COVID-19 pandemic and kidney disease in children: literature review and own regional observations

Introduction. Currently, the coronavirus infection pandemic caused by the SARS-CoV-2 virus continues around the world. Research data from domestic and foreign authors indicate that the kidneys are a target organ for a new infection, lesions vary from proteinuria and hematuria to acute kidney injury.Aim of the study – to determine the frequency and nature of kidney damage in children with confirmed coronavirus infection.Materials and methods. A retrospective and prospective analysis of cases of confirmed COVID-19 infection in children (n = 441) admitted to the Samara Regional Children’s Infectious Diseases Hospital from March 2020 to July 2021 was carried out. SARSCoV-2 RNA was detected in all patients by a one-step reverse transcription reaction combined with a polymerase chain reaction. The changes in the kidneys that occurred in 57 children were studied. The research results were processed using the Statistica 7.0 software (StatSoft, USA).Results. The involvement of the kidneys in the infectious process was detected in every 8 children with COVID-19 (12.9%), more often in the form of isolated urinary syndrome, the detection rate of which correlated with the severity of the course of coronavirus infection: in severe cases, proteinuria was detected in 31.6% of patients, hematuria – in 21%, acute kidney injury – in 10.5%, diabetic nephropathy – in 5.3%. Kidney damage was combined with damage to the respiratory and gastrointestinal tract, characterized by rapid recovery of urine output and azotemia parameters without special renal therapy. A clinical case of the onset of nephrotic syndrome that developed 2 weeks after suffering a coronavirus infection is described.Conclusions. Children with COVID-19 require kidney function monitoring for early detection and correction in case of impairment. Patients with isolated urinary syndrome in the acute period require long-term observation in order to detect latent renal pathology.