Latin American Registry of renal involvement in COVID-19 disease. The relevance of assessing proteinuria throughout the clinical course

The Latin American Society of Nephrology and Hypertension carried out a cohort prospective, multinational registry of patients with kidney impairment associated to COVID-19 in Latin America through open invitation in order to describe the characteristics of the disease in the region. A population of 870 patients from 12 countries were included. Median age was 63 years (54-74), most of patients were male (68.4%) and had comorbidities (87.2%). Acute kidney injury (AKI) was hospital-acquired in 64.7% and non-oliguric in 59.9%. Multiorgan dysfunction syndrome (MODS) due to COVID-19 and volume depletion were the main causes of AKI (59.2% and 35.7% respectively). Kidney replacement therapy was started in 46.2%. Non-recovery of renal function was observed in 65.3%. 71.5% of patients were admitted to ICU and 72.2% underwent mechanical ventilation. Proteinuria at admission was present in 62.4% of patients and proteinuria during hospital-stay occurred in 37.5%. Those patients with proteinuria at admission had higher burden of comorbidities, higher baseline sCr, higher mortality and MODS was severe. On the other hand, patients with de novo proteinuria had lower burden of comorbidities and near normal sCr at admission, but showed adverse course of disease and higher in-mortality. COVID-19 MODS was the main cause of AKI in both groups. All-cause mortality was 57.4%, and it was associated to age, chronic cardiac disease, fluid depletion, COVID-19 MODS, non-recovery of renal function, ICU admission, vasopressors, in-hospital complications and hospital stay. In conclusion, our study contributes to a better knowledge of this condition and highlights the relevance of the detection of proteinuria throughout the clinical course.