Long-Term Kidney Outcomes After SARS-CoV-2 Infection in Children Aged 0-12 Years: A Systematic Review

Area of Science:

• Pediatric Nephrology
• Infectious Diseases
• Public Health

Background:

• Acute kidney injury (AKI) is recognized in pediatric COVID-19 and multisystem inflammatory syndrome in children (MIS-C).
• Long-term renal consequences in children aged 0-12 years post-SARS-CoV-2 infection or MIS-C remain largely unknown.
• Existing studies often lack age-specific data for this younger demographic.

Purpose of the Study:

• To systematically review and synthesize evidence on post-acute (≥30 days) and long-term (≥90 days) kidney outcomes in children aged 0-12 years following SARS-CoV-2 infection or MIS-C.
• To evaluate outcomes including chronic kidney disease (CKD), eGFR decline, proteinuria, haematuria, hypertension, and kidney replacement therapy.
• To identify gaps in current knowledge and inform future research directions.

Main Methods:

• Systematic literature search of MEDLINE, Embase, CINAHL, and PubMed (December 2019-November 2025).
• Inclusion of observational studies reporting kidney outcomes ≥30 days post-infection in children aged 0-12 years, following PRISMA 2020 guidelines.
• Risk of bias assessment using Newcastle-Ottawa Scale or ROBINS-I; narrative synthesis due to data heterogeneity.

Main Results:

• Seven studies met inclusion criteria (five MIS-C, two COVID-19 cohorts); limited age-specific data for 0-12 years.
• No incident CKD, sustained eGFR decline, or kidney replacement therapy reported in long-term follow-up within the limited 0-12 age group data.
• One MIS-C study reported hypertension in 14%; mild COVID-19 cohort showed transient hyperfiltration, proteinuria, and microhaematuria.
• Broader pediatric EHR data suggest potential CKD risk post-COVID-19, but 0-12-year-specific data were not reported.

Conclusions:

• Evidence on long-term kidney outcomes in children aged 0-12 years post-SARS-CoV-2 infection is scarce, with limited age-specific data.
• MIS-C cohorts generally indicate favorable renal recovery, but small sample sizes and short follow-up limit confidence.
• Potential long-term renal risk in broader pediatric populations necessitates age-stratified prospective studies with comprehensive renal assessments.