Is COVID-19 Infection More Severe in Kidney Transplant Recipients?

Sophie Caillard; Nathalie Chavarot; Hélène Francois; Marie Matignon; Clarisse Greze; Nassim Kamar; Philippe Gatault; Olivier Thaunat; Tristan Legris; Luc Frimat; Pierre F. Westeel; Valentin Goutaudier; Mariam Jdidou; Renaud Snanoudj; Charlotte Colosio; Antoine Sicard; Dominique Bertrand; Christiane Mousson; Jamal Bamoulid; Christophe Masset; Antoine Thierry; Lionel Couzi; Jonathan M. Chemouny; Agnes Duveau; Valerie Moal; Gilles Blancho; Philippe Grimbert; Antoine Durrbach; Bruno Moulin; Dany Anglicheau; Yvon Ruch; Charlotte Kaeuffer; Ilies Benotmane; Morgane Solis; Yannick LeMeur; Marc Hazzan; Francois Danion


American Journal of Transplantation. 2021;21(3):1295-1303. 

In This Article

Abstract and Introduction


There are no studies which have compared the risk of severe COVID-19 and related mortality between transplant recipients and nontransplant patients. We enrolled two groups of patients hospitalized for COVID-19, that is, kidney transplant recipients (KTR) from the French Registry of Solid Organ Transplant (n = 306) and a single-center cohort of nontransplant patients (n = 795). An analysis was performed among subgroups matched for age and risk factors for severe COVID-19 or mortality. Severe COVID-19 was defined as admission (or transfer) to an intensive care unit, need for mechanical ventilation, or death. Transplant recipients were younger and had more comorbidities compared to nontransplant patients. They presented with higher creatinine levels and developed more episodes of acute kidney injury. After matching, the 30-day cumulative incidence of severe COVID-19 did not differ between KTR and nontransplant patients; however, 30-day COVID-19-related mortality was significantly higher in KTR (17.9% vs 11.4%, respectively, p = .038). Age >60 years, cardiovascular disease, dyspnea, fever, lymphopenia, and C-reactive protein (CRP) were associated with severe COVID-19 in univariate analysis, whereas transplant status and serum creatinine levels were not. Age >60 years, hypertension, cardiovascular disease, diabetes, CRP >60 mg/L, lymphopenia, kidney transplant status (HR = 1.55), and creatinine level >115 μmol/L (HR = 2.32) were associated with COVID-19-related mortality in univariate analysis. In multivariable analysis, cardiovascular disease, dyspnea, and fever were associated with severe disease, whereas age >60 years, cardiovascular disease, dyspnea, fever, and creatinine level>115 μmol/L retained their independent associations with mortality. KTR had a higher COVID-19-related mortality compared to nontransplant hospitalized patients.


Prior experience with respiratory viruses in patients who had undergone solid organ transplantation revealed how recipients have greater susceptibility, more rapid progression to pneumonia, greater disease severity, and prolonged viral shedding compared with nontransplant hosts. In light of past coronavirus outbreaks,[1,2] COVID-19 poses a significant threat for immunocompromised patients, and transplant physicians are particularly concerned about the impact of this new infection on this frail population. Single-center studies have reported a high mortality rate in kidney transplant recipients (KTR) with COVID-19.[3–5] There is also evidence that at least part of COVID-19's severity is linked to the "cytokine storm," which is a disproportionate hyperinflammatory reaction occurring in infected patients.[6] In this scenario, immunosuppressive drugs may be clinically useful in reducing this dysfunctional immune response by attenuating the positive feedback loop typical of the cytokine release syndrome (CRS). Nonetheless, the question as to whether KTR would actually exhibit a higher risk of severe COVID-19 or—alternatively—immunosuppression would protect them from CRS and critical forms of the disease remains unanswered.

Chronic kidney disease and acute kidney injury (AKI) have been reported to affect the prognosis of patients hospitalized for COVID-19.[7] Notably, KTR are in an immunosuppressed state with concurrent chronic kidney disease and are particularly susceptible to AKI. Starting from these premises, this research was undertaken to determine how these factors may influence the clinical outcomes of KTR with COVID-19. We also compared the prognosis of COVID-19 in KTR and nontransplant patients by using data from a French nationwide registry.