Polymorphism of matrix metalloproteinase-3 promoter gene as a risk factor for coronary artery lesions in Kawasaki disease

Bioinformatic analysis of underlying mechanisms of Kawasaki disease via Weighted Gene Correlation Network Analysis (WGCNA) and the Least Absolute Shrinkage and Selection Operator method (LASSO) regression model

BACKGROUND

Kawasaki disease (KD) is a febrile systemic vasculitis involvingchildren younger than five years old. However, the specific biomarkers and precise mechanisms of this disease are not fully understood, which can delay the best treatment time, hence, this study aimed to detect the potential biomarkers and pathophysiological process of KD through bioinformatic analysis.

METHODS

The Gene Expression Omnibus database (GEO) was the source of the RNA sequencing data from KD patients. Differential expressed genes (DEGs) were screened between KD patients and healthy controls (HCs) with the "limma" R package. Weighted gene correlation network analysis (WGCNA) was performed to discover the most corresponding module and hub genes of KD. The node genes were obtained by the combination of the least absolute shrinkage and selection operator (LASSO) regression model with the top 5 genes from five algorithms in CytoHubba, which were further validated with the receiver operating characteristic curve (ROC curve). CIBERSORTx was employed to discover the constitution of immune cells in KDs and HCs. Functional enrichment analysis was performed to understand the biological implications of the modular genes. Finally, competing endogenous RNAs (ceRNA) networks of node genes were predicted using online databases.

RESULTS

A total of 267 DEGs were analyzed between 153 KD patients and 92 HCs in the training set, spanning two modules according to WGCNA. The turquoise module was identified as the hub module, which was mainly enriched in cell activation involved in immune response, myeloid leukocyte activation, myeloid leukocyte mediated immunity, secretion and leukocyte mediated immunity biological processes; included type II diabetes mellitus, nicotinate and nicotinamide metabolism, O-glycan biosynthesis, glycerolipid and glutathione metabolism pathways. The node genes included ADM, ALPL, HK3, MMP9 and S100A12, and there was good performance in the validation studies. Immune cell infiltration analysis revealed that gamma delta T cells, monocytes, M0 macrophage, activated dendritic cells, activated mast cells and neutrophils were elevated in KD patients. Regarding the ceRNA networks, three intact networks were constructed: NEAT1/NORAD/XIST-hsa-miR-524-5p-ADM, NEAT1/NORAD/XIST-hsa-miR-204-5p-ALPL, NEAT1/NORAD/XIST-hsa-miR-524-5p/hsa-miR-204-5p-MMP9.

CONCLUSION

To conclude, the five-gene signature and three ceRNA networks constructed in our study are of great value in the early diagnosis of KD and might help to elucidate our understanding of KD at the RNA regulatory level.

Insights Into Coronary Artery Lesions in Kawasaki Disease

This review summarizes recent advances in understanding the development of coronary arteritis in Kawasaki disease. Kawasaki disease is the most common cause of acquired heart disease among children characterized with coronary artery abnormalities, which can cause myocardial ischemia, infarction, and even death. The pathogenic factors of Kawasaki disease and the pathological process of coronary artery disease are not clear at present, which brings challenges to the prevention and treatment of the disease. The treatment of Kawasaki disease focuses mainly on timely administration of intravenous high doses of immunoglobulin and aspirin. However, there are still some patients who do not respond well to this standard treatment, and its management remains a challenge. As a result, coronary artery lesions still occur in patients and affect their quality of life. In this review, we discuss updated research data of Kawasaki disease coronary artery lesions.

Lymphocyte hydrogen sulfide production predicts intravenous immunoglobulin resistance in children with Kawasaki disease: A preliminary, single-center, case-control study

The aim of the study was to identify whether lymphocyte hydrogen sulfide production is a potential biomarker to predict intravenous immunoglobulin (IVIG) resistance in children with Kawasaki disease (KD).This preliminary, single-center, case-control study conducted between June 2016 and March 2018 in Shaanxi Provincial People's Hospital, 85 children (50 with KD and 35 healthy controls) were included. Laboratory biomarkers were collected from the medical records. All patients with KD received 1 g/kg/d IVIG for 2 days and 30-50 mg/kg/d oral aspirin. The aspirin dose was reduced from 3 to 5 mg/kg/d after body temperature normalized. Plasma hydrogen sulfide levels were detected using sulfide electrode. Lymphocyte hydrogen sulfide levels were detected using the human hydrogen sulfide ELISA kits at the acute stage.Of 50 patients with KD, 31 and 19 were diagnosed with complete KD (cKD) and incomplete KD (iKD), respectively. Eleven patients with KD were resistant to IVIG treatment. The laboratory biomarker findings and levels of plasma and lymphocyte hydrogen sulfide were significantly different between the patients with KD and control group (P < .001). Moreover, lymphocyte hydrogen sulfide production was significantly greater in IVIG-resistant patients than in the IVIG-responsive patients, both in cKD and iKD (P = .018 and P < .001 respectively). Receiver operating characteristic curve indicated that when the lymphocyte hydrogen sulfide production was >15.285 nmol/min/10 lymphocytes, the sensitivity and specificity for predicting IVIG resistance were 90.9% and 76.9%, respectively.Lymphocyte hydrogen sulfide production could serve as a predictor of the therapeutic efficacy of IVIG in children with KD.

Thrombospondin-2 predicts response to treatment with intravenous immunoglobulin in children with Kawasaki disease

OBJECTIVE

To investigate the predictive value of thrombospondin-2 (TSP-2) in assessing the response to intravenous immunoglobulin (IVIG) in children with acute Kawasaki disease (KD).

METHODS

This was a cohort study with controls. 71 children with KD were recruited as the case group, including IVIG non-responder (n=17) and IVIG responder (n=54), and healthy children (n=27) and febrile children (n=30) were used as control groups. ELISA was used to measure plasma TSP-2 and TSP-1 levels. The rank-sum test was used to compare groups of non-normally distributed data. Predictive value was evaluated through the receiver operating characteristic (ROC) curve.

RESULTS

Compared with the control groups, the plasma TSP-2 levels in acute KD were significantly elevated (TSP-2: 31.00 (24.02, 39.28) vs 21.93 (17.00, 24.73) vs 16.23 (14.00, 19.64) ng/mL, P<0.001). The plasma TSP-2 level in the IVIG non-responder was significantly higher than the responder group (37.58 (31.86, 43.98) vs 27.84 (21.88, 33.48) ng/mL, P=0.002). When using an ROC curve to analyse the predictive effect of TSP-2 on non-responsiveness to IVIG treatment, the area under the curve was 0.752 (0.630, 0.875) (P=0.002). When the cut-off value for TSP-2 was 31.50 ng/mL, the sensitivity was 82.35%, the specificity was 64.81%.

CONCLUSION

The plasma TSP-2 level was elevated in acute KD and it might be a novel predictor for IVIG resistance, which could help guide clinicians to choose individualised initial therapeutic regimens.

Transcriptional regulation by infliximab therapy in Kawasaki disease patients with immunoglobulin resistance

BACKGROUND

Infliximab (IFX), a known monoclonal antibody against tumor necrosis factor-α (TNF-α), is used to treat Kawasaki disease (KD) patients with intravenous immunoglobulin (IVIG) resistance. The transcriptional modulation of inflammation following IFX therapy has not been reported in KD patients.

METHODS

We investigated the transcript abundance profiles in whole blood obtained from eight IVIG-resistant KD subjects treated with IFX therapy using microarray platforms and compared them with those in initially IVIG-responsive subjects. A pathway analysis was performed using WikiPathways to search for the biological pathways of the transcript profiles. Four transcripts changed by IFX therapy were subsequently validated using quantitative real-time polymerase chain reaction.

RESULTS

The pathway analysis showed the reduced abundance of transcripts in the nucleotide-binding oligomerization domain, matrix metalloproteinase (MMP), and inflammatory cytokine pathways and the increased abundance of transcripts in the T-cell receptor, apoptosis, TGF-β, and interleukin-2 pathways. Additionally, the levels of four transcripts (peptidase inhibitor-3, MMP-8, chemokine receptor-2, and pentraxin-3) related to KD vasculitis and IVIG resistance decreased after IFX therapy.

CONCLUSION

The administration of IFX was associated with both the signaling pathways of KD inflammation and several transcripts related to IVIG resistance factors. These findings provide strong theoretical support for the use of IFX in KD patients with IVIG resistance.

Update on Kawasaki disease: epidemiology, aetiology and pathogenesis

Kawasaki disease is an acute systemic vasculitis predominantly affecting young children. It is due to an abnormal host response to as yet unidentified infectious trigger(s). Kawasaki disease may cause coronary artery damage, long-term cardiovascular morbidity and occasionally mortality, especially if the diagnosis is missed or timely treatment is not given. This is the first of two updates on Kawasaki disease. Here we review recent advances in epidemiology, possible aetiologies, host susceptibility and pathogenesis of this fascinating condition.

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.

Understanding the pathogenesis of Kawasaki disease by network and pathway analysis

Kawasaki disease (KD) is a complex disease, leading to the damage of multisystems. The pathogen that triggers this sophisticated disease is still unknown since it was first reported in 1967. To increase our knowledge on the effects of genes in KD, we extracted statistically significant genes so far associated with this mysterious illness from candidate gene studies and genome-wide association studies. These genes contributed to susceptibility to KD, coronary artery lesions, resistance to initial IVIG treatment, incomplete KD, and so on. Gene ontology category and pathways were analyzed for relationships among these statistically significant genes. These genes were represented in a variety of functional categories, including immune response, inflammatory response, and cellular calcium ion homeostasis. They were mainly enriched in the pathway of immune response. We further highlighted the compelling immune pathway of NF-AT signal and leukocyte interactions combined with another transcription factor NF- κ B in the pathogenesis of KD. STRING analysis, a network analysis focusing on protein interactions, validated close contact between these genes and implied the importance of this pathway. This data will contribute to understanding pathogenesis of KD.

The Molecular Biology and Treatment of Systemic Vasculitis in Children

Primary systemic vasculitides are rare in childhood but are associated with significant morbidity and mortality. The cause of the majority of vasculitides is unknown, although it is likely that a complex interaction between environmental factors, such as infections and inherited host responses, triggers the disease and determines the vasculitis phenotype. Several genetic polymorphisms in vasculitides have now been described, which may be relevant in terms of disease predisposition or development of disease complications. Treatment regimens continue to improve with the use of different immunosuppressive medications and newer therapeutic approaches such as biologic agents. This chapter reviews recent studies shedding light on the pathogenesis of vasculitis with emphasis on molecular biology where known, and summarizes current treatment strategies. We discuss new emerging challenges particularly with respect to the long-term cardiovascular morbidity for children with systemic vasculitis and emphasize the importance of future international multicenter collaborative studies to further increase and standardize the scientific base investigating and treating childhood vasculitis.

Circulating markers of vascular injury and angiogenesis in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

To identify biomarkers that distinguish between active antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and remission in a manner superior or complementary to established markers of systemic inflammation.

METHODS

Markers of vascular injury and angiogenesis were measured before and after treatment in a large clinical trial in AAV: 163 subjects enrolled in the Rituximab in ANCA-Associated Vasculitis trial were screened for the present study. Serum levels of E-selectin, intercellular adhesion molecule 3 matrix metalloproteinase protein 1 (MMP-1), MMP-3, MMP-9, P-selectin, thrombomodulin, and vascular endothelial growth factor were measured at study screening (time of active disease) and at month 6. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels had been measured at the time of the clinical visit. The primary outcome measure was the difference in marker level between screening and month 6 among patients whose disease was in remission (Birmingham Vasculitis Activity Score for Wegener's granulomatosis [BVAS/WG] score of 0) at month 6.

RESULTS

All patients had severe active vasculitis at screening (mean ± SD BVAS/WG score 8.6 ± 3.2). Among the 123 patients whose disease was clinically in remission at month 6, levels of all markers except E-selectin showed significant declines. MMP-3 levels were also higher among the 23 patients with active disease at month 6 than among the 123 patients whose disease was in remission. MMP-3 levels correlated weakly with ESR and CRP levels.

CONCLUSION

Many markers of vascular injury and angiogenesis are elevated in severe active AAV and decline with treatment, but MMP-3 appears to distinguish active AAV from remission better than the other markers studied. Further study of MMP-3 is warranted to determine its clinical utility in combination with conventional markers of inflammation and ANCA titers.

Genetic polymorphisms in Kawasaki disease

Kawasaki disease (KD) is an acute febrile systemic vasculitis, and the cause of KD is not well understood. It is likely due to multiple interactions between genes and environmental factors. The development of genetic association and genome-wide association studies (GWAS) has opened an avenue to better understanding the molecular mechanisms underlying KD. A novel ITPKC signaling pathway was recently found to be responsible for the susceptibility to KD. Furthermore, the GWAS demonstrated the functionally related susceptibility loci for KD in the Caucasian population. In the last decade, the identification of several genomic regions linked to the pathogenesis of KD has made a major breakthrough in understanding the genetics of KD. This review will focus on genetic polymorphisms associated with KD and describe some of the possible clinical implications and molecular mechanisms that can be used to explain how genetic variants regulate the pathogenesis in 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.

Matrix metalloproteinase haplotypes associated with coronary artery aneurysm formation in patients with Kawasaki disease

Aneurysms of the vascular wall represent a final common pathway for a number of inflammatory processes including atherosclerosis and idiopathic vasculitis syndromes. Kawasaki disease is an acute, self-limited vasculitis in children and the leading cause of acquired coronary artery aneurysms. We sought to identify shared molecular mechanisms of aneurysm formation by genotyping 8 polymorphisms in MMP-1, 3, 7, 12 and 13 in the gene cluster on Chr.11q22 whose gene products have been implicated in aneurysm formation or are known to have elastase activity. We genotyped 482 US-UK Kawasaki disease patients (aneurysm+: n=111, aneurysm−: n=371) and tested our findings in an independent cohort of 200 Japanese Kawasaki disease patients (aneurysm+: n=58, aneurysm−: n=142). Analysis of the five MMP genes identified modest trends in allele and genotype frequencies for MMP-3 rs3025058 (−/T) and haplotypes containing MMP-3 rs3025058 (−/T) and MMP-12 rs2276109 (A/G) (nominal p= 2-4 × 10⁻⁵) that conferred increased risk of aneurysm formation in US-UK subjects. This finding was validated in Japanese subjects and suggests the importance of this locus in aneurysm formation in children with Kawasaki disease. The region encompassing these risk haplotypes is a prime candidate for re-sequencing to look for rare genetic variation that may influence aneurysm formation.

Association of CCR2-CCR5 haplotypes and CCL3L1 copy number with Kawasaki Disease, coronary artery lesions, and IVIG responses in Japanese children

Background

The etiology of Kawasaki Disease (KD) is enigmatic, although an infectious cause is suspected. Polymorphisms in CC chemokine receptor 5 (CCR5) and/or its potent ligand CCL3L1 influence KD susceptibility in US, European and Korean populations. However, the influence of these variations on KD susceptibility, coronary artery lesions (CAL) and response to intravenous immunoglobulin (IVIG) in Japanese children, who have the highest incidence of KD, is unknown.

Methodology/Principal Findings

We used unconditional logistic regression analyses to determine the associations of the copy number of the CCL3L1 gene-containing duplication and CCR2-CCR5 haplotypes in 133 Japanese KD cases [33 with CAL and 25 with resistance to IVIG] and 312 Japanese controls without a history of KD. We observed that the deviation from the population average of four CCL3L1 copies (i.e., < or > four copies) was associated with an increased risk of KD and IVIG resistance (adjusted odds ratio (OR)  = 2.25, p = 0.004 and OR = 6.26, p = 0.089, respectively). Heterozygosity for the CCR5 HHF*2 haplotype was associated with a reduced risk of both IVIG resistance (OR = 0.21, p = 0.026) and CAL development (OR = 0.44, p = 0.071).

Conclusions/Significance

The CCL3L1-CCR5 axis may play an important role in KD pathogenesis. In addition to clinical and laboratory parameters, genetic markers may also predict risk of CAL and resistance to IVIG.

IL-10 polymorphisms are associated with coronary artery lesions in acute stage of Kawasaki disease

BACKGROUND

The literature regarding interleukin (IL)-10 polymorphisms and coronary artery lesions (CALs) in Kawasaki disease (KD) is limited. We investigated whether 3 IL-10 genetic polymorphisms (-1082 A/G, -819 T/C, and -592 A/C) are associated with development of CALs in KD.

METHODS AND RESULTS

The genotyping of IL-10 polymorphisms was conducted for 279 KD children (172 without and 107 with CALs in acute stage). Thirty-three patients had CALs in chronic stage and 74 only with transient CALs. The homozygous variant genotype CC of IL-10-819 and IL-10-592 was associated with 80% (P=0.006) and 79% (P=0.008) reduction in risk of CALs in acute stage, respectively. The C allele of IL-10-819 and IL-10-592 was associated with 34% (P=0.034) and 33% (P=0.044) reduction in risk of CALs in acute stage, respectively. Compared with ATA haplotype (adjusted odds ratio (AOR) 0.63, P=0.029) or non-ACC haplotype (AOR 0.64, P=0.033), ACC haplotype was associated with a significantly reduced risk for CALs in acute stage, but not for CALs in chronic stage. Compared with non-ATA haplotype (AOR 1.53, P=0.034), ATA haplotype was associated with a significantly increased risk of CALs, except for CALs in the chronic stage.

CONCLUSIONS

The effects of IL-10 gene polymorphism on CALs in acute KD are important. The persistence of CALs in chronic stage depends much more on other factors such as the times of intravenous immunoglobulin treatment.

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.

Promoter polymorphism (rs3755724, -55C/T) of tissue inhibitor of metalloproteinase 4 (TIMP4) as a risk factor for Kawasaki disease with coronary artery lesions in a Korean population

Kawasaki disease (KD) is an acute febrile vasculitis that predominantly affects infants and young children. Tissue inhibitors of matrix metalloproteinases (TIMPs) comprise a family of four members, of which TIMP4 is characterized by its restriction to cardiovascular structures. In KD pathophysiology, TIMP4 is considered to be involved in the development of coronary artery lesions (CALs). Therefore, this study investigated single-nucleotide polymorphisms (SNPs) of the TIMP4 gene as risk factors for KD with CALs in Korean children. To observe this association, two SNPs (rs3755724, -55C/T, promoter; rs17035945, 3'-untranslated region) were genotyped in TIMP4 using direct sequencing. There were no SNPs in the coding region of TIMP4, and two SNPs were selected in the exon and promoter regions. This study recruited 250 control and 101 KD subjects. For data analysis, SNPStats, SNPAnalyzer, and Helixtree programs were used. These SNPs were not associated with KD. However, in the recessive model, a significant association was found between rs3755724 and the development of CALs in KD (P = 0.02; odds ratio, 0.31; 95% confidence interval, 0.11-0.85). The minor allele (C) of rs3755724 showed the susceptibility of CALs to risk in KD patients. These results suggest that TIMP4 is related to the development of KD with CALs in Korean children.

Association of the matrix metalloproteinase-3 (-439C/G) promoter polymorphism with Kawasaki disease in Korean children

Kawasaki disease (KD) is a multisystemic vasculitis that often includes coronary artery involvement. The serum levels of matrix metalloproteinase (MMP)-3 and -9 are significantly elevated in KD patients, and polymorphisms in the genes encoding MMP-3 and MMP-9 have been associated with the susceptibility, severity, and progression of atherosclerosis and aneurysm. However, the association between MMP-3 gene polymorphisms and development of aneurysm is somewhat controversial in a number of diseases. Ninety-seven children with KD and 194 children with congenital heart disease (CHD) were included in this study. Echocardiography was used to examine all children in the KD group for coronary artery aneurysm. Genotyping of the MMP-3 (-439C/G) promoter polymorphism was performed using the single-base extension method, and serum MMP-3 levels were estimated using the sandwich enzyme immunoassay method. There was no significant difference in MMP-3 (-439C/G) genotypes between KD and control groups. There was no association between this MMP-3 polymorphism and development of coronary aneurysm in KD. Serum MMP-3 levels were significantly higher in KD patients compared to control subjects. Among the KD patients, serum MMP-3 levels were higher in children with genotypes CG+GG compared to the CC group, but this difference was not significant. Although further large-scale studies will be required to fully examine the relationship between MMP-3 gene polymorphisms and coronary artery lesions (CAL) in KD, the present findings suggest that while MMP-3 may play a role in the pathogenesis of KD, there is no apparent association between CAL and the MMP-3 (-439C/G) gene polymorphism in Korean children with KD.

Matrix metalloproteinase (MMP)-3 polymorphism in patients with HBV related chronic liver disease

A common and important problem in patients with chronic hepatitis B is the progression of liver fibrosis. Matrix metalloproteinases (MMPs) play an important role in the progression of liver fibrosis. Our aim of this study was to examine the association of MMP-3 polymorphism with liver cirrhosis in Korean patients with chronic hepatitis B. Genomic DNA was extracted from 127 patients with chronic hepatitis B (CHB), 92 patients with hepatitis B virus (HBV)-related liver cirrhosis (HBV-LC), and 146 healthy subjects. MMP-3 polymorphism was determined by polymerase-chain reaction-based assays, and the association with the progression of liver cirrhosis was investigated. With regard to MMP-3 polymorphism, there was no statistical difference in genotype distributions among the three groups. However, the peripheral platelet count of the 5A carriers was significantly lower than that of the 6A homozygotes in the HBV-LV group (85.0 +/- 36.9 vs. 109.8 +/- 47.0 x 10(9)/l; P = 0.02). With MMP-3 promoter polymorphism (rs3025058), a lower peripheral blood platelet count, which was related to advanced liver cirrhosis, was observed in 5A carriers. Therefore, more studies of MMP-3 gene polymorphism with larger populations should be conducted to further understand its role in the progression of liver cirrhosis.

Genetic analysis of MMP gene polymorphisms in patients with Kawasaki disease

Kawasaki disease (KD) is an acute febrile disorder characterized by systemic vasculitis primarily occurring in coronary arteries. Matrix metalloproteinases (MMPs) have been considered to play pathophysiologic roles in the development of coronary artery lesions (CALs); therefore, an evaluation of the genetic contributions of the MMP genes to the development of CALs in KD patients would be beneficial for the prediction of CAL formation. We focused on the known functional single nucleotide polymorphisms (SNPs) in the MMP genes (MMP-2-735C>T, MMP-3-1612 5A/6A, MMP-9-1562C>T, MMP-12-82A>G, and MMP-13-77A>G) and performed the association study between these SNPs and CAL formation in KD. The study population consisted of 44 KD patients with CALs and 92 without CALs and 175 healthy controls. As a result, allele and genotype frequencies of MMP-13-77A>G showed significant differences between KD patients with CALs and without CALs (p = 0.00989 and p = 0.00551, respectively). The estimated frequencies of the G-C haplotype in the MMP-13 gene promoter were significantly lower in KD patients with CALs than in those without CALs. There was no association between other MMP genes and CAL formation. In conclusion, the genetic evaluation by association study demonstrated that the MMP-13 gene, at least in part, contributed to the development of CALs in KD.

The IL-10 (-627 A/C) promoter polymorphism may be associated with coronary aneurysms and low serum albumin in Korean children with Kawasaki disease

Kawasaki disease (KD) is an acute febrile vasculitic syndrome of unknown etiology that preferentially affects the coronary artery. Interleukin-10 (IL-10) is a key proinflammatory cytokine, and a polymorphism near the major transcriptional start site of the IL-10 gene was shown to influence IL-10 production in vitro. This study investigated the association of the IL-10 promoter polymorphism with KD and its clinical parameters in Korean children. A total of 194 children with congenital heart disease (CHD) and 95 children with KD were included in this study. IL-10 (-627 A/C) polymorphism genotypes were determined using the single-base extension method. There was no difference in the allele frequencies of IL-10 (-627 A/C) polymorphism between CHD children and KD children. KD children with one or two copies of the IL-10 (-627C) allele showed significantly lower albumin levels (p = 0.020) and higher frequencies of early coronary artery aneurysm [62.22% versus 37.78%, adjusted odds ratio (aOR) = 3.50, 95% confidence interval (CI): 1.50-8.16] compared with KD children with the common IL-10 (-627A) allele. These findings suggest that the IL-10 (-627 A/C) promoter polymorphism might be a genetic marker for the risk of early coronary artery complication in KD.

What's new in the aetiopathogenesis of vasculitis?

The cause of the majority of childhood vasculitides is unknown although it is likely that a complex interaction between environmental factors and inherited host responses trigger the disease and determine the vasculitis phenotype. Epidemiological clues continue to implicate infectious triggers in Kawasaki syndrome (KS) and Henoch Schonlein purpura (HSP). Several genetic polymorphisms have now been described in KS and HSP which predispose to disease or predict disease severity. Anti-neutrophil cytoplasmic antibodies (ANCA) are now known to be directly involved in the pathogenesis of vascular injury in ANCA-associated vasculitides, although why some individuals develop ANCA in the first instance is not yet understood. Endothelial injury and repair are active areas of research in vasculitis. It is now possible to track endothelial injury non-invasively in children with vasculitis using surrogate markers of endothelial injury. The vasculogenic pathways involved in vascular repair following vasculitis, including endothelial progenitor cells, are beginning to be studied. It is anticipated that an improved understanding of the aetiopathogenesis of vasculitis in the young will ultimately shape future novel diagnostic and therapeutic approaches and will help us predict which children may develop premature arteriosclerosis in later life.

Epidemiology and etiology of Kawasaki disease

Kawasaki disease was first reported in Japan in 1967 by Dr. Tomisaku Kawasaki. It has since been recognized worldwide, and in at the United States and Japan is the most important cause of acquired heart disease in children, surpassing other more recognized conditions such as rheumatic fever, endocarditis and myocarditis. It is primarily a disease of children less than 5 years of age but has been reported in older children and adults. Risk factors for the illness include Asian ancestry, male gender and certain familial predispositions. Observations such as similarity to certain exanthematous infectious diseases, temporal-geographic clustering of cases and seasonality in incidence favors an infectious etiology. Pathology and pathogenesis of the disease indicate that it is a medium-sized artery vasculitis that results from a dramatic immune activation that in most cases reversed by immune modulating agents such as intravenous immunoglobulin. Unfortunately, the etiology of the illness remains obscure, although recent studies favor a possible viral etiology.

Matrix metalloproteinases and atherogenesis in dependence of age

BACKGROUND

Changes in the proteoglycan metabolism of the intima of arteries belong to the initial lesions of atherosclerosis (AS). The accumulation of proteoglycans, alterations of pericellular glycoproteins and modulations of collagen turnover also play a fundamental role in the progression of AS. They influence lipid retention, cell behavior and calcinosis. The decisive role played by the matrix metalloproteinases (MMPs) and their inhibiting factors (tissue inhibitors of metalloproteinases [TIMPs]) in these processes is not yet fully understood and therefore the subject of this overview. The causes of the abrupt change of a long-term existing stabile AS to a vulnerable plaque as well as the participation of age-related vascular wall remodeling in the progression of AS also remain open questions.

DISCUSSION

Apart from the well-known risk factors for AS, less well-known influences like the disturbances of gene expression in vascular smooth muscle cells affect an MMP/TIMP imbalance. The various consequences of this imbalance range from intima cell proliferation as an early change in AS as well as accelerated progression to the destabilization of fibrous plaques by increased collagenolysis as well as the formation of aneurysms. Infectious or toxic influences may trigger these mechanisms; an involvement of age-related vessel wall changes should also be considered. The prognostic significance of circulating MMP concentrations for the existence of instabile plaques are of great interest, as is the plaque stabilizing effect of statins by suppression of MMPs.

CONCLUSIONS

MMPs navigate the behavior of vascular wall cells in different AS stages, in adaptive remodeling, in normal aging and in non-atherosclerotic vessel disease. The clinical relevance of a disturbance in the MMP/TIMP balance is demonstrated firstly by the initiation of AS due to migration and proliferation of intima cells and secondly in the collagenolysis, necrotic transformation and apoptosis of existing fibrous lesions resulting in instabile rupture proned plaques. Investigations into the genetic typing of MMPs and the results of experimental gene deficiency models have significantly contributed to the clarification of these facts.