Figure 1
Association between IL-6, hepcidin and hemoglobin decrease. (a) Humoral relation between inflammation and hepcidin levels: Pearson's correlation between the natural logarithm (Ln) of IL-6 and hepcidin-25 on day 2 (black diamonds, uninterrupted line), and day 3 (grey dots, dashed line. The correlation on day 1 (r = 0.28, P = 0.015), was omitted for reasons of clarity. The median reference level of serum hepcidin-25 is 4.2 nM, range 0.5 to 13.9 nM [15]. (b) Clinical relation between inflammation and hepcidin levels: hepcidin-25 levels according to the number of extended systemic inflammatory response syndrome (SIRS) criteria at presentation at the emergency ward [13]. Differences were tested with Kruskal-Wallis. (c) Spearman's correlation between rate of hemoglobin (Hb) decrease and hepcidin-25 concentration on day 2 (black dots, uninterrupted line) and day 3 (open triangles, dashed line). The rate of decrease was only calculated in patients that did not receive a blood transfusion and of whom Hb was measured at least once between day 7 and 14 of hospital admission (n = 44). (d) Relation between hepcidin-25 levels at admission and the number of blood transfusions received during 14 days of follow up. Boxes represent median and interquartile range, whiskers represent 5th and 95th percentile. Difference between transfused and non-transfused patients was tested with a Mann Whitney test.