[Coronavirus disease 2019 pandemic from a nephrological perspective]. / "Coronavirus-disease-2019"-Pandemie aus nephrologischer Perspektive.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has also resulted in substantial challenges for nephrology worldwide. Patients with chronic kidney diseases are a particularly vulnerable patient group in this context and in severe courses of COVID-19 the kidneys are most frequently affected by organ failure after the lungs. MATERIAL AND METHODS: In order to reliably evaluate the prevalence and mortality of dialysis patients in Germany with respect to COVID-19, during the first wave in spring 2020 the German Society of Nephrology implemented a registry for dialysis patients. Weekly data on the number and course of dialysis patients affected by COVID-19 were recorded and analyzed. RESULTS: The prevalence of COVID-19 in dialysis patients in Germany developed in two waves, similar to the course of the pandemic in the general population. In spring the prevalence in dialysis patients reached 1.4% and considerably declined during the summer. In December during the second wave of the pandemic the prevalence again rose to 1.9%, despite comprehensively implemented hygiene measures in dialysis centers. Similar to other industrial nations, dialysis patients in Germany also showed a very high lethality of COVID-19 of up to 20%. CONCLUSION: Immediate consequences for hygiene measures in dialysis institutions as well as vaccination strategies and vaccination prioritization for this patient group and the personnel treating them can be derived from the high mortality in dialysis patients. A consequence of the frequent involvement of the kidneys during infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients who had not previously suffered from advanced kidney disease should be the consistent nephrological aftercare.

Validation of a Prospective Urinalysis-Based Prediction Model for ICU Resources and Outcome of COVID-19 Disease: A Multicenter Cohort Study.

In COVID-19, guidelines recommend a urinalysis on hospital admission as SARS-CoV-2 renal tropism, post-mortem, was associated with disease severity and mortality. Following the hypothesis from our pilot study, we now validate an algorithm harnessing urinalysis to predict the outcome and the need for ICU resources on admission to hospital. Patients were screened for urinalysis, serum albumin (SA) and antithrombin III activity (AT-III) obtained prospectively on admission. The risk for an unfavorable course was categorized as (1) "low", (2) "intermediate" or (3) "high", depending on (1) normal urinalysis, (2) abnormal urinalysis with SA ≥ 2 g/dL and AT-III ≥ 70%, or (3) abnormal urinalysis with SA or AT-III abnormality. Time to ICU admission or death served as the primary endpoint. Among 223 screened patients, 145 were eligible for enrollment, 43 falling into the low, 84 intermediate, and 18 into high-risk categories. An abnormal urinalysis significantly elevated the risk for ICU admission or death (63.7% vs. 27.9%; HR 2.6; 95%-CI 1.4 to 4.9; p = 0.0020) and was 100% in the high-risk group. Having an abnormal urinalysis was associated with mortality, a need for mechanical ventilation, extra-corporeal membrane oxygenation or renal replacement therapy. In conclusion, our data confirm that COVID-19-associated urine abnormalities on admission predict disease aggravation and the need for ICU (ClinicalTrials.gov number NCT04347824).

Clonal expansion and activation of tissue-resident memory-like Th17 cells expressing GM-CSF in the lungs of severe COVID-19 patients.

Hyperinflammation contributes to lung injury and subsequent acute respiratory distress syndrome (ARDS) with high mortality in patients with severe coronavirus disease 2019 (COVID-19). To understand the underlying mechanisms involved in lung pathology, we investigated the role of the lung-specific immune response. We profiled immune cells in bronchoalveolar lavage fluid and blood collected from COVID-19 patients with severe disease and bacterial pneumonia patients not associated with viral infection. By tracking T cell clones across tissues, we identified clonally expanded tissue-resident memory-like Th17 cells (Trm17 cells) in the lungs even after viral clearance. These Trm17 cells were characterized by a a potentially pathogenic cytokine expression profile of IL17A and CSF2 (GM-CSF). Interactome analysis suggests that Trm17 cells can interact with lung macrophages and cytotoxic CD8+ T cells, which have been associated with disease severity and lung damage. High IL-17A and GM-CSF protein levels in the serum of COVID-19 patients were associated with a more severe clinical course. Collectively, our study suggests that pulmonary Trm17 cells are one potential orchestrator of the hyperinflammation in severe COVID-19.