Acute kidney disease in patients with COVID-19. A prospective, multicenter, multinational study in Latin America.

Introduction: Acute kidney disease (AKD) is defined as functional and/or structural abnormalities of kidneys with health implications and a duration of ≤90 days. This study aimed to evaluate AKD as a more appropriate approach to these conditions for which we used a cohort of COVID-19 patients in whom kidney impairment is expressed by proteinuria and/or loss of function.

Methods: Observational, prospective, longitudinal, multinational cohort study conducted across five Latin American countries. Adult patients with diagnosis of COVID-19 were included. Upon hospital admission, urinalysis or urine strip test was performed. If protein was not detected, a follow-up search was conducted five days later. Patients were classified in four AKD categories: non-kidney disease, proteinuria only, acute kidney injury (AKI) only, and proteinuria and AKI.

Results: Three hundred and sixty patients were included. AKD was present in 273 (75.8%), of whom 142 (52.0%) had only proteinuria, 11 (4.1%) had AKI without proteinuria, and 120 (43.9%) had both proteinuria and AKI. Overall, proteinuria with or without AKI was present in 262 patients (72.8%). AKI with or without proteinuria occurred in 131 patients (36.4%). AKI was mainly severe, non-oliguric, and hospital-acquired. In-hospital mortality increased with the severity of AKD: non-kidney disease 9.5%, proteinuria only 22.8%, AKI only 56.7%, and proteinuria plus AKI 53.0% (p = 0.001).

Conclusions: Our data endorse a comprehensive approach based on the concept of AKD. This integrative approach, encompassing the structural and functional continuum of AKI, AKD, and CKD, enables timely interventions and the implementation of preventive and therapeutic strategies.