Interleukin 6 gene promoter polymorphism is not associated with Kawasaki disease

Association between rs1800795 polymorphisms in the interleukin-6 gene and vasculitis: A meta-analysis

Interleukin (IL)-6 is associated with the development and progression of vasculitis, and inhibitors of this cytokine are used to treat this disease. Polymorphisms of the promoter region of IL-6 are associated with the production and expression of IL-6. The aim of this study was to perform a meta-analysis of eligible studies to derive a precise estimate of the association between IL6 polymorphisms and susceptibility to vasculitis. A meta-analysis was conducted to identify the associations between IL6 rs1800795 (-174 G/C) polymorphisms and vasculitis. A total of 13 studies involving 1,294 vasculitis patients and 1,594 controls were considered in the meta-analysis. There were significant associations between IL6 rs1800795 polymorphisms and vasculitis in allele contrast, dominant genetic model, and heterozygote vs. dominant homozygote comparison (OR 0.80, 95% CI 0.67-0.94, P =0.009 and OR 0.76, 95% CI 0.63-0.92, P =0.005, respectively). In subgroup analysis based on subtype, there were significant associations between IL6 polymorphisms and susceptibility in large and medium vessel vasculitis, but not in small and variable vessel vasculitis. The GC genotype of IL6 rs1800795 was suggested by the analyses to be related to low prevalence of vasculitis, especially for large and medium vessels.

The IL-1B Gene Polymorphisms rs16944 and rs1143627 Contribute to an Increased Risk of Coronary Artery Lesions in Southern Chinese Children with Kawasaki Disease

Background

Kawasaki disease (KD) is a systemic form of self-limited vasculitis in children less than five years old, and the main complication is coronary artery injury. However, the etiology of KD remains unclear. The IL-1B polymorphisms rs16944 GG and rs1143627 AA and their diplotype GA/GA have been associated with significantly increased risk of intravenous immunoglobulin (IVIG) resistance in a Taiwanese population, but the relationship between rs16944 A/G and rs1143627 G/A and coronary artery lesions (CALs) in patients with KD has not been investigated. The present study is aimed at investigating whether the rs16944 A/G and rs1143627 G/A polymorphisms in IL-1B were associated with KD susceptibility and CALs in a southern Chinese population.

Methods and Results

We recruited 719 patients with KD and 1401 healthy children. Multiplex PCR was used to assess the genotypes of single nucleotide polymorphisms (SNPs), including two SNPs of IL-1B, rs16944 A/G and rs1143627 G/A. According to the results, no significant association was observed between the IL-1B (rs16944 and rs1143627) polymorphisms and KD risk in the patients compared with the healthy controls in our southern Chinese population. However, in further stratified analysis, we found that children younger than 12 months with the rs16944 GG and rs1143627 AA genotypes of IL-1B had a higher risk of CALs than those with the AA/AG genotypes of rs16944 and GG/AG genotypes of rs1143627 (OR = 2.28, 95% CI = 1.32-3.95, P = 0.0032, adjusted OR = 2.33, 95% CI = 1.34-4.04, P = 0.0027).

Conclusions

Our results indicated that there was no association between the rs16944 A/G and rs1143627 G/A gene polymorphisms and KD susceptibility. However, the rs16944 GG and rs1143627 AA genotypes of IL-1B may significantly impact the risk of CAL formation in children younger than 12 months, which may contribute to the pathogenesis of KD. These findings need further validation in multicenter studies with larger sample sizes.

The role of infection in Kawasaki syndrome

Objectives

To analyse the evidence suggesting a possible infectious origin of Kawasaki syndrome (KS).

Methods

PubMed was searched for all of the studies published over the last 15 years using the key words “Kawasaki syndrome” or “mucocutaneous lymph node syndrome” and “infectious disease” or “genetics” or “vasculitis” or “pathogenesis”.

Results

Various levels of evidence support the hypothesis that KS is a complex disease triggered by an infection due to one or more pathogens. Viruses or bacteria may be the primum movens, although no specific infectious agent can be considered definitely etiological. A number of genetic polymorphisms have been identified in subjects with KS, but none of them can currently be considered a real marker of susceptibility.

Conclusions

Various data suggest that KS is intimately related to infectious diseases and that its clinical expression is influenced by predisposing genetic backgrounds, but our knowledge of the infectious agent(s) involved and the genetic characteristics of susceptible children remains only partial. Further studies are needed to address the many still open questions concerning the disease.

Interleukin-6 (-636 c/g) gene polymorphism in korean children with kawasaki disease

Background and Objectives

Kawasaki disease (KD) is a multi-systemic vasculitis with coronary artery involvement. Serum interleukin (IL)-6 levels during acute phase showed a significant correlation with the duration of fever in patients with KD who were not treated with intravenous immunoglobulin (IVIG), suggesting that the regulation of IL-6 expression in KD patients may differ from that in normal children. However, there are controversies surrounding the association between IL-6 (-636 C/G) gene polymorphism and development of KD.

Subjects and Methods

One hundred and nine children with KD and 191 children with congenital heart disease were included in this study. Echocardiography was performed to examine cardiac involvement in patients with KD. Genotyping of the IL-6 (-636 C/G) gene polymorphism was performed using the single-base extension method, and serum IL-6 concentrations were estimated using the sandwich enzyme immunoassay method.

Results

Neutrophil, platelet count, liver function test, total protein and albumin concentrations were significantly different in the KD group and the serum IL-6 concentration was significantly higher in the KD group than the control group. There was no difference between the patients with coronary arterial dilatation (CAD) and those without CAD in the IL-6 (-636 C/G) polymorphism. The serum albumin concentration was significantly lower in patients with KD who had the -636 C/G or GG genotype compared with the control group. The serum IL-6 concentration was significantly higher in patients with KD who had the -636 C/G or GG genotype.

Conclusion

There was no association between the IL-6 (-636 C/G) gene polymorphism and development of coronary arterial lesions in KD. Further multicenter studies are required to establish the relationship between the IL-6 (-636 C/G) gene polymorphism and development of KD.

Kawasaki disease: update on pathogenesis

PURPOSE OF REVIEW

This review will highlight recent advances in our understanding of the pathogenesis of Kawasaki disease, highlighting the molecular players involved in regulation of T-cell activation and their affect on disease incidence and outcome in both humans and mouse.

RECENT FINDINGS

Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The vessels most commonly damaged are the coronary arteries, making Kawasaki disease the number one cause of acquired heart disease in children from the developed world. The contribution of genetics to disease predisposition is clearly implicated, but the mechanisms involved in regulating predisposition to disease susceptibility and outcome are not clearly understood. Two independent approaches have recently identified regulation of T-cell activation as the critical factor in determining susceptibility and severity of Kawasaki disease. Firstly, genetic analysis of affected Japanese children identified ITPKC, 1,4,5-triphosphate 3-kinase C, a kinase involved in regulation of T-cell activation, to be significantly associated with susceptibility to and increased severity of Kawasaki disease. A second independent approach using an animal model of Kawasaki disease has also identified regulation of T-cell activation, specifically costimulation, the second signal regulating optimal T-cell activation as the critical regulator of susceptibility to and severity of disease.

SUMMARY

Understanding the molecular players responsible for dysregulation of the immune response in Kawasaki disease will foster development of improved diagnostic/predictive tools and more rational use of therapeutic agents to improve outcome in affected children.

Cytokine genetic polymorphisms and susceptibility to Kawasaki disease in Taiwanese children

BACKGROUND

The relationship between cytokine gene polymorphisms and susceptibility to Kawasaki diseases (KD) is still controversial, so the aim of the present study was to investigate the association of 14 various polymorphisms of 9 cytokine genes (interleukin (IL)-1A, IL-1B, IL-1RN, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor-A and transforming growth factor-B) with KD risk.

METHODS AND RESULTS

A total of 211 KD children and 221 adult controls were recruited. All controls were frequency matched to KD patients on sex and ethnicity. PCR and TaqMan assays were used for genotyping. There were no significant differences between KD children and adult controls in the genotype or allelic type frequencies of the 14 polymorphisms. No significant associations were found between haplotypes, constructed by IL-1B, IL-4, IL-8, and IL-10 cytokine genes, and risk of KD. Additionally, a linear trend was observed when these single nucleotide polymorphisms were combined, as evidenced by an increasing risk of KD as the number of at-risk genotypes increased (P(linear trend)=0.002). In the stratification analysis of age and sex, there was a linear trend of KD risk as the number of at-risk genotypes increased among those aged >12 months (P=0.014) or female (P=0.001), respectively.

CONCLUSIONS

No associations between individual cytokine genetic polymorphisms and susceptibility of KD were observed, but a gene-dosage effect on the risk of KD was found, especially for older or female subjects.

Molecular genetics of Kawasaki disease

Kawasaki disease (KD) is a leading cause of acquired cardiac disease of children in the developed countries. The pathogen that triggers this perplexing disease is still unknown after 40 y from the first description. Epidemiologic findings have made us believe that there are considerable genetic components in the etiology and some candidate genetic variations, which confer susceptibility to KD or risk for coronary artery lesions have been identified. However, most of them remain to be definitively confirmed by replication studies with large cohorts. In this article, I review the candidate gene association studies to date. I also introduce our recent findings in genome-wide approach, which revealed the importance of Ca2+/nuclear factor of activated T-cells pathway in the pathogenesis of KD.

Genetic Variations of HLA-DRB1 and Susceptibility to Kawasaki Disease in Taiwanese Children

Although some previous studies have reported that genetic and immunologic factors play important roles in the pathogenesis of Kawasaki disease (KD), the etiologic factors of this enigmatic pediatric disease are still poorly understood. The purpose of this study was to investigate whether polymorphisms of the human leukocyte antigen DRB1 (HLA-DRB1) gene are associated with KD and the development of coronary artery lesions (CAL) in Taiwanese children. Genomic DNA was extracted from whole blood samples from 145 children with KD and 331 healthy controls. The HLA-DRB1 gene was genotyped by polymerase chain reaction (PCR) and sequence-based typing assays. We found that the distribution of HLA-DRB1 allele families and alleles in children with KD did not differ from that in healthy controls. Stratified analysis did not demonstrate any association between particular HLA-DRB1 allele families or alleles and the development of CAL in children with KD. These findings suggest that susceptibility to KD and CAL is not associated with the HLA-DRB1 gene in a Taiwanese population. If immunogenetic determinants are involved in this disease and its complications in Taiwanese children, they must involve genes other than HLA-DRB1.

Kawasaki disease

Kawasaki disease is an acute febrile, systemic vasculitic syndrome of an unknown etiology that primarily occurs in children younger than five years of age. The principal presentations of Kawasaki disease include fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develops in 15% to 25% of untreated children with the disease, which may later lead to myocardial infarction, sudden death, or ischemic heart disease. Treatment with intravenous gamma globulin (IVIG) is effective, but the mode of action is still unclear. The development of a diagnostic test, a more specific therapy, and ultimately the prevention of this potentially fatal illness in children are all dependent upon the continued advances in determining the etiopathogenesis of this fascinating disorder.

Kawasaki syndrome

Kawasaki syndrome is an acute, self-limited vasculitis that occurs in children of all ages and presents a challenge for the clinician: the disorder can be difficult to recognise; there is no diagnostic laboratory test; there is an extremely effective therapy; and there is a 25% chance of serious cardiovascular damage if the treatment is not given early in the course of the disease. This review includes discussion of the history of the syndrome, the diagnostic challenges, epidemiology, aetiology, pathology, immunopathogenesis, therapy, genetic influences, and the long-term cardiovascular sequelae.

Epidemiology of the vasculitides

The past year has seen some notable publications in the field of vasculitis epidemiology. The appearance of reports from several different parts of the world has permitted comparisons to be made. In Europe, Wegener granulomatosis appears to be more common at high latitudes, whereas microscopic polyangiitis shows the reverse pattern. Kawasaki disease is most common in Japan. In China, the United States, and the United Kingdom, the incidence is lower, but the incidence appears to be increasing globally. Studies of infectious triggers continue to be disappointingly negative. Immunogenetic associations with cytokine polymorphisms are beginning to be reported.