Identification of an Association Between Genomic Hypomethylation of FCGR2A and Susceptibility to Kawasaki Disease and Intravenous Immunoglobulin Resistance by DNA Methylation Array

Abstract

Objective. Kawasaki disease (KD) is characterized by systemic vasculitis, and it is the most common acquired heart disease in children. However, the etiology and immunopathogenesis of KD are still unclear. A genome-wide association study (GWAS) identified polymorphisms in CD40, BLK, and FCGR2A as the susceptibility genes for KD. No epigenetic array studies of KD have previously been published. This study was undertaken to investigate differences in DNA methylation in patients with KD as compared to controls.Methods. The HumanMethylation27 BeadChip (Illumina) was used to survey the differences in DNA methylation between KD patients and controls. DNA methylation array validation was performed in a separate cohort by pyrosequencing assay and reporter gene assays. Messenger RNA (mRNA) expression was determined, and the association of methylation with response to intravenous immunoglobulin (IVIG) treatment was analyzed.Results. HumanMethylation27 BeadChip assay showed a 15% difference in methylation of 10 genes between KD patients and controls. The FCGR2A cg24422489 group, which was recently reported to be associated with KD susceptibility in a GWAS, had significant hypomethylation of 15.54% less in the KD group than in the control group. Validation of FCGR2A methylation in another cohort also showed significant hypomethylation in the KD group (5 of 5 CpG sites [P < 0.01]; n ‫؍‬ 43 in the KD group and n ‫؍‬ 55 in the control group). KD patients with IVIG resistance showed hypomethylation of 5 CpG sites (P < 0.05). FCGR2A mRNA expression was significantly increased in patients in the acute stage of KD compared to controls. Reporter gene assays indicated that the CpG sites of the FCGR2A promoter region were sufficient to modulate gene expression.Conclusion. This is the first study to examine the DNA methylation array in KD and identify a role of hypomethylation of FCGR2A in susceptibility to KD and IVIG resistance.Kawasaki disease (KD) is an acute febrile systemic vasculitis first described by Kawasaki et al (1) in English in 1974. The most serious complication of KD is the formation of coronary artery lesions, including myocardial infarction, coronary artery fistula, coronary artery dilatation, and aneurysm (2). In developed countries, it is the leading cause of acquired heart disease in children; however, its etiology remains unknown (3-6). KD mainly affects children younger than 5 years of age, especially those in Asian countries, but its incidence has increased worldwide.

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

“…All RNA samples passed the criterion of RIN ≥ 7. The DNA samples were isolated and treated with bisulfite as described in a previous study [37]. …”

Epigenetics and Vasculitis: a Comprehensive Review

“…KD predominantly affects young children and is most common in people of Asian descent [50]. The mechanisms involved in KD pathogenesis are mostly unknown; however, an imbalance between Th17 and regulatory T cells (Tregs) is suspected to have a role.…”

“…Moreover, aberrant DNA methylation in FCGR2A may contribute to the pathogenesis of KD. In a recent study, genome-wide DNA methylation was compared between whole blood of KD patients and age-matched controls that presented with fever and no history of KD [50]. In KD patients, multiple sites of the FCGR2A promoter were significantly hypomethylated compared with controls indicating greater transcriptional accessibility ( Table 2).…”

“…Ineffective silencing of MPO and PR3 auto-antigen [48] Kawasaki disease Whole blood FCGR2A ↓ Pro-inflammatory response [50,51] Behçet's disease CD4+ T cells and/or monocytes Microtubule-associated proteins (TBCD, KIF1B, DNAH3, TUBB8, and RSG14) Differential methylation Regulation of cytoskeletal dynamics and cell migration [52] Myosin genes (MYH15,…”

Cognitive Development After Kawasaki Disease ― Clinical Study and Validation Using a Nationwide Population-Based Cohort ―

“…5-7 Although its etiology remains unknown, both genetic and environmental factors have been associated with the occurrence of KD. 8, 9 Intravenous immunoglobulin (IVIG) infusion is the standard treatment for acute KD, but 10-20% of patients show resistance to IVIG therapy and are at risk of complications, 10 the most serious of which are cardiovascular complications (e.g., coronary artery aneurysms). 11 However, KD is also characterized by multisystemic vasculitis and may thus affect blood perfusion and cause inflammatory changes in the brain.…”