The study, published in Kidney International, was carried out in the New York City area in 4 hospitals owned by Northwell Health, looking at hospitalizations from March 9, 2020, through August 13, 2020.
The researchers used the CDC definition for MIS-C, which includes children who presented with fevers, significant evidence of inflammation, and evidence of dysfunction in 2 or more organs, and tested positive for current or recent SARS-CoV-2 infection.
Of the 166 children admitted for acute COVID-19 or MIS-C, 152 patients were included in the study, with 97 patients (63%) admitted for acute COVID-19 and 55 patients (36.2%) diagnosed with MIS-C.
Overall, AKI developed in 18 (11.8%) of all patients.
Of children diagnosed with COVID-19 alone, the median age was 8.2 years and more than half were male. Eight patients (8.2%) developed AKI; 4 presented with AKI on admission; 6 had stage 1 AKI, and 2 had stage 3 AKI. There were no significant differences in age, sex, race, and body mass index (BMI) among children with and without AKI. Other findings showed that 50% of patients with AKI had gastrointestinal symptoms, and AKI was linked with significantly lower serum calcium and albumin and significantly higher baseline white blood cell count.
Children hospitalized with MIS-C were a little younger (median age, 7.5 years) and again largely male. AKI was higher in these patients (10, or 18.2%) than in those with COVID-19; 80% had AKI on admission. Those with AKI had greater BMI and all had gastrointestinal symptoms. In addition, patients with AKI had lower median left ventricular ejection fraction as well as systolic dysfunction.
In addition, children identified as Black were 2.86 times more likely to have AKI (95% CI, 1.04-7.93; P = .042).
Patients with AKI had higher rates of vasopressor treatment and ionotropic support. Continuous kidney replacement therapy was needed in 2 children with COVID-19; 2 others needed extracorporeal membrane oxygenation. Two patients in the COVID-19 group died; no patients died in the MIS-C cohort.
The cases of AKI resolved by the time of discharge, the authors said, although these children had longer hospital stays.
Previous estimates of AKI in children have varied from 1.4% to 44%, and the authors said that likely reflects the heterogeneity of study populations or definitions of AKI.
“Further research in larger cohorts is needed to characterize AKI risk factors in children with acute-COVID-19 and MIS-C,” the authors concluded.
Basalely A, Gurusinghe S, Schneider J, et al. Acute kidney injury in pediatric patients hospitalized with acute COVID-19 and Multisystem Inflammatory Syndrome in Children associated with COVID-19. Kidney Int. Published online March 3, 2021. doi:10.1016/j.kint.2021.02.026