From population studies, solid organ transplant recipients are at increased risk of mortality from RT-PCR confirmed COVID-19 infection. The risk factors associated with infection acquisition and mortality in transplant recipients using serological data have not been reported.
From 1725 maintenance transplant recipients, 855 consecutive patients were screened for SARS-CoV-2 antibodies. Serological screening utilized assays to detect both the N protein and receptor binding domain antibodies. Thirty-three of 855 (3.9%) of the screened patients had prior infection confirmed with RT-PCR. Twenty-one additional patients from our 1725 maintenance cohort with RT-PCR confirmed infection were included in our analysis.
Eighty-nine of 855 (10.4%) patients tested positive for SARS-CoV-2 antibodies. Fifty-nine of 89 (66.3%) cases were patients newly identified as exposed, while 30/89 (33.7%) seropositive patients had previous infection confirmed by RT-PCR. A diagnosis of SARS-CoV-2 (RT-PCR or Ab+) was associated with being from a noncaucasoid background, P = 0.015; having a diagnosis of diabetes, P = 0.028 and a history of allograft rejection, P < 0.01. Compared with the RT-PCR+ cohort, patients with serological-proven infection alone were more likely to be receiving tacrolimus monotherapy, P < 0.01, and less likely to have a diagnosis of diabetes, P = 0.012. Seventeen of 113 (15.0%) of all patients with infection (RT-PCR and Ab+) died. Risk factors associated with survival were older age, odds ratio (OR): 1.07 (1.00–1.13), P = 0.041; receiving prednisolone, OR: 5.98 (1.65–21.60), P < 0.01 and the absence of diabetes, OR: 0.27 (0.07–0.99), P = 0.047.
This study identifies risk factors and outcome for COVID-19 infection incorporating data on serologically defined infection and highlights the important contribution of immunosuppression regimen on outcomes.