No associations between prolactin concentrations and response to erythropoiesis-stimulating agents in hemodialysis patients.

Background: The effect of serum prolactin levels on the response to erythropoiesis-stimulating agents (ESA) in patients on chronic hemodialysis is unknown.
Methods: We included 111 stable hemodialysis patients in this study and examined the association of serum prolactin concentrations with the response to ESA. Accordingly we implemented an ESA index as a measure of therapeutic efficacy. The two outcomes of this cohort study were the association of prolactin concentrations with response to ESA, both at baseline (cross-sectional component) and after 1-year of follow-up (prospective component), and the presence of macroprolactin.
Results: Two male patients, but none of the female patients, had serum prolactin concentrations within the reference range. Following precipitation with polyethylene glycol (PEG), 17 males (25.4%) and 9 females (20.6%) had serum prolactin concentrations within the reference range. Females had somewhat higher levels than males: 39.8 (IQR 32.3-64.5) versus 27.8 (IQR 23.4-47.8) ng/ml (p = 0.003). The ratio of prolactin(PEG)/prolactin(Native) was greater than 0.60 in 103 patients (92.8%), thus excluding significant amounts of macroprolactin. From uni- and multivariate analyses we did not find associations of serum prolactin concentrations with a response to ESA either at baseline or at follow-up.
Conclusions: From this prospective study we provide evidence that elevated serum prolactin levels are not related to the presence of macroprolactin in chronic hemodialysis patients. Furthermore, serum prolactin concentrations are not associated with the response to erythropoietic therapy in these individuals.
(Copyright 2007 S. Karger AG, Basel.)