[COVID-19 and the kidneys-Clinical aspects].

The aim of this article is to explain the clinical benefits of the growing knowledge about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to the lungs, SARS-CoV‑2 can invade multiple cell types in other organs, such as the kidneys and replicate there. Important damaging pathways of the virus, such as vascular endotheliitis, thrombotic events and systemic cytokine release are still incompletely understood. Coronavirus disease 2019 (COVID-19) is a systemic disease that necessitates intensive medical care and in particular, internal medicine involvement and represents a major challenge for all disciplines of internal medicine. Among these, nephrology in particular is involved in the fight against COVID-19 in a variety of ways: urine investigations can provide indications of multiple organ involvement, endotheliitis, microthrombi and microcirculation damage, etc. Experience with low serum albumin levels and antithrombin III activity in nephrotic patients helps to point out the decreasing effects of loop diuretics and heparin to other specialist disciplines. Nephrological knowledge of the complications of hypoalbuminemia and "resistance" to diuretics must lead to an early implementation of renal replacement procedures in order to be able to prevent mechanical ventilation in COVID-19 intensive care patients with increased extracellular lung fluid. The kidneys can be used as a seismograph for severe courses of COVID-19 and nephrological knowledge can be brought to use to optimize the intensive medical care for critically ill patients. Both together have the potential to considerably reduce morbidity and mortality further.