Journal Article

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

Al Nasser, Dawood Adnan, Almusabeh, Hassan M., Alhumaid, Saad, Alqahtani, Manahi Ayadh, Al Alawi, Zainab, Alabdullah, Abdulaziz Abdullah, Alamer, Abdulmohsen Ibrahim, Alhadab, Hassan Ali, Alsultan, Ali Ahmed, Al-Kamees, Mustafa A., Alhaddad, Kawther S., Alsaeed, Mohammed Jassim, Alkhamees, Abdullah Abdulrahman, Aljowaisem, Fahad Mohammed, Majzoub, Rabab Abbas, Alnami, Dalal Ahmed, AlShayeb, Rugayah Ahmed, Alatiyyah, Yaqoub Yousef, Al Dossary, Nourah, Almuslim, Anwar A., Alabdulqader, Muneera, ALDuhailan, Muath Ibrahim, Bukhamseen, Ali N., Almubarak, Yasin S., Almuhanna, Mohammed S., Alalwan, Qasem M., Alhumaid, Murtadha A.

2026

Overview

Background: Acute kidney injury (AKI) is increasingly recognised in children with acute COVID-19 and multisystem inflammatory syndrome in children (MIS-C), yet the long-term renal consequences in younger paediatric populations remain unclear. Most studies focus on acute illness or mixed-age cohorts, with limited data specific to children aged 0–12 years. Objectives: This study aimed to systematically identify, evaluate, and synthesise evidence on post-acute (≥30 days) and long-term (≥90 days) kidney outcomes following SARS-CoV-2 infection or MIS-C in children aged 0–12 years, including chronic kidney disease (CKD), eGFR decline, proteinuria, haematuria, hypertension, and need for kidney replacement therapy. Methods: We searched MEDLINE, Embase, CINAHL, and PubMed (December 2019–30 November 2025), following PRISMA 2020 guidelines and a registered PROSPERO protocol (CRD420251241949). Observational studies reporting kidney outcomes ≥30 days post-infection in children aged 0–12 years were included. Risk of bias was assessed using the Newcastle–Ottawa Scale or ROBINS-I. Owing to heterogeneity and absence of ≥3 comparable datasets, a narrative synthesis was performed. Results: Seven studies met inclusion criteria (five MIS-C cohorts, two acute COVID-19 cohorts). Only a subset provided extractable data specific to children aged 0–12 years. Follow-up ranged from 30 days to 12 months; four studies reported outcomes ≥ 180 days. Across all studies, no incident CKD, sustained eGFR decline, or kidney replacement therapy were reported among children completing long-term follow-up; however, most long-term outcome data were derived from MIS-C cohorts with median ages around 8–11 years that included some adolescents, rather than exclusively children aged 0–12 years. One MIS-C study reported long-term hypertension in 14% of children. A cross-sectional Italian cohort of mild COVID-19 demonstrated hyperfiltration, proteinuria, and microhaematuria at ~3 months, though chronicity could not be assessed due to absence of baseline values. A large US EHR-based cohort identified increased CKD risk after COVID-19 in the broader < 21-year population; however, 0–12-year-specific event counts were not reported, preventing quantitative synthesis for young children. Conclusions: Evidence on long-term kidney outcomes after SARS-CoV-2 infection in children aged 0–12 years remains limited, and only a small subset of studies provided extractable, age-specific data. On the other hand, MIS-C cohorts generally show favourable renal recovery, small sample sizes, lack of control groups, and short follow-up restrict confidence in these findings. Large paediatric EHR studies suggest potential long-term renal risk in broader paediatric populations, highlighting the need for age-stratified, prospective cohorts with serial eGFR, urine studies, and blood pressure assessments. Until definitive evidence emerges, structured renal follow-up may be warranted for children with AKI or MIS-C during COVID-19.

• Publisher: MDPI AG,Multidisciplinary Digital Publishing Institute (MDPI)
• Subject: Age / Bias / Blood pressure / children / Chronic kidney failure / Comorbidity / COVID-19 / Creatinine / Cross-sectional studies / Hematuria / Hypertension / Infection / Infections / kidney / Kidney diseases / long-term / Medical research / Medicine, Experimental / Multisystem inflammatory syndrome in children / outcomes / Pediatrics / Physiology / renal / Renal replacement therapy / Severe acute respiratory syndrome coronavirus 2 / Systematic Review / Teenagers