CXCL8 and pyelonephritis: Urinary IL-6 measured as urinary IL-6/creatinine was not significantly different in the pyelonephritis and UTI groups (median 2.83 pg/mg, range 0 to 122.55 vs. 3.81 pg/mg, range 0 to 41.67).27 Median urinary IL-8 measured as urinary IL-8/creatinine was 45.12 pg/mg (range 0 to 3200.77) in the pyelonephritis group and 0 pg/ml (range 0 to 117.45) in the UTI group.