Risk factors for low humoral response to BNT-162b2 in hemodialysis patients.

INTRODUCTION: Maintenance hemodialysis (HD) patients are at higher risk of both infection and mortality associated with the new SARS-CoV-2. Immunization through large-scale vaccination is the cornerstone of infection prevention in this population. This study aims to identify risk factors for low response to the BNT-162b2 (Pfizer BioNTech) vaccine in an HD cohort. MATERIALS AND METHODS: Observational prospective study of an HD group followed in a Portuguese Public Founded Hemodialysis Center who received BNT-162b2 vaccination. Specific anti-Spike IgG was evaluated as arbitrary units per milliliter (AU/mL) and compared against risk factors. RESULTS: Humoral response evaluated by IgG anti-Spike levels showed a strong correlation with Charlson comorbidity index (CCI) and intact parathormone (iPTH) after each inoculation (1st dose: rho = -0.64/0.54; 2nd dose: rho = -0.66/0.63, respectively; p < 0.01 throughout). After completing both doses: 1) no response (NR) was associated with female sex (p < 0.01), lower albumin and iPTH (p = 0.01); 2) weak response (WR) showed higher CCI, older age, lower iPTH, and lower albumin (p = < 0.01, p = 0.03, p < 0.01, p = 0.05, respectively). A binary regression model using CCI, sex (male), and central venous catheter (CVC) was statistically significant in prediction of WR after the 2nd dose with OR (95% CI): 1.81 (1.06 - 3.08); 0.05 (0.01 - 0.65); 13.55 (1.06 - 174.18), respectively (p = 0.01). CONCLUSION: Older age, higher CCI, lower iPTH and albumin as well as CVC as vascular access were associated with lower response to vaccination in our study. Comorbidity burden is suggested as a preferred indirect method to predict worst response when compared to age alone.

Vascular access type and mortality in elderly incident hemodialysis patients / Tipo de acceso vascular y mortalidad en pacientes ancianos en programa de hemodiálisis

Introduction: The ideal vascular access type for elderly hemodialysis (HD) patients remains debatable. The aim of this study was to analyze the association between patterns of vascular access use within the first year of HD and mortality in elderly patients. Methods: Single-center retrospective study of 99 incident HD patients aged≥80 years from January 2010 to May 2021. Patients were categorized according to their patterns of vascular access use within the first year of HD: central venous catheter (CVC) only, CVC to arteriovenous fistula (AVF), AVF to CVC, and AVF only. Baseline clinical data were compared among groups. Survival outcomes were analyzed using Kaplan–Meier survival curves and Cox's proportional hazards model. Results: When compared with CVC to AVF, mortality risk was significantly higher among CVC only patients and similar to AVF only group [HR 0.93 (95% CI 0.32–2.51)]. Ischemic heart disease [HR 1.74 (95% CI 1.02–2.96)], lower levels of albumin [HR 2.16 (95% CI 1.28–3.64)] and hemoglobin [HR 4.10(95% CI 1.69–9.92)], and higher levels of c-reactive protein [HR 1.87(95% CI 1.11–3.14)] were also associated with increased mortality risk in our cohort, p<0.05. Conclusion: Our findings suggested that placement of an AVF during the early stages of dialysis was associated with lower mortality compared to persistent CVC use among elderly patients. AVF placement appears to have a positive impact on survival outcomes, even in those who started dialysis with a CVC. (AU)

Introducción: El tipo de acceso vascular ideal para pacientes ancianos en hemodiálisis (HD) sigue siendo discutible. El objetivo de este estudio fue analizar la asociación entre los patrones de uso del acceso vascular en el primer año de HD y la mortalidad en pacientes ancianos. Métodos: Estudio retrospectivo unicéntrico de 99 pacientes incidentes en HD con edades ≥80años desde enero de 2010 hasta mayo de 2021. Los pacientes fueron categorizados según sus patrones de uso del acceso vascular en el primer año de HD: catéter venoso central (CVC) solo, CVC a fístula arteriovenosa (FAV), FAV a CVC y FAV solamente. Los datos clínicos iniciales se compararon entre los grupos. Los resultados de supervivencia se analizaron mediante las curvas de supervivencia de Kaplan-Meier y el modelo de riesgo proporcional de Cox. Resultados: En comparación con el CVC para la FAV, el riesgo de mortalidad fue significativamente mayor entre los pacientes que solo recibieron CVC y similar al grupo que solo utilizó FAV (HR: 0,93; IC95%: 0,32-2,51). Cardiopatía isquémica (HR: 1,74; IC95%: 1,02-2,96), niveles más bajos de albúmina (HR: 2,16; IC 95%: 1,28-3,64) y de hemoglobina (HR: 4,10; IC 95%: 1,69-9,92), y niveles más altos de proteína C reactiva (HR: 1,87; IC 95%: 1,11-3,14) también se asociaron con un mayor riesgo de mortalidad en nuestra cohorte (p<0,05). Conclusión: Nuestros hallazgos sugirieron que la colocación de una FAV durante las primeras etapas de la diálisis se asoció con una menor mortalidad en comparación con el uso persistente de CVC en pacientes ancianos. La colocación de una FAV parece tener un impacto positivo en los resultados de supervivencia, incluso en aquellos que comenzaron la diálisis con un CVC. (AU)

Vascular access type and mortality in elderly incident hemodialysis patients.

INTRODUCTION: The ideal vascular access type for elderly hemodialysis (HD) patients remains debatable. The aim of this study was to analyze the association between patterns of vascular access use within the first year of HD and mortality in elderly patients. METHODS: Single-center retrospective study of 99 incident HD patients aged≥80 years from January 2010 to May 2021. Patients were categorized according to their patterns of vascular access use within the first year of HD: central venous catheter (CVC) only, CVC to arteriovenous fistula (AVF), AVF to CVC, and AVF only. Baseline clinical data were compared among groups. Survival outcomes were analyzed using Kaplan-Meier survival curves and Cox's proportional hazards model. RESULTS: When compared with CVC to AVF, mortality risk was significantly higher among CVC only patients and similar to AVF only group [HR 0.93 (95% CI 0.32-2.51)]. Ischemic heart disease [HR 1.74 (95% CI 1.02-2.96)], lower levels of albumin [HR 2.16 (95% CI 1.28-3.64)] and hemoglobin [HR 4.10(95% CI 1.69-9.92)], and higher levels of c-reactive protein [HR 1.87(95% CI 1.11-3.14)] were also associated with increased mortality risk in our cohort, p<0.05. CONCLUSION: Our findings suggested that placement of an AVF during the early stages of dialysis was associated with lower mortality compared to persistent CVC use among elderly patients. AVF placement appears to have a positive impact on survival outcomes, even in those who started dialysis with a CVC.

Thrombotic microangiopathy in a patient with systemic lupus erythematosus and anti-factor H autoantibodies.

Thrombotic microangiopathy (TMA) is a serious complication that may occur in patients with systemic lupus erythematosus (SLE), adversely affecting the prognosis and increasing mortality. The pathogenesis of TMA in these patients may be multifactorial and overlap between different entities may exist. We present a case of a 24-year-old man, previously diagnosed with SLE, class IV lupus nephritis, and antiphospholipid antibody syndrome, who was admitted with acute kidney injury, severe pancytopenia, and other features consistent with lupus flare. A clinical TMA diagnosis was made and the patient was treated with plasmapheresis, rituximab and immunoglobulin endovenous (EV) infusions. Hemodialysis was initiated during hospitalization and, despite the hematological recovery, the patient remained dialysis dependent. The complementary study revealed high levels of anti-factor H (fH) autoantibodies with no pathogenic mutations on complement genes (namely CFHR1 and CFHR3). Initially, the most likely cause of TMA seemed to be secondary to SLE, but the presence of anti-fH antibodies in our patient may suggest a concomitant complement-mediated TMA.

Humoral response to BNT162b2 mRNA COVID-19 vaccine in peritoneal and hemodialysis patients: A comparative study.

INTRODUCTION: Maintenance dialysis patients (MDP) are at higher risk of exposure with increased mortality from COVID-19 with generalized immunization becoming the cornerstone in prevention. This study aims to compare humoral response between hemodialysis (HD) and peritoneal dialysis (PD) patients. MATERIALS AND METHODS: Observational prospective study following HD and PD programs from a Portuguese Center receiving BNT162b2 vaccine. Specific anti-Spike IgG quantification to compare both for absolute value and non-responders (NR) between modalities and against risk factors. RESULTS: Of 67 MDP, 42 were HD and 25 PD patients. PD developed higher antibody titers after both first (median 5.44 vs. 0.99 AU/ml, p < 0.01) and second dose (median 170.43 vs. 65.81 AU/ml; p < 0.01). HD associated with NR after the first dose (p < 0.01). CONCLUSION: This study demonstrated improved humoral immunogenicity with BNT162b2 in PD compared to HD patients. These differences are attributed to comorbidity burden and age differences, rather than dialysis modality.