IL6 and acute kidney injury: Furthermore, patients with AKI had markedly higher levels of serum creatinine (median: 75.5 vs. 67.1 μmol/L, P = 0.002), interleukin-6 (median: 17.9 vs. 12.3 pg/ml, P < 0.001) and serum ferritin (median: 2001.0 vs. 985.4 ng/ml, P < 0.001).