Interferon-gamma Genetic Polymorphism and Expression in Kawasaki Disease

A LncRNA gene polymorphism (rs1814343) is associated with the risk of coronary artery lesions in southern Chinese Kawasaki disease patients

BACKGROUND

Kawasaki disease (KD) is a multisystemic angiitis, and its most disastrous complication is coronary artery lesions (CALs). Recently, the role of long non-coding RNAs (lncRNAs) in KD has been reported. rs1814343 is a lncRNA, but the relationship between the lncRNA rs1814343 polymorphism and KD risk remains elusive.

METHODS

We enrolled 1625 Kawasaki disease patients (583 patients with CAL and 1042 without CAL) and 1000 healthy controls from a southern Chinese population. We genotyped the rs1814343 C > T polymorphism in KD and control patients using the TaqMan method. The odds ratio (OR) and 95% confidence interval (CI) were used to estimate the strength of the association.

RESULTS

There was no significant association between the lncRNA rs1814343 C > T polymorphism and KD susceptibility. However, we stratified patients in this study by CAL and sex. First, compared with the control groups, we found that the rs1814343 genotype increased risk for KD patients with CAL (TT vs. CC + CT: OR = 1.36, 95% CI = 1.08-1.71, p = 0.009). Moreover, when KD patients were stratified by CAL, the TT genotypes of this lncRNA polymorphism contributed to a relatively higher occurrence of KD with CAL than that was found in the CC/CT genotype patients (TT vs. CC + CT: OR = 1.35, 95% CI = 1.07-1.69, p = 0.011). In addition, our research suggested that the TT variant genotype in the lncRNA rs1814343 had an obvious risk of KD with CAL susceptibility in male children.

CONCLUSION

The lncRNA rs1814343 C > T polymorphism was related to higher susceptibility of KD with CAL.

The EIF2AK4/rs4594236 AG/GG Genotype Is a Hazard Factor of Immunoglobulin Therapy Resistance in Southern Chinese Kawasaki Disease Patients

Background: Kawasaki disease (KD) is an acute, self-limited vasculitis disorder of unknown etiology in children. Immunologic abnormalities were detected during the acute phase of KD, which reflected that the effect cells of the activated immune system markedly increased cytokine production. High-dose intravenous immunoglobulin (IVIG) therapy is effective in resolving inflammation from KD and reducing occurrence of coronary artery abnormalities. However, 10%–20% of KD patients have no response to IVIG therapy, who were defined as IVIG resistance. Furthermore, these patients have persistent inflammation and increased risk of developing coronary artery aneurysm (CAA). EIF2AK4 is a stress sensor gene and can be activated by pathogen infection. In addition, the polymorphisms of EIF2AK4 were associated with various blood vessel disorders. However, it remains unclear whether the EIF2AK4 gene polymorphisms were related to IVIG therapy outcome in KD patients.

Methods:EIF2AK4/rs4594236 polymorphism was genotyped in 795 IVIG response KD patients and 234 IVIG resistant KD patients through TaqMan, a real-time polymerase chain reaction. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of association between EIF2AK4/rs4594236 polymorphism and IVIG therapeutic effects.

Results: Our results showed that the EIF2AK4/rs4594236 AG/GG genotype was significantly associated with increased risk to IVIG resistance compared to the AA genotype (AG vs. AA: adjusted ORs = 1.71, 95% CIs = 1.17–2.51, and p = 0.0061; GG vs. AA: adjusted ORs = 2.09, 95% CIs = 1.36–3.23, and p = 0.0009; AG/GG vs. AA: adjusted ORs = 1.82, 95% CIs = 1.27–2.63, and p = 0.0013; and GG vs. AA/AG: adjusted ORs = 1.45, 95% CI = 1.04–2.02, and p = 0.0306). Furthermore, the stratified analysis of age and gender in the KD cohort indicated that male patients carrying the rs4594236 AG/GG genotype tends to be more resistant to IVIG therapy than female patients.

Conclusion: These results suggested that EIF2AK4/rs4594236 polymorphism might be associated with increased risk of IVIG resistance in southern Chinese KD patients.

Association of single nucleotide polymorphisms of interferon-γ with pulmonary tuberculosis in population of Himachal Pradesh, India

Interferon-gamma (IFN-γ) plays an integral role in the host immunity against tuberculosis (TB). The gene encoding IFN-γ is polymorphic and several studies have reported the association of its genetic polymorphisms with TB in different populations of the world. The present study investigated the association of rs2069705 (C/T), rs1861494 (C/T), rs1861493 (A/G) and rs2069718 (C/T) single nucleotide polymorphisms (SNPs) of IFN-γ with pulmonary TB in a population of Himachal Pradesh, India. For present study, 210 pulmonary TB patients and 205 healthy controls (HCs) were recruited. The selected SNPs of IFN-γ were genotyped by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and plasma IFN-γ levels were measured by ELISA. The 'T' allele of rs1861494 SNP was found to increase susceptibility to TB in the studied population (OR = 2.18, 95%CI = 1.57-3.03; p < 0.001). After stratifying the subjects on basis of sex, males with 'T' allele of rs2069718 SNP were found to be at higher risk to TB (OR = 1.55, 95%CI = 1.07-2.25; p = 0.02). We also found moderate linkage disequilibrium among the studied SNPs. The haplotypes C-T-A-T and T-T-G-T of rs2069705-rs1861494-rs1861493-rs2069718 were overrepresented in TB patients and found to increase susceptibility to TB (p = 0.012). The plasma IFN-γ levels in TB patients were around seven times higher in comparison to HCs (p < 0.0001). The HCs with genotype 'AA' of SNP rs1861493 were found with higher plasma IFN-γ levels than 'AG/GG' genotype (p = 0.023). In conclusion, the results suggest the association of rs1861494 (C/T) and rs2069718 (C/T) SNPs of IFN-γ with TB and genotype 'AA' of rs1861493 is associated with higher plasma IFN-γ levels in the population of Himachal Pradesh, India.

Mechanisms of Immune Dysregulation in COVID-19 Are Different From SARS and MERS: A Perspective in Context of Kawasaki Disease and MIS-C

Coronaviruses have led to three major outbreaks to date-Severe Acute Respiratory Syndrome (SARS; 2002), Middle East Respiratory Syndrome (MERS; 2012) and the ongoing pandemic, Coronavirus Disease (COVID-19; 2019). Coronavirus infections are usually mild in children. However, a few children with MERS had presented with a severe phenotype in the acute phase resulting in progressive pneumonic changes with increasing oxygen dependency and acute respiratory distress requiring ventilatory support. A subset of children with a history of SARS-CoV-2 infection develops a multisystem hyper-inflammatory phenotype known as Multisystem Inflammatory Syndrome in Children (MIS-C). This syndrome occurs 4-6 weeks after infection with SARS-CoV-2 and has been reported more often from areas with high community transmission. Children with MIS-C present with high fever and often have involvement of cardiovascular, gastrointestinal and hematologic systems leading to multiorgan failure. This is accompanied by elevation of pro-inflammatory cytokines such as IL-6 and IL-10. MIS-C has several similarities with Kawasaki disease (KD) considering children with both conditions present with fever, rash, conjunctival injection, mucosal symptoms and swelling of hands and feet. For reasons that are still not clear, both KD and MIS-C were not reported during the SARS-CoV and MERS-CoV outbreaks. As SARS-CoV-2 differs from SARS-CoV by 19.5% and MERS by 50% in terms of sequence identity, differences in genomic and proteomic profiles may explain the varied disease immunopathology and host responses. Left untreated, MIS-C may lead to severe abdominal pain, ventricular dysfunction and shock. Immunological investigations reveal reduced numbers of follicular B cells, increased numbers of terminally differentiated CD4+T lymphocytes, and decreased IL-17A. There is still ambiguity about the clinical and immunologic risk factors that predispose some children to development of MIS-C while sparing others. Host-pathogen interactions in SARS, MERS and COVID-19 are likely to play a crucial role in the clinical phenotypes that manifest. This narrative review focuses on the immunological basis for development of MIS-C syndrome in the ongoing SARS-CoV-2 pandemic. To the best of our knowledge, these aspects have not been reviewed before.

The rs7404339 AA Genotype in CDH5 Contributes to Increased Risks of Kawasaki Disease and Coronary Artery Lesions in a Southern Chinese Child Population

Background

Kawasaki disease (KD) is an acute, self-limited febrile illness of unknown cause. And it predominantly affects children <5 years and the main complication is coronary artery lesion (CAL). Studies demonstrated that vascular endothelial cells (VECs) played a very important role in the CAL of KD. VE-cad encoded by CDH5 may exert a relevant role in endothelial cell biology through controlling the cohesion of the intercellular junctions. The pathogenesis of KD remains unclear and genetic factors may increase susceptibility of KD. However, the relationship between CDH5 polymorphisms and KD susceptibility has not been reported before. The present study is aimed at investigating whether the rs7404339 polymorphism in CDH5 is associated with KD susceptibility and CAL in a southern Chinese child population.

Methods and Results

We recruited 1,335 patients with KD and 1,669 healthy children. Each participant had supplied 2 mL of fresh blood in the clinical biologic bank at our hospital for other studies. Multiplex PCR is used to assess the genotypes of rs7404339 polymorphism in CDH5. According to the results, we found significant correlated relationship between rs7404339 polymorphism in CDH5 and KD susceptibility [AA vs. GG: adjusted odds ratio (OR) = 1.43, 95% confidence interval (CI) = 1.00-2.05; p = 0.0493; recessive model: adjusted OR = 1.44, 95% CI = 1.01-2.06, P = 0.0431]. In further stratified analysis, we found that children younger than 60 months (adjusted OR = 1.46, 95% CI = 1.01-2.10; p = 0.0424) and male (adjusted OR = 1.70, 95% CI = 1.09-2.65; p = 0.0203) with the rs7404339 AA genotype in CDH5 had a higher risk of KD than carriers of the GA/GG genotype. Furthermore, stratification analysis revealed that patients with the rs7404339 AA genotype exhibited the significantly higher onset risk for CAL than carriers of the GA/GG genotype (adjusted age and gender odds ratio = 1.56, 95% CI = 1.01-2.41; P = 0.0433).

Conclusion

Our results showed that rs7404339 AA genotype in CDH5 is significant associated with KD susceptibility. And children younger than 60 months and male with the rs7404339 AA genotype had a higher risk of KD than carriers with the GA/GG genotype. Furthermore, patients with the rs7404339 AA genotype exhibited a significantly higher risk of CAL complication than carriers of the GA/GG genotype.

Comparison of Laboratory Data between Children with Kawasaki Disease and COVID-19

Background: Coronavirus disease 2019 (COVID-19) has been an emerging, rapidly evolving situation in China since late 2019 and has even become a worldwide pandemic. The first case of severe childhood novel coronavirus pneumonia in China was reported in March 2020 in Wuhan. The severity differs between adults and children, with lower death rates and decreased severity for individuals under the age of 20 years. Increased cases of Kawasaki disease (KD) have been reported from New York City and some areas of Italy and the U.K., with almost a 6–10 times increase when compared to previous years. We conducted this study to compare characteristics and laboratory data between KD and COVID-19 in children. Methods: We obtained a total of 24 children with COVID-19 from a literature review and 268 KD cases from our hospital via retrospective chart review. Results: We found that patients with KD have higher levels of white blood cells (WBCs), platelets, neutrophil percentage, C-reactive protein (CRP), procalcitonin, and aspartate aminotransferase (AST) and a higher body temperature, while patients with COVID-19 have a higher age, hemoglobin levels, and lymphocyte percentage. After performing multiple logistic regression analysis, we found that age, WBCs, platelets, procalcitonin, and AST are identical markers for distinguishing COVID-19 from KD in children. Conclusion: In this COVID-19 pandemic period, clinicians should pay attention to children with COVID-19 infection when high WBC, platelet, procalcitonin, and AST values are present in order to provide early diagnosis for KD or multisystem inflammatory syndrome in children (MIS-C).

Single-cell RNA sequencing of peripheral blood mononuclear cells from acute Kawasaki disease patients

Kawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries. Although functional and phenotypic changes of immune cells have been reported, a global understanding of immune responses underlying acute KD is unclear. Here, using single-cell RNA sequencing, we profile peripheral blood mononuclear cells from seven patients with acute KD before and after intravenous immunoglobulin therapy and from three age-matched healthy controls. The most differentially expressed genes are identified in monocytes, with high expression of pro-inflammatory mediators, immunoglobulin receptors and low expression of MHC class II genes in acute KD. Single-cell RNA sequencing and flow cytometry analyses, of cells from an additional 16 KD patients, show that although the percentage of total B cells is substantially decreased after therapy, the percentage of plasma cells among the B cells is significantly increased. The percentage of CD8+ T cells is decreased in acute KD, notably effector memory CD8+ T cells compared with healthy controls. Oligoclonal expansions of both B cell receptors and T cell receptors are observed after therapy. We identify biological processes potentially underlying the changes of each cell type. The single-cell landscape of both innate and adaptive immune responses provides insights into pathogenesis and therapy of KD.

Polymorphism of TUSC7 associated with gastric cancer susceptibility and binding with miR-133a-3p: a population-based case-control study

BACKGROUND

Previous studies have demonstrated that gene polymorphism is associated with cancer susceptibility. Most of these genes are involved in neoplastic processes. Previous studies demonstrated that tumor-suppressor candidate 7 (TUSC7) was a tumor-suppressor gene in various tumors. This study aims to explore the association between lncRNA TUSC7 polymorphism and gastric cancer susceptibility and the potential function.

METHODS

The tagging SNPs of TUSC7 were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a Chinese Han population-based case-control study. The relative expression level of TUSC7 in plasma was conducted by quantitative real-time PCR (qRT-PCR). The gene-environment interaction was analyzed by multifactor dimensionality reduction (MDR). The dual luciferase reporter assay was used to examine whether SNP rs12494960 of TUSC7 allele variation affected the binding of lncRNA-TUSC7 and miRNAs miR-133a-3p.

RESULTS

Three tagging SNPs (rs12494960, rs1518338, rs2867837) of TUSC7 were selected to validate in population. The unconditional multiple logistic regression showed that individuals with genotype AA (OR: 1.79, 95% CI: 1.16, 2.70) of rs12494960 and GG (OR: 2.24, 95% CI: 1.12, 4.46) of rs2867837 in TUSC7 had increased risk of GC susceptibility. The qRT-PCR showed that CA and AA genotype of rs12494960 in TUSC7 had significantly lower relative expression level in plasma, compared with CC genotype. The dual luciferase reporter assay showed that TUSC7 and miR-133a-3p had interaction.

CONCLUSION

The mutant genotype of rs12494960 could increase the susceptibility of gastric cancer and might affect the corresponding mRNA expression of lncRNA TUSC7 in plasma.

Homozygous of MRP4 Gene rs1751034 C Allele Is Related to Increased Risk of Intravenous Immunoglobulin Resistance in Kawasaki Disease

Background: Kawasaki disease (KD) is a systemic vasculitis in childhood, which mainly causes damage to coronary arteries, and intravenous immunoglobulin (IVIG) is the initial therapy. IVIG resistance increased risk of coronary complication in KD. And genetic background is involved in the occurrence of IVIG resistance. Our previous study indicated the susceptibility of Multi-drug resistance protein 4 (MRP4) SNPs to KD. This study was to clarify the relationship between MRP4 polymorphisms and IVIG resistance.

Methods: We genotyped the six polymorphisms of MRP4 gene in 760 cases of KD using Taqman methods.

Results: Among the six polymorphisms, only the rs1751034 polymorphism was significantly associated with IVIG resistance in KD [CC vs. TT: adjusted odds ratio (OR) = 2.54, 95% confidence interval (CI) = 1.21–5.34; CC vs. TT/TC: adjusted OR = 2.33, 95% CI = 1.12–4.83, p = 0.023]. Combined analysis of three polymorphisms indicated that patients with 3–6 risk genotypes exhibited significantly elevated risk of IVIG resistance, when compared with those with 0–2 risk genotypes (adjusted OR = 1.52, 95% CI = 1.04–2.22, p = 0.0295). Stratified analysis revealed that in term of age and gender, rs1751034 CC carriers were associated with increased risk of IVIG resistance in those aged ≤ 60 months (adjusted OR = 2.65, 95% CI = 1.23–5.71, p = 0.0133). The presence of three or more risk genotypes was significantly associated with risk of IVIG resistance in children younger than 5 years of age and males.

Conclusion: Our results suggest that MRP4 rs1751034 CC is associated with increased risk of IVIG resistance in KD.

A novel score system of blood tests for differentiating Kawasaki disease from febrile children

Background

Kawasaki disease is the most common cause of acquired heart disease among febrile children under the age of 5 years old. It is also a clinically diagnosed disease. In this study, we developed and assessed a novel score system using objective parameters to differentiate Kawasaki disease from febrile children.

Methods

We analyzed 6,310 febrile children and 485 Kawasaki disease subjects in this study. We collected biological parameters of a routine blood test, including complete blood count with differential, C-reactive protein, aspartate aminotransferase, and alanine aminotransferase. Receiver operating characteristic curve, logistic regression, and Youden’s index were all used to develop the prediction model. Two other independent cohorts from different hospitals were used for verification.

Results

We obtained eight independent predictors (platelets, eosinophil, alanine aminotransferase, C-reactive protein, hemoglobin, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and monocyte) and found the top three scores to be eosinophil >1.5% (score: 7), alanine aminotransferase >30 U/L (score: 6), and C-reactive protein>25 mg/L (score: 6). A score of 14 represents the best sensitivity value plus specificity prediction rate for Kawasaki disease. The sensitivity, specificity, and accuracy for our cohort were 0.824, 0.839, and 0.838, respectively. The verification test of two independent cohorts of Kawasaki disease patients (N = 103 and 170) from two different institutes had a sensitivity of 0.780 (213/273).

Conclusion

Our findings demonstrate a novel score system with good discriminatory ability for differentiating between children with Kawasaki disease and other febrile children, as well as highlight the importance of eosinophil in Kawasaki disease. Using this novel score system can help first-line physicians diagnose and then treat Kawasaki disease early.

Epidemiology, Treatments, and Cardiac Complications in Patients with Kawasaki Disease: The Nationwide Survey in Japan, 2017-2018

OBJECTIVE

To report the epidemiologic characteristics, treatments, and cardiac complications of Kawasaki disease, using data from the nationwide survey in Japan.

STUDY DESIGN

The nationwide Kawasaki disease survey in Japan has been conducted biennially since 1970. The most recent survey was completed in 2019, obtaining information for patients who developed Kawasaki disease during 2017-2018. Survey respondents were hospitals specializing in pediatrics and those with ≥100 beds and a pediatric department throughout Japan, where patients with Kawasaki disease were eventually hospitalized.

RESULTS

The survey identified 32 528 patients with Kawasaki disease, which consisted of 15 164 (46.6%) in 2017 and 17 364 (53.4%) in 2018. The highest annual incidence rate was recorded in 2018 (359 per 100 000 children aged 0-4 years). After 1982, patients with ≤4 principal Kawasaki disease signs gradually increased, resulting in 6847 (21.1%) patients diagnosed during 2017-2018. Among the 30 784 patients receiving initial intravenous immunoglobulin administration, 6061 (19.7%) did not respond. Within 30 days of Kawasaki disease onset, 9.0% of patients were diagnosed with cardiac complications, and 2.6% of patients developed cardiac sequelae after the acute illness.

CONCLUSIONS

The annual number of patients developing Kawasaki disease in Japan increased from 1970 through 2018, whereas the proportion of patients with Kawasaki disease with cardiac complications decreased in the most recent 2 decades. Early diagnosis of Kawasaki disease as well as advances in initial treatments could explain these findings.

Association of IFN-γ polymorphisms with ankylosing spondylitis risk

The case‐control study was designed to investigate the genetic effects of interferon‐gamma (IFN‐γ) rs2069727 and rs1861494 polymorphisms on ankylosing spondylitis (AS) susceptibility in a Chinese Han population. Blood samples were collected from 108 AS patients and 110 healthy controls. IFN‐γ polymorphisms were genotyped by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP). Hardy‐Weinberg equilibrium (HWE) test was performed in control group. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using chi‐square test to evaluate the association between AS susceptibility and IFN‐γ polymorphisms, and the results were adjusted by logistic regressive analysis. The frequency of rs2069727 CC genotype was much higher in cases than that in controls, suggested its significant association with increased AS risk (adjusted OR = 5.899, 95% CI = 1.563‐22.261; P = .009). In addition, C allele also showed close association with increased risk of AS (adjusted OR = 2.052, 95% CI = 1.286‐1.704, P  = 0 .003). While the genotype and allele frequencies of IFN‐γ rs1861494 polymorphism were not significantly different between patients and controls (P  > 0.05 for all), IFN‐γ rs2069727 polymorphism is significantly associated with increased AS risk in a Chinese Han Population.

Interferon-gamma polymorphisms and risk of iron deficiency and anaemia in Gambian children

Background: Anaemia is a major public health concern especially in African children living in malaria-endemic regions. Interferon-gamma (IFN-γ) is elevated during malaria infection and is thought to influence erythropoiesis and iron status. Genetic variants in the IFN-γ gene (IFNG) are associated with increased IFN-γ production. We investigated putative functional single nucleotide polymorphisms (SNPs) and haplotypes of IFNG in relation to nutritional iron status and anaemia in Gambian children over a malaria season. Methods: We used previously available data from Gambian family trios to determine informative SNPs and then used the Agena Bioscience MassArray platform to type five SNPs from the IFNG gene in a cohort of 780 Gambian children aged 2-6 years. We also measured haemoglobin and biomarkers of iron status and inflammation at the start and end of a malaria season. Results: We identified five IFNG haplotype-tagging SNPs ( IFNG-1616 [rs2069705], IFNG+874 [rs2430561], IFNG+2200 [rs1861493], IFNG+3234 [rs2069718] and IFNG+5612 [rs2069728]). The IFNG+2200C [rs1861493] allele was associated with reduced haemoglobin concentrations (adjusted β -0.44 [95% CI -0.75, -0.12]; Bonferroni adjusted P = 0.03) and a trend towards iron deficiency compared to wild-type at the end of the malaria season in multivariable models adjusted for potential confounders. A haplotype uniquely identified by IFNG+2200C was similarly associated with reduced haemoglobin levels and trends towards iron deficiency, anaemia and iron deficiency anaemia at the end of the malaria season in models adjusted for age, sex, village, inflammation and malaria parasitaemia. Conclusion: We found limited statistical evidence linking IFNG polymorphisms with a risk of developing iron deficiency and anaemia in Gambian children. More definitive studies are needed to investigate the effects of genetically influenced IFN-γ levels on the risk of iron deficiency and anaemia in children living in malaria-endemic areas.

Interferon-gamma polymorphisms and risk of iron deficiency and anaemia in Gambian children

Background: Anaemia is a major public health concern especially in African children living in malaria-endemic regions. Interferon-gamma (IFN-γ) is elevated during malaria infection and is thought to influence erythropoiesis and iron status. Genetic variants in the IFN-γ gene (IFNG) are associated with increased IFN-γ production. We investigated putative functional single nucleotide polymorphisms (SNPs) and haplotypes of IFNG in relation to nutritional iron status and anaemia in Gambian children over a malaria season. Methods: We used previously available data from Gambian family trios to determine informative SNPs and then used the Agena Bioscience MassArray platform to type five SNPs from the IFNG gene in a cohort of 780 Gambian children. We also measured haemoglobin and biomarkers of iron status and inflammation at the start and end of a malaria season. Results: We identified five IFNG haplotype-tagging SNPs ( IFNG-1616 [rs2069705], IFNG+874 [rs2430561], IFNG+2200 [rs1861493], IFNG+3234 [rs2069718] and IFNG+5612 [rs2069728]). The IFNG+2200C [rs1861493] allele was associated with reduced haemoglobin concentrations (adjusted β -0.44 [95% CI -0.75, -0.12]; Bonferroni adjusted P = 0.03) and a trend towards iron deficiency compared to wild-type at the end of the malaria season in multivariable models adjusted for potential confounders. A haplotype uniquely identified by IFNG+2200C was similarly associated with reduced haemoglobin levels and trends towards iron deficiency, anaemia and iron deficiency anaemia at the end of the malaria season in models adjusted for age, sex, village, inflammation and malaria parasitaemia. Conclusion: We found limited statistical evidence linking IFNG polymorphisms with a risk of developing iron deficiency and anaemia in Gambian children. More definitive studies are needed to investigate the effects of genetically influenced IFN-γ levels on the risk of iron deficiency and anaemia in children living in malaria-endemic areas.

Multisystem Inflammatory Syndrome in Children (MIS-C), a Post-viral Myocarditis and Systemic Vasculitis-A Critical Review of Its Pathogenesis and Treatment

MIS-C is a newly defined post-viral myocarditis and inflammatory vasculopathy of children following COVID-19 infection. This review summarizes the literature on diagnosis, parameters of disease severity, and current treatment regimens. The clinical perspective was analyzed in light of potential immunopathogenesis and compared to other post-infectious and inflammatory illnesses of children affecting the heart. In this paradigm, the evidence supports the importance of endothelial injury and activation of the IL-1 pathway as a common determinant among MIS-C, Kawasaki disease, and Acute Rheumatic fever.

Prediction for Intravenous Immunoglobulin Resistance Combining Genetic Risk Loci Identified From Next Generation Sequencing and Laboratory Data in Kawasaki Disease

Background: Kawasaki disease (KD) is the most common cause of acquired heart disease. A proportion of patients were resistant to intravenous immunoglobulin (IVIG), the primary treatment of KD, and the mechanism of IVIG resistance remains unclear. The accuracy of current models predictive of IVIG resistance is insufficient and doesn't meet the clinical expectations. Objectives: To develop a scoring model predicting IVIG resistance of patients with KD. Methods: We recruited 330 KD patients (50 IVIG non-responders, 280 IVIG responders) and 105 healthy children to explore the susceptibility loci of IVIG resistance in Kawasaki disease. A next generation sequencing technology that focused on 4 immune-related pathways and 472 single nucleotide polymorphisms (SNPs) was performed. An R package SNPassoc was used to identify the risk loci, and student's t-test was used to identify risk factors associated with IVIG resistance. A random forest-based scoring model of IVIG resistance was built based on the identified specific SNP loci with the laboratory data. Results: A total of 544 significant risk loci were found associated with IVIG resistance, including 27 previous published SNPs. Laboratory test variables, including erythrocyte sedimentation rate (ESR), platelet (PLT), and C reactive protein, were found significantly different between IVIG responders and non-responders. A scoring model was built using the top 9 SNPs and clinical features achieving an area under the ROC curve of 0.974. Conclusions: It is the first study that focused on immune system in KD using high-throughput sequencing technology. Our findings provided a prediction of the IVIG resistance by integrating the genotype and clinical variables. It also suggested a new perspective on the pathogenesis of IVIG resistance.

Leveraging Genetic Findings for Precision Medicine in Vasculitis

Vasculitides are a heterogeneous group of low frequent disorders, mainly characterized by the inflammation of blood vessels that narrows or occlude the lumen and limits the blood flow, leading eventually to significant tissue and organ damage. These disorders are classified depending on the size of the affected blood vessels in large, medium, and small vessel vasculitis. Currently, it is known that these syndromes show a complex etiology in which both environmental and genetic factors play a major role in their development. So far, these conditions are not curable and the therapeutic approaches are mainly symptomatic. Moreover, a percentage of the patients do not adequately respond to standard treatments. Over the last years, numerous genetic studies have been carried out to identify susceptibility loci and biological pathways involved in vasculitis pathogenesis as well as potential genetic predictors of treatment response. The ultimate goal of these studies is to identify new therapeutic targets and to improve the use of existing drugs to achieve more effective treatments. This review will focus on the main advances made in the field of genetics and pharmacogenetics of vasculitis and their potential application for ameliorating long-term outcomes in patient management and in the development of precision medicine.

Proinflammatory cytokine IFN-γ, lncRNA BANCR and the occurrence of coronary artery disease

AIMS

Coronary artery disease (CAD) ranks the leading cause of death globally. Interferon-γ (IFN-γ) gene, along with long noncoding RNA (lncRNA) BRAF-activated noncoding RNA (BANCR), could coordinately function in the occurrence of CAD. We hypothesized that level of IFN-γ, genetic variants of IFN-γ and BANCR gene should be associated with the occurrence of CAD.

MATERIALS AND METHODS

A case-control study was conducted in Chinese population.

KEY FINDINGS

We found that serum level of IFN-γ in CAD cases was significantly higher than that in controls (P < 0.001). Compared with the first quartile, all of the second (OR: 1.87; 95% CIs: 1.33-2.62), the third (OR: 1.79; 95% CIs: 1.30-2.45), and the fourth (OR: 3.98; 95% CIs: 2.59-6.12) quartiles of serum level of IFN-γ were associated with increased risk of CAD (P < 0.05). We found IFN-γ gene (rs2069705 and rs2430561), and 2 variants in lncRNA BANCR (rs6559446 and rs79823312) could increase CAD susceptibility in allelic and dominant model, while IFN-γ rs2069705 and rs2430561, BANCR rs79823312 were also associated with CAD risk in additive model. IFN-γ rs2069705 and rs2430561 were associated with higher level of serum IFN-γ in CAD patients (P < 0.001).

SIGNIFICANCE

This study confirmed the crucial role of IFN-γ and lncRNA BANCR in the occurrence of CAD, and might serve as the biomarkers of CAD screening and prevention.

Lack of association between miR-218 rs11134527 A>G and Kawasaki disease susceptibility

Kawasaki disease (KD) is a type of disease that includes the development of a fever that lasts at least 5 days and involves the clinical manifestation of multicellular vasculitis. KD has become one of the most common pediatric cardiovascular diseases. Previous studies have reported that miR-218 rs11134527 A>G is associated with susceptibility to various cancer risks. However, there is a lack of evidence regarding the relationship between this polymorphism and KD risk. The present study explored the correlation between the miR-218 rs11134527 A>G polymorphism and the risk of KD. We recruited 532 patients with KD and 623 controls to genotype the miR-218 rs11134527 A>G polymorphism with a TaqMan allelic discrimination assay. Our results illustrated that the miR-218 rs11134527 A>G polymorphism was not associated with KD risk. In an analysis stratified by age, sex, and coronary artery lesions, we found only that the risk of KD was significantly decreased for children older than 5 years (GG vs. AA/AG: adjusted OR = 0.26, 95% CI = 0.07–0.94, P=0.041). The present study demonstrated that the miR-218 rs1113452 A>G polymorphism may have an age-related relationship with KD susceptibility that has not previously been revealed.

HAMP promoter hypomethylation and increased hepcidin levels as biomarkers for Kawasaki disease

Kawasaki disease (KD) is the most common coronary vasculitis to appear in children with anemia and has been associated with elevated plasma hepcidin levels. We recruited a total of 241 cases, including 18 KD patients, who were tested both prior to receiving intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, and 18 febrile controls, who were observed in the Illumina HumanMethylation450 BeadChip study for their CpG markers. The remaining cases consisted of another 92 KD patients and 113 controls that were used for validation by pyrosequencing. We performed a genetic functional study using Luciferase assays. A support vector machine (SVM) classification model was adopted to identify KD patients and control subjects. In this study, KD patients clearly demonstrated a significantly epigenetic hypomethylation of HAMP promoter compared to controls. After receiving IVIG treatment, the hypomethylation status in KD patients was restored, and we observed a significant opposite tendency between the DNA methylation of target CpG sites (cg23677000 and cg04085447) and the hepcidin level. Furthermore, reporter gene assays were used to detect target CpG sites, the methylation of which displayed decreased levels of HAMP gene expression. Of particular note, we developed a SVM classification model with a 90.9% sensitivity, a 91.9% specificity, and 0.94 auROC in the training set. An independent blind cohort also had good performance (96.1% sensitivity and 89.7% specificity). In this study, we demonstrate HAMP promoter hypomethylation, which upregulates hepcidin expression in KD patients. Furthermore, the reliability and robustness of our SVM classification model can accurately serve as KD biomarkers.

The IFNG rs1861494 Single Nucleotide Polymorphism Is Associated with Protection against Tuberculosis Disease in Argentina

Interferon gamma (IFNG) plays a key role during Mycobacterium tuberculosis (Mtb) infection, and several polymorphisms located in its gene are associated with risk of tuberculosis in diverse populations. Nevertheless, the genetic resistance/susceptibility to tuberculosis in Argentina is unknown. The IFNG rs1861494 polymorphism (G→A) was reported to alter the binding of transcription factors to this region, influencing IFNG production. Using a case-control study, we found an association between the AA and AG genotypes and tuberculosis resistance (AA vs. GG: odds ratio (OR) = 0.235, p-value = 0.012; AG vs. GG: OR = 0.303, p-value = 0.044; AA vs. AG: OR = 0.776, p-value = 0.427; AA + AG vs. GG: OR = 0.270, p-value = 0.022). Moreover, Mtb-antigen stimulated peripheral blood mononuclear cells (PBMCs) from healthy donors and AA carriers secreted the highest amounts of IFNG in culture supernatants (p-value = 0.034) and presented the greatest percentage of CD4⁺IFNG⁺ lymphocytes (p-value = 0.035), in comparison with GG carriers. No association between the polymorphism and clinical parameters of tuberculosis severity was detected. However, our findings indicate that the rs1861494 single nucleotide polymorphism (SNP) could be considered as a biomarker of tuberculosis resistance in the Argentinean population.

Effect of Interferon-γ Polymorphisms on Ankylosing Spondylitis: A Case-Control Study

Background

This research aimed to explore the effects of interferon-γ (IFN-γ) polymorphisms and expression profile on susceptibility to ankylosing spondylitis (AS) in a Chinese population.

Material/Methods

Blood samples were collected from 89 AS patients and 106 healthy controls. IFN-γ polymorphisms were genotyped by polymerase chain reaction (PCR) and sequencing methods. The genotype distribution of polymorphism in the control group was detected by Hardy-Weinberg equilibrium (HWE). Odds ratios (OR) with 95% confidence intervals (95%CI) were calculated using the χ² test to evaluate the association between AS susceptibility and IFN-γ polymorphisms. Moreover, serum IFN-γ level was measured by ELISA.

Results

rs1861493 and rs2430561 polymorphisms were conformed to be in HWE in genotypes distribution of the control group (P>0.05 for both). However, only TT genotype and T allele of rs2430561 presented significantly higher frequencies in AS patients than in healthy controls (P=0.04 and 0.03, respectively), indicating that they obviously increased the risk of AS in a Chinese population (OR=2.54, 95%CI=1.01–6.40; OR=1.60, 95%CI=1.04–2.46). In AS patients, serum IFN-γ level was higher than in controls, and its expression patterns showed significant association with genotypes of rs2430561.

Conclusions

IFN-γ rs2430561 polymorphism may contribute to the risk of AS through influencing IFN-γ expression.

Identifying genetic hypomethylation and upregulation of Toll-like receptors in Kawasaki disease

Kawasaki disease (KD) is an acute febrile systemic vasculitis that occurs in children and is characterized by elevated levels of proinflammatory cytokines. Toll-like receptors (TLRs) serve as the sensor arm of the innate immune system and induce proinflammatory cytokine expressions.

We recruited a total of 18 paired KD patients, before intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, 18 healthy controls, and 18 febrile controls. For TLR genes and their cytosine-phosphate-guanine (CpG) markers, we used Affymetrix GeneChip^® Human Transcriptome Array 2.0 and Illumina HumanMethylation450 BeadChip to evaluate gene expression levels and methylation patterns, respectively.

KD patients demonstrated a significantly differential expression of TLR mRNA levels compared to both the healthy and febrile controls, with only TLR 3 and 7 not differing between the KD patients and the controls. After patients underwent IVIG treatment, the TLR mRNA levels, except for TLR3, decreased significantly in KD patients. In contrast, the methylation status of the CpG sites of TLR1, 2, 4, 6, 8, and 9 demonstrated an opposite tendency between the two stages of both the KD samples and the controls.

TLRs, particularly TLR1, 2, 4, 6, 8, and 9, may stimulate the immunopathogenesis of KD. These results are among the first to use TLRs to prove that a bacterial inflammatory response may trigger KD.

Epigenetic hypomethylation and upregulation of matrix metalloproteinase 9 in Kawasaki disease

Background

Kawasaki disease (KD) is a type of febrile coronary vasculitis occurring in children. Some researchers have suggested that changes in genetic signatures, such as matrix metalloproteinases (MMPs), are critical markers for cardiovascular diseases. This study aims to provide a comprehensive survey of global DNA methylation levels and MMP transcripts of KD patients compared to control subjects.

Materials and Methods

For chips studies, we recruited a total of 18 KD patients, prior to receiving intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, as well as 18 healthy and 18 febrile control subjects. We applied Illumina HumanMethylation450 BeadChip and Affymetrix GeneChip® Human Transcriptome Array 2.0 to evaluate their CpG markers and expression levels, respectively. Then we used a separate cohort to carry out real-time quantitative PCR validations of mRNA levels.

Results

The expressions of mRNA levels of MMP-8, -9, and -25 were significantly upregulated in KD patients compared to the healthy and febrile controls. Once KD patients underwent IVIG treatment, these MMPs considerably decreased. In particular, the methylation status of CpG sites of MMP-9 indicated a significant opposite tendency between both stages of not only the KD samples but also the controls. We also observed the mRNA level of MMP-9 to be higher in KD patients with coronary arterial lesion formation.

Conclusion

This study is the first to report epigenetic hypomethylation, an increased MMP-9 transcript, and the upregulation of MMP-9 in KD patients who had formed coronary arterial lesions.

Correlation of HAMP gene polymorphisms and expression with the susceptibility and length of hospital stays in Taiwanese children with Kawasaki disease

Kawasaki disease (KD) is a form of systemic vasculitis. Regarding its pathogenesis, HAMP gene encoding hepcidin, which is significant for iron metabolism, has a vital function. In this study, we recruited a total of 381 KD patients for genotyping. Data from 997 subjects (500 subjects from cohort 1; 497 subjects from cohort 2) were used for analysis. Using TaqMan allelic discrimination, we determined five tag SNPs (rs916145, rs10421768, rs3817623, rs7251432, and rs2293689). Treatment outcome data related to such clinical phenotypes as coronary artery lesions (CAL), coronary artery aneurysms (CAA), and intravenous immunoglobulin (IVIG) effects were also collected. Furthermore, we measured plasma hepcidin levels with an enzyme-linked immunosorbent assay. We found that HAMP gene polymorphism (rs7251432, and rs2293689) was significantly correlated with KD risk and that plasma hepcidin levels both before and after IVIG treatment had a significantly positive correlation with length of hospital stays (R = 0.217, p = 0.046 and R = 0.381, p < 0.0001, respectively). In contrast, plasma hepcidin levels has a negative correlation with KD patients’ albumin levels (R = −0.27, p < 0.001) prior to IVIG treatment. This study's findings indicate that HAMP might have a role in the disease susceptibility, as well as its expressions correlated length of hospital stays, and albumin levels in Taiwanese children with KD.

Anemia in Kawasaki Disease: Hepcidin as a Potential Biomarker

Kawasaki disease (KD) is an autoimmune-like disease and acute childhood vasculitis syndrome that affects various systems but has unknown etiology. In addition to the standard diagnostic criteria, anemia is among the most common clinical features of KD patients and is thought to have a more prolonged duration of active inflammation. In 2001, the discovery of a liver-derived peptide hormone known as hepcidin began revolutionizing our understanding of anemia’s relation to a number of inflammatory diseases, including KD. This review focuses on hepcidin-induced iron deficiency’s relation to transient hyposideremia, anemia, and disease outcomes in KD patients, and goes on to suggest possible routes of further study.