Renal Involvement in Hospitalized Children With COVID-19

COVID-19 usually causes respiratory and gastrointestinal symptoms, Clinical features range from a common cold to severe diseases such as bronchitis, pneumonia, severe acute respiratory distress syndrome, multi-organ failure, and even death. SARS-CoV, MERS-CoV, and SARS-CoV-2 seem to less commonly affect children and to cause fewer symptoms and less severe disease in this age group compared with adults and are associated with much lower case-fatality rates. Coronaviruses are a large family of enveloped, single-stranded, zoonotic RNA viruses. Clinicians have observed many extrapulmonary manifestations of COVID-19, as hematologic, cardiovascular, renal, and gastrointestinal and hepatobiliary, endocrinologic, neurologic, ophthalmologic, and dermatologic systems can all be affected.

Acute kidney injury (AKI) is a frequent complication of COVID-19 and is associated with mortality. In adults, the incidence of AKI in hospitalized patients with COVID-19 ranged from 0.5% to 29% and occurred within a median of 7-14 days after admission. Studies from the USA have reported much higher rates of AKI. In a study of nearly 5,500 patients admitted with COVID-19 in a New York City hospital system, AKI occurred in 37%, with 14% of the patients requiring dialysis. AKI occurred at much higher rates in critically ill patients admitted to New York City hospitals, ranging from 78% to 90%. Of 257 adult patients admitted to ICUs in a study from New York City, 31% received renal replacement therapy (RRT). Furthermore, hematuria has been reported in nearly half of patients with COVID-19, and proteinuria has been reported in up to 87% of critically ill patients with COVID-19 (11). Hyperkalemia and acidosis are common electrolyte abnormalities seen in patients with COVID-19, even among patients without AKI. COVID-19 is also increasingly reported among patients with end-stage renal disease and kidney transplant recipients, with higher mortality rates than those seen in the general population.

Children and adolescents with COVID-19 fare considerably better than adults, with mortality rates in pediatric patients (age <18 years) of less than 1% reported in early studies . The most common clinical features in children described in the literature are fever, dry cough, and pneumonia . However, multisystem involvement is increasingly being recognized, including the development of hyperinflammatory shock.

In other studies, acute kidney injury has been reported in adult patients with COVID-19, with a high prevalence across inpatient admissions (≤7%) and admissions to adult intensive care units (ICUs; ≤23%), as first reported in Wuhan, China . In adult patients with COVID-19, acute kidney injury is related to increased mortality risk, even after adjustment for age, sex, and comorbidities. In addition, a large proportion of adults have proteinuria (44%) and hematuria (27%) at presentation, despite an elevated serum creatinine prevalence of only 16% .

In children, there is scanty data compared to adults, Douglas et al studied 52 pediatric patients (ages 0-16 years) admitted to Great Ormond Street Hospital for Children NHS Foundation Trust (London, UK) since March 25, 2020, with confirmed severe acute respiratory syndrome coronavirus infection, and diagnosed by either a positive PCR result or seropositivity. Of the 52 inpatients, 24 (46%) had a serum creatinine greater than the upper limit of reference interval (ULRI), 22 [42%] had proteinuria, and hematuria was found in 40 [77%] patients. Qui and colleagues (18) did not find any renal dysfunction in 36 hospitalized pediatric patients (ages 0-16 years) with COVID-19 in China. Renal dysfunction defined by a serum creatinine greater than 110 μmol/L or serum urea greater than 7 mmol/L.