The role of blood purification therapies in the treatment of chronic kidney disease-associated pruritus: a systematic review

Background Chronic kidney disease-associated pruritus (CKD-aP) is a common complication in dialysis patients not fully addressed by pharmacological and dialytic therapy. Objective to review the literature on the effects of extracorporeal blood purification modalities on CKD-aP. Population patients aged ≥ 18 years on chronic dialysis. Selection criteria PubMed, Embase, and Medline were systematically searched until February 2024 for clinical studies comparing the effect of different dialysis modalities on pruritus intensity. 2 reviewers extracted data independently. Risk of bias for RCTs was assessed using the Cochrane tool. Intervention any extracorporeal blood purification therapy for the treatment of CKD-aP was included. Outcomes quantitative change in pruritus intensity on a validated itching scale. Synthesis of results This review included 8 RCTs examining 5 different dialysis modalities, 3 observational studies examining 3 dialysis modalities, and 6 prospective clinical trials assessing 4 dialysis modalities. These treatments included peritoneal dialysis, low-flux, and high-flux dialysis, hemodiafiltration, expanded hemodialysis, hemadsorption, hemodiafiltration with endogenous reinfusion, and dialysis with PMMA membrane. Risk of bias was high in most studies. The largest body of evidence was found for the efficacy of hemadsorption. Limitations of evidence heterogeneity in diagnostic tools and treatment, risk of selection bias, small sample sizes, and short follow-up durations that made it challenging to perform a robust systematic review and meta-analysis. Interpretation Despite the high prevalence of pruritus among dialysis patients, except for hemadsorption, current evidence for dialytic treatment is weak. More high-quality studies are needed to confirm the long-term benefits.