Changing of therapeutic trends between the 1st and 2nd wave did not reduce COVID-19 related mortality of renal transplant recipients: a national registry study. (preprint)

SARS-CoV-2 pandemic evolved in two consecutive waves over 2020 (for France: 1st wave from March 1 to July 31; and 2nd wave from August 1 to December 31). Improvements in the management of COVID-19 led to a reduction of mortality rates in hospitalized patients during the second wave. Whether this progress also benefited to kidney transplant recipients (KTR), a population particularly vulnerable to severe COVID-19, remained unclear. In France, 957 KTR were hospitalized for COVID-19 in 2020 and their data were prospectively collected in the French SOT COVID registry. The presentation, management, and outcomes of the 359 KTR diagnosed during the 1st wave were compared to those of the 598 of the 2nd wave. Baseline comorbidities were largely similar between KTR of the 2 waves. Maintenance immunosuppression was reduced in most patients but withdrawal of antimetabolite (73.7% vs 58.4%, p<0.001) or CNI (32.1% vs 16.6%, p<0.001) was less frequent during the 2nd wave. Hydroxychloroquine and azithromycin that were commonly used during the 1st wave (21.7% and 30.9%, respectively) were almost abandoned during the 2nd. In contrast, the use of high dose corticosteroids doubled (19.5% vs. 41.6%, p<0.001). Despite these changing trends in COVID-19 management, 60-day mortality was not statistically different between the 2 waves (25.3% vs. 23.9%; Log Rank, p=0.48). We conclude that changing of therapeutic trends during 2020 did not reduce COVID-19 related mortality in KTR. Our data indirectly support the importance of vaccination and monoclonal neutralizing anti-SARS-CoV-2 antibodies to protect KTR from severe COVID-19.

Proteinuria in COVID-19: prevalence, characterization and prognostic role (preprint)

Background: Proteinuria has been commonly reported in patients with COVID-19, suggesting a renal involvement in this infection. However, only dipstick tests have been used thus far. Here, the quantification and characterization of proteinuria and hematuria are investigated. Their potential association with mortality was assessed. Methods: This retrospective, observational and monocentric study includes 153 patients hospitalized with COVID-19 between March 28th and April 30th 2020, in whom total proteinuria and urine α1-microglobulin (a marker of tubular injury) have been measured. Association with mortality was evaluated with a follow-up until May 7th 2020. Results: According to the Kidney Disease Improving Global Outcomes staging, 14% (n=21) had stage 1 proteinuria (<150 mg/g of urine creatinine), 42% (n=64) had stage 2 (between 150 and 500 mg/g) and 44% (n=68) had stage 3 (over 500 mg/g). Urine α1-microglobulin concentration was higher than 10 or 15 mg/g in 94% and 89% of patients, respectively. After a median follow-up of 27 [14;30] days, the mortality rate reached 18%. Total proteinuria and urine α1-microglobulin (as continuous and/or categorical variables) were associated with mortality in unadjusted and adjusted models. This association was even stronger in subgroups of patients with normal renal function or without urinary catheter. Conclusions: Proteinuria is frequent in patients with COVID-19. Its characterization suggests a tubular origin with increased urine α1-microglobulin. Tubular proteinuria seems associated with mortality in COVID-19.