Nontransferrin-bound iron in the plasma of haemodialysis patients after intravenous iron saccharate infusion.
BACKGROUND
Many haemodialysis patients treated with recombinant human erythropoietin (r-HuEPO) receive intravenous iron supplementation on a regular basis. It has been shown previously that this may result in a transient "oversaturation" of transferrin.


METHODS
Ten stable haemodialysis patients on r-HuEPO treatment received 100 mg iron saccharate in 60 min, and 1 week later 100 mg in 6 min. Conventional iron metabolism parameters and nontransferrin-bond iron, detected with HPLC after addition of nitrilotriacetate and pretreatment with cobalt, were measured. Also, iron was measured in dialysate.


RESULTS
Serum iron increased from 9.6 +/- 6.2 to 213.7 +/- 49.4 micromol L(-1) (P < 0.001) when iron was given in 60 min, and from 11.1 +/- 4.7 to 219.3 +/- 43.7 micromol L(-1) (P < 0.001) when iron was given in 6 min. Transferrin saturation increased from 0.22 +/- 0.18 to 4.75 +/- 1.35 in protocol 1 and 0.26 +/- 0.16 to 4.91 +/- 1.38 in protocol 2. Nontransferrin-bound iron increased from 0.74 +/- 0.69 to 3.79 +/- 1.41 micromol L(-1) in protocol 1, and from 0.90 +/- 0.92 to 2.90 +/- 0.96 micromol L(-1) in protocol 2. No significant iron concentrations were found in dialysate before or during the iron saccharate infusion.


CONCLUSIONS
Nontransferrin-bound iron exists in plasma of dialysis patients after infusion of iron saccharate. There was no difference when 100 mg iron was given in 60 min or in 6 min. Before iron infusion, appreciable concentrations of nontransferrin-bound iron could already be detected. The clinical significance is not clear, but the findings may be important since nontransferrin-bound iron can act as a catalytic agent in the formation of hydroxyl radicals, thus potentially inducing cell damage and atherosclerosis.
Kooistra
M P
MP
Stichting DIANET Dialysis Centres, Brennerbaan 130, 3524 BN Utrecht, The Netherlands. m.kooistra@utr.dianet.nl
Kersting
S
S
Gosriwatana
I
I
Lu
S
S
Nijhoff-Schutte
J
J
Hider
R C
RC
Marx
J J M
JJ
D000740:Anemia / Q000188:drug therapy* / Q000378:metabolism; D015314:Dialysis Solutions / Q000737:chemistry; D005260:Female; D005290:Ferric Compounds / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D000077605:Ferric Oxide, Saccharated; D005293:Ferritins / Q000378:metabolism; D005937:Glucaric Acid; D006801:Humans; D007262:Infusions, Intravenous; D007501:Iron / Q000032:analysis / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy; D008297:Male; D011485:Protein Binding; D006435:Renal Dialysis; D014168:Transferrin / Q000378:metabolism
D015314:Dialysis Solutions; D005290:Ferric Compounds; D014168:Transferrin; D005293:Ferritins; D007501:Iron; D000077605:Ferric Oxide, Saccharated; D005937:Glucaric Acid