β2M Post-HD Rebound Prediction

End Stage Renal Disease on haemodialysis

Adult, End Stage Renal Disease established on maintenance haemodialysis for at least 3 months

诊断测试：β2-microglobulin blood concentration in mg/L

Blood samples for β2-microglobulin measurement will be collected by study investigator across two haemodialysis sessions. During the first study visit (HD1), blood samples will be obtained pre-dialysis (0%), at 20%, 40%, 60%, and 80% of the prescribed dialysis duration, at the end of dialysis (100%), and at 1 hour and 2 hours following completion of dialysis. During the second study visit (HD2), a single pre-dialysis β2-microglobulin sample will be collected at the start of the participant's next routine haemodialysis session, which is second and last study visit.

All study samples will be used to measure β2-Microglobulin concentration in mg/L

Post-dialysis β2-microglobulin blood concentration (mg/L) at 1 and 2 hours after completion of haemodialysis

β2-microglobulin blood samples will be collected at time points including pre-dialysis (0%), at 20%, 40%, 60%, 80%, and 100% of the dialysis session, as well as at 1 hour and 2 hours post-dialysis. An additional pre-dialysis sample will be obtained before the next routine haemodialysis session (approximately 48 hours later).

The primary outcome measure will be the β2-microglobulin concentration (mg/L) at 1 and 2 hours post-dialysis, which will serve as the dependent variable in regression-based and software-assisted modelling. These models will be used to develop an algorithm capable of accurately predicting the equilibrated post-dialysis β2-microglobulin concentration from measurements obtained during the dialysis session.

We will record small panel of solute clearance markers such as blood urea measured in mmol/L and creatinine umol/L

This is recorded from the standard of care blood tests assessing monthly dialysis adequacy. Derived from routine monthly dialysis adequacy testing done at same time period of the study sample collection.

We will assess Patient-Reported Outcome Measures (PROMs) related to dialysis quality and dialysis-associated symptom burden, using validated questionnaires

The following validated Questionnaires will be used to assess Patient Reported Outcome Measure (PROM): SONG-HD Fatigue, Recovery time and IPOS Renal questionnaires .

The questionnaire burden was discussed at the Patients and Public Involvement Group meeting within the trust and considered in study design. The questionnaires were considered relevant and the burden on patients was judged to be acceptable and not a major barrier to participation. To minimise the participants being overwhelmed with questionnaires, we will offer them flexibility of completing the questionnaires during and or after first study visit (either on dialysis or at home). They may also receive support from family, friend and or medical staff team to help filling these questionnaires as needed. It is anticipated that each questionnaire will take approximately 5 minutes to complete. We expect most patients will complete this during their dialysis treatment