Incidence and Outcome of SARS-CoV-2 Infection on Solid Organ Transplantation Recipients

A Nationwide Population-Based Study

Silvia Trapani; Lucia Masiero; Francesca Puoti; Maria C. Rota; Martina Del Manso; Letizia Lombardini; Flavia Riccardo; Antonio Amoroso; Patrizio Pezzotti; Paolo A. Grossi; Silvio Brusaferro; Massimo Cardillo


American Journal of Transplantation. 2021;21(7):2509-2521. 

In This Article

Abstract and Introduction


Since February 21 2020, when the Italian National Institute of Health (Istituto Superiore di Sanità–ISS) reported the first autochthonous case of infection, a dedicated surveillance system for SARS-CoV-2-positive (COVID+) cases has been created in Italy. These data were cross-referenced with those inside the Information Transplant System in order to assess the cumulative incidence (CI) and the outcome of SARS-COV-2 infection in solid organ transplant recipients (SOTRs) who are assumed to be most at risk. We compared our results with those of COVID+ nontransplanted patients (Non-SOTRs) with follow-up through September 30, 2020. The CI of SARS-CoV-2 infection in SOTRs was 1.02%, higher than in COVID+ Non-SOTRs (0.4%, p < .05) with a greater risk in the Lombardy region (2.89%). The CI by type of organ transplant was higher for heart (CI 1.57%, incidence rate ratio [IRR] 1.36) and lower for liver (CI 0.63%, IRR 0.54). The 60-day CI of mortality was 30.6%, twice as much that of COVID+ Non-SOTRs (15.4%) with a 60-day gender and age adjusted odds ratio (adjusted-OR) of 3.83 for COVID+ SOTRs (95% confidence interval [3.03–4.85]). The lowest 60-day adjusted-OR was observed in liver SOTRs (OR 0.46, 95% confidence interval [0.25–0.86]). More detailed studies on disease management and evolution will be necessary in these patients at greater risk of COVID-19.


Italy has faced a real health emergency in the past months. The Coronavirus Disease 2019 (COVID-19) pandemic has spread rapidly in the initial months of 2020, leading to the saturation of Intensive Care Unit (ICU) beds and channeling of all of the efforts of healthcare workers towards COVID-19 management and containment. Due to the upward daily trend of positive cases, the Italian government set the so-called national lock-down period from March 9 to May 18 2020, during which increasingly strict measures were introduced for the entire population, in order to curb contagion. The maximum number of positive cases was reached in April (108 237 confirmed positive cases as of April 20), then a steady decrease was recorded during the months of May, June and July (12 230 confirmed cases as of 30 July).[1] On June 3, the government ordered the reopening of the interregional borders. To date, with 542 789 cumulative cases confirmed as of October 27, 2020, Italy is among the most affected countries by the pandemic, after the Russian Federation (1 547 774 confirmed cases), France (1 134 296 confirmed cases), Spain (1 046 132 confirmed cases) and the United Kingdom (894 694 confirmed cases) in Europe, that is after the United States (8 548 111 confirmed cases) and South-East Asia (8 969 707 confirmed cases) globally.[2]

During the initial months of the COVID-19 outbreak, all the efforts of the Italian National Transplant Center (CNT), the competent authority in the donation and transplantation field, were focused on the preservation of donation and transplantation activities, as urgent and life-saving procedures calling for continuity. Regulatory measures were issued to safely continue this activity in Italy, by routinely testing donors and recipients on the waiting list for SARS-CoV-2 and creating COVID-free pathways inside the transplant centers. The collaboration between transplant centers in the regions most affected by COVID-19 with those of less involved areas was fostered.[3–5] Adopted measures allowed the balanced performance of transplantation activity in Italy in the first 4 weeks of the COVID-19 epidemic compared to the same period of previous years, despite a reduction of 30% in the deceased donor rate being observed in the Northern regions, where 70% of all Italian deceased donors are procured.[6]

As of October 31, 2020 a minimal reduction in donation and transplantation activities in Italy (−10% and −6.6% compared to the same period of 2019, respectively) is confirmed.[7] Another end-point for the Italian Competent Authorities was the surveillance of the solid organ transplant recipients (SOTRs) in relation to the ongoing pandemic.

COVID-19 has proven to be more severe and lethal in subjects of older age and with various preexisting comorbidities.[8–11] Therefore, due to the need for chronic immunosuppressive therapy and to more or less prolonged end-stage organ disease, it is conceivable that SOTRs might present a less favorable outcome of the disease.[12] In the first month of epidemic in Italy, the Bergamo experience showed that, among patients followed-up for cirrhosis, transplantation, autoimmune disease, or chemotherapy for hepatoblastoma, none developed a clinical pulmonary disease, despite some testing positive for SARS-CoV-2 (both children and adults).[13] Conflicting opinions about this are currently being expressed and so far there are no conclusive data in the literature allowing us to say a final word.

For these reasons, this study aims at evaluating whether SOTRs were at increased risk of SARS-CoV-2 infection and mortality in the early peak period of the pandemic, by assessing the cumulative incidence (CI) of infection and analyzing mortality and the role of solid organ transplantation (SOT) as mortality risk factor in SOTRs compared to the global infected population.