Urine IL-8 concentrations in infectious and non-infectious urinary tract conditions

Urine IL-8 concentrations are known to be elevated in urinary tract infection (UTI), as well as in vesicoureteral reflux (VUR) even in the absence of infection. In this study we further investigated urine IL-8 in infants with congenital anomalies of the kidneys and urinary tract and with antenatally diagnosed isolated pelvic dilatation. Urine IL-8 was measured in 159 infants aged 1 month to 1 year with acute UTI (group A, n = 26), resolved UTI (group B, n = 16), VUR without recent UTI (group C, n = 44), non-VUR congenital urinary anomalies without recent UTI (group D, n = 30), isolated antenatal pelvic dilatation (group E, n = 14) and in infants without known urinary tract condition (control group F, n = 29). Median values of urine IL-8/creatinine levels were 61.5, 4.64, 15.5, 14.3, 1.06 and 4.19 pg/μmol in groups A, B, C, D, E and F respectively. Compared with the control group, urine IL-8 was elevated in infants with acute UTI, VUR without acute UTI and congenital anomalies without acute UTI (p < 0.0001; p < 0.005; and p = 0.027 respectively), but not in infants with resolved UTI or with antenatal pelvic dilatation. Urine IL-8 levels are elevated in a variety of infectious and non-infectious urinary tract conditions, and hence may serve as a sensitive but not specific screening biomarker of urinary tract diseases.