L Huang1,2, D Lee1,2, LP McMahon1,2, S Troster1, I Macdougall3
1Department of Renal Medicine, Eastern Health, Melbourne, Australia; 2Department of Medicine, Eastern Health Clinical School, Monash University, Australia; 3Department of Renal Medicine, King’s College Hospital, London, United Kingdom
Background: The IDENTIFY Study investigated the effects of IV ferric carboxymaltose (FCM) on markers of bone metabolism in chronic kidney disease (CKD), pregnancy, and healthy controls, but data on iron status were also collected. When the results of the latter were analysed, it became clear that there were differences among the three groups of patients, and the aim of this analysis was to examine this in more detail.
Methods: IDENTIFY was a prospective observational study comprising 1g of IV FCM administered to 3 patient populations: CKD (n=25); healthy Controls (n=20); and Pregnancy (n=20). The following markers of iron status were collected on days 0, 2, 7 and 21: serum iron, ferritin, transferrin saturation (TSAT) and hepcidin (by mass spectrometry).
Results: Following IV FCM, there was a similar increase in serum iron and TSAT in all groups, which peaked at day-2, and returned to baseline at day-7. Ferritin increased to the same extent in all groups, reaching a maximum at day-7, and remaining significantly above baseline at day-21. Serum hepcidin peaked at day-2 in all groups, but the zenith varied (127±61 vs. 106±62 vs. 61±44 ng/mL, p=0.001) and the AUCs differed (1503±1173 vs. 953±718 vs. 629±360, p=0.004) in the CKD, Controls and Pregnancy groups, respectively.
Conclusions: Despite receiving the same dose of FCM, and with comparable levels of haematinics, the rise in hepcidin was significantly greater in CKD patients compared to healthy controls and pregnant women. The reason for this novel finding is unclear, and requires further study. Finally, the ferritin response observed in this study supports a recommendation that following administration of 1g FCM, serum ferritin should not be rechecked for at least 1-month.