MIS-C and AKI in Pediatric COVID-19

Multisystem inflammatory syndrome (MIS-C) is a rare pediatric hyper-inflammatory disorder that may follow SARS-CoV-2 infection in children. Approximately 1/4 to 1/3 of patients with MIS-C develop acute kidney injury (AKI) and face increased risk for poor prognosis.

Anchal Kumar Tripathi, MBBS, and colleagues performed a review to assess the incidence of AKI, mortality, and the need for renal replacement therapy (RRT) in patients with MIS-C. Results were reported online in Pediatric Nephrology [doi.org/10.1007/s00467-022-05701-3].

The researchers searched databases from Medline, EMBASE, Cochrane Register, and Google Scholar from December 2019 to December 2021. Eligible studies included the following criteria: (1) articles on AKI in MIS-C; (2) studies that provided data on AKI in MIS-C and COVID-19 infection separately; (3) studies reporting outcomes related to mortality, RRT, serum creatinine level, and length of hospital and/or intensive care stay. The National Heart Lung and Blood Institute quality assessment tool was used to assess the quality of the cohort studies and case series included in the review.

Outcomes and their 95% CIs were reported if a meta-analysis of the outcomes of interest was conducted. Heterogeneity was reported using I2 statistics, and heterogeneity ≥50% was considered high.

The review included 24 studies. Of those, 11 were included in the meta-analysis. The pooled proportion of patients with MIS-C developing AKI was 20% (95% CI, 14%-28%; I2=80%). Pooled proportion of death in children with MIS-C was 4% (95% CI, 1%-14%; I2=93%). The odds of death in patients with AKI were 4.68 times higher than in patients without AKI (95% CI, 1.06%-20.7%; I2=17%). The overall proportion of patients with MIS-C who required RRT was 15% (95% CI, 4%-42%; I2=91%).

In summary, the researchers said, “Approximately 1/5 of children with MIS-C develop AKI which is associated with higher odds of death.”