Modifications in relaxin's serum levels during acetate-free biofiltration (AFB): only a new biomarker?

Summary Aims.We evaluated relaxin's behaviour during a haemodialytic session and the effects of its intradialytic variability on blood pressure. Methods. We enrolled 25 patients and evaluated relaxin's levels during a haemodialytic session. We also dosed interdialytic relaxin and enrolled 10 healthy subjects and 16 patients with III stage chronic renal failure as controls. Results. Haemodialyzed patients have relaxin's baseline concentrations higher than healthy controls, but lower than chronic patients. During the treatment, relaxin is removed; it increases again throughout the interdialytic phase. Furthermore, relaxin's pre- haemodialytic concentra- tion positively and significantly correlates with systolic, diastolic, and mean BP; such correla- tions disappear at the end of the treatment. Conclusion. Relaxin's removal during the treatment may intervene in the pathogenesis of intra- dialytic hypertension. Hence, relaxin could be not only a new biomarker but also an active player in the intradialytic variations of blood pressure.