Volatility of elevated serum ferritin in anemic hemodialysis patients

Abstract

Background: Value of serum ferritin (SF) as an iron store index in hemodialysis (HD) patients has been questioned, especially at ranges >or=200. The objective of this study was to determine the variability of SF in patients with high SF (500-1,200.) and low TSAT (<or=25%).

Methods: This was a multicenter observational study. Data were obtained from Dialysis Patients' Response to IV Iron with Elevated Ferritin (DRIVE) study voluntary subject screening surveys (n=96), which reported epoetin dose, pre-screening and screening hemoglobin, TSAT and SF. Entry criteria were age >or=18 years, HD >or=90 days, SF 500-1,200., TSAT <or=25%, hemoglobin <or=11 g/dL, epoetin >or=22,500 IU/week or >or=225 IU/kg/week and <or=125 mg i.v. iron/week in the 4 weeks prior to screening. Groups were stratified by intervals of time between laboratory dates: 1-14 days (group 1), 15-28 (group 2) and 29-42 (group 3). Changes from pre-screening to screening were evaluated.

Results: SF changes (Delta SF) in groups 1, 2 and 3 were -63. (range -414 to +415.; p=0.013), -191. (range -379 to +427.; p=0.001) and -144. (range -541 to +181.; p=0.018), respectively. Within group 1, proportions of patients experiencing an absolute Delta SF >or=100., >or=200. and >or=300. were 61.0%, 29.3% and 12.2%, respectively, and 27% exhibited positive changes in SF.

Conclusions: SF is a volatile and imprecise indicator of tissue iron stores in anemic HD patients with high SF and low TSAT. This volatility limits clinical utility of SF in this population.