renal involvement in MISC

Abstract

The initial report of multisystem inflammatory syndrome in children (MIS-C) was documented in the UK in April 2020. Renal involvement is notably common, occurring in approximately 10% to 46% of the cases, and has been associated with elevated morbidity and mortality rates. This study aims to systematically review the current understanding of kidney involvement in MIS-C, focusing on the incidence of acute kidney injury (AKI), underlying pathophysiology, and therapeutics prescribed.

Introduction

COVID-19, caused by the novel coronavirus SARS-CoV-2, has been shown to induce severe outcomes in children, particularly those with pre-existing kidney conditions. MIS-C has emerged globally, exhibiting clinical features resembling those of incomplete Kawasaki disease or toxic shock syndrome. This syndrome is characterized by a delayed presentation of symptoms, typically occurring 2-4 weeks after confirmed or suspected COVID-19 infection. AKI has been frequently reported in these cases, with incidence rates ranging from 10% to 60%. It’s important to note that case definitions may vary slightly among differing health organizations.

Methodology

This review was conducted through a systematic literature search in PubMed for studies that relate to MIS-C and AKI from January 2020 to February 2021. Non-English studies and case reports were excluded to maintain the focus on comprehensive research articles, resulting in 18 studies that met the selection criteria.

Clinical Features and Symptoms

Common symptoms associated with MIS-C include persistent fever, skin rashes, conjunctivitis, and abdominal pain. A significant number of affected children present with hypotension that necessitates vasopressor support and subsequent admission to the Pediatric Intensive Care Unit (PICU). Laboratory findings typically reveal signs of severe inflammation, including elevated levels of C-reactive protein (CRP) and liver transaminases.

Pathogenesis

The pathogenesis of MIS-C is hypothesized to stem from an abnormal immune response triggered by SARS-CoV-2. Accumulated research highlights multiple factors contributing to AKI, such as cytokine storms, endothelial dysfunction, and tubular injury. Additionally, there may be potential involvement of risk alleles, such as APOL1, which could modulate the severity of renal disease during COVID-19 infection.

Treatment

Currently, there are no standardized treatment guidelines for addressing MIS-C; therapeutic strategies have been primarily adapted from established protocols for similar diseases. Common treatment regimens often involve administration of intravenous immunoglobulin (IVIG) and corticosteroids aimed at mitigating inflammation. For children exhibiting progressive AKI, renal replacement therapy is critically important. A strong emphasis is placed on the necessity for early intervention and a multidisciplinary management approach to circumvent complications associated with such severe inflammatory responses.

Conclusion

The understanding of kidney disease in relation to MIS-C continues to evolve as new studies and data emerge. Ongoing research remains crucial in clarifying the immunopathogenesis of this syndrome and improving management strategies, thereby enhancing the overall care and outcome for children suffering from these severe inflammatory conditions associated with COVID-19.