IL6 and hydrops fetalis: Recent studies, however, report rather low-hepcidin levels in HF patients and no association between pro-inflammatory activation (as evidenced by circulating IL-6) and hepcidin levels.13,32,33 There is only one small clinical study showing the advantage of i.v. iron therapy over oral iron on exercise capacity in anaemic iron-deficient HF patients,34 but with only 18 subjects analysed it is far from being conclusive.