Serum hepcidin concentration in chronic haemodialysis patients: associations and effects of dialysis, iron and erythropoietin therapy.
BACKGROUND
Hepcidin, a liver-derived peptide induced by iron overload and inflammation, is a major regulator of iron homeostasis. As hepcidin decreases gastrointestinal iron absorption and recirculation from monocytes, over-expression is associated with the development of anaemia.


METHODS
We studied the associations between circulating hepcidin levels and various laboratory parameters related to anaemia and/or inflammation in 20 patients on chronic haemodialysis. Furthermore, we determined the impact of dialysis and iron and/or erythropoietin (rhEpo) supplementation therapy on hepcidin serum concentrations. The patients were withheld from iron and rhEpo for 2 weeks before study entry. Hepcidin was measured by liquid chromatography-mass spectrometry (LC-MS/MS); serum iron and haematological parameters, cytokines and pro-hepcidin by commercially available enzyme-linked immunosorbent assays (ELISA) or standard automated methods.


RESULTS
While hepcidin levels at baseline were not correlated to pro-hepcidin, interleukin-6 or transforming growth factor-beta concentrations, we found significant associations with reticulocyte count (r = -0.55; P = 0.015), serum iron (r = 0.7; P = 0.004) and ferritin levels (r = 0.63; P = 0.004) and transferrin saturation (r = 0.69, P = 0.001). Dialysis using either a high or a low flux biocompatible dialyser resulted in a significant decrease of hepcidin concentrations, which returned to pre-dialysis values before the next dialysis session. When studying the effects of anaemia treatment, we observed a significant reduction of hepcidin levels following administration of rhEpo but not iron.


CONCLUSIONS
Hepcidin levels in stable haemodialysis patients appear to reflect systemic iron load, but not inflammation. Due to the negative association between reticulocyte counts and hepcidin, the reduction of circulating hepcidin concentrations by dialysis and/or rhEpo treatment may positively affect erythropoiesis.
Weiss
G
G
Department of Internal Medicine IV, Nephrology and Hypertension, Medical University Innsbruck, A - 6020 Innsbruck, Austria.
Theurl
I
I
Eder
S
S
Koppelstaetter
C
C
Kurz
K
K
Sonnweber
T
T
Kobold
U
U
Mayer
G
G
D000368:Aged; D000740:Anemia / Q000097:blood*; D023181:Antimicrobial Cationic Peptides / Q000097:blood* / Q000494:pharmacology; D003430:Cross-Sectional Studies; D004921:Erythropoietin / Q000009:adverse effects; D005260:Female; D064451:Hepcidins; D006801:Humans; D007501:Iron / Q000097:blood*; D019190:Iron Overload; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins; D006435:Renal Dialysis / Q000009:adverse effects
D023181:Antimicrobial Cationic Peptides; C578702:HAMP protein, human; D064451:Hepcidins; D011994:Recombinant Proteins; D004921:Erythropoietin; D007501:Iron