To the editor:

We read with interest the Impact of the COVID-19 Epidemic on the Mortality of Kidney Transplant Recipients and Candidates in a French Nationwide Registry study (IMPORTANT) study, focused on the impact that coronavirus disease 2019 (COVID-19) has had on dialysis and transplant patients.¹ The authors report that 44% and 42% of the deaths recently recorded in kidney transplant recipients and dialysis patients candidates for transplantation, respectively, are attributable to COVID-19 and clearly show that these deaths are in excess of the mortality observed in the previous year. Interpreting these results, the authors are in favor of maintaining kidney transplant activity, at least in areas of low viral circulation, to remove patients from the dialysis pool and thereby protect them from the excess mortality related to dialysis. While agreeing with the importance of maintaining transplant programs, we would like to draw attention to a complementary reading of the results. In fact, 122 deaths after kidney transplantation and 60 in waitlisted patients when considering 606 and 478 COVID-19 diagnoses, respectively, correspond to 19.5% mortality in kidney transplant patients and 12.5% in waitlisted patients found to be severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–positive. This mortality rate is consistent with previous reports on kidney transplant recipients (approximately 22.8%)² and is even lower compared with the overall mortality in COVID-19 patients on dialysis (approximately 20%)³ in the same country in the same period, even in areas of high-viral circulation.⁴ The lower mortality in waitlisted dialysis patients is presumably due to the positive selection of these cases.

It is noteworthy that the cumulative incidence of SARS-CoV-2 positivity was almost double in waitlisted patients compared with kidney transplant recipients (2.95% in waitlisted patients vs. 1.46% after kidney graft), and this difference is still being found during the second wave of the pandemic (6.3% in the overall dialysis population vs. 2.3% in kidney transplant patients), according to the latest data published by the French Agency of Biomedicine, on November 9, 2020.

The excess of mortality in dialysis observed during the first COVID-19 pandemic wave was therefore not due to a different viral aggressiveness but depended on the higher risk of becoming infected. Hemodialysis patients are compelled to come to the hospital for renal replacement therapy and cannot be confined at home, thus multiplying occasions for contagion; the risk exposure is not shared only by the relatively few home-dialysis patients.⁵ More frequent contact with a hospital was in fact also considered one of the reasons for a higher death risk in the first year after kidney transplantation.

In parallel to the suggestions regarding kidney transplant activity, we believe that the data reported clearly underline the need for optimizing protection of hemodialysis patients, trying also to identify the best strategies for personal protection, screening, and follow-up of positive cases. Development of home-based dialysis, the advantages of which have been demonstrated, in particular in areas of high viral circulation,⁶ is probably the best long-term strategy, effective not only in increasing patient empowerment, adherence, and perhaps survival but also in protecting our fragile population from present and future epidemic outbreaks.