Patients with end-stage kidney disease (ESKD) are at increased risk for SARS-CoV-2 infection and its complications compared with the general population. Several studies evaluated the effectiveness of COVID-19 vaccines in the dialysis population but showed mixed results. The aim of this study was to determine the effectiveness of COVID-19 mRNA vaccines against confirmed SARS-CoV-2 infection in hemodialysis (HD) patients in the State of Qatar. We included all adult ESKD patients on chronic HD who had at least one SARS-CoV-2 PCR test done after the introduction of the COVID-19 mRNA vaccines on 24 December 2020. Vaccinated patients who were only tested before receiving any dose of their COVID-19 vaccine or within 14 days after receiving the first vaccine dose were excluded from the study. We used a test-negative case–control design to determine the effectiveness of the COVID-19 vaccination. Sixty-eight patients had positive SARS-CoV-2 PCR tests (cases), while 714 patients had negative tests (controls). Ninety-one percent of patients received the COVID-19 mRNA vaccine. Compared with the controls, the cases were more likely to be older (62 ± 14 vs. 57 ± 15, p = 0.02), on dialysis for more than one year (84% vs. 72%, p = 0.03), unvaccinated (46% vs. 5%, p < 0.0001), and symptomatic (54% vs. 21%, p < 0.0001). The effectiveness of receiving two doses of COVID-19 mRNA vaccines against confirmed SARS-CoV-2 infection was 94.7% (95% CI: 89.9–97.2) in our HD population. The findings of this study support the importance of using the COVID-19 mRNA vaccine in chronic HD patients to prevent SARS-CoV-2 infection in such a high-risk population.

Introduction: : This study aimed to evaluate the incidence of coronavirus disease 2019 (COVID-19) infection on kidney transplant, mortality, and risk factors associated with infection acquisition and severe illness in kidney transplant recipients with COVID-19. Methods: : Among 693 kidney transplant recipients who reported to our center, 249 were tested for COVID-19 by throat and nasal swab reverse transcription polymerase chain reaction. Of these, 43 and 206 recipients tested positive and negative, respectively. Among the 43 positive recipients, nine were treated within an isolation facility, 25 were admitted to the hospital, and nine were admitted to the intensive care unit (ICU). Risk factors associated with positive results and ICU admission were evaluated. Results: : COVID-19 was found in 6% of transplant recipients. Asian ethnicity (P=0.003), history of hypertensive nephropathy (P=0.01), AB blood group (P=0.04), and higher tacrolimus trough levels (P=0.007) were more frequent in the COVID-19 positive than in the COVID-19 negative group. ICU admission was more frequent in recipients presenting with fever, shortness of breath, and acute allograft dysfunction. Renal replacement therapy was required in 3 (7%) of 43 recipients, and mortality was reported in 1 (2.3%) recipient. Acute allograft dysfunction was an independent risk factor for severe COVID-19 (odds ratio 93.7 [95% confidence interval 2.37-3710.94], P=0.02). Conclusion: : Higher tacrolimus targets may be associated with COVID-19 development. Acute kidney injury during the COVID-19 course may be a sign of severe disease. Prognostication of COVID-19 severity in kidney transplant recipients is crucial for early recognition of critical illness and may ensure early intervention.

Kidney transplantation is the optimal treatment for end-stage kidney disease (ESKD); however, access to transplantation remains limited by donor availability. Data on transplant evaluation outcomes and waiting times in the Middle East are scarce. This study aimed to assess eligibility for kidney transplantation, outcomes of referred patients, waiting time to cadaveric transplantation, and factors associated with receiving a cadaveric kidney transplant in Qatar. We conducted a retrospective cohort study of adult patients with ESKD referred for kidney transplant evaluation at the national transplant center in Qatar between 2003 and 2017. Patients were assessed for transplant suitability through a multidisciplinary process. Among those listed for cadaveric transplantation, outcomes included transplantation, death, or remaining on the waiting list. Multivariable logistic regression was used to identify factors associated with undergoing cadaveric transplantation. A total of 1201 patients were referred, of whom 835 (69.5%) completed transplant evaluation. Among these, 797 (95.4%) were deemed suitable for transplantation, while 38 (4.6%) were rejected, primarily due to advanced age or cardiovascular disease. Of eligible patients, 361 (45.3%) underwent living donor transplantation, and 436 were listed for cadaveric transplantation. During the study period, 84 patients (19.3%) received a cadaveric transplant after a mean waiting time of 1.79 ± 1.71 years, 59 (13.5%) died, and 293 (67.2%) remained on the waiting list. In multivariable analysis, peritoneal dialysis was associated with a higher likelihood of transplantation (p = 0.003). Most patients referred for kidney transplantation in Qatar were deemed suitable; however, access to cadaveric transplantation remained limited. While waiting time among transplanted patients appeared relatively shorter compared to some international settings, a substantial proportion of patients remained on the waiting list or died before transplantation. The association between peritoneal dialysis and transplantation likely reflects underlying differences in patient characteristics rather than a causal effect.