COVID-19 in Solid Organ Transplant Recipients

A National Cohort Study From Sweden

John M. Søfteland; Gustav Friman; Bengt von Zur-Mühlen; Bo-Göran Ericzon; Carin Wallquist; Kristjan Karason; Vanda Friman; Jan Ekelund; Marie Felldin; Jesper Magnusson; Ida Haugen Löfman; Andreas Schult; Emily de Coursey; Susannah Leach; Hanna Jacobsson; Jan-Åke Liljeqvist; Ali R. Biglarnia; Per Lindnér; Mihai Oltean


American Journal of Transplantation. 2021;21(8):2762-2773. 

In This Article

Abstract and Introduction


Solid organ transplant (SOT) recipients run a high risk for adverse outcomes from COVID-19, with reported mortality around 19%. We retrospectively reviewed all known Swedish SOT recipients with RT-PCR confirmed COVID-19 between March 1 and November 20, 2020 and analyzed patient characteristics, management, and outcome. We identified 230 patients with a median age of 54.0 years (13.2), who were predominantly male (64%). Most patients were hospitalized (64%), but 36% remained outpatients. Age >50 and male sex were among predictors of transition from outpatient to inpatient status. National early warning Score 2 (NEWS2) at presentation was higher in non-survivors. Thirty-day all-cause mortality was 9.6% (15.0% for inpatients), increased with age and BMI, and was higher in men. Renal function decreased during COVID-19 but recovered in most patients. SARS-CoV-2 antibodies were identified in 78% of patients at 1–2 months post-infection. Nucleocapsid-specific antibodies decreased to 38% after 6–7 months, while spike-specific antibody responses were more durable. Seroprevalence in 559 asymptomatic patients was 1.4%. Many patients can be managed on an outpatient basis aided by risk stratification with age, sex, and NEWS2 score. Factors associated with adverse outcomes include older age, male sex, greater BMI, and a higher NEWS2 score.


Solid organ transplant (SOT) recipients are considered a risk group regarding Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This may be due to, in part, immunosuppressive treatment and frequent comorbidities. A recent meta-analysis reports an overall mortality of 18.6% among SOT recipients.[1] However, three relatively large studies from different countries[2–4] have reported a mortality rate of around 10%, which is lower than observed in other extensive studies on SOT recipients with COVID-19.[5–10] This heterogenicity may be due to inherent shortcomings of single-center reports[11] or limitations of registry studies.[12] The majority of previously reported cohorts included a high proportion of hospitalized patients who are more likely to have severe disease. Outpatients who have less severe symptoms and better prognosis may have been missed, which could partly explain the difference between studies.

This inconsistency of available data confounds interpretation of the impact of COVID-19 on the transplanted patient population. Large and detailed studies of the relationship between patient management and outcomes, preferably in a multicenter setting, are crucial to creating efficient guidelines for managing affected transplant recipients. Furthermore, it is essential to explain how age, sex, body mass index (BMI), immunosuppression, and comorbidities affect the clinical course and outcomes.

COVID-19 is known to have adverse effects on renal function,[13] and it is important to understand how this affects transplanted patients, particularly those with a renal graft. Lastly, given the rapid development of vaccines, it is crucial to examine whether patients on immunosuppressants can mount an adequate and lasting serological response.

Sweden has a highly developed, universally free, public healthcare system. While it was strained in the spring and autumn of 2020, it was not overwhelmed. From a policy viewpoint, the country has tackled the pandemic differently from many other countries, with no mandatory lockdowns and fewer obligatory restrictions. Authorities emphasized general recommendations concerning hygienic measures and social distancing to reduce the spread of the infection in the population.

Transplant recipients were initially encouraged to follow the age-stratified general recommendations from the public health agency without any additional self-isolation practices.

This report describes the Swedish national experience with COVID-19 in SOT recipients, accumulated at Sweden's transplant centers. We present a national perspective on the patient variables, clinical management, outcomes, renal function, and serological response.