P314. The type of iron deficiency anaemia, but not the underlying disease, predicts intestinal iron absorption in IBD patients
M. Wiesenthal1, A. Dignass2, F. Hartmann1, J. Stein1, 1Crohn Colitis Center, DGD Krankenhaus Sachsenhausen, Frankfurt, Germany, 2Agaplesion Markus Hospital, Department of Medicine I, Frankfurt, Germany
Anaemia in patients with inflammatory bowel disease (IBD) is multifactorial. However, the two most common causes of anaemia in IBD are iron deficiency and anaemia of chronic inflammation (ACI). Although the exact pathogenesis of ACI is unknown, one hypothesis suggests that ACI arises in part as a result of impaired intestinal iron absorption, due to the effects of inflammatory cytokines. The acute-phase protein hepcidin has recently been shown to impair intestinal iron uptake. We therefore hypothesized that iron absorption impairment in patients with active IBD is due at least in part to increased hepcidin release by the liver.
71 adult subjects with IBD (31 UC, 40 CD) and 26 healthy controls were recruited up until February 2013. Following overnight fasting, serum haemoglobin levels, serum ferritin (SF) and serum markers of inflammation [high-sensitivity C-reactive protein (hsCRP) and IL-6] were determined. Serum samples for hepcidin assay were obtained at 8 a.m. and measured by LC-MS. Oral administration of ferrous sulfate (100 mg) was followed by measurement of serum iron concentrations hourly for 4 hours. An area under the curve (AUC) for iron absorption was calculated for each patient data set. Anaemia was classified as iron deficiency anaemia (IDA), anaemia of chronic inflammation (ACI) according to Weiss, Goodnough , or a mixed form (ACI/IDA).
In all anaemic patients, a significant inverse correlation was observed both between the AUC and hsCRP (p < 0.001) and between the AUC and hepcidin levels (P = 0.017). In both UC and CD patients, the difference between baseline and 2-hour serum iron level (Δ[Fe]2hr) was significantly decreased independent of disease location in patients with ACI, but not in those with IDA or ACI/IDA (Figure 1).
Compared to healthy controls and subjects with inactive disease, IBD patients with ACI have impaired oral iron absorption which correlates with disease activity and inflammation markers but is independent of disease location and type of IBD.
1. Weiss G, Goodnough LT, (2005), Anemia of chronic disease, N Engl J Med 352: 1011–23.