Kawasaki disease is a systemic vasculitis of unknown etiology, with clinical observations suggesting a substantial genetic contribution to disease susceptibility. We conducted a genome-wide association study and replication analysis in 2,173 individuals with Kawasaki disease and 9,383 controls from five independent sample collections. Two loci exceeded the formal threshold for genome-wide significance. The first locus is a functional polymorphism in the IgG receptor gene FCGR2A (encoding an H131R substitution) (rs1801274; P = 7.35 × 10(-11), odds ratio (OR) = 1.32), with the A allele (coding for histadine) conferring elevated disease risk. The second locus is at 19q13, (P = 2.51 × 10(-9), OR = 1.42 for the rs2233152 SNP near MIA and RAB4B; P = 1.68 × 10(-12), OR = 1.52 for rs28493229 in ITPKC), which confirms previous findings(1). The involvement of the FCGR2A locus may have implications for understanding immune activation in Kawasaki disease pathogenesis and the mechanism of response to intravenous immunoglobulin, the only proven therapy for this disease.

Background and ObjectivesThe pathogenesis of hyponatremia (serum sodium <135 mEq/L) in Kawasaki disease (KD) remains unclear. We investigated the clinical significance of hyponatremia, and the role of interleukin (IL)-6 and IL-1β in the development of hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) in KD.Subjects and MethodsFifty KD patients were prospectively enrolled and analyzed for clinical and laboratory variables according to the presence of hyponatremia or SIADH.ResultsThirteen KD patients (26%) had hyponatremia and 6 of these had SIADH. In patients with hyponatremia, the percentage of neutrophils (% neutrophils), C-reactive protein (CRP), and N-terminal pro-brain natriuretic peptide (NT-proBNP) were higher than in those without hyponatremia, while serum triiodothyronine (T3) and albumin were lower. Patients with hyponatremia had a higher incidence of intravenous immunoglobulin-resistance but this was not statistically significant. No differences existed between patients with and without SIADH with regard to clinical or laboratory variables and the incidence of IVIG-resistance. Serum sodium inversely correlated with % neutrophils, CRP, and NT-proBNP, and positively correlated with T3 and albumin. Serum IL-6 and IL-1β levels increased in KD patients and were higher in patients with hyponatremia. Plasma antidiuretic hormone increased in patients with SIADH, which tended to positively correlate with IL-6 and IL-1β levels.ConclusionHyponatremia occurs in KD patients with severe inflammation, while increased IL-6 and IL-1β may activate ADH secretion, leading to SIADH and hyponatremia in KD.

PurposeKawasaki disease (KD) is the main cause of acquired heart disease in children. In addition to cardiovascular involvement, many complications have been recognized in KD. However, respiratory complications have been rarely reported. We investigated the differences in clinical characteristics, laboratory findings, radiography findings, and echocardiography findings of Mycoplasma pneumoniae infection and other types of pneumonia in KD patients.MethodsAmong 358 patients with KD, 54 developed concurrent pneumonia. Among the 54 patients, 12 (22.2%) with high titers of anti-M. pneumoniae antibody (AMA) (>1:640) were grouped in the M. pneumoniae group and 42 were included in the control group. Serum AMA was measured in each patient. Clinical laboratory findings and total duration of fever were analyzed.ResultsThe duration of fever, serum hemoglobin, white blood cell count, platelet count, erythrocyte sedimentation rate, C-reactive protein level, albumin level, and the incidence of coronary arterial lesions showed no statistical difference in the 2 groups. Neutrophil count was significantly higher in the M. pneumoniae group than in the control group. Among various radiography findings observed in pneumonia, consolidation and pleural effusion were more frequent in the M. pneumoniae group than in the control group. On the other hand, parahilar peribronchial opacification, diffuse interstitial lesion, and normal findings prevailed in the control group.ConclusionKD patients can have concurrent infections, especially pulmonary symptoms. The cause of KD is likely to be associated with M. pneumoniae infection. Thus, immediate treatment of M. pneumoniae infection in KD patients is very important.

Background and ObjectivesWe sought to determine parameters to guide the decision of retreatment in patients with Kawasaki disease (KD) who remained febrile after initial intravenous immunoglobulin (IVIG).Subjects and MethodsA total of 129 children with KD were studied prospectively. Patients were treated with IVIG 2 to 9 days after the onset of disease. Laboratory measures, such as white blood cell (WBC), percentage of neutrophils, C-reactive protein (CRP), and N-terminal pro-brain natriuretic peptide (NT-proBNP), were determined before and 48 to 72 hours after IVIG treatment. Patients were classified into IVIG-responsive and IVIG-resistant groups, based on the response to IVIG.ResultsOf a total of 129 patients, 107 patients (83%) completely responded to a single IVIG therapy and only 22 patients (17%) required retreatment: 14 had persistent fever and 8 had recrudescent fever. There was no significant difference between the groups in age, gender distribution, and duration of fever to IVIG initiation, but coronary artery lesions developed significantly more often in the resistant group than in the responsive group (31.8% vs. 2.8%, p=0.000). Compared with pre-IVIG data, post-IVIG levels of WBC, percentage of neutrophils, CRP, and NT-proBNP decreased to within the normal range in the responsive group, whereas they remained high in the resistant group. Multivariate logistic regression indicated that neutrophil counts, CRP, and NT-proBNP were independent parameters of retreatment.ConclusionAdditional therapy at an early stage of the disease should be administered for febrile patients who have high values of CRP, NT-proBNP, and/or neutrophil counts after IVIG therapy.

There is a high incidence of intimal tears and dissections immediately after balloon angioplasty for native and recurrent CoAs. Intravascular ultrasound is more sensitive than angiography in detecting the vascular wall changes. Even significant intimal tears are not necessarily associated with aneurysm formation, and many decrease in size or disappear at short-term follow-up.