Study population
A total of 1,257 patients with KD at six institutions between June 2013 and May 2020 were retrospectively analyzed in the present study. The diagnostic criteria for KD conformed to the guidelines of the AHA 2004[19], and subsequently, by the AHA 2017[20]. The exclusion criteria were as follows: (1) History of KD; (2) incident cases in receipt of IVIG treatment in another hospital; (3) non-use of IVIG during hospitalization; (4) poor laboratory data records during hospitalization; and (5) the patients with inflammatory diseases, immune diseases, hematological diseases, metabolic diseases, cancer, liver and kidney diseases, and other heart diseases. All children with KD were treated with IVIG [1-2 g/(kg/day)] plus oral aspirin [30-50 mg/(kg/day)]. IVIG-resistant patients were those with recurrent fever ≥38°C and recrudescence of one or more of the initial symptoms, or persistent fever for at least 36 h after completion of initial IVIG infusion [19]. The present study was approved by the Ethics Committee of the Affiliated Hospital of Southwest Medical University, Sichuan Academy of Medical Sciences, Sichuan People’s Hospital, The First People’s Hospital of Yibin, The Second People’s Hospital of Yibin, Luzhou People’s Hospital, Southwest Medical University Affiliated Hospital of traditional Chinese Medicine, which strictly complied with the 1975 Helsinki Declaration, revised in 1996.
The clinical parameters of patients, such as age and sex, were collected from the medical data. Laboratory investigations included the following: The counts of white blood cells, neutrophils, lymphocytes, monocytes and platelets, hemoglobin level, albumin level, serum sodium level and total bilirubin were collected before IVIG treatment. The definitions of PNI, NLR and PLR were shown as follows: PNI = albumin (g/L) + 5×total lymphocyte count (109/L); NLR = neutrophil/lymphocyte counts; and PLR = platelet/lymphocyte counts [10].