Effectiveness and safety of intravenous iron in ulcerative colitis: A real-world study of impact of disease activity and iron preparations.

Abstract

Background: There is lack of evidence on how disease activity in inflammatory bowel disease influences response to intravenous iron.

Methods: A single-centre prospective study was conducted to study responses to intravenous iron in ulcerative colitis. Patients with iron deficiency anemia (hemoglobin < 8 g/dL OR < 12 g/dL with intolerance to oral iron or active disease) received protocolized intravenous iron dosing per European Crohn's and Colitis Organisation (ECCO) guidelines. Ferric carboxymaltose (FCM) or iron isomaltoside was used per patient preference. The outcomes were increase in Hb ≥ 2 g/dL, normalization of Hb at four weeks and normalization of iron indices (serum ferritin >100 ng/mL in active and > 30 ng/mL in inactive disease and transferrin saturation > 20%) assessed at four weeks.

Results: Thirty-two patients (females = 21 [65.6%], mean age = 32.78 ± 12.65 years, active disease = 17 [53.1%]) received IV iron. Twenty-one received FCM, while 11 received iron isomaltoside. Complete normalization of Hb was seen in seven (41%) in active patients and nine (60%) in remission groups (p = 0.47). Normalization of iron profile was seen in 11 (64%) and 12 (80%) patients in two groups, respectively (p = 0.32). Secondary objectives of mean change in Hb and iron indices tended towards better response in inactive group, but were not statistically significant except change in transferrin saturation that was better in inactive group (20.8 ± 9.1% and 14.2 ± 8.1%, p = 0.04). FCM was associated with hypophosphatemia in 6/21 (28.5%) patients vs. none in isomaltoside group. The predictive performance for complete hematological response with the reticulocyte hemoglobin and percentage of hypochromic cells was low (area under the receiver operating characteristic [AUROC] of 0.67 and 0.685, respectively).

Conclusion: Although there was a tendency towards better response to intravenous iron in those with remission, the findings were not statistically different. Larger studies are needed to provide conclusive evidence. Iron isomaltoside may be preferable over FCM due to risk of hypophosphatemia with the latter.