ABSTRACT
BACKGROUND AND AIMS: COVID-19 is associated with an increased mortality in maintenance haemodialysis patients. Considering the baseline immunosuppressed status of this population, humoral immune responses to SARS-CoV-2 vaccination remain to be studied. There is no information regarding sustained immune response in this population after a third booster dose following complete m-RNA vaccination. The aim of our study was to describe the humoral immune response in haemodialysis patients following a complete SARS-CoV-2 vaccine schedule and a third booster dose, and explore the factors associated with a sustained immune response. METHOD: We conducted a retrospective study in which we included haemodialysis patients with or without (naïve) previous COVID-19 infection. Patients received the following vaccination schedule: two initial doses of m-RNA vaccine with a 4-week interval (complete immunization) followed by a third booster dose at least 4 months after the second initial dose. IgG anti-SARS-CoV-2 spike antibody titles were measured before the first initial vaccine dose and then monthly up to 3 months after the booster dose. We excluded patients without baseline serological samples and those who did not receive the full vaccination schedule. RESULTS: The study included 182 haemodialysis patients with a mean age of 68.5 ± 14.5 years, 63.2% were males and 14.3% were under immunosuppression, 67.7% were responders to HBV vaccine and 18.1% had been infected with SARS-CoV-2 prior to vaccination. After the first two vaccine doses, 96.5% developed immediate humoral immune response, and 91.5% remained with positive anti-SARS-CoV-2 spike antibodies after 4 months from complete vaccination. Median antiSARS-CoV-2 spike antibody titles were significantly higher in patients with previous COVID-19 infection and HBV vaccine responders, both immediately (40 000 AU/mL versus 2926 AU/mL, P < 0.001 and 4885 versus 2056 AU/mL, P = 0.003, respectively) and after 4 months from complete vaccination (27 741 versus 663 AU/mL, P < 0.001 and 1356 versus 341 AU/mL, P = 0.001). In the 4 months between complete initial vaccination and the third booster dose, the mean monthly decrease in antiSARS-CoV-2 spike antibody titles was of 31.8% (±18.9) and was significantly lower in patients with prior COVID-19 infection compared with naïve patients (17.2% versus 34.8%, P < 0.001). After the third booster dose, 98.2% of patients showed positive anti-SARS-CoV-2 S antibodies, and this proportion remained stable in the following 3 months. Nevertheless, median anti-SARS-CoV-2 spike antibody titles remained higher in patients with prior COVID-19 both immediately and after 3 months. However, we observed a more sustained humoral response after the booster dose, with a lower mean monthly decrease in antibody titles compared with the initial vaccine schedule (31.8% to 22.6%, P < 0.001). This finding was reciprocated in all groups, regardless of prior serological COVID-19 status, HBV vaccine response, age or sex. Multivariate logistic regression for the risk of a >25% monthly decrease in antibodies showed that prior infection with COVID-19 was a protective factor both after the complete initial vaccination {OR: 0.23, [95% confidence interval (95% CI) 0.06-0.87]} as well as after the third dose (OR: 0.23, 95% CI 0.06-0.81). CONCLUSION: Vaccination with m-RNA anti-SARS-CoV-2 is effective in eliciting an immediate humoral response in haemodialysis patients, with a progressive reduction in immune response after 4 months particularly in COVID-19 naive patients. A third booster dose enhances the immune response with significantly higher antibody levels and more sustained humoral immune after 3 months in haemodialysis patients.
ABSTRACT
BACKGROUND AND AIMS: Age and chronic kidney disease have been described as mortality risk factors for coronavirus disease 2019 (COVID-19). Currently, an important percentage of patients in hemodialysis are elderly. This study aimed to investigate the impact of COVID-19 in this population and to determine risk factors associated with mortality. METHOD: Data was obtained from the Spanish COVID-19 CKD Working Group Registry, that included patients in renal replacement therapy (dialysis and kidney transplantation) infected by COVID-19. From March 18, 2020, to August 27, 2020, 1165 patients on hemodialysis affected by COVID-19 were included in the Registry. A total of 328 patients were under 65 years-old and 837 were 65 years old or older (elderly group). RESULTS: Mortality was 18.6% higher (95% confidence interval (CI): 13.8%-23.4%) in the elderly hemodialysis patients compared to the non-elderly group (see figure). Death from COVID-19 infection was increased 5.5-fold in hemodialysis patients compared to mortality in the general population for a similar period, and there was an age-associated mortality increase in both populations (see figure 1). In multivariate Cox regression analysis, age (hazard ratio (HR) 1.58, 95% CI: 1.31-1.92), dyspnea at presentation (HR 1.61, 95% CI: 1.20-2.16), pneumonia (HR 1.76, 95% CI: 1.12-2.75) and admission to hospital (HR 4.13, 95% CI: 1.92-8.88) were identified as independent mortality risk factors in the elderly hemodialysis population. Treatment with glucocorticoids reduced the risk of death (HR 0.71, 95% CI: 0.51-0.98) in aged patients on hemodialysis. CONCLUSION: Mortality is dramatically increased in elderly hemodialysis patients affected by COVID-19. Age, dyspnea at presentation, pneumonia or hospitalization are factors associated with a worse prognosis, after adjusting dialysis population to other confounding factors. Treatment with glucocorticoids could be a therapeutic option for this specific population. (Table Presented).
ABSTRACT
BACKGROUND AND AIMS: There is an increased risk of thrombotic complications in patients with COVID-19. Hemodialysis patients are already at an increased risk for thromboembolic events such as stroke and pulmonary embolism. The aim of our study was to determine the incidence of late thrombotic complications (deep vein thrombosis, pulmonary embolism, stroke, new-onset vascular access thrombosis) in maintenance hemodialysis patients after recovery from COVID-19. METHOD: We performed a retrospective cohort study of 200 prevalent hemodialysis patients in our center at the start of the pandemic. We excluded incident patients after the cohort entry date and those who required hemodialysis for acute kidney injury, and excluded patients with less than 1 month follow-up due to kidney transplantation or death from non-thrombotic causes. RESULTS: 185 prevalent hemodialysis patients finally met the inclusion criteria;37 patients (17.6%) had SARS-CoV-2 infection, out of which 10 (27%) died during the acute phase of disease without evidence of thrombotic events. There was an increased risk of thrombotic events in COVID-19 survivors compared to the non-infected cohort (18.5% vs 1.9%, p=0.002) after a median follow-up of 7 months. Stroke incidence was 38.9 episodes/1000 patient-years in patients infected with SARS-CoV-2, compared to an incidence of 2.8 episodes/1000 patient-years in non-infected patients during the follow-up period. The median time from diagnosis of SARS-CoV-2 to the first thrombotic event was 62 days (interquartile range 5-118 days). Survival analysis with Kaplan-Meier curves revealed an increase in the rate of thrombotic events after SARSCoV- 2 compared to non-infected patients (see Figure 1). Mean survival from thrombotic event was 6.160.4 months in the COVID-infected group, compared to 6.97±0.04 months in the non-infected group (p<0.001). Multivariate regression analysis showed that COVID-19 infection increased risk for late thrombotic events adjusted for age, sex, hypertension, diabetes, antithrombotic treatment and previous thrombotic events (OR 26.4, 95% CI 2.5-280.6, p=0.01). Clinical and laboratory markers did not predict thrombotic events. CONCLUSION: There is an increased risk of late thrombotic complications in hemodialysis patients after infection with COVID-19. Further studies should evaluate the benefit of prolonged prophylactic anticoagulation in hemodialysis patients after recovery from COVID-19. (Table Presented).