Kawasaki disease is a vasculitis that can lead to cardiac complications, including coronary artery disease and cardiogenic shock. Various scoring systems have been developed to determine those that will be refractory to routine intravenous immunoglobulin therapy or develop coronary artery disease. The objective of this study was to determine if the neutrophil–lymphocyte ratio could predict refractory disease and coronary artery lesions in patients with Kawasaki disease.

A systematic review of the literature was performed to identify manuscripts describing comparisons of neutrophil–lymphocyte ratio between those who had refractory disease and those who did not, and between those who developed coronary artery lesions and those who did not. Mean difference was compared between groups. Areas under the curve were utilised to determine the pooled area under the curve.

12 studies with 5593 patients were included in the final analyses of neutrophil–lymphocyte ratio for the prediction of refractory disease. Neutrophil–lymphocyte ratio before therapy was higher in refractory disease with a mean difference of 2.55 (p < 0.01) and pooled area under the curve of 0.724. Neutrophil–lymphocyte ratio after therapy was higher in refractory disease with a mean difference of 1.42 (p < 0.01) and pooled area under the curve for of 0.803. Five studies with 1690 patients were included in the final analyses of neutrophil–lymphocyte ratio for the prediction of coronary artery lesions. Neutrophil–lymphocyte ratio before therapy was higher in coronary artery lesions with a mean difference of 0.65 (p < 0.01).

The use of neutrophil–lymphocyte ratio may help physicians in the identification of patients at risk of refractory disease and coronary artery lesions in patients with Kawasaki disease.

Dilated cardiomyopathy is a rare but serious disorder in children. No effective diagnostic or treatment tools are readily available. This study aimed to evaluate the efficacy of intravenous immunoglobulins in children with new onset dilated cardiomyopathy.

In this retrospective cohort study, 94 children with new onset dilated cardiomyopathy were followed during a median period of 33 months. All patients with secondary dilated cardiomyopathy – for example, genetic, auto-immune or structural defects – had been excluded. Viral tests were performed in all patients and 18 (19%) children met the criteria for the diagnosis “probable or definite viral myocarditis”. Intravenous immunoglobulins were administered to 21 (22%) patients. Overall transplant-free survival was 75% in 5 years and did not differ between treatment groups. The treatment was associated with a higher recovery rate within 5 years, compared with non-treated children (70 versus 43%, log rank=0.045). After correction for possible confounders the hazard ratio for recovery with intravenous immunoglobulins was not significant (hazard ratio: 2.1; 95% CI: 1.0–4.6; p=0.056). Administration of intravenous immunoglobulins resulted in a greater improvement in the shortening fraction of the left ventricle.

In our population of children with new onset dilated cardiomyopathy, of either viral or idiopathic origin, intravenous immunoglobulins were administered to a minority of the patients and did not influence transplant-free survival, but were associated with better improvement of systolic left ventricular function and with better recovery. Our results support the concept that children with new onset dilated cardiomyopathy might benefit from intravenous immunoglobulins.