Single-nucleotide polymorphisms in the interleukin-10 gene: differences in frequencies, linkage disequilibrium patterns, and haplotypes in three United States ethnic groups

Neuroinflammatory Loop in Schizophrenia, Is There a Relationship with Symptoms or Cognition Decline?

Schizophrenia (SZ), a complex psychiatric disorder of neurodevelopment, is characterised by a range of symptoms, including hallucinations, delusions, social isolation and cognitive deterioration. One of the hypotheses that underlie SZ is related to inflammatory events which could be partly responsible for symptoms. However, it is unknown how inflammatory molecules can contribute to cognitive decline in SZ. This review summarises and exposes the possible contribution of the imbalance between pro-inflammatory and anti-inflammatory interleukins like IL-1beta, IL-4 and TNFalfa among others on cognitive impairment. We discuss how this inflammatory imbalance affects microglia and astrocytes inducing the disruption of the blood-brain barrier (BBB) in SZ, which could impact the prefrontal cortex or associative areas involved in executive functions such as planning and working tasks. We also highlight that inflammatory molecules generated by intestinal microbiota alterations, due to dysfunctional microbial colonisers or the use of some anti-psychotics, could impact the central nervous system. Finally, the question arises as to whether it is possible to modulate or correct the inflammatory imbalance that characterises SZ, and if an immunomodulatory strategy can be incorporated into conventional clinical treatments, either alone or in complement, to be applied in specific phases, such as prodromal or in the first-episode psychosis.

IL-10 (-1082 G/A) polymorphism in Bataknese with schizophrenia

Objectives

Three biallelic polymorphisms at the promoter region of the interleukin-10 (IL-10) gene have been associated with susceptibility to schizophrenia. The aim of this case-control study was to investigate the association between IL-10 (-1082) G/A gene polymorphisms and schizophrenia among Bataknese, a native tribe inhabiting the North Sumatera province in Indonesia.

Methods

A total of 194 unrelated participants (n = 97 for each case and control groups) participated in this study. Polymerase chain reaction restriction fragment length polymorphism molecular genotyping was conducted to assess the genotype and allele distribution of IL-10 (-1082 G/A).

Results

Allele variations indicated that the dominant allele in the Batak tribe was allele A, whereas homozygous GG genotypes were not found in either group. The A allele and AA genotype were found to be risk factors for developing schizophrenia (OR = 2.26, 95% CI = 1.1825-4.3559 and OR = 2.56, 95% CI = 1.280-5.152, respectively).

Conclusion

Only the A allele and AA genotype of the IL-10 gene polymorphism at -1082 G/A contribute to schizophrenia susceptibility in Bataknese.

IL-10 in cancer: an essential thermostatic regulator between homeostatic immunity and inflammation - a comprehensive review

Cytokines are soluble proteins that mediate intercellular signaling regulating immune and inflammatory responses. Cytokine modulation represents a promising cancer immunotherapy approach for immune-mediated tumor regression. However, redundancy in cytokine signaling and cytokines' pleiotropy, narrow therapeutic window, systemic toxicity, short half-life and limited efficacy represent outstanding challenges for cytokine-based cancer immunotherapies. Recently, there has been interest in the paradoxical role of IL-10 in cancer, its controversial prognostic utility and novel strategies to enhance its therapeutic profile. Here, the authors review the literature surrounding the role of IL-10 within the tumor microenvironment, its prognostic correlates to cancer patient outcomes and its pro- and antitumor effects, and they assess the legitimacy of potential therapeutic strategies harnessing IL-10 by outlining the notable preclinical and clinical evidence to date.

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.

Immune Responses and Risk of Triple-negative Breast Cancer: Implications for Higher Rates among African American Women

The etiology of triple-negative breast cancers (TNBC) is poorly understood. As many TNBCs develop prior to the initiation of breast cancer screening or at younger ages when the sensitivity of mammography is comparatively low, understanding the etiology of TNBCs is critical for discovering novel prevention approaches for these tumors. Furthermore, the higher incidence rate of estrogen receptor-negative breast cancers, and specifically, of TNBCs, among young African American women (AAW) versus white women is a source of racial disparities in breast cancer mortality. Whereas immune responses to TNBCs have received considerable attention in relation to prognosis and treatment, the concept that dysregulated immune responses may predispose to the development of TNBCs has received limited attention. We present evidence that dysregulated immune responses are critical in the pathogenesis of TNBCs, based on the molecular biology of the cancers and the mechanisms proposed to mediate TNBC risk factors. Furthermore, proposed risk factors for TNBC, especially childbearing without breastfeeding, high parity, and obesity, are more prevalent among AAW than white women. Limited data suggest genetic differences in immune responses by race, which favor a stronger Thr type 2 (Th2) immune response among AAW than white women. Th2 responses contribute to wound-healing processes, which are implicated in the pathogenesis of TNBCs. Accordingly, we review data on the link between immune responses and TNBC risk and consider whether the prevalence of risk factors that result in dysregulated immunity is higher among AAW than white women.

Interleukin 10 gene polymorphisms and frailty syndrome in elderly Mexican people: (Sadem study)

Frailty is a geriatric syndrome, characterized by a loss in functional reserve with an increase in morbidity and mortality. There are no reports that link the genetic polymorphisms between interleukin 10 (IL10) and frailty; for this reason, our objective was used to analyze the role of the polymorphisms of IL10 (rs1800896, rs1800871) in the susceptibility to frailty in a Mexican population. Our study included 984 participants divided into 368 nonfrail, 309 prefrail, and 307 frail. The models for the polymorphisms rs1800896 and rs1800871 were recessive models in association with frailty (OR = 2.3, CI 95% = 1.6–3.2; OR = 1.53, CI 95% = 1.0–2.6), respectively. Two risk haplotypes were identified: ACG and CCG (p < .0001), and three protective haplotypes were identified: ACA, ATG, and ATA (p < .05). This study evaluated the relationship between IL10 and the three subtypes of this geriatric syndrome (frail, prefrail, and nonfrail). These results support a greater susceptibility to frailty for the minor alleles of rs1800871 and rs1800896. In addition, we found two risk haplotypes supporting the participation of the IL10 in the susceptibility for frailty in the Mexican population.

Interleukin-10 polymorphisms and susceptibility to ARV associated hepatotoxicity

Interleukin-10 (IL-10) is an anti-inflammatory cytokine associated with the inhibition of HIV replication. IL-10 polymorphisms were found to be linked to drug-induced hepatotoxicity. Hence we examined the prevalence of IL-10 (-819C/T,-1082A/G) polymorphisms in a total of 165 HIV patients which included 34 patients with hepatotoxicity, 131 without hepatotoxicity and 155 healthy controls by the PCR-RFLP method. In HIV patients with hepatotoxicity, the IL-10-819TT genotype increased the risk of ARV associated hepatotoxicity severity (OR = 1.61, P = 0.35). IL-10-819TT genotype was overrepresented in patients with hepatotoxicity as compared to healthy controls (26.5% vs. 13.5%, OR = 1.61, P = 0.46). IL-10 -819CT genotype was associated with advance HIV disease stage (OR = 0.49, P = 0.045). In HIV patients without hepatotoxicity, the IL-10-819TT genotype was more prevalent in patients consuming tobacco as compared to non-users (OR = 1.60, P = 0.41). In HIV patients without hepatotoxicity using both alcohol + efavirenz along with IL-10 -819CT genotype resulted in increased risk for the acquisition of ARV associated hepatotoxicity (OR = 4.00, P = 0.36). In multivariate logistic regression, taking nevirapine was associated with the risk hepatotoxicity severity (OR = 0.23, P = 0.005). In conclusion, an insignificant association between IL-10 polymorphisms and susceptibility to ARV associated hepatotoxicity.

Association of interleukin-10 polymorphisms with risk factors of Alzheimer's disease and other dementias (SADEM study)

Some studies have reported a genetic association between single nucleotide polymorphisms (SNPs) in the promoter region of Interleukin (IL) 10 and Alzheimer's disease (AD), with conflicting results. To further investigate the proposed association and to clarify the role of cytokines as a potential cause for AD susceptibility, we analyzed genotypes, allele distributions and haplotypes of IL-10 promoter polymorphisms -1082 (rs1800896) and -819 (rs1800871) in a Mexican population: 986 normal controls and 221 cases divided as follows: 122 with Alzheimer disease (AD), 67 with (VaD) and 32 with mixed dementia (AD/VaD). Patients with dementia showed increased frequency of "ATA, CTG, and CTA" haplotypes when compared to controls. We identified two risk haplotypes: ATA (OR=3.56, 95%CI=2.84-4.45, p<0.0001), and CTA (OR=1.90, 95%CI=1.38-2.62, p<0.0001), and four protection haplotypes: ATG (OR=0.60, 95%CI=0.45-0.82, p=0.0012), CTG (OR=0.38, 95%CI=0.23-0.62, p<0.0001), ACG (OR=0.01, 95%CI=0.002-1.13, p<0.0001), and CCG (OR=0.02, 95%CI=0.004-0.203, p<0.0001). In summary, this is the first study in Mexican population that considers the analysis of IL-10 in patients with AD, VaD and AD/VaD. Our results showed the relevance of the role that IL-10 plays in the pathological mechanisms that result in the development of dementia. In addition, in our study, it was possible to distinguish two protective and two risk haplotypes for the development of dementia.

Genetic Factors That Affect Risk of Alcoholic and Nonalcoholic Fatty Liver Disease

Genome-wide association studies and candidate gene studies have informed our understanding of factors contributing to the well-recognized interindividual variation in the progression and outcomes of alcoholic liver disease and nonalcoholic fatty liver disease. We discuss the mounting evidence for shared modifiers and common pathophysiological processes that contribute to development of both diseases. We discuss the functions of proteins encoded by risk variants of genes including patatin-like phospholipase domain-containing 3 and transmembrane 6 superfamily member 2, as well as epigenetic factors that contribute to the pathogenesis of alcoholic liver disease and nonalcoholic fatty liver disease. We also discuss important areas of future genetic research and their potential to affect clinical management of patients.

Polymorphisms of Transporter Associated with Antigen Presentation, Tumor Necrosis Factor-α and Interleukin-10 and their Implications for Protection and Susceptibility to Severe Forms of Dengue Fever in Patients in Sri Lanka

Context:

To date, a clear understanding of dengue disease pathogenesis remains elusive. Some infected individuals display no symptoms while others develop severe life-threatening forms of the disease. It is widely believed that host genetic factors influence dengue severity.

Aims:

This study evaluates the relationship between certain polymorphisms and dengue severity in Sri Lankan patients.

Settings and Design:

Polymorphism studies are carried out on genes for; transporter associated with antigen presentation (TAP), promoter of tumor necrosis factor-α (TNF-α), and promoter of interleukin-10 (IL-10). In other populations, TAP1 (333), TAP2 (379), TNF-α (−308), and IL-10 (−1082, −819, −592) have been associated with dengue and a number of different diseases. Data have not been collected previously for these polymorphisms for dengue patients in Sri Lanka.

Materials and Methods:

The polymorphisms were typed by amplification refractory mutation system polymerase chain reaction in 107 dengue hemorrhagic fever (DHF) patients together with 62 healthy controls.

Statistical Analysis Used:

Pearson's Chi-square contingency table analysis with Yates′ correction.

Results:

Neither the TAP nor the IL-10 polymorphisms considered individually can define dengue disease outcome with regard to severity. However, the genotype combination, IL-10 (−592/−819/−1082) CCA/ATA was significantly associated with development of severe dengue in these patients, suggesting a risk factor to developing DHF. Also, identified is the genotype combination IL-10 (−592/−819/−1082) ATA/ATG which suggested a possibility for protection from DHF. The TNF-α (−308) GG genotype was also significantly associated with severe dengue, suggesting a significant risk factor.

Conclusions:

The results reported here are specific to the Sri Lankan population. Comparisons with previous reports imply that data may vary from population to population.

The CD4 T cell response to respiratory syncytial virus infection

Respiratory syncytial virus (RSV) can induce severe lower respiratory tract infections in infants and is the leading cause of bronchiolitis in children worldwide. RSV-induced inflammation is believed to contribute substantially to the severity of disease. T helper (Th)2-, Th9-, and Th17-related cytokines are all observed in infants hospitalized following a severe RSV infection. These cytokines cause an influx of inflammatory cells, resulting in mucus production and reduced lung function. Consistent with the data from RSV-infected infants, CD4 T cell production of Interleukin (IL)-9, IL-13, and IL-17 has all been shown to contribute to RSV-induced disease in a murine model of RSV infection. Conversely, murine studies indicate that the combined actions of regulatory factors such as CD4 regulatory T cells and IL-10 inhibit the inflammatory cytokine response and limit RSV-induced disease. In support of this, IL-10 polymorphisms are associated with susceptibility to severe disease in infants. Insufficient regulation and excess inflammation not only impact disease following primary RSV infection it can also have a major impact following vaccination. Prior immunization with a formalin-inactivated (FI-RSV) vaccine resulted in enhanced disease in infants following a natural RSV infection. A Th2 CD4 T cell response has been implicated to be a major contributor in mediating vaccine-enhanced disease. Thus, future RSV vaccines must induce a balanced CD4 T cell response in order to facilitate viral clearance while inducing proper regulation of the immune response.

Influence of interleukin 10 polymorphisms -592 and -1082 to the HIV, HBV and HCV serostatus among intravenous drug users

BACKGROUND

Interleukin 10 (IL-10) is a multifunctional cytokine produced by macrophages, monocytes, and T-helper cells. Two polymorphisms at positions -592 and -1082 have been associated with HIV susceptibility. However, their associations with susceptibility to HIV and its co-infections among intravenous drug users (IDUs) are largely unknown.

METHODS

A total of 345 IDUs were recruited. Of the 173 HIV negative IDUs, 20 were classified as highly exposed HIV seronegative subjects (HESNs). A control group consisted of 496 blood donors; all HIV, HCV, and HBV negative. The IL-10-592C/A and -1082A/G were determined using TaqMan allelic discrimination assay.

RESULTS

Of the IDUs, 50% were HIV positive, 89% HCV positive, 67% HBV positive and 41% had triple infection. IL-10-592C allele and -1082A allele were the most common and the -1082AG/-592CC was the most common genotype pair. All HESNs exhibited -1082A allele as compared to 81.4% of the HIV positive IDUs and 79% of donors (p=0.029 and p=0.019, respectively). None of HESNs had GG/CC genotype pair compared with 18.6% of HIV positive IDUs and 21.0% of donors (p=0.029 and p=0.019, respectively). The possession of -592AC and genotype pair AG/AC were associated with the decreased odds of HBV infection (OR=0.28; 95% CI 0.09-0.87; p=0.028 and OR=0.19; 95% CI 0.06-0.61; p=0.052, respectively).

CONCLUSIONS

The presence of low producing IL-10-1082A and -592A alleles and their containing genetic variants protect highly exposed IDUs against acquisition of HIV and HBV infections.

Association of SNP (-G1082A) IL-10 with increase in severity of periportal fibrosis in schistosomiasis, in the northeast of Brazil

Interleukin 10 (IL-10) is an important anti-inflammatory cytokine that modulates severe periportal fibrosis (PPF). We hypothesized that genetic polymorphisms (-G1082A/-C819T/-C592A) of the IL-10 gene and classic factors (age, sex, alcohol, exposure, and specific treatment) are associated with the severity of PPF and that these polymorphisms influence IL-10 expression. In this cross-sectional study, we genotyped these polymorphisms within the IL-10 gene in 203 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF. There was an association of protection between the ages of 41 and 60 years and advanced standard PPF. The -1082AA genotype was significantly associated with severity in PPF when compared with the -1082GG genotype. Similarly, when analyzed together, both the -1082GA+AA genotypes were significantly associated. The ACC and GTA haplotypes indicated a protective effect against PPF, while the ATA haplotype was significantly associated with PPF severity when compared with the GCC haplotype. There was no significant difference between average levels of IL-10 between clinical groups, and there was no association between average serum levels of IL-10 and (-G1082A) IL-10 polymorphism. Our results suggest that (-G1082A) IL-10 polymorphism and putative haplotypes are associated with PPF severity in the Brazilian population.

Polymorphisms of interleukin 6 and interleukin 10 in Egyptian people with Behcet's disease

Cytokines play critical roles in the pathogenesis of Behçet's disease (BD). They mediated many of the effectors and regulatory functions of immune and inflammatory responses. Many studies have linked Interleukin-6 (IL-6) and Interleukin-10 (IL-10) pathologically to BD. Thus, this study aimed to investigate the associations between IL-6 and IL-10 promoter single-nucleotide polymorphisms (SNPs) and the susceptibility to BD and their implication on plasma levels. We genotyped IL-6 -174 G/C (rs1800795) using Mutagenically Separated Polymerase Chain Reaction PCR (MS-PCR) and IL-10 -1082 G/A (rs1800896) and -819 C/T (rs1800871) using Sequence Specific Primer PCR (SSP-PCR) in 87 Egyptian patients and 97 controls. The plasma levels of IL-6 and IL-10 were measured using Enzyme-linked Immunosorbent Assay (ELISA). Significant increase in the frequency of -1082 GG genotype (P<0.05, OR=2.25, 95%CI=1.03-4.91) and significant decrease in the frequency of -1082 GA genotype (P<0.05, OR=0.53, 95%CI=0.29-0.96) was demonstrated in BD patients compare to controls. Patients with genital ulcer had significantly lower frequency of -1082 GG (P<0.05, OR 0.2, 95% CI=0.04-0.99) and G allele (P<0.05, OR=0.28, 95%CI=0.08-0.93), while patients with ocular manifestations had significantly higher frequency of -1082 G allele (P<0.01, OR=2.28, 95%CI=1.19-4.36). BD patients had significantly higher level of IL-6 (P<0.001) and significantly lower level of IL-10 (P<0.001) compared to controls. The changes in the level of cytokines were independent of any genotype of IL-6 or any genotype/haplotype of IL-10. Patients with active disease state had significantly higher level of IL-6 compared to patients in remission (P<0.05). In conclusion, our preliminary study indicates that the polymorphism at IL-10 -1082 G/A may play a role in BD susceptibility. The significant increase in IL-6 level and the significant decrease in IL-10 level in BD patients were independent of any particular genotype in IL-6 or any particular genotype/haplotype in IL-10.

Cytokines in schizophrenia: possible role of anti-inflammatory medications in clinical and preclinical stages

AIMS

In this paper, we review the literature on the efficacy of anti-inflammatory agents as neuroprotectors in clinical and preclinical stages of schizophrenia.

METHOD

A synthetic and integrative approach was applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early-onset schizophrenia.

RESULTS

Abnormal inflammatory activation has been demonstrated in schizophrenia. Increases or imbalances in cytokines before birth or during childhood may impact neurodevelopment and produce vulnerability to schizophrenia. The specificity of inflammatory abnormalities in psychiatric disorders is controversial. Similar increases in pro-inflammatory cytokines have been described in other disorders, especially mood and anxiety disorders. One of the most important challenges at this point is the understanding of neurobiological correlates of prodromal stages of schizophrenia.

CONCLUSION

Although future research should investigate the exact role of different cytokines in pathophysiology of schizophrenia, these mediators emerge as promising molecular targets to its prevention and treatment.

Is interleukin-10 gene polymorphism a predictive marker in HCV infection?

The clinical outcome of hepatitis C virus (HCV) infection varies between individuals - from spontaneous viral clearance and persistence without complication, to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Also patterns of response to interferon-based anti-HCV therapy are different from person to person. This diversity may be affected by host genetic factors, including alterations in genes encoding cytokines. Interleukin-10, as an anti-inflammatory cytokine and immune response modulator, may influence on HCV infection susceptibility as well as spontaneous and treatment-induced HCV eradication. Moreover, it is stated that IL-10 has antifibrotic properties and play a role in progression of liver disease. This review summarized studies on interleukin-10 gene polymorphisms (mainly promoter SNPs at positions -1082(G/A), -819(C/T) and -592(C/A)), which may determine IL-10 production, regarding susceptibility to HCV infection, course of HCV-related liver disease (fibrosis, cirrhosis, hepatocellular carcinoma, ALT abnormalities), spontaneous viral elimination as well as hepatitis C treatment outcomes. Analysis of hereby summarized studies shows that it is difficult to unambiguously determine the importance of IL-10 polymorphism as a predictor of clinical outcome of hepatitis C and response to anti-HCV therapy before its beginning. Thus, future larger studies need to address these issues. Continuation of studies on interleukin-10 polymorphisms as well as identification of other candidate predictive markers in HCV infection has important practical implications and there is a chance that may contribute to reduce the scale of hepatitis C problem.

T-helper 1, T-helper 2, and T-regulatory cytokines gene polymorphisms in irritable bowel syndrome

Inflammation and mucosal immune system activation have an important role in irritable bowel syndrome (IBS), whereas genetic factors can control some immunological mediators. In this study, a number of polymorphic genes coding for T-helper 1, T-helper 2, and T-regulatory cytokines were genotyped in 71 patients with IBS, and the results were compared with controls. IL-4 CC genotype at position -590, IL-4 TT genotype at position -33, and IL-10 GA genotype at position -1082 were significantly overrepresented in the patients with IBS in comparison with controls (P < 0.001). The frequencies of the following haplotypes in the patient group were significantly higher than in the control group: IL-2 (-330, +160) GT haplotype (P = 0.002), IL-4 (-1098, -590, -33) TCC haplotype (P < 0.001), and TCT haplotype (P < 0.001). While production of cytokines could be affected by genetic polymorphisms within coding and promoter regions of cytokine genes, IL-4 and IL-10 gene polymorphisms could affect individual susceptibility to IBS.

MCP1 -2518 polymorphism and chronic obstructive pulmonary disease in Taiwanese men

Monocyte chemoattractant protein-1 (MCP-1) plays a major role in the recruitment of inflammatory cells to the lungs of patients with chronic obstructive pulmonary disease (COPD). However, the influence of MCP1 gene polymorphism on COPD development has not been studied. This study aimed to investigate the association between MCP1 -2518 polymorphisms and COPD and between this polymorphism and plasma MCP-1 levels. The plasma MCP-1 was measured by using an enzyme-linked immunosorbent assay and polymorphisms detection was performed by denaturing high-performance liquid chromatography. COPD group had higher plasma MCP1 levels than healthy participants (257.0 versus 194.4 pg/mL) in the univariate analysis (P = .005); and in stepwise liner regression analysis after adjustment for age, alcohol, body mass index, cancer history, and steroid use (P = .002; 95% confidence interval [CI]: 30.72-128.02). Plasma MCP-1 was negatively correlated with forced expiratory volume in one second (FEV(1)%) (P = .003; r = -.274). SNPStats including codominant, dominant, recessive, overdominant, and log-additive model analysis showed MCP1 -2518 polymorphisms had no association with the risk of COPD. Generalized linear model showed no association between plasma MCP-1 levels and MCP1 -2518 genotypes. In conclusion, there is no association between MCP1 -2518 gene polymorphisms and COPD or between this gene polymorphisms and plasma MCP-1 levels in the Taiwanese men.

Interleukin-10 gene promoter polymorphism in patients with schizophrenia in a region of East Turkey

Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Immunological abnormalities have been found to be associated with schizophrenia for decades. Cytokines are key proteins involved in the immune system activation. Interleukin-10 (IL-10), an important immunoregulatory cytokine, is located on chromosome 1q31-32, a region previously reported to be linked to schizophrenia in genetic studies. In the present study it was aimed to examine the IL-10 gene promoter region's polymorphic variants in patients with schizophrenia in a population of the Elazig Region of East Anatolia, Turkey. Polymorphisms at position -1082, -819 and-592 in the IL-10 promoter region were determined in 171 Turkish patients who were diagnosed with schizophrenia, based on the DSM-IV, and 168 healthy controls, by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). We analyzed allele, genotype, and haplotype distributions using a case-control association study. Genotyping was performed by RFLP. Statistically significant differences were observed in both allelic and genotypic frequencies of the-592A/C polymorphism (Allele, P=0.034, OR = 1.26, 95% CI 1.02-1.56; Genotype, P=0.048), while the other two polymorphisms in distribution of the alleles and genotypes in patients with schizophrenia were not significantly different from those of controls (P>0.05). Our results show a significant increase of GTA homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (P=0.0001). These data suggest that the IL-10 gene promoter polymorphism may be one of the susceptibility factors to develop schizophrenia in the Turkish population, and apparently in all humans.

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.

TNFA and IL10 gene polymorphisms are not associated with periodontitis in Brazilians

IL-10 and TNF-α are cytokines that have complex and opposing roles in the inflammatory responses. G/A polymorphisms at position –1082 of IL10 and –308 of TNFA genes have been reported to influence the expression of IL-10 and TNF-α, respectively. The aim of this study was to investigate the association between the IL10 (-1082) and TNFA (- 308) gene polymorphisms with different clinical forms or severity of periodontitis in a sample of Brazilian individuals. DNA was obtained from oral swabs of 165 Brazilian individuals, which were divided into three groups: individuals with chronic periodontitis, aggressive periodontitis and individuals without clinical evidence of periodontitis. Evaluation of IL10 and TNFA polymorphisms was performed by RFLP analysis. Statistical analysis of data was performed using the χ² likelihood ratio and Fisher`s exact test. No significant differences in the genotype and allele distribution of either IL10 or TNFA were observed among individuals with different clinical forms or with different degrees of severity of periodontitis. Moreover, combined analysis of IL10 and TNFA polymorphisms did not show any association with periodontal status. As conclusion, the IL10 and TNFA gene promoter polymorphisms investigated are not associated with different clinical forms of periodontitis or with severity of the disease in the Brazilian population polymorphisms.

Interleukin 10 (IL-10) gene variants and susceptibility for paediatric onset Crohn's disease

BACKGROUND

A recent genome-wide association study in adult patients with ulcerative colitis (UC) has implicated the interleukin 10 (IL-10) gene as an important candidate gene. Moreover, a UC-associated single nucleotide polymorphism (SNP) rs3024405 was also significantly associated with adult Crohn's disease (CD).

AIMS

To examine whether IL-10-CD associations extended to paediatric-onset CD.

METHODS

We implemented the case-control design at three paediatric gastroenterology clinics in Canada. CD patients (<or=20 years) were recruited along with healthy controls. DNA samples were genotyped for tag-single nucleotide polymorphisms (tag-SNPs) in the IL-10 gene. Allelic, genotype and haplotype associations with CD were studied.

RESULTS

A total of 270 patients and 336 controls were studied. The mean age (+/-s.d.) at diagnosis was 12.1 (+/-3.5). There were a slightly higher proportion of male patients (56.3%). Of the five IL-10 tag-SNPs, rs2222202 (C/T) (P = 0.03) and rs1800871 (C/T) (P = 0.05) showed significant allelic associations with CD. Specific IL-10 SNPs were associated with CD disease location and/or disease behaviour.

CONCLUSIONS

Our gene-wide analysis replicates recent findings of associations between IL-10 and adult CD, and suggests that these associations extend to paediatric-onset CD as well.

Cytokine SNPs: Comparison of allele frequencies by race and implications for future studies

The role of inflammation is being considered in chronic diseases. Previous studies have examined SNPs in a few key inflammatory genes and have included small numbers of African American participants. Variation in the frequencies of inflammatory pathway SNPs may help to explain racial disparities in disease risk. Through a population-based study of 103 African American and 380 Caucasian unrelated, healthy women, we examined the relationships between race and allele frequencies of 70 cytokine and cytokine receptor SNPs. The associations between genotypic and haplotype frequencies and race were also analyzed. Allelic frequencies for 52 out of the 70 SNPs meeting criteria for analysis differed significantly by race. Of the 32 pro-inflammatory and 20 anti-inflammatory SNPs for which the allele frequencies varied significantly by race, variant allele frequency differences between Caucasians and African Americans ranged between 6-37% and 7-53% for pro-inflammatory SNPs and anti-inflammatory SNPs, respectively. Our findings suggest that while allele frequencies do vary by race, racial groups are not simplistically represented by a pro-inflammatory or anti-inflammatory genetic profile. Given the racial variability in allele frequencies in inflammatory gene SNPs, studies examining the association between these SNPs and disease should at least incorporate self-reported race in their analyses.

Associations between cytokine/cytokine receptor single nucleotide polymorphisms and humoral immunity to measles, mumps and rubella in a Somali population

We genotyped a Somali population (n = 85; age < or =30 years) for 617 cytokine and cytokine receptor single nucleotide polymorphisms (SNPs) using Illumina GoldenGate genotyping to determine associations with measles, mumps and rubella immunity. Overall, 61 significant associations (P < or = 0.01) were found between SNPs belonging to cytokine receptor genes regulating T helper (Th)1 (IL12RB2, IL2RA and B) and Th2 (IL4R and IL10RB) immunity, and cytokine (IL1B, TNFA, IL6 and IFNB1) and cytokine receptor (IL1RA, IFNAR2, IL18R1, TNFRSF1A and B) genes regulating innate immunity and variations in antibody levels to measles, mumps and/or rubella. SNPs within two major inflammatory cytokine genes, TNFA and interleukin (IL) 6, showed associations with measles-specific antibodies. Specifically, the minor allele variant of rs1799964 (TNFA -1211 C>T) was associated with primarily seronegative values (median enzyme immunoassay index values < or =0.87; P = 0.002; q = 0.23) in response to measles disease and/or vaccination. A heterozygous variant CT for rs2069849 (IL6 +4272C>T; Phe201Phe) was also associated with seronegative values and a lower median level of antibody response to measles disease and/or vaccination (P = 0.004; q = 0.36) or measles vaccination alone (P = 0.008). Several SNPs within the coding and regulatory regions of cytokine and cytokine receptor genes showed associations with mumps and rubella antibody levels but were less informative as strong linkage disequilibrium patterns and lower frequencies for minor alleles were observed among these SNPs. Our study identifies specific SNPs in innate immune response genes that may play a role in modulating antibody responses to measles vaccination and/or infection in Somali subjects.

Cytokine polymorphisms in women with recurrent pregnancy loss: meta-analysis

BACKGROUND

Inflammatory cytokine cascades have been implicated in the pathogenesis of recurrent pregnancy loss (RPL). Polymorphisms in cytokine genes may affect the risk of RPL, but genetic association studies are often limited by small sample sizes. Meta-analysis of all available studies can increase the precision of these estimates.

AIMS

To assess and synthesise the available data from association studies of inflammatory cytokine polymorphisms with RPL.

METHODS

Systematic review and random effects meta-analysis of genetic association studies.

RESULTS

Sixteen reports of genetic association studies of cytokine polymorphisms with RPL were identified. Meta-analyses did not identify any significant associations with tumour necrosis factor (-308A, or -238A), interferon-gamma (+874T), interleukin (IL)-1beta (-511T), IL-6 (-174G), or IL-10 (-1082A, or -819T, or -592A). Significant associations were found with IL-1B (-31T) (two studies: pooled odds ratio (OR) 2.12 (95% confidence interval (CI) 1.04 to 4.33)) and IL-6 (-634G) (one study: OR 0.22 (95% CI 0.09 to 0.57)).

CONCLUSIONS

The available data are not consistent with more than modest associations between these candidate cytokine polymorphisms and RPL. Data from future association studies may be added to the meta-analyses to obtain more precise estimates of effect sizes.

Dust mite exposure modifies the effect of functional IL10 polymorphisms on allergy and asthma exacerbations

BACKGROUND

The allergenicity of dust mite exposure might be dependent on variants in the gene for IL-10 (IL10).

OBJECTIVES

To evaluate whether dust mite exposure modifies the effect of single nucleotide polymorphisms (SNPs) in IL10 on allergy and asthma exacerbations.

METHODS

We genotyped 6 SNPs in IL10 in 417 Costa Rican children and 503 white children in the Childhood Asthma Management Program (CAMP) with asthma and their parents. We used family-based and population-based approaches to test for interactions between IL10 SNPs and dust mite allergen on serum IgE to dust mite in Costa Rica and on asthma exacerbations in Costa Rica and CAMP.

RESULTS

Dust mite exposure significantly modified the relation between 3 SNPs in IL10 (rs1800896, rs3024492, and rs3024496) and IgE to dust mite in Costa Rica (P for interaction, .0004 for SNP rs1800896). For each of these SNPs, homozygosity for the minor allele was associated with increased levels of IgE to dust mite with increased dust mite exposure. Homozygosity for the minor allele of each of the 3 SNPs was associated with increased risk of occurrence (approximately 3-fold to 39-fold increase) and frequency of asthma exacerbations among children exposed to > or = 10 microg/g dust mite allergen in Costa Rica. Similar results were obtained for 2 of these SNPs (rs1800896 and rs3024496) among white children in CAMP.

CONCLUSION

Our findings suggest that dust mite allergen levels modify the effect of IL10 SNPs on allergy and asthma exacerbations and may partly explain conflicting findings in this field.

Cytokine gene polymorphisms in Colombian patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) patients exhibit alterations in cytokine production that may be relevant to SLE pathogenesis. There is evidence that cytokine gene polymorphisms control cytokine production; thus, these polymorphisms may be associated with SLE or its clinical manifestations. To establish the association of tumor necrosis factor alpha (TNF-alpha), transforming growth factor (TGF) beta1, interleukin (IL)-10, and IL-6 gene polymorphisms in Colombian SLE patients and their clinical manifestations, 120 SLE patients and 102 healthy controls were studied. Single nucleotide polymorphisms were studied by sequence-specific primers polymerase chain reaction (SSP-PCR) at: TNFalpha-308 (G/A), TGFbeta1 codon 10 (C/T) and codon 25 (G/C), IL-10 -1082 (G/A), -819 (C/T) and -592 (C/A), and IL-6 + 174 (G/C). Human leukocyte antigen (HLA)-DRbeta1 was typed by SSP-PCR. SLE patients had increased frequency of allele C at TGFbeta1 codon 25 (P = 0.0001, odds ratio (OR): 4.25, 95% confidence interval (CI): 2.17-8.35) and allele A at TNFalpha-308 (P = 0.0004 OR: 3.9, 95% CI: 1.65-5.80) compared with healthy controls. There was higher frequency of GC genotype at TGFbeta1 codon 25 in SLE patients (P < 0.0001). Extended genotypic analysis showed that SLE patients have decreased frequency of TNFalphaLow/TGFbeta1High (0.50) compared with healthy controls (0.80) (P < 0.0001). No association was found between these polymorphisms and SLE clinical manifestations except for Sm and Ro autoantibodies that were associated with TNFalpha allele A. There is an association between TNFalpha-308A/TGFbeta1 codon 25C with SLE susceptibility in Colombian population. This association may result in a highly inflammatory response with a decrease regulatory function mediated by TNFalpha and TGFbeta1, respectively. The TNFalpha-308A/TGFbeta1 25C genotype may be one component of genetic susceptibility to SLE in Colombian population.

Interleukin-10 gene (IL10) polymorphisms and human papillomavirus clearance among immunosuppressed adolescents

Persistent infection with high-risk human papillomavirus (HPV) is a major risk factor for cervical cancer, and HPV clearance seems to be under host genetic influence. This study evaluated associations between three single nucleotide polymorphisms in the IL10 promoter and clearance of low- or high-risk HPV infection in a cohort of 226 largely HIV-1-infected African-American adolescent females. Among immunosuppressed individuals (HIV-1 seropositive and CD4(+) </= 500), the GCC haplotype in the IL10 promoter was associated with reduced clearance of high-risk HPV16-like [relative hazard (RH), 0.46; 95% confidence interval (95% CI), 0.25-0.85; P = 0.01], HPV18-like (RH, 0.33; 95% CI, 0.16-0.67; P = 0.002), and any high-risk type (RH, 0.37; 95% CI, 0.20-0.68; P = 0.002) but not with low-risk HPV type (RH, 0.60; 95% CI, 0.29-1.25; P = 0.17). No associations were observed among immunocompetent individuals. The IL10 GCC haplotype has been associated with production of relatively high levels of interleukin (IL)-10, which could (a) inhibit cytokines such as IL-2, TNF-alpha, IL-4, IL-6, and IL-12 that are involved in the T(H)1-T(H)2 immunoregulation; (b) down-regulate expression of MHC class I and class II molecules; or (c) induce the transcription of early promoter of HPV, all potentially contributing to duration of HPV infection among immunosuppressed individuals. These results support the hypothesis that IL10 polymorphisms influence the clearance of infection with high-risk HPV types and warrant further studies of host genetic control of HPV pathogenesis and cervical cancer in the context of immunosuppression.

Mechanisms of Disease: genetics of functional gastrointestinal disorders—searching the genes that matter

There is evidence to suggest that genetic factors contribute to the manifestation of functional gastrointestinal disorders (FGID). As such, it is important to note that FGID are heterogeneous; they have quite different clinical features and (probably) different underlying pathophysiologic mechanisms. Evidence from family and twin studies indicates that there is clustering of FGID in families and increased concordance in monozygotic compared with dizygotic twins. The clinical features of FGID implicate polymorphisms in the genes that encode adrenergic, opioidergic or serotonergic receptors, as well as in the G-protein beta3 subunit (GNB3) gene and serotonin-transporter genes, in their manifestations. As mediators or regulators of mucosal inflammation can trigger events that ultimately result in manifestations of FGID, polymorphisms in genes that encode proteins with immunomodulatory and/or neuromodulatory features (e.g. OPRM1, IL4, IL4R, TNF) might also have a role in the manifestation of FGID. A two-step model for the role of genetic factors in the manifestation of functional gastrointestinal pain can, therefore, be proposed. In the presence of specific hereditary factors, environmental factors that do not usually cause long-term functional alterations are linked to the manifestation of symptoms.

IL-10 genotype analysis in patients with Behçet's disease

Behçet's disease (BD) is a multisystem inflammatory disease characterized by recurrent orogenital ulceration, ocular inflammation, and skin lesions. The etiology of the disease is currently unknown but evidence suggests that there is a strong genetic component mediating the chronicity of the disorder. We have examined the association between polymorphisms at position -1082, and -819 in the promoter region of the gene encoding IL-10 in patients with Behçet's disease from two distinct patient populations. The IL-10 -1082AA genotype was weakly associated with BD when all patients were analyzed as a group (pc = 0.04, OR 1.4, 95% CI 1.1-1.9), but not in the UK or Middle Eastern (ME) cohorts of patients alone compared to local controls. An association with IL-10 -819T was evident in all BD patients, (pc = 0.02, OR 1.5, 95% CI 1.1-2.0), and this was because of an association in the UK but not ME patients (pc = 0.0004, OR 2.1, 95% CI 1.4-3.3). The -1082A/-819T haplotype, which is linked to low production of this cytokine, was not significantly associated with Behçet's disease. This link between BD, a chronic, relapsing, autoinflammatory condition, and a genotype associated with low IL-10 production provides evidence that abnormalities in the genetic control of cytokine levels may be relevant in influencing the immune response in Behçet's disease in some patient groups.

SLC34A3 mutations in patients with hereditary hypophosphatemic rickets with hypercalciuria predict a key role for the sodium-phosphate cotransporter NaPi-IIc in maintaining phosphate homeostasis

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare disorder of autosomal recessive inheritance that was first described in a large consanguineous Bedouin kindred. HHRH is characterized by the presence of hypophosphatemia secondary to renal phosphate wasting, radiographic and/or histological evidence of rickets, limb deformities, muscle weakness, and bone pain. HHRH is distinct from other forms of hypophosphatemic rickets in that affected individuals present with hypercalciuria due to increased serum 1,25-dihydroxyvitamin D levels and increased intestinal calcium absorption. We performed a genomewide linkage scan combined with homozygosity mapping, using genomic DNA from a large consanguineous Bedouin kindred that included 10 patients who received the diagnosis of HHRH. The disease mapped to a 1.6-Mbp region on chromosome 9q34, which contains SLC34A3, the gene encoding the renal sodium-phosphate cotransporter NaP(i)-IIc. Nucleotide sequence analysis revealed a homozygous single-nucleotide deletion (c.228delC) in this candidate gene in all individuals affected by HHRH. This mutation is predicted to truncate the NaP(i)-IIc protein in the first membrane-spanning domain and thus likely results in a complete loss of function of this protein in individuals homozygous for c.228delC. In addition, compound heterozygous missense and deletion mutations were found in three additional unrelated HHRH kindreds, which supports the conclusion that this disease is caused by SLC34A3 mutations affecting both alleles. Individuals of the investigated kindreds who were heterozygous for a SLC34A3 mutation frequently showed hypercalciuria, often in association with mild hypophosphatemia and/or elevations in 1,25-dihydroxyvitamin D levels. We conclude that NaP(i)-IIc has a key role in the regulation of phosphate homeostasis.

Les gènes modificateurs dans la mucoviscidose

Cystic fibrosis is the most common lethal autosomal recessive disease among the Caucasian population. It is caused by defects in the CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator). Although over 1600 disease-causing mutations in the CFTR gene have been described, the highly variable disease phenotype in cystic fibrosis cannot be explained on the basis of this gene alone. Both the environment and other non-CFTR genes are likely to be important. The increased understanding of pathophysiological processes in the cystic fibrosis lung has led to several studies on genes in these pathways. One of the major aims of such studies is to produce targets for novel drug developments.

Risk of small-for-gestational age is associated with common anti-inflammatory cytokine polymorphisms

BACKGROUND

Anti-inflammatory cytokines play a key role in pregnancy maintenance. Genetic variation in anti-inflammatory cytokines could influence a woman's risk of adverse reproductive outcomes.

METHODS

We investigated the relationship of polymorphisms in interleukin 4 (IL4), IL5, IL10, IL13, and transforming growth factor (TGFbeta1) with spontaneous preterm birth and small-for-gestational age (SGA) in a nested case-control study of a prospective pregnancy cohort. Women were recruited between 24 and 29 weeks' gestation at the Wake County and University of North Carolina, Chapel Hill obstetric clinics between February 1996 and June 2000. We inferred haplotypes using the EM algorithm and the Bayesian method, PHASE. Semi-Bayesian hierarchical logistic regression was used to obtain odds ratio (OR) estimates and 95% confidence intervals (CIs) for each polymorphism.

RESULTS

African-American mothers who carried the IL4 GCC haplotype had greater risk of spontaneous preterm birth (OR = 2.9; 95% CI = 1.2-7.4). In white mothers, carriers of the "low-producing" IL4 CC and IL10 ATA haplotypes had markedly reduced risk of SGA (for the CC haplotype, 0.2 [0.0-1.2]; for the ATA haplotype, 0.5 [0.3-0.8]), whereas carriers of the "high-producing" IL4(-589)T variant had increased risk of SGA in both African-American and white mothers.

CONCLUSIONS

Variants related to decreased anti-inflammatory cytokine production may lower risk of SGA. Furthermore, the same mechanism that protects against SGA might increase risk of spontaneous preterm birth.

Interleukin-10 haplotype associated with increased mortality in critically ill patients with sepsis from pneumonia but not in patients with extrapulmonary sepsis

STUDY OBJECTIVE

To test the hypothesis that haplotypes of the interleukin (IL)-10 gene are associated with clinical outcomes, comparing critically ill patients with sepsis from pneumonia vs those with extrapulmonary sepsis.

DESIGN

Genetic association study.

SETTING

Medical/surgical ICUs in a tertiary-care, university-affiliated teaching hospital.

PATIENTS

Of 550 white patients with sepsis, 158 had pneumonia as the principle cause of their sepsis and 392 had an extrapulmonary source of sepsis.

MEASUREMENTS

Haplotypes of the IL-10 gene were defined by measurement of haplotype tag single-nucleotide polymorphisms (SNPs). Primary outcome was 28-day survival. Secondary outcomes were days alive and free of organ dysfunction.

RESULTS

Three SNPs in the IL-10 gene (-592 C/A, +734 G/T, and +3367 G/A) identified four major haplotypes: CGG, AGG, CTA, and CTG. Patients with pneumonia who carried one or two copies of the CGG haplotype had greater 28-day mortality (51.4%) than patients who did not carry this haplotype (29.1%, p = 0.007). Carriers of CGG had significantly more cardiovascular dysfunction (and use of vasopressors), renal dysfunction (and requirement of dialysis), hepatic dysfunction, and hematologic dysfunction (p < 0.05 in each case). In contrast, in patients with an extrapulmonary source of infection there was no significant association of the CGG haplotype (or any measured IL-10 genotype) with 28-day mortality or organ dysfunction.

CONCLUSIONS

The IL-10 haplotype - 592C/734G/3367G is associated with increased mortality and organ dysfunction in critically ill patients with pulmonary sepsis but not in similarly ill patients with extrapulmonary sepsis. Therefore, polymorphisms within the IL-10 gene may be predictors of outcome in patients with sepsis from pneumonia.

The epidemiology of Kawasaki disease in an urban hospital: does African American race protect against coronary artery aneurysms?

The etiology and pathogenesis of Kawasaki disease (KD) is largely unknown. Certain demographic factors and laboratory findings are predictive of the development of coronary artery (CA) aneurysms. The objectives of this study were to determine the epidemiology of KD patients in an urban hospital and determine risk factors associated with their development of CA abnormalities. A longitudinal case series of KD patients admitted to Children's National Medical Center from 1990 to 2002 was examined. Age, sex, ethnic background, duration of fever prior to diagnosis, address, month diagnosed, and CA abnormalities (ectasia or aneurysms) on echocardiography were recorded. Median household income was obtained from the U.S. Census Bureau Web site. The Student t-test, logistic regression analyses, and the Kruskal-Wallis test were used, with significance assumed at p < 0.05. A total of 302 patients were evaluated. CA abnormalties were found in 27 patients (9%), with aneurysms identified in 13 patients (4%). Age was 2.9 +/- 2.4 years (range, 2 months to 14 years). A total of 51 patients (16%) were < or =1 year and 35 patients (12%) were > or =5 years. Ethnic distribution was 54% (164) African American, 24% (72) Caucasian, 9% (29) Asian/Pacific Islander, 8% (23) Hispanic, and 5% (14) Middle Eastern. Only 2/164 (1.2%) African Americans developed CA aneurysms. Neighborhood median income of the cohort was $45,400 +/- $21,200 ($52,200 +/-$25,800 for patients with aneurysms). A total of 28% of cases clustered between December and January. Cases doubled annually in 1999-2001 compared to 1990-1998 (39 vs 19). Multivariate logistic regression found age between 1 and 5 years [p = 0.045; odds ratio, 0.31; 95% confidence interval (CI), 0.10-0.97] and African American race (p = 0.014; odds ratio, 0.15; 95% CI, 0.03-0.68) to be independently protective against CA aneurysms. Duration of fever prior to diagnosis, considered in 210 patients, was different between patients with and without aneurysms (11 +/- 5.3 vs 6.5 +/- 3.8 days, respectively, p = 0.0007). Multivariate logistic regression found fever longer than 5 days to be the only predictive factor associated with the development of aneurysms and any abnormality. African Americans had a shorter duration of fever than the rest of the cohort (6.03 vs 7.31 days), (p = 0.0087). The epidemiology of KD at our hospital is similar to that at other centers except for the predominance of African Americans with a shorter duration of fever prior to diagnosis and a decreased incidence of CA aneurysms compared to other ethnicities. The protective nature of African American ethnicity against the development of CA aneurysms raises speculation about the role of genetics and its interaction with immunity in the pathogenesis of KD.

Role of tumor necrosis factor-alpha and interleukin-10 gene polymorphisms in irritable bowel syndrome

OBJECTIVES

Imbalances in the genetically controlled pro- and anti-inflammatory cytokine production may promote ongoing low-grade inflammation after an acute gastroenteritis, and subsequently, irritable bowel syndrome (IBS) (post-infectious IBS, PI-IBS). We studied gene promoter single nucleotide polymorphisms (SNPs) of tumor necrosis factor-alpha (TNF-alpha, pro-inflammatory) and interleukin-10 (IL-10, anti-inflammatory) in IBS patients and controls.

METHODS

DNA was extracted from peripheral blood leucocytes of 111 IBS patients and 162 healthy controls. Genotype and allele frequencies were assessed by analyzing SNPs at position -308 (TNF-alpha) and -1082 and -819 (IL-10).

RESULTS

Homozygous high producers for TNF-alpha (A/A) were rare (overall prevalence 2.6%). The heterozygous TNF-alpha genotype (G/A, high producer) was significantly more prevalent in IBS compared to controls (41%vs 26%, p= 0.02). More patients (41%) than controls (30%) were positive for the A allele (p= 0.044; odds ratio (OR) 1.68, 95% confidence interval (CI) 1.01-2.79), with a similar trend for diarrhea (54%) versus constipation and alternating subtypes (<33%, p= 0.079), but not for subgroups according to a history of acute gastroenteritis. IL-10 genotypes were similarly distributed in patients and controls for both SNPs. Possession of a high producer TNF-alpha and a low producer IL-10 genotype were significantly more prevalent in IBS (9%) versus controls (3%, p= 0.035; OR 3.11, 95% CI 1.03-9.36) and in diarrhea (20%) compared to other IBS subtypes (<4%, p= 0.026).

CONCLUSIONS

Our results support the emerging hypothesis that genetically determined immune activity plays a role in the pathophysiology of IBS. Future studies in larger, clinically relevant, IBS subgroups are warranted to establish definite associations with cytokine gene polymorphisms.

Analysis of IL10 haplotypic associations with severe malaria

We investigated the association between severe malaria and genetic variation of IL10 in Gambian children, as several lines of evidence indicate that IL10 is protective against severe malaria and that IL10 production is genetically determined. We began by identifying five informative SNPs in the Gambian population that were genotyped in a combined case-control and intrafamilial study including 654 cases of severe malaria, 579 sets of parents and 459 ethnically matched controls. No significant associations were identified with individual SNPs. One haplotype of frequency 0.11 was strongly associated with protection against severe malaria in the case-control analysis (odds ratio 0.52, P=0.00002), but the transmission disequilibrium test in families showed no significant effect. These findings raise the question of whether IL10 associations with severe malaria might be confounded by foetal survival rates or other sources of transmission bias.

Basal cell carcinoma and variants in genes coding for immune response, DNA repair, folate and iron metabolism

Basal cell carcinoma (BCC) is one of the most common neoplasms in the world and its incidence has been increasing worldwide in recent years. BCCs are caused by an interplay between genetic and environment factors. We conducted a case-control association study in BCC patients and controls from Sweden and Finland. Fifteen single nucleotide polymorphisms (SNPs), IL-6-174G/C, -634G/C, and -597G/A; IL-10-1082G/A and -592C/A; IL-1beta-511C/T; NBS1 exon 5 Glu185Gln; XPC exon 15 Lys939Gln; XPD exon 23 Lys751Gln; XRCC1 exon 10 Arg399Gln; XRCC3 exon 7 Thr241Met; cyclin D1 exon 4 G870A; MTHFR exon 4 Ala222Val and exon 7 Glu429Ala; HFE exon 4 C282Y were performed by Pyrosequencing and RFLP techniques. Most of the genotype distributions were in accordance with the Hardy-Weinberg equilibrium (HWE), except for IL-10-1082G/A, where cases with BCC showed a significant deviation from HWE (P = 0.04). Linkage disequilibrium was observed between the -174 and -597 alleles in the IL-6 gene in the present populations. No difference between BCC and controls appeared in any of the SNPs analyzed. Only the combined distributions of TT/AA genotypes in MTHFR exon 4 (C/T) and exon 7 (A/C) showed slight increase in BCC compared to controls (P < 0.07, OR: 1.94; 95% CI: 0.96-3.89).

Cytokine genotypes correlate with pain and radiologically defined joint damage in patients with juvenile rheumatoid arthritis

OBJECTIVES

Single nucleotide polymorphisms (SNPs) in cytokine genes have been associated with risk of a number of autoimmune diseases. Moreover, some SNPs are associated with variations in rates of in vitro gene expression, and it is therefore possible that these functional polymorphisms may differentially affect inflammatory processes and disease outcome. This project's objective was to determine whether cytokine genotypes correlate with disease outcomes in patients with juvenile rheumatoid arthritis (JRA).

METHODS

Genotypes of SNPs of pro-inflammatory cytokines, tumour necrosis factor-alpha -308G -->A, interleukin-6 (IL-6) -174G -->C and interferon-gamma +874G -->A, and anti-inflammatory, immunosuppressive cytokines, interleukin-10 -1082G -->A, -819C -->T and -592A -->C and transforming growth factor-beta1 (TGF-beta1) codon 10T -->C and codon 25G -->C, were determined for patients with JRA who previously participated in a long-term outcome study. Cytokine genotypes and clinical variables showing significant correlations with clinical outcomes at the alpha = 0.100 level in univariate analyses were entered in multivariate tests.

RESULTS

In multivariate tests, the IL-6 genotype -174G/G was positively correlated with pain [regression coefficient B = 0.899, 95% confidence intervals (CI) 0.185, 1.612, P = 0.014]. The homozygous TGF-beta1 codon 25G/G genotype showed a protective effect against joint space narrowing on radiographs taken within 2 yr of disease onset, but confidence intervals were wide [odds ratio (OR) 0.176, 95% CI 0.037, 0.837 P = 0.029].

CONCLUSIONS

The correlation of IL-6 genotype with pain and the possible association of the TGF-beta1 codon 25 genotype with short-term radiographic damage (G/C with greater risk and G/G with decreased risk) suggests that both these polymorphisms may be useful early prognostic indicators. Further studies of the relation between cytokine genotypes and outcomes in patients with all forms of juvenile idiopathic arthritis (JIA) are warranted.

Effect of cytokine genotypes on the hepatitis B virus-hepatocellular carcinoma association

BACKGROUND

In Southern Guangxi, China, chronic infection with the hepatitis B virus (HBV) acquired during the perinatal period from carrier mothers is a primary cause of hepatocellular carcinoma. However, only a minority of HBV carriers eventually develop hepatocellular carcinoma. The authors hypothesized that cytokine genotypes may be important codeterminants of the risk of HBV-related hepatocellular carcinoma.

METHODS

The authors examined the correlation between polymorphisms in T-helper 1 (Th1) and Th2 cytokine genes among a group of 250 patients with incident hepatocellular carcinoma (cases) and a group of 250 hospital controls who were matched individually to the index case by age, gender, ethnicity, residence, and month of hospital admission in the city of Nanning, Guangxi, China.

RESULTS

Relative to the putative high-activity genotypes, each individual low-activity genotype of interferon gamma, interleukin 12 (IL12), and IL18 was associated with a statistically nonsignificant increase (40-60%) in the risk of hepatocellular carcinoma. This risk increased with increasing numbers of low-activity Th1 genotypes after adjusting for potential confounders (2-sided P value for trend=0.04). Conversely, individual Th2 (IL4, IL10) low-activity genotypes were associated with a statistically nonsignificant reduced risk of hepatocellular carcinoma. This risk decreased with increasing number of low-activity Th2 genotypes after adjusting for potential confounders (2-sided P value for trend=0.01). Individuals who had the maximum number (i.e., 3) of low-activity Th1 genes and the minimum number (i.e., 0) of low-activity Th2 genes showed a relative risk of 20.0 (95% confidence interval, 1.7-235.0).

CONCLUSIONS

Diminished cell-mediated immune response, which is controlled genetically, appeared to be an important risk determinant of HBV-related hepatocellular carcinogenesis.

Use of pyrosequencing to detect clinically relevant polymorphisms of genes in basal cell carcinoma

BACKGROUND

Pyrosequencing is a new method to detect single nucleotide polymorphisms (SNPs). Basal cell carcinoma (BCC) is one of the most common neoplasms in the world, and its incidence has been increasing worldwide in recent years. BCC is caused by an interplay between genetic and environment factors.

METHODS

Pyrosequencing and restrict fragment length polymorphism (RFLP) were used in the study. We conducted a case-control association study in BCC cases and controls from Sweden. For SNPs in IL-6, IL-10 and IL-1beta, 241 cases were at the age of 27-70 years (mean 50 years) and 260 healthy controls were 26-71 years (mean 48 years), 241 cases were 27-70 years (mean 50 years) and 574 healthy controls were 22-74 years (mean 52 years) for cyclin D1 G870A, 197 cases were 29-69 years (mean 47 years) and 574 healthy controls were 22-74 years (mean 52 years) for MTHFR C677T and A1298C. Nine SNPs for IL-6-174G/C, -634G/C and -597G/A; IL-10-1082G/A and -592C/A; IL-1beta-511C/T; cyclin D1 G870A; MTHFR C677T and A1298C were analyzed.

RESULTS

Most genotype distributions were in accordance with Hardy-Weinberg equilibrium (HWE), except IL-10-1082G/A, which had a significantly deviation from HWE in BCC cases (P<0.05). Linkage disequilibrium was observed between the -174 and -597 alleles in the IL-6 gene in the studied populations. The differences for cyclin D1 G870A and methylenetetrahydrofolate reductase (MTHFR) C677T were found between BCC cases group and control group (P<0.05, OR=1.34, 95% CI, 1.00-1.74; P<0.05, OR=1.67, 95% CI, 1.13-2.47, respectively).

CONCLUSIONS

Cyclin D1 G870A and MTHFR C677T were associated with BC cases from Sweden, the other SNPs studied here were not associated with BCC, but chance cannot be excluded.

IL-10 gene polymorphisms in infectious disease and SIDS

Interleukin-10 (IL-10) is a regulatory cytokine, and its principal role in vivo is to limit inflammatory response. IL-10 has been shown to influence both the susceptibility and course of various diseases, and the different polymorphisms in the IL-10 gene promoter have been associated with disease prevalence and severity. The genes involved in the immune system are also assumed to be of importance with regard to sudden infant death syndrome (SIDS), and specific haplotypes in the IL-10 gene promoter have been reported associated both with SIDS and sudden unexpected death due to infection.

Single-nucleotide polymorphisms in genes relating to homocysteine metabolism: how applicable are public SNP databases to a typical European population?

To facilitate the association studies in complex diseases characterized by hyperhomocysteinemia, we collected structural and frequency data on single-nucleotide polymorphism (SNPs) in 24 genes relating to homocysteine metabolism. Firstly, we scanned approximately 1.2 Mbp of sequence in the NCBI SNP database (dbSNP) build 110 and we detected 1353 putative SNPs with an average in silico genic density of 1:683. Out of 112 putative SNPs in coding regions (cSNPs), we selected a subset of 42 cSNPs and we assessed the applicability of the NCBI dbSNP to the Czech population - a typical representative of European Caucasians - by determining the frequency of the putative cSNPs experimentally by PCR-RFLP or ARMS-PCR in at least 110 control Czech chromosomes. As only 25 of the 42 analyzed cSNPs met the criterion of >/=1% frequency, the positive predictive value of the NCBI data set for our population reached 60%, which is similar to other studies. The correlation of SNP frequency between Czechs and other Caucasians - obtained from NCBI and/or literature - was stronger (r(2)=0.90 for 20 cSNPs) than between Czechs and general NCBI database entries (r(2)=0.73 for 27 cSNPs). Moreover, frequencies of all 20 putative cSNPs, for which data in Caucasians were available, were congruently below or above the 1% frequency criterion both in Czechs and in other Caucasians. In summary, our study shows that the NCBI dbSNP is a useful tool for selecting cSNPs for genetic studies of hyperhomocysteinemia in European populations, although experimental validation of SNPs should be performed, especially if the cSNP entry lacks any frequency data in Caucasians.

Longitudinal Decline in Lung Function: Evaluation of Interleukin-10 Genetic Polymorphisms in Firefighters

During annual medical monitoring, some firefighters are found to have rates of decline in forced expiratory volume in one second (FEV1) far exceeding their peers. Interleukin-10 (IL-10) suppresses inflammation, and single nucleotide polymorphisms (SNPs) in the IL-10 gene may confer variable susceptibility to more rapid decline in lung function. In 1204 firefighters with at least six annual FEV1 measurements, increased age and greater initial FEV1 were associated with more rapid decline in lung function. DNA collected from 379 of these firefighters was screened for IL-10 SNPs at -1117, -854, 919, 1668, and 1812. A statistically significant difference in decline in lung function was found based on genotyping at the 1668 SNP. Evaluation of gene polymorphisms regulating lung inflammation may help to explain some of the variation in rate of decline in lung function in firefighters.

Comprehensive Analysis of Genetic Polymorphisms in the Interleukin-10 Promoter: Implications for Immune Regulation in Specific Ethnic Populations

The association of interleukin-10 (IL-10) promoter single-nucleotide polymorphisms (SNPs) as risk factors for certain inflammatory diseases, viral infections, cancers, and transplant rejection have been the subject of recent studies. The SNPs -1082 G --> A, -819 C --> T, and -592 C --> A, which have been associated with differential IL-10 production, are strongly linked with ethnicity. In this study, we determined the ethnic distribution of IL-10 promoter SNPs and their haplotype rates among Hispanics, African Americans, and Caucasians from Texas and Ashkenazi Jews from New York. Significant differences in prevalence rates of IL-10 SNPs (and their haplotype distribution) were found. African Americans and Hispanics have a lower rate of putative high-producer SNPs and a higher rate of low IL-10 producers when compared to Caucasians or Ashkenazi Jews. No statistically significant differences in allelic frequencies and haplotype rates were observed between Caucasians and Ashkenazi Jews. This study provides critical new information on the ethnic distribution of IL-10 promoter SNPs in a regional U. S. population and is the first to analyze the rate of SNPs in an unstudied ethnic population, Ashkenazi Jews. Knowledge of IL-10 promoter polymorphisms may prove useful in prediction of immunization responses, disease severity, and in the intelligent design of customized immunotherapy.

Association study of Notch 4 polymorphisms with Alzheimer's disease

BACKGROUND

The NOTCH4 gene is located at 6p21.3, a site shown in several studies to have significant linkage with Alzheimer's disease.

OBJECTIVE

To investigate the potential impact of two polymorphisms within this gene on the risk of developing Alzheimer's disease.

METHODS

Genotyping of promoter and 5'-UTR polymorphisms was done in Scottish, English, and French populations. The potential functionality of the 5'-UTR polymorphism was assessed by testing its impact on A beta load in Alzheimer brains and also by undertaking electrophoretic mobility shift assays and transfection experiments.

RESULTS

No association of the Notch4 polymorphisms alone with the disease was observed in any of the populations. However, an interaction of the 5'-UTR C/T polymorphism with the epsilon 4 allele of the APOE gene was detected in United Kingdom populations but not in the French. No relation between the 5'-UTR polymorphism and A beta loads was detected overall or in the presence or absence of the epsilon 4 allele. No DNA protein specific binding was found with proteins from neuroblastoma, glioma, or astrocytoma cells, and no allele dependent transcriptional activity was detected.

CONCLUSIONS

No association between two NOTCH4 polymorphisms alone and Alzheimer's disease was observed in the three populations, but there was evidence of an increased risk associated with the 5'-UTR CC genotype in epsilon 4 bearers in the United Kingdom. As no functionality for this polymorphism could be determined, it is likely that the interaction is spurious or results from a linkage disequilibrium of this 5'-UTR polymorphism with another marker elsewhere in the 6p21.3 locus.

IL10 gene polymorphisms are associated with asthma phenotypes in children

IL10 is an anti-inflammatory cytokine that has been found to have lower production in macrophages and mononuclear cells from asthmatics. Since reduced IL10 levels may influence the severity of asthma phenotypes, we examined IL10 single-nucleotide polymorphisms (SNPs) for association with asthma severity and allergy phenotypes as quantitative traits. Utilizing DNA samples from 518 Caucasian asthmatic children from the Childhood Asthma Management Program (CAMP) and their parents, we genotyped six IL10 SNPs: 3 in the promoter, 2 in introns, and one in the 3' UTR. Using family-based association tests, each SNP was tested for association with asthma and allergy phenotypes individually. Population-based association analysis was performed with each SNP locus, the promoter haplotypes and the 6-loci haplotypes. The 3' UTR SNP was significantly associated with FEV(1) as a percent of predicted (FEV(1)PP) (P=0.0002) in both the family and population analyses. The promoter haplotype GCC was positively associated with IgE levels and FEV(1)PP (P=0.007 and 0.012, respectively). The promoter haplotype ATA was negatively associated with lnPC(20) and FEV(1)PP (P=0.008 and 0.043, respectively). Polymorphisms in IL10 are associated with asthma phenotypes in this cohort. Further studies of variation in the IL10 gene may help elucidate the mechanism of asthma development in children.