Viral Clearance and Serological Response to SARS-CoV-2 in Kidney Transplant Recipients.

OBJECTIVES: Knowledge about the impact of coronavirus disease 2019 (COVID-19) on kidney transplant recipients (KTRs) concerning viral shedding and humoral immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is limited. The aim of this study is to analyze viral dynamics and the antibody response to SARS-CoV-2 in KTRs with COVID-19 and study their association with clinical data. MATERIALS AND METHODS: Consecutive KTRs diagnosed with COVID-19 at our center were evaluated for clinical presentation and outcome; duration of viral shedding and viral burden by reverse transcription-polymerase chain reaction assay cycle threshold; and magnitude of seroconversion to SARS-CoV-2. RESULTS: Six KTRs identified with COVID-19 were hospitalized. Presenting symptoms were similar to those in the general population. Four patients had severe disease and, of these, 2 required mechanical ventilation, 4 had acute kidney injury, and 3 had secondary bacterial infections. Immunosuppression was reduced in all patients. Five patients were treated with hydroxychloroquine. No patient required dialysis or died. Patients with severe disease had a longer duration of viral shedding, which lasted more than 40 days, and had IgG antibodies against SARS-CoV-2, which were detected from 3 weeks to as long as 10 weeks after symptom onset. In patients with less severe disease no IgG antibodies where detected between 9 and 14 weeks after symptom onset. CONCLUSIONS: In our series, KTRs with severe COVID-19 had prolonged viral shedding and a stronger humoral immune response to SARS-CoV-2. These preliminary data need to be confirmed with further studies and over a longer period of time.