, CD16, CD19, CD20, CD56], HLA‐DR+, CD304, CD11c, ILT3 and CD86).

Results

A higher median frequency of myeloid DCs (mDCs) but not plasmacytoid DCs (pDCs) was observed in the blood of SR as compared to SS asthmatics (P = .03). Glucocorticoid therapy significantly increased median B cell, but not T cell numbers in both cohorts, with a trend for increased numbers of Foxp3+ Tregs in SS (P = .07), but not SR subjects. Oral prednisolone therapy significantly reduced the median numbers and frequencies of total DCs and pDCs in both SS and SR asthmatics. Interestingly, the expression of HLA‐DR and ILT3 was also reduced on pDCs in all patients. In contrast, therapy increased the median frequency of mDCs in SS, but reduced it in SR asthmatics.

Conclusions

Myeloid DC frequency is elevated in SR compared with SS asthmatics, and mDC shows a differential response to oral prednisolone therapy.

IL-10-592 polymorphism is associated with IL-10 expression and severity of enterovirus 71 infection in chinese children

BACKGROUND

Enterovirus 71 (EV71) infection results in some severe complications with high mortality and disability in Hand, Foot and Mouth Disease (HFMD) in children. Recent studies have shown that cytokine genetic predispositions have associations with both the development of EV71 infection and severity of HFMD.

OBJECTIVE

This study was designed to investigate whether the IL-10-592 polymorphism is associated with IL-10 levels and disease severity in Chinese children with EV71 infection.

STUDY DESIGN

In patients selected, there were 378 cases with EV71 infection (including 291 mild cases, 70 severe cases and 17 critical cases), as well as 406 health controls. EV71 in serum was tested by RT-PCR, and IL-10-592 genotype was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis techniques.

RESULT

The IL-10-592C allele was observed with higher frequency in patients with critical EV71 infection (70.59%) compared with severe EV71 infection (41.43%, P<0.01), mild EV71 infection (43.81%, P<0.01) and healthy children (44.46%, P<0.01). The blood IL-10 levels of critical cases were significantly higher than severe cases, mild cases, and healthy children. Among all of the four groups, IL-10 levels in patients with genotype AA were significantly lower than those with genotypes AC+CC (t=4.86, P<0.05; t=2.30, P<0.05; t=3.44, P<0.05; t=5.58, P<0.05).

CONCLUSION

IL-10-592C allele is associated with IL-10 expressions and the severity of EV71 infection in Chinese patients.

Associations of TNFα -308G>A, TNFα -238G>A, IL-1α -889C>T and IL-10 -1082G>A Genetic Polymorphisms with Atopic Diseases: Asthma, Rhinitis and Dermatitis

BACKGROUND

Polymorphisms of cytokine genes are an interesting focus for association studies involving atopic diseases due to their role in immune cell communications during inflammation. The aim of this study was to investigate associations of TNFα -308G>A, TNFα -238G>A, IL-1α -889C>T and IL-10 -1082G>A polymorphisms with atopic diseases with adjustment for confounding lifestyle and environmental factors.

METHODS

This study was performed on 356 Croatian students. The diagnosis of atopic asthma, atopic rhinitis and atopic dermatitis was based on symptoms reported by the modified International Study of Asthma and Allergies in Childhood questionnaire and a positive skin prick test (SPT) to at least one common inhalatory allergen. Genetic polymorphisms were genotyped using the polymerase chain reaction-based technique. The influence of personal (gender, body mass index, parental history of atopic disease), lifestyle (cigarette smoking, pet ownership) and environmental (urban/rural residency, residency in continental/Mediterranean region) factors reported in the questionnaire was investigated by univariate and multivariate analysis.

RESULTS

Compared to the control subjects, univariate analysis showed a significant negative association of the TNFα -308G>A polymorphism with atopic asthma, atopic dermatitis, asthma and skin symptoms and positive SPT. These observations were confirmed in a multivariate model only for atopic dermatitis and skin symptoms (atopic dermatitis: OR = 0.27; 95% CI 0.07-1.00; p = 0.050; skin symptoms: OR = 0.29; 95% CI 0.10-0.83; p = 0.021).

CONCLUSIONS

The results indicate a protective role of TNFα -308G>A genetic polymorphisms regarding atopic dermatitis and skin symptoms even after controlling for personal, lifestyle and environmental factors. Further studies are needed to elucidate the molecular patterns of this association in atopic dermatitis and other chronic inflammatory skin disorders.

IL-10-592 A/C polymorphisms is associated with EBV-HLH in Chinese children

OBJECTIVES

The aim of this study is to investigate the relationship between cytokine gene polymorphisms and Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) in children, and to further reveal the possible mechanisms of EBV-HLH.

METHODS

Forty-one patients with EBV-HLH, 70 patients with infectious mononucleosis (IM), and 170 EBV-seropositive healthy children were evaluated. Gene polymorphism typing was performed by a polymerase chain reaction with a sequence-specific primer of a commercially available cytokine genotyping kit. Comparison of cytokine gene polymorphisms between EBV-HLH, IM patients, and healthy controls was analyzed statistically using Chi-square test or Fisher's exact test.

RESULTS

The frequencies of IL-10-592 C allele or IL-10-592 CC genotype were significantly higher in patients with EBV-HLH than in IM and healthy children (P < 0.001), but no significant difference was observed between IM and healthy children.

CONCLUSION

IL-10-592 locus gene polymorphism is associated with the development of EBV-HLH in Chinese children.

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.

Significant roles played by IL-10 in Chlamydia infections

Chlamydia species are obligate intracellular parasites which cause usually asymptomatic genital tract infections and also are associated with several complications. Previous studies demonstrated that immune responses to Chlamydia species are different and the diseases will be limited to some cases. Additionally, Chlamydia species are able to modulate immune responses via regulating expression of some immune system molecules including cytokines. IL-10, as the main anti-inflammatory cytokine, plays important roles in the induction of immune-tolerance against self-antigen and also immune-homeostasis after microbe elimination. Furthermore, it has been documented that ectopic expression of IL-10 is associated with several chronic infectious diseases. Therefore, it can be hypothesized that changes in the regulation of this cytokine can be associated with infection with several species of Chlamydia and their associated complications. This review collected the recent information regarding the association and relationship of IL-10 with Chlamydia infections. Another aim of this review article is to address recent data regarding the association of genetic variations (polymorphisms) of IL-10 and Chlamydia infections.

Association of serum cytokines levels, interleukin 10 -1082G/A and interferon-γ +874T/A polymorphisms with atopic asthma children from Saudi Arabia

The aim of this study was to clarify the role of IL-4, IL-10, IL-13 and interferon (IFN) -γ levels in atopic asthma patients by studying the relation between their serum levels and severity of the disease. The effect of IL-10 -1082G/A and IFN-γ +874T/A SNPs was also studied. The study included 200 atopic children with asthma and 50 age- and gender matched healthy children as controls. The levels of both IL-4 and IL-13 were significantly (p<0.001) higher, while IFN-γ was significantly (p<0.001) lower in patients compared to that of the controls. There was a significant effect of gene polymorphisms of IL-10 (p<0.05) and IFN-γ (p<0.001) in occurrence of atopic asthma and increased IgE level. Polymorphism of IFN-γ gene had an effect on the serum level of IFN-γ. In conclusion, IFN-γ gene polymorphism at position +874 and IL-10 gene polymorphism at position -1082A/G are genetic determinants which contribute to susceptibility to atopic asthma in children from Saudi Arabia.

Polymorphisms in recent GWA identified asthma genes CA10, SGK493, and CTNNA3 are associated with disease severity and treatment response in childhood asthma

Recent genome-wide association studies (GWAs) have identified several new genetic risk factors for asthma; however, their influence on disease behavior and treatment response is still unclear. The aim of our study was the association analysis of the most significant single nucleotide polymorphisms (SNPs) recently reported by GWAs in different phenotypes of childhood asthma and analysis of correlation between these SNPs and clinical parameters. We have genotyped 288 children with asthma and 276 healthy controls. We provided here first replication of bivariate associations between CA10 (p = 0.001) and SGK493 (p = 0.011) with asthma. In addition, we have identified new correlation between SNPs in CA10, SGK493, and CTNNA3 with asthma behavior and glucocorticoid treatment response. Asthma patients who carried G allele in SNP rs967676 in gene CA10 were associated with more pronounced airway obstruction, higher bronchial hyper-reactivity, and increased inflammation. Higher bronchial hyper-reactivity was also associated with C allele in SNP rs1440095 in gene SGK493 but only in nonatopic asthmatics. In addition, we found that patients who carried at least one T allele in SNP rs1786929 in CTNNA3 (p = 0.022) and atopic patients who carried at least one G allele in SNP rs967676 in gene CA10 (p = 0.034) had higher increase in pulmonary function after glucocorticoid therapy. Our results suggest genetic heterogeneity between atopic and nonatopic asthma. We provided further evidence that treatment response in childhood asthma is genetically predisposed, and we report here two novel SNPs in genes CA10 and CTNNA3 as potential pharmacogenetic biomarkers that could be used in personalized treatment in childhood asthma.

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.

TNF-alpha, IL-4R-alpha and IL-4 polymorphisms in mild to severe asthma from Italian Caucasians

Asthma is a chronic airway inflammatory disease associated with airway hyperresponsiveness which affects subjects with genetic predisposition. An association has been reported between some polymorphisms in various cytokine genes and asthma. Most of them are single nucleotide polymorphisms (SNPs). These polymorphisms are detected in the protein coding sequence or in the promoter region thus influencing cytokine production. We investigated the involvement of SNP mapping in 5 cytokine genes in mild to severe asthmatics of Italian Caucasians. The frequency of alleles and genotypes, relatively to 10 allelic specificities of the cytokine genes, was defined in 57 asthmatics and in 124 control subjects by a Polymerase Chain Reaction-Sequence Specific Primer method. TNF-alpha -308A and TNF-alpha -238A allele frequencies were higher in asthmatics than in controls (p less than 0.001). Significant differences in the frequency of IL-4 -590T allele and of IL-4Ralpha +1902A allele were also detected in asthmatics in comparison with controls (pless than 0.001 and p=0.005, respectively). Similarly, IL-1alpha -889C allele was present in 84.1 percent of asthmatics and in 70.2 percent of controls (p=0.013). Furthermore, the IL-4Ralpha +1902A/A and IL-1alpha -889C/C homozygous conditions and the TNF-alpha -308G/A, TNF-alpha -238G/A, IL-4 -590T/C and IL-10 -1082G/A heterozygous conditions were significantly associated with asthma (p less than 0.05). ACA haplotype of IL-10 was observed only in asthmatic patients. This study reports, for the first time, the frequency of 10 different single nucleotide polymorphisms in 5 cytokine genes in the Italian Caucasians. Furthermore, we also indicate that in our population some single nucleotide polymorphisms are associated with mild to severe bronchial asthma.

Is the IL-10 promoter polymorphism at position -592 associated with immune system-related diseases?

Immune responses are the main causes of immune system-related diseases such as hypersensitivities and autoimmunity. It has also been established that cytokines play key roles in the regulation of immune responses which have been shown to be important in the pathogenesis of the diseases. IL-10, the main anti-inflammatory cytokine, is produced by several immune cells such as T regulatory and Th2 lymphocytes, activated macrophages, B regulatory lymphocytes as well as other cell types. It plays a key role in the regulation of immune responses after microbe elimination (homeostasis) and against self-antigens to prevent hypersensitivity and autoimmune diseases, respectively. Studies showed that a single nucleotide polymorphism (SNP) at the -592 position of IL-10 is associated with its regulation of expression. This review addresses the recent information regarding the association of the polymorphism at position -592 of IL-10 with immune-related diseases including type 2 diabetes with and without nephropathy, multiple sclerosis, and asthma with an emphasize on Iranian patients.

Human leukocyte antigen-G expression in differentiated human airway epithelial cells: lack of modulation by Th2-associated cytokines

Background

Human leukocyte antigen (HLA)-G is a nonclassical class I antigen with immunomodulatory roles including up-regulation of suppressor T regulatory lymphocytes. HLA-G was recently identified as an asthma susceptibility gene, and expression of a soluble isoform, HLA-G5, has been demonstrated in human airway epithelium. Increased presence of HLA-G5 has been demonstrated in bronchoalveolar lavage fluid recovered from patients with mild asthma; this suggests a role for this isoform in modulating airway inflammation though the mechanisms by which this occurs is unclear. Airway inflammation associated with Th2 cytokines such as IL-4 and IL-13 is a principal feature of asthma, but whether these cytokines elicit expression of HLA-G is not known.

Methods

We examined gene and protein expression of both soluble (G5) and membrane-bound (G1) HLA-G isoforms in primary differentiated human airway epithelial cells collected from normal lungs and grown in air-liquid interface culture. Cells were treated with up to 10 ng/ml of either IL-4, IL-5, or IL-13, or 100 ng/ml of the immunomodulatory cytokine IL-10, or 10,000 U/ml of the Th1-associated cytokine interferon-beta, for 24 hr, after which RNA was isolated for evaluation by quantitative PCR and protein was collected for Western blot analysis.

Results

HLA-G5 but not G1 was present in dAEC as demonstrated by quantitative PCR, western blot and confocal microscopy. Neither G5 nor G1 expression was increased by the Th2-associated cytokines IL-4, IL-5 or IL-13 over 24 hr, nor after treatment with IL-10, but was increased 4.5 ± 1.4 fold after treatment with 10,000 U/ml interferon-beta.

Conclusions

These data demonstrate the constitutive expression of a T lymphocyte regulatory molecule in differentiated human airway epithelial cells that is not modulated by Th2-associated cytokines.

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.

The facial evolution: looking backward and moving forward

Three-dimensional (3D) facial analysis is ideal for high-resolution, nonionizing, noninvasive objective, high-throughput phenotypic, and phenomic studies. It is a natural complement to (epi)genetic technologies to facilitate advances in the understanding of rare and common diseases. The face is uniquely reflective of the primordial tissues, and there is evidence supporting the application of 3D facial analysis to the investigation of variation and disease including studies showing that the face can reflect systemic health, provides diagnostic clues to disorders, and that facial variation reflects biological pathways. In addition, facial variation has been related to evolutionary factors. The purpose of this review is to look backward to suggest that knowledge of human evolution supports, and may instruct, the application and interpretation of studies of facial morphology for documentation of human variation and investigation of its relationships with health and disease. Furthermore, in the context of advances of deep phenotyping and data integration, to look forward to suggest approaches to scalable implementation of facial analysis, and to suggest avenues for future research and clinical application of this technology.

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.

The IL-10 promoter polymorphism at position -592 is correlated with susceptibility to occult HBV infection

Occult hepatitis B infection (OBI) is characterized as a form of hepatitis in which detectable amounts of HBV-DNA can be monitored in the peripheral blood of patients whereas the hepatitis B surface antigen is undetectable. The main aim of this study was to investigate whether there is a relationship between OBI and single nucleotide polymorphisms in the -592 region of the IL-10 gene. In this study, the polymorphism at position -592 of the IL-10 promoter of 57 OBI cases was compared and correlated to that of 100 healthy controls by PCR-RFLP techniques. Our results showed that patient and control groups had significant differences regarding genotypes and alleles of the -592 polymorphism in the IL-10 gene. Based on our results, it can be concluded that the -592 polymorphism within the promoter of the IL-10 gene is associated with OBI.

Association between human IL-10 gene polymorphisms and serum IL-10 level in patients with food allergy

BACKGROUND/PURPOSE

Single nucleotide polymorphisms (SNPs) of the interleukin-10 (IL-10) gene are associated with allergic diseases in different populations. This study aimed to determine the distribution of two SNPs at -1082A/G and -592A/C (rs1800896 and rs1800872, respectively) in the IL-10 gene promoter of Taiwanese food allergy (FA) patients, and also to compare the serum IL-10 levels between patients with (FA) and controls.

METHODS

Thirty-seven patients with FA and 52 controls were enrolled, and their peripheral blood was collected for IL-10 SNP genotyping and the corresponding serum IL-10 level of each genotype.

RESULTS

The thirty-seven FA patients had positive food-specific IgE (≥ 0.75kU/L) to more than one food, and the most frequent allergens wereshrimp and crab (56.8% and 35.1%, respectively). The genotype distributions in the FA patients compared to the control group were AA and AG at -1082A/G (86.5% and 13.5% vs. 86.6% and 13.4%, respectively), and AA, AC, and CC at -592A/C (45.9%, 43.3% and 10.8% vs. 38.5%, 48.1% and 13.4%, respectively). Serum IL-10 levels were significantly lower in the FA group than in the control group (p=0.0187), and the IL-10 level of -592A/C of genotype AA was significantly lower than that of the other genotypes (AC+CC) (p=0.007). Patients with AA/AA haplotype homozygotes (10 of 24) had significantly lower serum IL-10 levels than those with other haplotypes.

CONCLUSIONS

The two SNPs at -1082A/G and -592A/C of IL-10 were associated with FA in our Taiwanese population, and FA patients with the genotype AA/AA haplotype homozygotes had lower serum IL-10 levels. This suggests that IL-10 might play a critical role in the pathogenesis of FA. We suggest that it may be practicable to evaluate the serum IL-10 levels of FA patients and to predict the possibility of FA if genotypes and haplotypes are checked regularly.

Interleukin (IL)-10 gene polymorphisms are associated with type 2 diabetes with and without nephropathy: a study of patients from the southeast region of Iran

The impact of several environmental and genetic factors on diabetes and its complications is well documented. It has also been established that cytokines play a key role in the regulation of immune responses which have been shown to be important in the pathogenesis of diabetes. Studies showed that single-nucleotide polymorphisms within the -592 region of interleukin-10 (IL-10) are associated with the regulation of its expression. In this study, we aimed to find polymorphisms of this region that may be associated to type 2 diabetic (T2D) patients with and without nephropathy. In this study, peripheral blood samples were collected from 100 T2D patients without nephropathy, 100 T2D patients with nephropathy, and 100 healthy controls. DNA was extracted, and a polymerase chain reaction-restriction fragment length polymorphism technique was performed to examine the polymorphisms within the -592 region of the IL-10 gene. Our results showed a significant difference between the genotypes and alleles of the -592 region of IL-10 in nephropathic and non-nephropathic patients in comparison to the healthy controls. The differences between the two patient groups in relation to genotypes and alleles were not significant. Results of this study suggest that the functional gene polymorphism of IL-10 reported here may play an important role in the pathogenesis of diabetes, but it seems that these polymorphisms do not have an effect on the nephropathic complications of the disease.

Involvement of IL-10 gene promoter polymorphisms in the susceptibility for childhood asthma

Asthma and atopy have a complex background that may result from the interaction of genes and the environment. Interleukin (IL)-10 is known to play various roles in immune-regulating and anti-inflammatory responses. The aim of this study was to evaluate the possible effect of the IL-10 promoter polymorphisms on susceptibility to childhood asthma. We recruited 333 patients with atopic asthma, 55 with nonatopic asthma, and 248 normal controls. We performed a genetic association study of three genetic polymorphisms (IL-10 -1082A>G, IL-10 -819T>C, and IL-10 -592A>C) of the IL-10 promoter. There was no difference between atopic asthma, nonatopic asthma, and normal controls with respect to allele, genotype, or haplotype frequencies of these IL-10 polymorphisms. However, the -1082A>G polymorphism and ATA haplotype in the IL-10 promoter gene were associated with airway hyper responsiveness (AHR) and the -819T>C, -592A>C, and ATA and ACC haplotypes were also shown to be related to serum eosinophil cationic protein (ECP). Our results suggest that the polymorphisms within the IL-10 promoter may have a disease-modifying effect in the asthmatic airway.

Association between genes encoding components of the IL-10/IL-0 receptor pathway and asthma in children

BACKGROUND

Asthma is a chronic inflammation of the airways associated with recurrent symptoms that range from mild to debilitating. Interleukin-10 (IL-10) is a cytokine that displays pleiotropic effects in asthma and allergy.

OBJECTIVE

To determine whether polymorphisms of IL-10/IL-10R pathway contribute to asthma susceptibility in Egyptian children.

METHODS

The IL-10 (-1082G/A), IL-10R1 (G330R), and signal transducer and activator of transcription 3 (STAT3) rs2293452 single-nucleotide polymorphism (SNP) were genotyped in 110 atopic children with asthma, 110 non-atopic children with asthma, and 110 healthy children. Serum IL-10 and immunoglobulin E (IgE) levels were determined by enzyme-linked immunosorbent assay.

RESULTS

A significant association was observed between the IL-10 polymorphism and asthma in both atopic (P = .03) and non-atopic asthma groups (P = .04). The genotype frequencies of IL-10R1 polymorphisms did not differ between all groups. We identified a significant association between STAT3 polymorphism and asthma susceptibility in atopic asthma (P < .001), whereas no such association was observed in the non-atopic asthma group (P = .9). No evidence of gene interactions was found.

CONCLUSION

Polymorphisms of IL-10 and STAT3 may be useful as a new DNA-based diagnostic biomarker for identifying high-risk children susceptible to asthma.

Gene-gene interaction in regulatory T-cell function in atopy and asthma development in childhood

BACKGROUND

Regulatory T-cell dysfunction is associated with development of the complex genetic conditions atopy and asthma. Therefore, we hypothesized that single nucleotide polymorphisms in genes involved in the development and function of regulatory T cells are associated with atopy and asthma development.

OBJECTIVE

To evaluate main effects and gene-gene interactions of haplotype tagging single nucleotide polymorphisms of genes involved in regulatory T-cell function-IL6, IL6R, IL10, heme-oxygenase 1 (HMOX1), IL2, Toll-like receptor 2 (TLR2), TGFB1, TGF-beta receptor (TGFBR)-1, TGFBR2, IL2RA, and forkhead box protein 3 (FOXP3)-in relation to atopy and asthma.

METHODS

Single-locus and multilocus associations with total IgE (3rd vs 1st tertile); specific IgE to egg, milk, and indoor allergens; and asthma were evaluated by chi(2) tests and the multifactor dimensionality-reduction method in 3 birth cohorts (Allergenic study).

RESULTS

Multiple statistically significant multilocus associations existed. IL2RA rs4749926 and TLR2 rs4696480 associated with IgE in both age groups tested (1-2 and 6-8 years). TGFBR2 polymorphisms associated with total and specific IgE in both age groups and with asthma. TGFBR2 rs9831477 associated with specific IgE for milk at age 1 to 2 years and indoor allergens at age 6 to 8 years. For milk-specific IgE, interaction between TGFBR2 and FOXP3 polymorphisms was confirmed by logistic regression and consistent in 2 birth cohorts and when stratified for sex, supplying internal replications.

CONCLUSION

Genes involved in the development and function of regulatory T cells, specifically IL2RA, TLR2, TGFBR2, and FOXP3, associate with atopy and asthma by gene-gene interaction. Modeling of multiple gene-gene interactions is important to unravel further the genetic susceptibility to atopy and asthma.

The interleukin 6 -174 C/C genotype predicts greater rhinovirus illness

Background. In adults and children with respiratory syncytial virus (RSV) infection, a polymorphism in the interleukin 6 (IL-6) promoter at position −174 predicts illness magnitude. In addition, polymorphisms in the interleukin 10 (IL-10), tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ) genes are associated with immune responsiveness and the frequency of complications. Here, the effect of these polymorphisms on illness and seroconversion during infection with rhinovirus type 39 (RV39) was evaluated.

Methods. Seventy-two adults were genotyped for the selected polymorphisms, experimentally exposed to RV39, and followed to track infection, seroconversion, and symptoms and signs of illness. Regression analysis was used to determine whether these polymorphisms predicted seroconversion and illness magnitude in 57 infected subjects.

Results. The low-production IL-6 −174 phenotype (C/C genotype) was associated with greater symptom magnitudes, and the IFN-γ phenotype +874 predicted the frequency of seroconversion. No relationship between the IL-10 or TNF-α polymorphisms and any measured outcome was documented. The concentration of IL-6 protein, as measured in nasal wash fluids from subjects, was positively correlated with symptom magnitude, but it was independent of the IL-6 −174 genotypes representing the high- and low-production phenotypes.

Conclusions. These results document statistically significant associations between the IL-6 −174 and IFN-gγpolymorphisms and specific responses to experimental RV39 infection. For the IL-6 −174 polymorphism, the results replicate those for experimental RSV infection.

Recommendations for using standardised phenotypes in genetic association studies

Genetic association studies of complex traits often rely on standardised quantitative phenotypes, such as percentage of predicted forced expiratory volume and body mass index to measure an underlying trait of interest (eg lung function, obesity). These phenotypes are appealing because they provide an easy mechanism for comparing subjects, although such standardisations may not be the best way to control for confounders and other covariates. We recommend adjusting raw or standardised phenotypes within the study population via regression. We illustrate through simulation that optimal power in both population- and family-based association tests is attained by using the residuals from within-study adjustment as the complex trait phenotype. An application of family-based association analysis of forced expiratory volume in one second, and obesity in the Childhood Asthma Management Program data, illustrates that power is maintained or increased when adjusted phenotype residuals are used instead of typical standardised quantitative phenotypes.

Asthma and genes encoding components of the vitamin D pathway

BACKGROUND

Genetic variants at the vitamin D receptor (VDR) locus are associated with asthma and atopy. We hypothesized that polymorphisms in other genes of the vitamin D pathway are associated with asthma or atopy.

METHODS

Eleven candidate genes were chosen for this study, five of which code for proteins in the vitamin D metabolism pathway (CYP27A1, CYP27B1, CYP2R1, CYP24A1, GC) and six that are known to be transcriptionally regulated by vitamin D (IL10, IL1RL1, CD28, CD86, IL8, SKIIP). For each gene, we selected a maximally informative set of common SNPs (tagSNPs) using the European-derived (CEU) HapMap dataset. A total of 87 SNPs were genotyped in a French-Canadian family sample ascertained through asthmatic probands (388 nuclear families, 1064 individuals) and evaluated using the Family Based Association Test (FBAT) program. We then sought to replicate the positive findings in four independent samples: two from Western Canada, one from Australia and one from the USA (CAMP).

RESULTS

A number of SNPs in the IL10, CYP24A1, CYP2R1, IL1RL1 and CD86 genes were modestly associated with asthma and atopy (p < 0.05). Two-gene models testing for both main effects and the interaction were then performed using conditional logistic regression. Two-gene models implicating functional variants in the IL10 and VDR genes as well as in the IL10 and IL1RL1 genes were associated with asthma (p < 0.0002). In the replicate samples, SNPs in the IL10 and CYP24A1 genes were again modestly associated with asthma and atopy (p < 0.05). However, the SNPs or the orientation of the risk alleles were different between populations. A two-gene model involving IL10 and VDR was replicated in CAMP, but not in the other populations.

CONCLUSION

A number of genes involved in the vitamin D pathway demonstrate modest levels of association with asthma and atopy. Multilocus models testing genes in the same pathway are potentially more effective to evaluate the risk of asthma, but the effects are not uniform across populations.

Chronic inflammation and asthma

Allergic asthma is a complex and chronic inflammatory disorder which is associated with airway hyper-responsiveness and tissue remodelling of the airway structure. Although originally thought to be a Th2-driven inflammatory response to inhaled innocuous allergen, the immune response in asthma is now considered highly heterogeneous. There are now various in vivo systems which have been designed to examine the pathways leading to the development of this chronic immune response and reflect, in part this heterogeneity. Furthermore, the emergence of endogenous immunoregulatory pathways and active pro-resolving mediators hold great potential for future therapeutic intervention. In this review, the key cellular and molecular mediators relating to chronic allergic airway disease are discussed, as well as emerging players in the regulation of chronic allergic inflammation.

Combined effect of IL-10 and TGF-beta1 promoter polymorphisms as a risk factor for aspirin-intolerant asthma and rhinosinusitis

BACKGROUND

It has been known that interleukin (IL)-10 promoter polymorphisms at -1082A/G, -819T/C and -592A/C, may influence IL-10 expression and associate with asthma. Interleukin-10 facilitates the regulatory function of transforming growth factor (TGF)-beta. The goal of this study was to investigate a gene-gene interaction between IL-10 and TGF-beta1 polymorphisms in Korean asthmatics with aspirin hypersensitivity.

METHODS

Single-nucleotide polymorphism genotyping of IL-10 and TGF-beta1 genes was performed and the functional effect of the IL-10 polymorphisms was analysed applying a luciferase reporter assay and an electrophoretic mobility shift assay.

RESULTS

Among the patients with asthma, polymorphism at -1082A/G was significantly associated with the phenotype of aspirin-intolerant asthma, AIA (P = 0.007, P(c) = 0.021). Moreover, a synergistic effect between the TGF-beta1-509C/T and IL-10-1082A/G polymorphisms on the phenotype of AIA was noted; when stratified by the presence of rhinosinusitis, the frequency of rare alleles (the CT or TT genotype of TGF-beta1-509C/T and AG or GG genotype of IL-10-1082A/G) was significantly higher in the patients with AIA (15.2%) when compared with those with ATA (6.3%, P = 0.031; odds ratio 4.111; 95% confidence interval 1.504-11.235). In an in vitro functional assay, the -1082G reporter plasmid exhibited significantly greater promoter activity when compared with the -1082A construct in Jurkat T cells (P = 0.011). Moreover, we found that the transcription factor Myc-associated zinc-finger protein preferentially bound the -1082G allele.

CONCLUSION

Our results suggest that IL-10 promoter polymorphisms contribute to the development of AIA and that rhinosinusitis may interact genetically with TGF-beta1.

Interaction between BCL2 and interleukin-10 gene polymorphisms alter outcomes of diffuse large B-cell lymphoma following rituximab plus CHOP chemotherapy

PURPOSE

Rituximab may overcome bcl-2-mediated chemoresistance through the inhibition of interleukin-10 (IL-10)-mediated loops, thus down-regulating bcl-2 expression. We examined the effects of genetic variation in BCL2/IL10 gene loops on treatment outcomes of diffuse large B-cell lymphoma when treated with either CHOP or rituximab plus CHOP (R-CHOP) chemotherapy.

EXPERIMENTAL DESIGN

Four genotypes were tested including BCL2 -938 C>A (rs2279115), +21 A>G (rs1801018), IL10 -819 T>C (rs1800871), and -592 A>C (rs1800872) in patients receiving either R-CHOP (n = 125) or CHOP (n = 110).

RESULTS

IL10 SNPs, -819 TT/TC or -592 AA/AC genotypes correlated with improved CHOP response rates (P = 0.04). Neither polymorphism separately influenced the failure-free survival (FFS) or overall survival in patients, but the IL10 haplotype was associated with treatment outcomes after R-CHOP for FFS (P = 0.03) or progression (P = 0.007), whereas the -938 AA BCL2 genotype significantly affected overall survival (P = 0.04). An interactive effect between BCL2 and IL10 SNPs was significant in the group with both -938 AA BCL2 genotype and 1 to 2 copies of CC IL10 haplotype. This group showed a better FFS (P = 0.01) and a lower probability of progression (P = 0.004) compared with other genotype groups when treated with R-CHOP chemotherapy.

CONCLUSIONS

These data indicated that R-CHOP chemotherapy resistance in diffuse large B-cell lymphoma may involve interactions between the BCL2 and IL10 genes.

MYLK polymorphism associated with blood eosinophil level among asthmatic patients in a Korean population

The myosin light chain kinase (MYLK) gene encodes both smooth muscle and nonmuscle cell isoforms. Recently, polymorphisms in MYLK have been reported to be associated with several diseases. To examine the genetic effects of polymorphisms on the risk of asthma and related phenotypes, we scrutinized MYLK by re-sequencing/genotyping and statistical analysis in Korean population (n = 1,015). Seventeen common polymorphisms located in or near exons, having pairwise r ( 2 ) values less than 0.25, were genotyped. Our statistical analysis did not replicate the associations with the risk of asthma and log-transformed total IgE levels observed among African descendant populations. However, two SNPs in intron 16 (+89872C > G and +92263T >C), which were in tight LD (|D'| = 0.99), revealed significant association with log-transformed blood eosinophil level even after correction multiple testing (P = 0.002/P( corr )= 0.01 and P = 0.002/P( corr ) = 0.01, respectively). The log-transformed blood eosinophil levels were higher in individuals bearing the minor alleles for +89872C > G and +92263T > C, than in those bearing other allele. In additional subgroup analysis, the genetic effects of both SNPs were much more apparent among asthmatic patients and atopic asthma patients. Among atopic asthma patients, the log-transformed blood eosinophil levels were proportionally increased by gene-dose dependent manner of in both +89872C > G and +92263T > C (P = 0.0002 and P = 0.00007, respectively). These findings suggest that MYLK polymorphisms might be among the genetic factors underlying differential increases of blood eosinophil levels among asthmatic patients. Further biological and/or functional studies are needed to confirm our results.

Association of the gene polymorphisms IFN-gamma +874, IL-13 -1055 and IL-4 -590 with patterns of reinfection with Schistosoma mansoni

Background

The immunologic findings that most consistently correlate with resistance in human schistosomiasis are high levels of IgE and low levels of IgG4. We have genotyped gene and promoter polymorphisms of cytokines associated with regulation of these isotypes in a cohort of men occupationally exposed to Schistosoma mansoni in western Kenya and evaluated their patterns with respect to resistance and susceptibility to reinfection after treatment and cure with praziquantel (PZQ).

Methodology/Principal Findings

In this cohort, polymorphisms in IL-4 (−590T high IgE), IL-13 (−1055T high producer) and IFN-γ (+874A high producer) demonstrated several correlations with resistance to reinfection. Resistance to reinfection was significantly correlated with the heterozygous IL-4 −590 genotype C/T (OR 3.5, [CI 1.2, 10.2]) compared to T/T. Among men with a homozygous IL-13 genotype CC/TT, having a T allele at the IFN-γ +874 position increased the odds of resistance relative to individuals with the IFN-γ +874 A/A genotype (OR = 17.5 [CI 3.0, 101.5]). Among men with homozygous A/A IFN-γ genotype, the heterozygous IL-13 genotype C/T was associated with resistance relative to the homozygous C/C or T/T genotypes (OR = 22.5 [CI 3.5, 144.4]). No increases in odds of resistance were found in relation to the IL-13 genotype among those with a T allele in the IFN-γ gene or in relation to the IFN-γ genotype among those with a heterozygous IL-13 genotype. Calculation of the attributable proportion of resistance showed a significant synergistic interaction between IL-13 −1055 C/T and IL-4 −590 C/T.

Conclusions

The identified polymorphisms do not by themselves confer resistance or susceptibility, but we propose that these genotypes allow the resistant phenotype to be developed and expressed upon suitable immune exposure. Based on the literature, these polymorphisms contribute to the regulation of their respective cytokines, likely leading to downstream differences in the production and interrelationships of critical defense mechanisms.

Approximately 200 million people have schistosomiasis in parts of Africa, South America, the Middle East, the Caribbean and Asia. Several studies of multiple treatments and reinfections indicate that some people develop resistance to reinfection. Of all the immunologic findings associated with such studies, the most consistent observation is that resistance (usually defined as lower levels of infection upon reinfection) correlates with high IgE and low IgG4 antibodies against schistosome antigens. Our studies test whether single nucleotide polymorphisms residing in the gene or promoter regions of cytokines pivotal in controlling production of these antibody isotypes are different amongst those that develop resistance to reinfection as opposed to those that do not. Through genotyping of these polymorphisms in a cohort of occupationally exposed car washers, we found that men with certain genotypic patterns of polymorphisms in IL-4, IFN-γ, and IL-13 were significantly more likely to be resistant to reinfection than those with different patterns. These data provide initial insights into the potential genetic foundation of propensities of people to develop resistance to reinfection by schistosomes, and offer a basis for further molecular studies of how these polymorphisms might work at the transcriptional and gene product level in cells stimulated by schistosome antigens.

Gene-environment interactions in asthma

Asthma is a complex disease, and its incidence is determined by an intricate interplay of genetic and environmental factors. The identification of novel genes for asthma suggests that many genes with small effects rather than few genes with strong effects contribute to the development of asthma. These genetic effects may in part differ with respect to a subject's environmental exposures, although some genes may also exert their effect independently of the environment. Whereas the geneticist uses highly advanced, rapid, comprehensive technologies to assess even subtle changes in the human genome, the researcher interested in environmental exposures is often confronted with crude information obtained from questionnaires or interviews. There is thus substantial need to develop better tools for individual exposure assessment in all relevant environmental fields. Despite these limitations, a number of important gene-environment interactions have been identified. These interactions point to the biology of environmental exposures as the involved genetic variation is suggestive of certain underlying mechanisms. Furthermore, the identification of subjects who are particularly susceptible to environmental hazards through genetic analyses helps to estimate better the strength of effect of environmental exposures. Finally, the analysis of gene-environment interactions may result in a reconciliation of seemingly contradictory findings from studies not taking environmental exposures into account.

IL-10, TGF-beta, IL-2, IL-12, and IFN-gamma cytokine gene polymorphisms in asthma

Asthma is a complex respiratory disease, characterized by airway inflammation and reversible airway obstruction. Both genetic and environmental factors are important in the development and expression of the disease. In order to analyze the genetic profile of Th1 and Th2 cytokines in Iranian asthmatic patients, this study was performed. The allele and genotype frequencies of a number of polymorphic genes coding for IL-10, TGF-beta, IL-2, IL-12, and IFN-gamma were investigated in 60 patients with asthma in comparison with 140 controls. The most frequent genotypes in our patients were IL-10 GA at position-1082 (p = 0.001), IL-10 CT at position -819 (p = 0.001), IL-10 CA at position -592 (p = 0.0001), IL-12 CA at position -1188 (p = 0.003), TGF-beta CG at codon 25 (p = 0.002), IL-2 GT at position -330 (p = 0.004). In contrast, the frequencies of the genotypes IL-10 AA at position -1082 (p = 0.0001) and GG at position -1082 (p = 0.01), IL-10 CC at position -819 (p = 0.001) and TT at position -819 (p = 0.01), TGF-beta TT at codon 10 (p = 0.001), TGF-beta GG at codon 25 (p = 0.005), IL-12 AA at position -1188 (p = 0.004), IL-2 TT at position -330 (p = 0.01) were significantly lower in the patient group. The most frequent haplotypes in the patients were IL-10 GCC (p = 0.008) and ATA (p = 0.0001) at position -1082, -819, -592, and TGF-beta CC (p = 0.036) at codon 10 and codon 25. In contrast, the frequencies of the IL-10 ACC (p = 0.001), TGF-beta TG (p = 0.024), and IL-2 TT (p = 0.001) and GT (p= 0.0001) in the patients were significantly lower than controls. Considering the high frequency of presence of IL-10 ATA haplotype and the IL-2 GT genotype, it seems that the production of IL-10 and IL-2 in the asthmatic patients could be lower than normal subjects.

Genetic association of IL-10 gene promoter polymorphism and HIV-1 infection in North Indians

INTRODUCTION

Cytokines play a significant role in host immune defense. IL-10 is an anti-inflammatory, immunomodulatory cytokine that can both stimulate and suppress the immune response and inhibits HIV-1 replication in vivo. Interindividual variations in IL-10 production were genetically contributed to polymorphisms within IL-10 promoter region.

AIMS

The aim of this study was to investigate the association of IL-10 gene promoter -1082 G/A, -819 C/T, and 592 C/A polymorphism on HIV-1 transmission /progression in North Indian individuals.

PATIENTS AND METHODS

A total of 180 HIV-1 seropositive (HSP) stratified on the basis of disease severity (stage I, II, and III), 50 HIV-1 exposed seronegative (HES) and 305 HIV-1 seronegative (HSN) individuals were genotyped for IL-10 gene promoter by polymerase chain reaction-restriction fragment length polymorphism. A suggestive evidence of association was obtained for IL-10 592 C/A promoter polymorphism at the level of allele and genotype distribution. The frequency of IL-10 592 A allele and genotype was significantly increased in HSP compared to HSN (p = 0.013; OR = 1.412 and p = 0.034; OR = 1.685 respectively). Further comparison in between different clinical stages of HIV-1 infected patients of IL-10 592 A allele and genotype revealed a significant increase in its frequency in the stage III compared with those together in stage I (p = 0.004, OR = 2.181 and p = 0.002, OR = 4.156, respectively). This study reports for the first time that IL-10 gene promoter 592 C/A polymorphism may be a risk factor for HIV-1 transmission/progression in HIV-1 infected North Indian individuals.

Analysis of IL-10, IL-4 and TNF-alpha polymorphisms in drug-induced liver injury (DILI) and its outcome

BACKGROUND/AIMS

The aim of this study was to assess whether genetic polymorphism of three important candidate cytokine genes, IL-10 (-1082G/A, -819C/T, and -592C/A), IL-4 (-590C/T) and TNF-alpha (-308G/A), play a role in the susceptibility to developing drug-induced liver injury (DILI), and in determining its phenotypic expression and severity.

METHODS

Cytokine genotyping was analysed using TaqMan 5' allelic discrimination assay in 140 DILI patients (mean age 51 y, range 13-82, with equal sex distribution) included in the Spanish Registry and 268 healthy controls.

RESULTS

Genotypes, haplotypes and allele frequencies were similar for both cases and controls. The low IL-10 producing haplotype was more prevalent in DILI patients with the absence of peripheral blood eosinophilia (Pc=0.004, OR=5.29, 95% CI: 2.04-13.67), revealing significantly lower median eosinophil counts (0.19 x 10(9)L; P<0.0002) compared to the intermediate (0.24 x 10(9)L) and high (0.40 x 10(9)L) IL-10 haplotypes. All cases with serious DILI outcome carried low or intermediate IL-10 producing haplotype and had normal or low eosinophil counts.

CONCLUSIONS

IL-10, IL-4 and TNF-alpha genetic polymorphisms were not related to the risk of developing DILI. Low IL-10 producing haplotype is associated with low eosinophil count, absence of eosinophilia and may be associated with worse clinical outcome from DILI.

Cytokine polymorphisms predict the frequency of otitis media as a complication of rhinovirus and RSV infections in children

Previous studies suggested that the otitis media (OM) complication rate of viral upper respiratory infection (vURI) is conditioned by genes affecting cytokine production. Two hundred and thirty children (114 male; 187 White, 25 Black; aged 1–9.3 years, average = 3.6 ± 1.6 years) were prospectively followed over the typical cold season for cold-like illness and OM. Nasopharyngeal secretion samples collected during cold-like illness and OM were assayed for upper respiratory viruses and buccal samples were assayed for TNFα (−308), IL-10(−1082, −819, −592), IL-6 (−174) and IFN-γ (+874) polymorphisms. Logistic regression was used to identify genotypes that predict OM coincident with RSV and rhinovirus (RV) infection. Of the 157 children with RV detection (79 male; 132 White, 13 Black, 12 Other; aged 3.6 ± 1.5 years), simple logistic regression identified age (B = −0.34, Z = −2.8, P < 0.01, OR = 0.71), IL-6 (B = −0.76, Z = −3.3, P < 0.01, OR = 0.47) and IL-10 (B = 0.49, Z = 2.0, P = 0.05, OR = 1.6) as significant predictors of OM coincidence. A more complex logistic regression model for RV detection that included selected OM risk factors identified these factors as well as the TNFα genotype, OM history, breastfeeding history and daily environment as significant predictors of OM coincidence. Of the 43 children with RSV detection (21 male; 35 White, 5 Black, 3 Other, aged 3.9 ± 1.7 years), logistic regression identified IL-10 (B = 1.05, Z = 2.0, P = 0.05, OR = 2.9) as a significant predictor of OM coincidence. New OM episodes coincident with evidence of RSV and RV infection were significantly more frequent in children with high production IL-10 phenotypes. The low production IL-6 and high production TNFα phenotypes also contributed to OM risk during RV detection. Cytokine polymorphisms may be one of an expectedly large number of genetic factors contributing to the known heritability of OM.

Gender-specific effects of cytokine gene polymorphisms on childhood vaccine responses

Cytokine gene polymorphisms affect vaccine responses and gender-specific effects are known for many phenotypes. Therefore, this study investigated gender-specific effects of cytokine gene polymorphisms on vaccine responses. In 263 2-year-old subjects selected for parental history of atopy, boys with IL-4 C-589T and IL-4Ralpha I50V genotypes associated with atopy had increased Diptheria Toxoid (DiphTox) and Tetanus Toxoid (TetTox) responses compared with the remaining alleles (IL-4 C-589T: DipTox p=0.01, TetTox p=0.04; IL-4Ralpha.I50V: DipTox p=0.04, TetTox p=0.08). Contrastingly, girls with IL-10 -592C genotypes associated with atopy had lower levels of DiphTox (p=0.03) and TetTox (p=0.02) responses compared with the remaining allele. Additionally, interaction effects were found for IL-4 C-589T (p=0.01) and IL-4Ralpha I50V (p=0.04) polymorphisms. In conclusion, these findings support the interaction of primary genetic and modifying factors on vaccine responses and the importance of atopic genetics to these responses.

IL-10 gene polymorphism at -1082 A/G is associated with severe rhinovirus bronchiolitis in infants

We analyzed polymorphisms of IL-10 -1082 G/A, IL-18 -137 G/C, TLR4 +896 A/G, and IFNG +874 T/A in 139 infants under 6 months of age hospitalized with bronchiolitis and 400 unselected blood donors. Causative viruses were determined by PCR. Infants with bronchiolitis associated with a virus other than respiratory syncytial virus (N = 18), were more often IL-10 -1082 allele G non-carriers, that is, homozygous for allele A (AA) than controls (66.7% vs. 28.0%, P < 0.0001). Infants with RSV bronchiolitis did not differ from controls. This finding suggests a different pathogenic mechanism for RSV bronchiolitis as compared with wheezing associated with other viral infections, for example, rhinovirus in infants under 6 months of age.