Association between serum miR-221-3p and intravenous immunoglobulin resistance in children with Kawasaki disease.

Objectives: Intravenous immunoglobulin (IVIG) resistance was a major cause of coronary artery lesions in children with Kawasaki disease (KD). However, the cause of IVIG resistance in KD remains unknown. miR-221-3p has been confirmed involved in cardiovascular diseases and rheumatoid arthritis. The purpose of this study was to investigate the association between miR-221-3p and IVIG resistance in children with KD.

Methods: Fifty-five KD patients and 29 healthy controls (HCs) were enrolled in this study. KD patients were divided into group of sensitive to IVIG (IVIG-response, n = 42) and group of resistant to IVIG (IVIG-resistance, n = 13), group of 10 KD patients with coronary artery lesions (CALs, KD-CALs) and group of 10 sex- and age-matched KD patients without CALs (KD-NCALs). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of miR-221-3p.

Results: Compared with the HCs group, miR-221-3p were significantly increased in the KD group (p < 0.05), and the IVIG-resistance group had higher levels of miR-221-3p than those in the IVIG-response group (p < 0.05). CRP (C-reactive protein), PCT (procalcitonin), NLR (neutrophil-lymphocyte ratio) were positively correlated with miR-221-3p in KD patients. In addition, the group of IVIG resistance had a higher level of Kobayashi Score (p < 0.001). The receiver operating characteristic curve showed that miR-221-3p had a better value for diagnosis IVIG resistance in children with KD than Kobayashi Score with the AUC of 0.811 (95% CI, 0.672-0.951), 0.793 (95% CI, 0.618-0.968), respectively. Additionally, miR-221-3p was elevated (p < 0.05) and showed an AUC value of 0.83 (95% CI, 0.648-1.000, p < 0.05) for the prediction of the complication of coronary artery abnormalities in the group of KD with CALs.

Conclusions: miR-221-3p might be involved in the pathogenesis of KD and IVIG resistance and miR-221-3p can be used as a new potential biomarker to predict IVIG resistance in children with KD.