Anti_IL-6 Ab's neutralize the induction of hepcidin mRNA. Hepcidin mRNA was analyzed relative to G3PDH mRNA by quantitative RT-PCR (qRT-PCR). P values were determined by one-way RM-ANOVA with a Tukey test. (A) Primary hepatocytes (n = 4 donors): untreated (0), treated for 24 hours with 100 ng/ml LPS (LPS), or treated with 100 ng/ml LPS + 6 ∝g/ml anti_IL-6 Ab's (LPS + IL-6 Ab's). (B) Hep3B cells: untreated (0), treated for 24 hours with 16.6% medium from monocyte-derived macrophages (n = 2 donors) or Kupffer cells (n = 2 donors) either unstimulated (M) or stimulated with 100 ng/ml LPS (M-LPS) or treated for 24 hours with the same 16.6% M-LPS + 6 μg/ml anti_IL-6 Ab's (M-LPS + IL-6 Ab's).