The authors reply
Authors: Marc Hazzan, Sophie Caillard
Journal: Kidney International (2020)

We thank Søfteland et al.1Søfteland J.M. Karason K. Magnusson J. et al.Registry reports in COVID-19 patients: juggling with big data, poor data, and no data.Kidney Int. 2020; 98: 1618Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar for their interest in our registry based-study focusing on coronavirus disease 2019 (COVID-19) in kidney transplant recipients.2Caillard S. Anglicheau D. Matignon M. et al.An initial report from the French SOT COVID Registry suggests high mortality due to COVID-19 in recipients of kidney transplants.Kidney Int. 2020; 98: 1549-1558Abstract Full Text Full Text PDF PubMed Scopus (199) Google Scholar They lament that a discrepancy exists between the number of patients reported in the introductory section (n = 426) and those included in the final analysis (n = 279). However, the 147 excluded patients had <30 days of follow-up at the time of the report (April 2020), and their data were incomplete. Their inclusion would have resulted in biased results, especially in terms of COVID-19–related mortality. As of June 2020, our registry has been expanded to included 491 kidney transplant recipients with complete follow-up data for >2 months. The results from the updated dataset are entirely in line with the published study.2Caillard S. Anglicheau D. Matignon M. et al.An initial report from the French SOT COVID Registry suggests high mortality due to COVID-19 in recipients of kidney transplants.Kidney Int. 2020; 98: 1549-1558Abstract Full Text Full Text PDF PubMed Scopus (199) Google Scholar Søfteland et al. also question our definition for severe COVID-19 as a composite endpoint of intensive care unit admission, need for mechanical ventilation, and death. Although our choice was not without caveats, 81 of the 106 patients considered to have severe disease met the updated criteria for severe or critical illness3National Institutes of HealthClinical presentation of people with SARS-CoV-2 infection.https://www.covid19treatmentguidelines.nih.gov/overview/management-of-covid-19/Google Scholar; that is, had SpO2 <94 mmHg and/or required mechanical ventilation. This consensus definition was not yet reached at the time of our report. Finally, we acknowledge that registry-based studies are prone to unavoidable confounding or residual confounding on unmeasured variables. The French SOT COVID Registry has strived to investigate the characteristics of the COVID-19 pandemic among immunosuppressed patients in a timely and highly committed fashion. We are confident in the reliability and robustness of our published findings. An initial report from the French SOT COVID Registry suggests high mortality due to COVID-19 in recipients of kidney transplantsKidney InternationalVol. 98Issue 6PreviewNotwithstanding the ongoing coronavirus disease-2019 (Covid-19) pandemic, information on its clinical presentation and prognosis in recipients of a kidney transplant remain scanty. The aim of this registry-based observational study was to explore characteristics and clinical outcomes of recipients of kidney transplants included in the French nationwide Registry of Solid Organ Transplant Recipients with Covid-19. Covid-19 was diagnosed in symptomatic patients who had a positive PCR assay for SARS-CoV-2 or having typical lung lesions on imaging. Full-Text PDF Registry reports in COVID-19 patients: juggling with big data, poor data, and no dataKidney InternationalVol. 98Issue 6PreviewWe read with great interest the recent paper by Caillard et al.,1 which is an interesting addition to the burgeoning coronavirus disease 2019 (COVID-19) literature.2 However, we noted a discrepancy between the 426 kidney transplant recipients reported to the registry and the 279 cases presented, which corresponds to one-third of all patients. These available but unreported cases may have significantly impacted the results, but the authors neither explain this omission nor acknowledge it as a limitation. Full-Text PDF