The purpose of this study is to test whether a dialyzer with a higher than usual permeability for proteins can eliminate proinflammatory proteins from the blood of patients on regular maintenance hemodialysis who have chronically elevated levels of inflammation markers such as C-reactive protein (CRP) in their blood.

Patients with ESRD on chronic hemodialysis patients frequently have elevated markers of inflammation (e.g. serum CRP values). Hemodialysis may clear the blood from low molecular weight toxins and retention products such as creatinine, potassium, or urea. The dialyzer clearance of middle to high molecular weight substances such as cytokines and cytokine receptors is low. Nearly 50% of chronic dialysis patients have persistent subclinical inflammation which is strongly associated with cardiovascular disease and mortality. The study tests the hypothesis that removal of proteins in the weight range of 10.000-30.000 D via a more permeable dialyzer membrane reduces chronic inflammation in these patients.

Inclusion Criteria:

• regular hemodialysis for at least 3 months
• treatment thrice weekly
• high-flux hemodialyzer for at least 4 weeks
• age > 18 years and < 80 years
• at least one CRP value > 5mg/L within 8 weeks before inclusion
• able to understand and consent the study
• written informed consent

Exclusion Criteria:

• no consent
• clinically apparent acute infection
• CRP > 50 mg/L
• serum albumin < 3,5 mg/L
• central venous line as dialysis access
• immunosuppressive medication
• pregnancy or lactation
• inclusion into any other interventional trial