ICHARUS: Italian Cooperative HemoAdsorption Study for Relief of Uremic Symptoms

Rationale Despite major advances in dialysis technology, a substantial proportion of patients receiving maintenance hemodialysis continue to experience persistent uremic symptoms, including pruritus, fatigue, sleep disturbances, reduced physical performance, and impaired quality of life. Conventional dialysis modalities primarily rely on diffusive and convective solute transport and may be insufficient to remove specific classes of uremic toxins, particularly protein-bound solutes and selected middle molecules. Hemoadsorption combined with hemodialysis (HAHD) provides an additional adsorptive mechanism that may enhance the removal of these solutes and potentially contribute to symptom relief.

Study overview The ICHARUS study (Italian Cooperative HemoAdsorption Study for Relief of Uremic Symptoms) is a prospective, multicenter, observational real-world registry designed to describe the clinical use of HAHD in adult patients undergoing maintenance hemodialysis. The registry aims to collect standardized data on indications, treatment patterns, symptom evolution, and safety outcomes associated with HAHD when prescribed as part of routine clinical practice.

Study design ICHARUS is a non-interventional cohort registry. Patient enrollment is based on clinical indication for hemoadsorption, as determined by the treating physician, in the presence of persistent uremic symptoms despite optimized conventional dialysis. The decision to initiate, continue, or discontinue hemoadsorption is entirely independent of study participation and follows local clinical practice. No randomization, mandated treatment changes, or protocol-driven interventions are applied.

Treatment characteristics Hemoadsorption is performed in combination with standard hemodialysis modalities, including low-flux hemodialysis, high-flux hemodialysis, expanded hemodialysis, or hemodiafiltration, according to center expertise and patient-specific prescription. Dialysis session duration, blood and dialysate flow rates, anticoagulation strategy, and treatment frequency are not dictated by the registry and remain at the discretion of the treating team.

Data collection and follow-up Data are collected at baseline and during routine follow-up visits at approximately 1, 3, and 6 months after enrollment. Collected variables include demographic and clinical characteristics, dialysis prescription parameters, patient-reported symptoms, selected laboratory markers, and safety-related information. Follow-up assessments are aligned with standard clinical care and do not require additional procedures beyond routine practice.

Safety considerations As an observational registry, ICHARUS does not introduce experimental treatments or additional risks beyond standard clinical care. Adverse events and safety signals potentially associated with HAHD are recorded descriptively, without predefined stopping rules or intervention thresholds.

Ethical aspects The registry is conducted in accordance with the Declaration of Helsinki and applicable local regulations. Ethical approval is obtained at each participating center prior to patient enrollment. Written informed consent is collected according to local requirements.

Objectives and perspective The primary objective of the ICHARUS registry is to describe real-world patterns of HAHD use and associated changes in uremic symptoms and patient-reported outcomes over time. Secondary objectives include characterization of laboratory trends and treatment tolerability. By providing structured real-world evidence across multiple centers, the registry aims to support harmonization of clinical practice, improve patient endophenotyping, and generate hypotheses for future interventional studies.

• Absolute change in serum β2 microglobulin concentration [Time frame: Baseline, 1, 3, and 6 months]
• Relative change in serum β2 microglobulin concentration [Time frame: Baseline, 1, 3, 6 months]
• Change in erythropoietin resistance index [Time frame: Baseline, 3 and 6 months]
• Incidence of treatment emergent adverse events [Time frame: Baseline, 6 months]
• Change in 5 D Itch Scale score [Time frame: Baseline, 6 months]
• Change in International Restless Legs Syndrome Rating Scale score [Time frame: Baseline, 6 months]
• Change in Pittsburgh Sleep Quality Index score [Time frame: Baseline, 6 months]