Prediction of response to iron sucrose in inflammatory bowel disease-associated anemia

Inflammatory bowel disease (IBD)-associated anemia responds to i.v. iron therapy. However, because of concurrent chronic inflammation, some patients do not respond adequately. Erythropoietin therapy has been shown to be effective in the latter cohort. Our goal was to find parameters that can predict the effectiveness of iron sucrose in IBD-associated anemia.

One hundred three patients with severe IBD-associated anemia (Hb < or = 10.5 g/dl) were treated prospectively for 4 wk with iron sucrose (total iron dose = 1.2 g) in an open label, multicenter trial. Treatment response was defined as an increase in Hb of > or =2.0 g/dl. A logistic regression analysis was performed with treatment response as the dependent variable and the following independent variables: serum erythropoietin, mean corpuscular Hb, transferrin, ferritin, soluble transferrin receptor (sTfR), C-reactive protein, interleukin 6 (IL-6), and disease activity.

Sixty-seven of 103 patients (65%) responded to iron sucrose. From the variables under investigation, erythropoietin, sTfR, transferrin, and IL-6 were significantly associated with treatment response. The R2 values showed that erythropoietin (8.0%), sTfR (11.4%), and transferrin (10.4%), but not IL-6 (1.3%), contribute a relevant amount of information to the model. An estimated 80% probability of treatment response was found at erythropoietin levels of >166 U/L, sTfR levels of >75 nmol/L, or transferrin levels of >3.83 g/L.

Serum erythropoietin, sTfR, and transferrin concentrations have the potential to predict the response to iron sucrose therapy in IBD-associated anemia. These parameters may help to identify individuals who benefit the most from additional erythropoietin treatment.