Value of neutrophil-lymphocyte ratio in predicting outcomes in Kawasaki disease

Total and differential leukocyte counts are useful inflammatory biomarkers. The ability of the neutrophil-to-lymphocyte ratio (NLR) to predict outcomes in patients with Kawasaki disease (KD) was assessed in this study. All patients with KD who underwent consecutive complete blood count analyses during the acute febrile phase before intravenous immunoglobulin (IVIG), 2 days after IVIG regardless of defervescence, and 3 to 4 weeks after defervescence were enrolled. NLR was calculated by dividing the neutrophil count by the lymphocyte count. NLR values that best predicted IVIG resistance and the development of coronary artery abnormalities were determined by receiver-operating characteristic curve and multivariate analyses. Of the 587 patients with KD, 222 were IVIG resistant. IVIG-resistant patients had higher NLRs than IVIG-responsive patients. The best NLR cut-off values during the acute febrile phase and 2 days after IVIG for predicting IVIG resistance were 5.49 (p <0.001) and 1.26 (p <0.001), respectively. Sixty-two patients developed coronary artery abnormalities; 47 had coronary dilatation, and 15 had aneurysms. Patients with aneurysms, but not patients with dilatation, had higher NLRs than patients without coronary artery abnormalities. The best NLR cut-off value 2 days after IVIG for predicting aneurysm development was 1.01 (p <0.001). Multivariate analysis revealed that the NLR 2 days after IVIG independently predicted coronary aneurysm development (p = 0.03) and IVIG resistance (p <0.001). In conclusion, the NLR can be used for risk stratification in patients with KD. An NLR 2 days after IVIG that exceeded 1 was predictive of coronary aneurysm development and IVIG resistance.