COVID-19 and chronic kidney disease: a comprehensive review

Kidney impairment in hospitalized patients with SARS-CoV-2 infection is associated with increased in-hospital mortality and worse clinical evolution, raising concerns towards patients with chronic kidney disease (CKD). From a pathophysiological perspective, COVID-19 is characterized by an overproduction of inflammatory cytokines (IL-6, TNF-alpha), causing systemic inflammation and hypercoagulability, and multiple organ dysfunction syndrome. Emerging data postulate that CKD under conservative treatment or renal replacement therapy (RRT) is an important risk factor for disease severity and higher in-hospital mortality amongst patients with COVID-19. Regarding RAAS blockers therapy during the pandemic, the initial assumption of a potential increase and deleterious impact in infectivity, disease severity, and mortality was not evidenced in medical literature. Moreover, the challenge of implementing social distancing in patients requiring dialysis during the pandemic prompted national and international societies to publish recommendations regarding the adoption of safety measures to reduce transmission risk and optimize dialysis treatment during the COVID-19 pandemic. Current data convey that kidney transplant recipients are more vulnerable to more severe infection. Thus, we provide a comprehensive review of the clinical outcomes and prognosis of patients with CKD under conservative treatment and dialysis, and kidney transplant recipients and COVID-19 infection.