The Importance of Early Diagnosis and Intervention in Chronic Kidney Disease: Calls-to-Action from Nephrologists Based Mainly in Central/Eastern Europe.

Background: Chronic kidney disease (CKD) has a global prevalence of 9.1-13.4%.

Optical Real-Time Cardiorenal Toxin Uric Acid Measurement During Hemodialysis Using a Miniaturized Optical Sensor.

Patients with chronic kidney disease (CKD) are at higher cardiovascular risk than the general population. Cardiovascular diseases, vascular calcification among them, are the leading cause of death in these patients. Factors influencing vascular calcification are oxidative stress, inflammation, and accumulation of uremic toxins during CKD.

Time-averaged concentration estimation of uraemic toxins with different removal kinetics: a novel approach based on intradialytic spent dialysate measurements.

Background: Kt/V is the most used marker to estimate dialysis adequacy; however, it does not reflect the removal of many other uraemic toxins, and a new approach is needed. We have assessed the feasibility of estimating intradialytic serum time-averaged concentration (TAC) of various uraemic toxins from their spent dialysate concentrations that can be estimated non-invasively online with optical methods.

Methods: Serum and spent dialysate levels and total removed solute (TRS) of urea, uric acid (UA), indoxyl sulphate (IS) and β2-microglobulin (β2M) were evaluated with laboratory methods during 312 haemodialysis sessions in 78 patients with four different dialysis treatment settings.

Treatment with Paracetamol Can Interfere with the Intradialytic Optical Estimation in Spent Dialysate of Uric Acid but Not of Indoxyl Sulfate.

Optical online methods are used to monitor the haemodialysis treatment efficiency of end stage kidney disease (ESKD) patients. The aim of this study was to analyse the effect of the administration of UV-absorbing drugs, such as paracetamol (Par), on the accuracy of optical monitoring the removal of uremic toxins uric acid (UA) and indoxyl sulfate (IS) during standard haemodialysis (HD) and haemodiafiltration (HDF) treatments. Nine patients received Par in daily dosages 1−4 g for 30 sessions.

Optical Method and Biochemical Source for the Assessment of the Middle-Molecule Uremic Toxin β2-Microglobulin in Spent Dialysate.

Optical monitoring of spent dialysate has been used to estimate the removal of water-soluble low molecular weight as well as protein-bound uremic toxins from the blood of end stage kidney disease (ESKD) patients. The aim of this work was to develop an optical method to estimate the removal of β2-microglobulin (β2M), a marker of middle molecule (MM) uremic toxins, during hemodialysis (HD) treatment. Ultraviolet (UV) and fluorescence spectra of dialysate samples were recorded from 88 dialysis sessions of 22 ESKD patients, receiving four different settings of dialysis treatments.

Serum Levels and Removal by Haemodialysis and Haemodiafiltration of Tryptophan-Derived Uremic Toxins in ESKD Patients.

Tryptophan is an essential dietary amino acid that originates uremic toxins that contribute to end-stage kidney disease (ESKD) patient outcomes. We evaluated serum levels and removal during haemodialysis and haemodiafiltration of tryptophan and tryptophan-derived uremic toxins, indoxyl sulfate (IS) and indole acetic acid (IAA), in ESKD patients in different dialysis treatment settings. This prospective multicentre study in four European dialysis centres enrolled 78 patients with ESKD.

Removal of Urea, β2-Microglobulin, and Indoxyl Sulfate Assessed by Absorbance and Fluorescence in the Spent Dialysate During Hemodialysis.

In this study, simultaneous removal assessment of marker molecules from three uremic toxin groups was performed during different hemodialysis treatment modalities using optical characteristics of spent dialysate. Results from optical measurements were compared with the results from chemical laboratory. Ten chronic dialysis patients, mean age 59 ± 15 years, were included in the study during 40 hemodialysis sessions.

Free Pentosidine Assessment Based on Fluorescence Measurements in Spent Dialysate.

The aim of this study was to primarily explore the relationship between free pentosidine and the fluorescence properties of spent dialysate, and also to develop a model to assess the levels of free pentosidine in spent dialysate based on the fluorescence measurements. First, 40 patients (20 females and 20 males) were examined during 40 dialysis sessions. High-pressure liquid chromatography (HPLC) was used to measure the free pentosidine concentrations from the spent dialysate.

Significance of clinical and morphological prognostic risk factors in IgA nephropathy: follow-up study of comparison patient groups with and without renoprotection.

Background: IgA nephropathy (IgAN) is the most frequent glomerulonephritis in many countries including Estonia. There is no specific treatment for IgAN but renoprotection is indicated when proteinuria is >1 g/day. We aimed to assess the clinicopathological correlations of IgAN and to compare the follow-up outcome of the IgAN patients receiving renoprotection with the patients with other antihypertensive regimen treatments.

IgA nephropathy clinicopathologic study following the Oxford classification: Progression peculiarities and gender-related differences.

Background And Aim: Immunoglobulin A nephropathy (IgAN) is the most frequent glomerular disease worldwide and one of the main causes of chronic kidney disease. We aimed to investigate clinicopathological correlations in IgAN patients by gender.

Materials And Methods: The study was based on a retrospective analysis of renal biopsy data and clinical manifestations of the disease.

4-Pyridoxic Acid in the Spent Dialysate: Contribution to Fluorescence and Optical Monitoring.

Aim: In this work we estimated the contribution of the fluorescence of 4-pyridoxic acid (4-PA) to the total fluorescence of spent dialysate with the aim of evaluating the on-line monitoring of removal of this vitamin B-6 metabolite from the blood of patients with end-stage renal disease (ESRD).

Methods: Spectrofluorometric analysis of spent dialysate, collected from hemodialysis and hemodiafiltration sessions of 10 patients receiving regularly pyridoxine injections after dialysis treatment, was performed in the range of Ex/Em 220-500 nm. 4-PA in dialysate samples was identified and quantified using HPLC with fluorescent and MS/MS detection.

Is Fluorescence Valid to Monitor Removal of Protein Bound Uremic Solutes in Dialysis?

The aim of this study was to evaluate the contribution and removal dynamics of the main fluorophores during dialysis by analyzing the spent dialysate samples to prove the hypothesis whether the fluorescence of spent dialysate can be utilized for monitoring removal of any of the protein bound uremic solute. A high performance liquid chromatography system was used to separate and quantify fluorophoric solutes in the spent dialysate sampled at the start and the end of 99 dialysis sessions, including 57 hemodialysis and 42 hemodiafiltration treatments. Fluorescence was acquired at excitation 280 nm and emission 360 nm.

Lean body mass assessment based on UV absorbance in spent dialysate and dual-energy x-ray absorptiometry.

Purpose: The aim of the study was to explore the possibility of assessing lean body mass (LBM) based on UV absorbance measurements in spent dialysate.

Methods: 9 patients on chronic three-times-a-week HD (4 female, 5 male, mean age 58.8 ± 8.

An optical method for serum calcium and phosphorus level assessment during hemodialysis.

Survival among hemodialysis patients is disturbingly low, partly because vascular calcification (VC) and cardiovascular disease are highly prevalent. Elevated serum phosphorus (P) and calcium (Ca) levels play an essential role in the formation of VC events. The purpose of the current study was to reveal optical monitoring possibilities of serum P and Ca values during dialysis.

Improvements in renal replacement therapy practice patterns in estonia.

Background: The clinical performance indicators (CPI) are important tools to assess and improve the quality of renal replacement therapy (RRT). The aim of the current study was to compare the results of a longitudinal set of CPI in RRT patients and to determine the extent to which the guidelines for anaemia, calcium phosphate management and other CPI are met in Estonian renal centres.

Methods: A long-term retrospective, observational, cross-sectional CPI analysis was undertaken in RRT patients from 2007 to 2011.

Estimation of removed uremic toxin indoxyl sulphate during hemodialysis by using optical data of the spent dialysate.

The aim of this study was to explore the possibility to determine the amount of total removed Indoxyl Sulphate (TR_IS) during dialysis session, an optical method utilizing absorbance and fluorescence spectral data of the spent dialysate was used. Eight uremic patients from Linköping, Sweden and 10 from Tallinn, Estonia, were studied during dialysis treatments. Dialysate samples were taken during each treatment and analyzed at a laboratory.

Paracetamol interference in uric Acid levels in uremic patients revealed by monitoring spent dialysate.

The aim of this study was to assess removal dynamics of paracetamol (PAR), as an extraordinary chromophore in spent dialysate, upon the optical monitoring of dialysis of end-stage renal disease patients with inflammation complications. Seven dialysis sessions of different patients were followed to whom PAR was used as a pain reliever or antipyretic. Spent dialysate was sampled hourly and analyzed using HPLC with MS/MS and UV detection.

Optical measurement of creatinine in spent dialysate.

Aim: The aim of the study was to develop an optical method for the estimation of creatinine (Cr) removal during dialysis using UV-absorbance.

Material And Methods: 29 hemodialysis patients on chronic 3-times-a-week hemodialysis were studied in 6 separate studies. Double-beam pectrophotometer was used for the determination of UV-absorbance in the collected spent dialysate samples.

Optical method for cardiovascular risk marker uric acid removal assessment during dialysis.

The aim of this study was to estimate the concentration of uric acid (UA) optically by using the original and processed ultraviolet (UV) absorbance spectra of spent dialysate. Also, the effect of using several wavelengths (multi-wavelength algorithms) for estimation was examined. This paper gives an overview of seven studies carried out in Linköping, Sweden, and Tallinn, Estonia.

Concentration of uric acid removed during dialysis. Estimated by multi wavelength and processed ultra violet absorbance spectra.

The aim of this study was to estimate the concentration of uric acid (UA) optically by using original and processed ultra violet (UV) absorbance spectra's of the spent dialysate. Also the effect of using several wavelengths for estimation was examined.

HPLC study of uremic fluids related to optical dialysis adequacy monitoring.

Purpose: The aim of this study was to investigate uremia-related high-performance liquid chromatography (HPLC) ultraviolet (UV) absorbance profiles of serum and spent dialysate and to study the removal of uremic retention solutes in connection with optical dialysis adequacy monitoring.

Methods: 10 uremic patients were investigated using online spectrophotometry at a wavelength of 280 nm over the course of 30 hemodialysis treatments. The dialysate and blood samples were taken and analyzed simultaneously using standard biochemical methods and reversed-phase HPLC.

A multicentre study of an enhanced optical method for measuring concentration of uric acid removed during dialysis.

The aim of this study was to compare concentration measurements of uric acid (UA) removed during dialysis by two algorithms based on UV-absorbance and the 1st derivate of UV absorbance. Ten uremic patients from Tallinn and ten from Linköping, during 30+40 haemodialysis treatments, were followed at the Departments of Dialysis and Nephrology at North-Estonian Medical Centre and at Linköping University Hospital. The dialysate samples were taken and analyzed by means of UA concentration at the chemical laboratory and with a double-beam spectrophotometer.

Optical online monitoring of uric acid removal during dialysis.

This study estimates the total removal of uric acid (TR(UA)) by online UV absorbance measurements in the spent dialysate in two different dialysis centers in Estonia and Sweden. Sixteen dialysis patients were included. All dialysate was collected that gave the reference for TR(UA).

Optical dialysis adequacy sensor: wavelength dependence of the ultra violet absorbance in the spent dialysate to the removed solutes.

A need for dialysate-based, on-line, continuous monitoring systems for the control of dialysis efficiency and the prevention of dialysis-associated complications is arisen due to increasing number of dialysis patients and related treatment quality requirements. The aim of this study was to investigate the wavelength dependence between the the ultra-violet (UV) absorbance in the spent dialysate and the retained solutes removed during the hemodialysis in order to explain possibilities to estimate removal of the solutes by the optical dialysis adequacy sensor. Ten uremic patients, during 30 hemodialysis treatments, were followed at the Department of Dialysis and Nephrology, North-Estonian Regional Hospital.

Optical dialysis adequacy sensor: contribution of chromophores to the ultra violet absorbance in the spent dialysate.

Several on-line methods have been developed to standardize the assessment of dialysis adequacy. Earlier studies have demonstrated that on-line monitoring of total ultra violet (UV) absorbance in spent dialysate can be utilized to follow continuously a single hemodialysis session. The aim of this study was to investigate the contribution of different compounds, acting as chromophores, to the UV-absorbance in the spent dialysate in order to explain origin of the cumulative and integrated UV-absorbance measured by the optical dialysis adequacy sensor.