Absence of Mortality Differences Between the First and Second COVID-19 Waves in Kidney Transplant Recipients

Abstract

Introduction: SARS-CoV-2 pandemic evolved in 2 consecutive waves during 2020. Improvements in the management of COVID-19 led to a reduction in mortality rates among hospitalized patients during the second wave. Whether this progress benefited kidney transplant recipients (KTRs), a population particularly vulnerable to severe COVID-19, remained unclear.

Methods: In France, 957 KTRs were hospitalized for COVID-19 in 2020 and their data were prospectively collected into the French Solid Organ Transplant (SOT) COVID registry. The presentation, management, and outcomes of the 359 KTRs diagnosed during the first wave were compared to those of the 598 of the second wave.

Results: Baseline comorbidities were similar between KTRs of the 2 waves. Maintenance immunosuppression was reduced in most patients but withdrawal of antimetabolite (73.7% vs. 58.4%, P < 0.001) or calcineurin inhibitor (32.1% vs. 16.6%, P < 0.001) was less frequent during the second wave. Hydroxychloroquine and azithromycin that were commonly used during the first wave (21.7% and 30.9%, respectively) but were almost abandoned during the second wave. 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) and COVID-19 hospitalization period was not associated with death due to COVID-19 in multivariate analysis (Hazard ratio 0.89, 95% confidence interval 0.67-1.17, P = 0.4).

Conclusion: We conclude that changing of therapeutic trends during 2020 did not reduce COVID-19 related mortality among KTRs. Our data indirectly support the importance of vaccination and neutralizing monoclonal anti-SARS-CoV-2 antibodies to protect KTRS from severe COVID-19.

Keywords: COVID-19; SARS-CoV-2; transplantation.

Graphical abstract

Figure 1

Clinical and biological presentation of COVID-19 at admission. (a) Summary of the main clinical and biological characteristics of the entire cohort (N = 957 KTRs), Median [IQR] or n (%), at hospital admission for COVID-19. b. Comparison of characteristics at hospital admission for COVID-19 of patients from the first versus second pandemic wave. c. Comparison of chest computed tomography scan severity between the first and second pandemic waves. c² test; P > 0.05, ns. CRP, C-reactive protein; PCT, procalcitonin; SCr, serum creatinine.

Figure 2

Changing of therapeutic trends between the first and second COVID-19 pandemic waves. Comparison of (a) the management of immunosuppression and (b) the use of COVID-19 specific treatments between the first (blue) versus second (red) pandemic waves. c² test; P > 0.05, ns. ATB, antibiotics; CNI, calcineurin inhibitor; mTor, mechanistic target of rapamycin.

Figure 3

Variables associated with the risk of death due to COVID-19 in KTRs. This forest plot shows the variable independently associated with the risk of death in multivariate analysis for the 957 KTRs diagnosed with COVID-19 during the first or the second pandemic waves. ATG, antithymocyte globulin; CI, confidence interval; CRP, C-reactive protein; CsA, cyclosporin A; eGFR, estimated glomerular filtration rate; HR, hazard ratio.

Figure 4

Comparison of COVID-19 outcomes between the first and second waves. (a) In-hospital survival of KTRS diagnosed with COVID-19 during the first and second wave. (b) Cumulative incidence of Intensive Care Unit admission of KTRS diagnosed with COVID-19 during the first and second wave. (c) Survival of KTRS diagnosed with COVID-19 transferred in ICU. (d) Map of the geographic distribution of the cases of COVID-19 in France during the first wave. Area in which the incidence of COVID-19 was the highest are in red. (e) In-hospital survival of KTRs diagnosed with COVID-19 during the second wave according to their geographic location (in the red or green area defined in panel d). Comparison were made using the Log Rank test.