Lower seroprevalence for SARS-CoV-2-specific antibodies among kidney transplant recipients compared to the general population in the city of Sao Paulo, Brazil.

BACKGROUND: Kidney transplant recipients have higher COVID-19 associated mortality compared to the general population. However, as only symptomatic patients seek medical attention, the current level of exposure, the main sources of acquisition, and the behavior of humoral immunity over time are poorly understood. METHODS: This cross-sectional prospective single-center study recruited kidney transplant recipients of any age living in Sao Paulo. A sample size of 401 patients was calculated considering the 17.2% seroprevalence in the municipality population from a published survey, a 95% confidence interval and an absolute error of 2%. RESULTS: Of the 2636 eligible patients, 416 were included. The seroprevalence for IgG anti-SARS-CoV-2 was 8.2%. Seroconversion rate decreased with increasing age, from 15.7% (18-35 years) to 8.3% (36-60 years) and 4.2% (>60 years, p = 0.042). Seropositivity among previously confirmed COVID-19 patients was 68.4%, followed by 9.4% in those with flu-like symptoms and only 4.6% among asymptomatic patients (p < 0.0001). Seroprevalence was significantly higher among patients reporting household contact (p = 0.018). Twenty-seven from the 34 IgG+ patients had a second test after 59 (IQR 50-63) days, and, in 33%, the IgG index became below the positivity threshold. CONCLUSIONS: In this cohort of kidney transplant recipients, the seroprevalence for IgG anti-SARS-CoV-2 was lower than that of the general population, decreased with ageing, and was associated with household contacts. In a considerable proportion of the patients, there was a significant decay in the IgG levels in a short period of time. Therefore, preventive strategies, such as prioritization for vaccination, should be urgently considered.

Kidney transplantation in the time of COVID-19: Dilemmas, experiences, and perspectives.

INTRODUCTION: Hospital do Rim is a high-volume kidney transplant (KT) center located in São Paulo, a city with 12.2 million inhabitants. Over the last 18 years, we performed 11 436 KT, 70% of which from deceased donors. To mitigate the effects of reduction in the number of transplants on the waiting list, sequential measures were implemented when COVID-19 was declared pandemic. METHODS: The first step was to provide SARS-COV-2 RT-PCR testing for all symptomatic employees and patients and the compulsory use of personal protective equipment in the hospital facilities. Living donor KT were postponed, and all deceased donors and recipients were tested before the transplantation. The immunosuppressive protocols were maintained, and telehealth strategies were developed. RESULTS: Among the 1013 employees, there were 214 cases of COVID-19, nine required ward hospitalization, and no deaths occurred. In 26%, the probable source of contamination was occupational. From the first patient diagnosed with COVID-19 in 03/20/2020 till 10/21/2020, 523 deceased KT were performed, a 21% increase compared with 2019, with no confirmed donor-derived SARS-CoV-2 infection. Four patients were transplanted with a positive pretransplant SARS-CoV-2 test, but none of them developed the disease. Overall, of 11 875 KT followed in our center, 674 developed COVID-19. Among the hospitalized, 53% required mechanical ventilation, and 45% required hemodialysis. Their overall mortality rate was 27.5%. CONCLUSION: This experience shows the challenges that transplant centers faced as the pandemic unfolded and illustrates the effectiveness of the sequential measures implemented to provide a safe environment for transplantation.

The Full Spectrum of COVID-19 Development and Recovery Among Kidney Transplant Recipients.

BACKGROUND: Coronavirus disease 2019 (COVID-19) fatality rate is high among kidney transplant recipients. Among survivors, kidney outcomes, seroconversion, and persistence of viral shedding are unexplored. METHODS: Single-center prospective cohort study including data from kidney transplant recipients with confirmed COVID-19 between March 20, 2020 and July 31, 2020. Outcomes were adjudicated until August 31, 2020 or the date of death. RESULTS: There were 491 patients with COVID-19 among the 11 875 recipients in follow-up. The majority were middle aged with ≥1 comorbidities. Thirty-one percent were treated at home, and 69% required hospitalization. Among the hospitalized, 61% needed intensive care, 75% presented allograft dysfunction, and 46% needed dialysis. The overall 28-day fatality rate was 22% and among hospitalized patients it was 41%. Age (odds ratio, 3.08; 95% confidence interval, 1.86-5.09), diabetes mellitus (odds ratio, 1.69; 95% confidence interval, 1.06-2.72), and cardiac disease (odds ratio, 2.00; 95% confidence interval, 1.09-3.68) were independent factors for death. Among the 351 survivors, 19% sustained renal graft dysfunction, and there were 13 (4%) graft losses. Biopsy (n = 20) findings were diverse but decisive to guide treatment and estimate prognosis. Seroconversion was observed in 79% of the survivors and was associated with disease severity. Persistence of viral shedding was observed in 21% of the patients without detectable clinical implications. CONCLUSIONS: This prospective cohort analysis confirms the high 28-day fatality rate of COVID-19, associated primarily with age and comorbidities. The high incidence of allograft dysfunction was associated with a wide range of specific histologic lesions and high rates of sequelae and graft loss. Seroconversion was high and the persistence of viral shedding deserves further studies.