Response to is the reduction in urea distribution volume over time in clinically stable dialysis patients real?

Background and Objectives: While most maintenance dialysis patients exhibit initial seroresponse to vaccination, concerns remain regarding the durability of this antibody response. This study evaluated immunity over time. Design, setting, participants, and measurements: This retrospective cohort study included maintenance dialysis patients from a midsize national dialysis provider who received a complete SARS-CoV-2 vaccine series and had at least one antibody titer checked after full vaccination. Immunoglobulin G spike antibodies (SAb-IgG) titers were assessed monthly with routine labs beginning after full vaccination and followed over time; the semiquantitative SAb-IgG titer reported a range between 0 and ≥20 U/L. Descriptive analyses compared trends over time by prior history of COVID-19 and type of vaccine received. Time-to-event analyses were conducted for the outcome of loss of seroresponse (SAb-IgG < 1 U/L or development of COVID-19). Cox proportional hazards regression was used to adjust for additional clinical characteristics of interest. Results: Among 1898 maintenance dialysis patients, 1567 (84%) had no prior history of COVID-19. Patients without a history of COVID-19 had declining titers over time. Among 441 BNT162b2/Pfizer recipients, median [IQR] SAb-IgG titer declined from 20 [5.99-20] U/L in month 1 to 1.30 [0.15-3.59] U/L by month 6. Among 779 mRNA-1273/Moderna recipients, median [IQR] SAb-IgG titer declined from 20 [20-20] in month 1 to 6.20 [1.74-20] by month 6. The 347 Ad26.COV2.S/Janssen recipients had a lower titer response than mRNA vaccine recipients over all time periods. In time-to-event analyses, Ad26.COV2.S/Janssen and mRNA-1273/Moderna recipients had the shortest and longest time to loss of seroresponse, respectively. The maximum titer reached in the first two months after full vaccination was predictive of the durability of the SAb-IgG seroresponse; patients with SAb-IgG titer 1-19.99 U/L were more likely to have loss of seroresponse compared to patients with SAb-IgG titer ≥20 U/L (HR 23.9 [95% CI: 16.1-35.5]). Conclusions: Vaccine-induced seroresponse wanes over time among maintenance dialysis patients across vaccine types. Early titers after full vaccination predict the durability of seroresponse.

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Time evolution of restless legs syndrome in haemodialysis patients

Clinical Kidney Journal ◽

10.1093/ckj/sfz148 ◽

2019 ◽

Author(s):

Irene Capelli ◽

Fabio Pizza ◽

Marco Ruggeri ◽

Lorenzo Gasperoni ◽

Elisa Carretta ◽

...

Keyword(s):

Quality Of Life ◽

Kidney Transplantation ◽

Restless Legs Syndrome ◽

Statistical Significance ◽

Dialysis Patients ◽

Restless Legs ◽

Continuous Form ◽

Over Time

Abstract Background Restless legs syndrome (RLS) is characterized by an urge to move the extremities, accompanied by paraesthesiae, in the evening and at night. Uraemic RLS, a type of secondary RLS, occurs commonly in chronic kidney disease and end-stage renal disease. Progression of uraemic RLS over time is unclear. Therefore we investigated the prevalence, progression over time, risk factors and impact on survival of uraemic RLS in a cohort of dialysis patients. Methods We reviewed at the 7-year follow-up a cohort of haemodialysis (HD) patients we had previously investigated for RLS, through interviews, validated questionnaires and analysis of demographic and clinical data. Results At the 7-year follow-up, RLS was present in 16% of patients, with a persistence rate of 33%. A correlation was obtained between RLS and older age, diabetes, low albumin and low body mass index. RLS was associated with reduced overall survival (median survival of 3.3 versus 3.7 years), particularly with the continuous form of RLS (1.61 years). There was a higher incidence of myocardial infarction and peripheral vascular disease, although not reaching statistical significance. RLS patients had absolute higher scores in all quality of life domains. A large majority of study patients (96%) reported being symptom-free within a few days or weeks following kidney transplantation. Conclusions The development of RLS, especially the continuous form, in patients undergoing HD has important consequences associated with decreased survival. Our results indicated an association between uraemic RLS and ageing, diabetes and malnutrition. Considerable efforts should be focused on the treatment of RLS, since it significantly and persistently impacts the quality of life of HD patients. Kidney transplantation could represent an effective treatment option for that RLS impacts on dialysis patients' quality of life, thus confirming the secondary nature of RLS in most HD patients.

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Longitudinal Effect of Pressure Drop on the Intima-Media Thickening of the Venous Segment of the Arteriovenous Fistula

Volume 1A: Abdominal Aortic Aneurysms; Active and Reactive Soft Matter; Atherosclerosis; BioFluid Mechanics; Education; Biotransport Phenomena; Bone, Joint and Spine Mechanics; Brain Injury; Cardiac Mechanics; Cardiovascular Devices, Fluids and Imaging; Cartilage and Disc Mechanics; Cell and Tissue Engineering; Cerebral Aneurysms; Computational Biofluid Dynamics; Device Design, Human Dynamics, and Rehabilitation; Drug Delivery and Disease Treatment; Engineered Cellular Environments ◽

10.1115/sbc2013-14478 ◽

2013 ◽

Author(s):

Ehsan Rajabi-Jaghargh ◽

Mahesh K. Krishnamoorthy ◽

Rupak K. Banerjee

Keyword(s):

Pressure Drop ◽

Arteriovenous Fistula ◽

Dialysis Patients ◽

Luminal Diameter ◽

Post Surgery ◽

Opposite Trend ◽

Venous Stenosis ◽

Arteries And Veins ◽

Venous Segment ◽

Over Time

Venous stenosis is one of the primary causes of the arteriovenous fistula (AVF) maturation-failure and is characterized by vasoconstriction and significant intima-media thickening (IMT). Although the hemodynamic endpoints are believed to play a crucial role in the pathogenesis of venous stenosis, the exact mechanism behind this is unclear. Our hypothesis is that the changes in the pressure drop over time (Δp′) can influence the remodeling factors in AVFs: changes in luminal diameter (ΔDh) and IMT. Curved (C-AVF; n = 3) and straight (S-AVF; n = 3) AVFs were created between the femoral arteries and veins of 3 pigs. CT-scan and ultrasound were utilized to numerically evaluate the flow field, and thus pressure drop in AVFs at 2D (D: days), 7D, and 28D post-surgery. For each AVF, IMT was also measured at 4 histological blocks along the vein. For the C-AVF, the pressure drop consistently decreased over time (from 18.32 mmHg at 2D to 4.58 mmHg at 28D), while opposite trend was found for the S-AVF (from 12.91 mmHg at 2D to 24.49 mmHg at 28D). The Δp′ was negative at all the histology blocks for C-AVF which showed the reduction in the resistance over time due to dilation (positive ΔDh) and outward hypertrophy of the venous segment (positive ΔDh/IMT). In contrast, Δp′ was mostly positive for the S-AVF which showed the increase in the resistance due to vasoconstriction (negative ΔDh) and inward hypertrophy (negative ΔDh/IMT). Thus, measuring Δp′ at the successive post-surgery time points can provide important information on the remodeling behavior of AVFs. Also, creating AVFs in a surgical configuration that can result in negative Δp′ and thus favorable remodeling could influence the life expectancy of the dialysis patients.

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P1214RELATIONSHIP BETWEEN CHANGE IN DIALYSATE CONDUCTIVITY AND INTRAPERITONEAL VOLUME DURING PET

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p1214 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Laura Rosales Merlo ◽

Fansan Zhu ◽

Peter Kotanko

Keyword(s):

The Body ◽

Unanswered Question ◽

Bioimpedance Spectroscopy ◽

Dialysis Patients ◽

Future Studies ◽

Number Of Patients ◽

Equilibrium Test ◽

The Relationship ◽

Fluid Conductivity ◽

Over Time

Abstract Background and Aims Bioimpedance spectroscopy (BIS) has been widely applied to measure fluid volume in dialysis patients. A fundamentally important, yet unanswered question is how changes in fluid conductivity affects the accuracy of BIS measurements. The aim of this study was to investigate whether the change in intraperitoneal volume (IPV) is – as hypothesized - linearly correlated with the change in dialysate conductivity during a peritoneal equilibrium test (PET). Method Four PD patients (age 58±13 years, three males, weight 87.8±28 kg) were studied during a standard PET. Segmental BIS was continuously measured with eight electrodes placed between rib and buttock on both sides of the body using a Hydra 4200 (Xitron Technologies Inc ). IPV was calculated based on BIS recordings as recently published (Zhu, Kidney Blood Press Res 2019;44:1465–1475). Dialysate samples were collected hourly from baseline to the end of dwell. Dialysate conductivity was measured with a portable conductivity meter (CDH-280-KIT, Omega Engineering Inc, CT, USA). Results In all patients dialysate conductivity increased significantly (p<0.0001) from baseline (11.14±0.15 mS/cm) to the end of dwell (12.5±0.58 mS/cm) (Fig a). In 2 patients (Fig b and c) IPV and conductivity were linearly correlated; in one patient (Fig d) the relationship was nonlinear and absent in another one (Fig e). Conclusion Although the number of patients in this study was small, the results clearly indicated that dialysate conductivity increased linearly over time during PET. The correlation between dialysate conductivity and IPV is not linear and may be driven by other factors, such as dialysate electrolyte levels. In future studies measurements of dialysate electrolytes are necessary to better understand the drivers of the IPV / conductivity relationship.

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