Association of an IGHV3-66 gene variant with Kawasaki disease.

In a meta-analysis of three GWAS for susceptibility to Kawasaki disease (KD) conducted in Japan, Korea, and Taiwan and follow-up studies with a total of 11,265 subjects (3428 cases and 7837 controls), a significantly associated SNV in the immunoglobulin heavy variable gene (IGHV) cluster in 14q33.32 was identified (rs4774175; OR = 1.20, P = 6.0 × 10-9). Investigation of nonsynonymous SNVs of the IGHV cluster in 9335 Japanese subjects identified the C allele of rs6423677, located in IGHV3-66, as the most significant reproducible association (OR = 1.25, P = 6.8 × 10-10 in 3603 cases and 5731 controls). We observed highly skewed allelic usage of IGHV3-66, wherein the rs6423677 A allele was nearly abolished in the transcripts in peripheral blood mononuclear cells of both KD patients and healthy adults. Association of the high-expression allele with KD strongly indicates some active roles of B-cells or endogenous immunoglobulins in the disease pathogenesis. Considering that significant association of SNVs in the IGHV region with disease susceptibility was previously known only for rheumatic heart disease (RHD), a complication of acute rheumatic fever (ARF), these observations suggest that common B-cell related mechanisms may mediate the symptomology of KD and ARF as well as RHD.

Identification of SAMD9L as a susceptibility locus for intravenous immunoglobulin resistance in Kawasaki disease by genome-wide association analysis.

Kawasaki disease (KD) is a systemic vasculitis affecting infants and children; it manifests as fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) treatment effectively attenuates the fever and systemic inflammation. However, 10-20% patients are unresponsive to IVIG. To identify genetic variants influencing IVIG non-response in KD, a genome-wide association study (GWAS) and a replication study were performed using a total of 148 IVIG non-responders and 845 IVIG-responders in a Korean population. rs28662 in the sterile alpha motif domain-containing protein 9-like (SAMD9L) locus showed the most significant result in the joint analysis of GWAS and replication samples (odds ratio (OR) = 3.47, P = 1.39 × 10-5). The same SNP in the SAMD9L locus was tested in the Japanese population, and it revealed a more significant association in a meta-analysis with Japanese data (OR = 4.30, P = 5.30 × 10-6). These results provide new insights into the mechanism of IVIG response in KD.

Association of the IL16 Asn1147Lys polymorphism with intravenous immunoglobulin resistance in Kawasaki disease.

Kawasaki disease (KD) is an acute, self-limited vasculitis, mainly affecting children younger than 5 years old, with accompanying fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) is the standard treatment for KD; however, ~15% of patients are resistant to IVIG treatment. To identify protein coding genetic variants influencing IVIG resistance, we re-analyzed our previous genome-wide association study (GWAS) data from 296 patients with KD, including 101 IVIG non-responders and 195 IVIG responders. Five nonsynonymous SNPs (nsSNPs) in five immune-related genes, including a previously reported SAMD9L nsSNP (rs10488532; p.Val266Ile), were associated with IVIG non-response (odds ratio [OR] = 1.89-3.46, P = 0.0109-0.0035). In a replication study of the four newly-identified nsSNPs, only one in the interleukin 16 (IL16) gene (rs11556218, p.Asn1147Lys) showed a trend of association with IVIG non-response (OR = 1.54, P = 0.0078). The same IL16 nsSNP was more significantly associated with IVIG non-response in combined analysis of all data (OR = 1.64, P = 1.25 × 10-4). Furthermore, risk allele combination of the IL16 CT and SAMD9L TT nsSNP genotypes exhibited a very strong effect size (OR = 9.19, P = 3.63 × 10-4). These results implicate IL16 as involved in the mechanism of IVIG resistance in KD.

The Risk Prediction of Coronary Artery Lesions through the Novel Hematological Z-Values in 4 Chronological Age Subgroups of Kawasaki Disease.

Background and Objectives: Most cases of Kawasaki disease (KD) occur between the ages of 6 months and 5 years. Differences in immunological reaction and CAL (coronary artery lesion) by the age subgroups classified according to the prevalence of KD and those particularly in the earlier life of KD should be investigated. Materials and Methods: The laboratory data of 223 infantile and 681 non-infantile KD cases from 2003 to 2018 at Korea University Hospital were retrospectively analyzed. Patients with KD were divided into infants and non-infants and further subdivided into four subgroups by age. The age-adjusted Z-values were compared among the subgroups. Febrile controls were identified as patients with fever for >5 days and who showed some of the KD symptoms. Results: IVIG (intravenous immunoglobulin) resistance at the age of 6 months or less was significantly lower than that at the ages of 7-12 months and 13-60 months (respectively, p < 0.05). The significant risk factors for CAL in total KD patients were age, incomplete KD, post-IVIG fever, IVIG resistance, convalescent Z-eosinophil, and subacute platelet (p < 0.05). The significant risk factors for CAL at the age of 6 months or less were IVIG resistance, acute Z-neutrophil, subacute Z-neutrophil, subacute NLR (neutrophil to lymphocyte ratio), and subacute platelet (respectively, p < 0.05). Conclusion: Younger age and incomplete presentation in KD can be independent risk factors for CAL. The immune reactions of KD at a younger age are more tolerated compared with those at older ages during the acute phase. The immune response at the age of 6 months or less showed immune tolerance in terms of incomplete presentation and IVIG responsiveness. The risk factors such as IVIG resistance, subacute platelet, subacute NLR, and acute or subacute Z-neutrophil at the age of 6 months or less can be very useful parameters to predict CAL in young, incomplete KD.

Identification of the TIFAB Gene as a Susceptibility Locus for Coronary Artery Aneurysm in Patients with Kawasaki Disease.

Kawasaki disease (KD) is a self-limiting systemic vasculitis of unknown etiology. KD is often complicated by coronary artery aneurysms (CAAs), which develop in about 20-25% of untreated children and 3-5% of children treated with intravenous immunoglobulin therapy. To identify the risk loci for CAA susceptibility in patients with KD, we performed a genome-wide association study (GWAS) using our previous Illumina HumanOmni1-Quad BeadChip data (296 KD patients) and a new replication study in an independent sample set (713 KD patients) by grouping KD patients without CAA (control) versus KD patients with extremely large aneurysms (diameter ≥ 5 mm) (case). Among 44 candidate single -nucleotide polymorphisms (SNPs) selected from the initial GWAS data (33 cases vs. 215 controls), a SNP (rs899162) located 7 kb upstream of the TIFAB gene on chromosome five was replicated in an independent sample (12 cases vs. 532 controls). In the combined analysis (45 cases vs. 747 controls), the SNP (rs899162) showed a highly significant association with CAA formation (diameter ≥ 5 mm) in patients with KD (odds ratio = 3.20, 95% confidence interval = 2.02-5.05, Pcombined = 1.95 × 10-7). These results indicate that the TIFAB gene may act as a CAA susceptibility locus in patients with KD.

Chronological Echocardiographic Changes in Healthy Term Neonates within Postnatal 72 Hours Using Doppler Studies.

BACKGROUND: This study evaluated echocardiographic changes in full-term healthy neonates during early transitional period from postnatal 0-72 hours at 12-hour intervals by echocardiography. METHODS: This was a prospective, observational, and longitudinal single-center cohort study. Morphometric, functional, systolic, diastolic, and tissue Doppler imaging (TDI) parameters (patent ductus arteriosus [PDA], aorta, superior vena cava [SVC], stroke volume [SV], cardiac output [CO], cardiac index [CI], early diastolic flow velocity [E], late diastolic flow velocity [A], early filling in TDI [E'], peak systolic annular velocity in TDI [S'], late velocity peak in TDI [A'], and myocardial performance index [MPI]) were evaluated in left ventricle (LV) and right ventricle (RV) with 56 newborns. RESULTS: Sizes and peak velocities of PDA before postnatal 24 hours were significantly changed than those after postnatal 24 hours. Aortic velocity time integral (VTI), systolic blood pressure (BP), LV SV/kg, LV CO/kg, LV CI, and SVC flow/LV CO before 24 hours showed significantly changes than those after 24 hours. Also, LV and RV MPI before 24 hours were significantly higher than those after 24 hours. LV E/E' was significantly higher than RV E/E'. CONCLUSION: Postnatal 24 hours is critical time for hemodynamic closure of PDA because aortic VTI, systolic BP, LV SV, LV CO, LV CI, and SVC flow/LV CO showed simultaneously significant changes after 24 hours at the same time as 24 hours of physiological closure of PDA. Chronological and dramatic changes of systolic, diastolic, and TDI parameters during early postnatal period can be used to compile normal baseline data of healthy full-term neonates.

A genome-wide association analysis identifies NMNAT2 and HCP5 as susceptibility loci for Kawasaki disease.

Kawasaki disease (KD), a systemic vasculitis of infants and children, manifests as fever and mucocutaneous inflammation. Although its etiology is largely unknown, the epidemiological data suggest that genetic factors are important in KD susceptibility. To identify genetic variants influencing KD susceptibility, we performed a genome-wide association study (GWAS) and replication study using a total of 915 children with KD and 4553 controls in the Korean population. Six single-nucleotide polymorphisms (SNPs) in three loci were associated significantly with KD susceptibility (P<1.0 × 10-5), including the previously reported BLK locus (rs6993775, odds ratio (OR)=1.52, P=2.52 × 10-11). The other two loci were newly identified: NMNAT2 on chromosome 1q25.3 (rs2078087, OR=1.33, P=1.15 × 10-6) and the human leukocyte antigen (HLA) region on chromosome 6p21.3 (HLA-C, HLA-B, MICA and HCP5) (rs9380242, rs9378199, rs9266669 and rs6938467; OR=1.33-1.51, P=8.93 × 10-6 to 5.24 × 10-8). Additionally, SNP rs17280682 in NLRP14 was associated significantly with KD with a family history (18 cases vs 4553 controls, OR=6.76, P=5.46 × 10-6). These results provide new insights into the pathogenesis and pathophysiology of KD.

Impact of time to treatment of oseltamivir on influenza hospitalization cost among Korean children.

BACKGROUND: Although oseltamivir is a common influenza treatment, there is a lack of data on the economic benefits of timely oseltamivir treatment. METHODS: From February 2004 through June 2007, 116 hospitalized children ≤ 15 years of age with laboratory-confirmed influenza who received oseltamivir were identified via retrospective medical chart review. Demographic, clinical, and cost data were abstracted and multivariate linear regression was used to assess the association between oseltamivir time to treatment and treatment-related costs among hospitalized children with laboratory-confirmed influenza. RESULTS: Overall, 28% (n = 33) of patients were treated with oseltamivir ≥ day 3 of admission. Rapid influenza diagnostic test was used in a significantly lower proportion of patients treated with oseltamivir ≥ day 3 of admission compared with those who received oseltamivir earlier. On multivariate linear regression, initiation of oseltamivir ≥ day 3 of admission was associated with a 60.84% increase (95%CI: 32.59-95.11) in treatment-related hospital costs, compared with initiation on admission. CONCLUSION: Delayed initiation of oseltamivir was found to be associated with increased treatment-related hospital costs among children hospitalized with laboratory-confirmed influenza.

Nationwide survey of coronary aneurysms with diameter >6 mm in Kawasaki disease in Korea.

BACKGROUND: We investigated the course of coronary aneurysm with diameter > 6 mm in Kawasaki disease (KD), as well as related therapeutic trends and prognosis in Korea. METHODS: A nationwide questionnaire survey was carried out in 77 hospitals, to investigate, retrospectively, patients with KD who had coronary aneurysms with a diameter > 6 mm between 1990 and 2011. RESULTS: The median age of onset was 3 years (range, 2 months-16 years) in a total of 239 patients. During the acute stage of KD, most patients received i.v. immunoglobulins and aspirin. In addition, 27 patients received steroid therapy. In the current study, the mean coronary aneurysm size was 8.7 ± 3.2 mm (range, 6-21 mm). Twenty-two patients underwent interventional catheterization. Procedures included percutaneous transluminal coronary balloon angioplasty (n = 10), stent placement (n = 9), and percutaneous transluminal coronary rotational ablation (n = 3). Fourteen patients underwent coronary artery bypass graft surgery. Of the 239 patients who had coronary aneurysms with diameter > 6 mm, 13 (5.4%) presented with findings suggestive of myocardial infarction. Five patients died during the follow-up period. CONCLUSIONS: Severe stenosis or occlusion of the coronary artery may occur in some patients who develop coronary aneurysms with diameter > 6 mm; early management such as coronary interventions or surgery should be considered in such cases.

Common variants in the CRP promoter are associated with a high C-reactive protein level in Kawasaki disease.

Kawasaki disease (KD) is an acute self-limiting form of vasculitis that afflicts infants and children and manifests as fever and signs of mucocutaneous inflammation. Children with KD show various laboratory inflammatory abnormalities, such as elevations in their white blood cell (WBC) count, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). We here performed a genome-wide association study (GWAS) of 178 KD patients to identify the genetic loci that influence 10 important KD laboratory markers: WBC count, neutrophil count, platelet count, CRP, ESR, hemoglobin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and total protein. A total of 165 loci passed our arbitrary stage 1 threshold for replication (p < 1 × 10(-5)). Of these, only 2 SNPs (rs12068753 and rs4786091) demonstrated a significant association with the CRP level in replication study of 473 KD patients (p < 0.05). The SNP located at the CRP locus (rs12068753) demonstrated the most significant association with CRP in KD patients (beta = 4.73 and p = 1.20 × 10(-6) according to the stage 1 GWAS; beta = 3.65 and p = 1.35 × 10(-8) according to the replication study; beta = 3.97 and p = 1.11 × 10(-13) according to combined analysis) and explained 8.1% of the phenotypic variation observed. However, this SNP did not demonstrate any significant association with CRP in the general population (beta = 0.37 and p = 0.1732) and only explained 0.1% of the phenotypic variation in this instance. Furthermore, rs12068753 did not affect the development of coronary artery lesions or intravenous immunoglobulin resistance in KD patients. These results indicate that common variants in the CRP promoter can play an important role in the CRP levels in KD.