Difference in serum miRNA expression between immunoglobulin-sensitive and -insensitive incomplete Kawasaki disease patients

The present study aimed to investigate the expression of microRNAs (miRNAs/miRs) and inflammatory factors in patients with immunoglobulin-sensitive and IVIG-insensitive incomplete Kawasaki disease (KD). One hundred and eighty-five patients with incomplete KD were included as the study group (KD group), and 182 patients with respiratory infection as the control group. Neutrophil to lymphocyte ratio (NLR), C-reactive protein (CRP) levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cell count (WBC), hemoglobin level (Hb), platelet count (PLT) and T cell subsets (CD3(+), CD3(+) CD4(+)) were compared. Patients in the KD group received aspirin (30 mg/kg orally daily) and gamma globulin (IVIG, 1 g/kg intravenously daily). According to the sensitivity to IVIG, patients were divided into IVIG-sensitive group and IVIG-insensitive KD group. The relative expression levels of miRNA-21, miRNA-145, miRNA-155 and miRNA-199b-5p in the serum were detected by RT-qPCR. Serum TNF-α, IL-6 and IL-1β levels were assessed using ELISA. Before treatment, the neutrophil to lymphocyte ratio (NLR), levels C-reactive protein, and leukocytes in the KD group were significantly higher compared with the control group (P<0.05). After medical intervention, the relative expression of miRNA-21, miRNA-145 and miRNA-155 in the serum of patients in IVIG-sensitive and IVIG-insensitive KD groups were increased when compared with these levels in the control group (P<0.05). Meanwhile, the relative expression of miRNA-199b-5p was decreased (P<0.05). Compared with the IVIG-sensitive KD group, the relative expression levels of miRNA-145 and miRNA-155 were increased in the serum of patients in the IVIG-insensitive KD group (P<0.05). Compared with the control group, the levels of TNF-α, IL-6 and IL-1β were increased in the serum of patients in the IVIG-sensitive and IVIG-insensitive KD groups (P<0.05). Compared with the IVIG-sensitive KD group, the serum levels of TNF-α and IL-6 were increased in patients of the IVIG-insensitive KD group (P<0.05). Except for NLR and CRP, there were differences in the expression of peripheral blood miRNA-145, miRNA-155 and serum TNF-α and IL-6 in patients with immunoglobulin-sensitive and -insensitive incomplete KD.