MO671COMPARASION OF EXPENDED HEMODIALYSIS USING A MEDIUM CUT-OFF DIALYZER VERSUS HEMODIAFILTRATION: AN OBSERVATIONAL PROSPECTIVE STUDY
Authors: Azasevac Tijana , Knezevic Violeta , Strazmester Majstorovic Gordana , Markovic Mira , Veselinov Vladimir , Eremic Kojic Nevena , Celic Dejan , Mitic Igor 
Published: May 2021

Abstract

Background and Aims
Expended hemodialysis (HDx) with medium cut-off (MCO) membrane enables efficient depuration of middleweight uremic toxins, which play significant roles in inflammation and cardiovascular morbidity. Hemodiafiltration (HDF) is known for good removal of middle molecules but it requires more technical resources and well-functioning dialysis access.
The aim of this study is to evaluate the efficacy of depuration of uremic toxins with a high-flux dialyzer during HDF session and with a MCO membrane (Theranova®) in HDx session and its impact on quality of life (QoL) in hemodialysis patients.

Method
In an open, single-centre, prospective observational clinical study, 28 adult stable HD patients without residual renal function were assigned to be treated by on-line HDF (HDF group) with the APS-21H dialyzer (polysulfone membrane, 2.1 m2, Asahi Kasei Medical Co., Japan) or by HDx (HDx group) with the Theranova® 400 (1.7 m2) and Theranova® 500 (2.0 m2) dialyzers (Baxter International Inc, USA). The study was conducted during 2019-2020 and completed after 12 months period. All patients were receiving maintenance high-flux membrane HDF treatment at least six months before they were enrolled in the study. Groups of patients were matched in age, sex, BMI, dialysis length and underlying disease. Complete blood count (CBC), renal function and inflammation, electrolytes, liver function tests, iron and nutritional status were evaluated at the beginning of the study and after 3, 6, 9 and 12 months. Pre and postdialysis levels for urea, creatinine, albumin, calcium, phosphorus, C-Reactive Protein, kappa and lambda free light chains (FLC), vitamin B12, β2 microglobulin levels were determined in each patient quarterly and reduction rate (RR) for uremic toxins were calculated. Furthermore single-pool Kt/V, dose of erythropoietin therapy (EPO) and vascular access were evaluated during the study, while bioimpedance analysis using Body composition monitor (Fresenius Medical Care, Germany) and QoL using SF-36 questionnaire (Kidney Disease Quality of Life Short Form-KDQOLTM-36) were evaluated at the end of observation period. The values have been reported as mean ±SD.

Results
There were 28 patients (14 in each group) mean age of 54.24 years (57.71±9.65 in HDx group vs 59.81±7.99 in HDF group). Median dialysis vintage was 4.77 years (5.33 in HDx group vs 6.46 in HDF group, p=0.55). Vascular access was native arteriovenous fistula in 23 patients, arteriovenous graft in 2 patients and tunnelled dialysis catheter in 3 patients (p=0.98). Kt/V was similar in both groups (1.57±0.31 vs 1.45±0.24, p=0.9), as well as weekly dose of EPO (4533.3±1922.3 vs 4233.3±1971.8, p=0.67). Patients in HDF group had a significantly higher interdialysis fluid overload (2,48±1,37 in HDx group vs 3,64±1,33 in HDF group, p=0.04), without difference in relation to the systolic and diastolic blood pressure values, as well as others BCM parameters. There were not significant differences in examined parameters of CBC, renal function and inflammation, electrolytes, liver function tests, iron and nutritional status at the beginning and at the end of the study. RR of small and middle molecules are presented in Table 1. Serum albumin level has decreased from 37.8 g/dL to 36.4 g/dL in 12 months during HDx treatment with maximal change of serum albumin level of -3.7% during that period (Figure 1). Evaluation of Kidney Disease Quality of Life Short Form at the end of study period in both groups is shown in Figure 2.

Conclusion
Compared to HDF, HDx with MCO membranes show greater RR for large middle molecules such as lambda FLC (45kD), while RRs for middle molecules- kappa FLC (23kD), β2 microglobulin (12kD) and small uremic toxins are similar. During one year of treatment with MCO membranes serum albumin levels remain stable. HDx treatment may improve quality of life, making an impact primarily in energy status and emotional satisfaction.