Urinalysis for interleukin-8 in the non-invasive diagnosis of acute and chronic inflammatory diseases

Abstract

Background and aims: Given its role in mediating inflammation, the use of urinary interleukin-8 (IL-8) was assessed in the non-invasive diagnosis of acute and chronic inflammatory diseases. Methods: IL-8 was measured by an enzyme linked immunosorbent assay in random urine samples (1 ml each) carrying code numbers and taken from 208 patients: 177 adults and 31 children presenting with a range of active or inactive inflammatory conditions. Results: In the appropriate controls and in patients with inactive inflammation, the median urinary IL-8 levels ranged from 7-12 pg/ml, compared with 104 pg/ml in active ulcerative colitis (p = 0.002), 54 in active Crohn's disease (p = 0.025), 93 in active rheumatoid arthritis (p = 0.001), 107 in acute cholecystitis (p<0.0001), 127 in acute appendicitis (p = 0.0001), and 548 pg/ml in urinary tract infection (p<0.0001). Children with non-viral inflammation/infection also had higher IL-8 values (median, 199 pg/ml; p = 0.0001) than those with viral infection (median, 7 pg/ml) or non-specific conditions (median, 10 pg/ml). In the study group as a whole urinary IL-8 values correlated positively with peripheral blood white cell count (r= 0.32; p < 0.001), erythrocyte sedimentation rate (r= 0.41; p<0.001), and C-reactive protein (r = 0.33; p<0.001). Conclusion: Taking the appropriate clinical situation into account, urinary IL-8 measurement helps in the non-invasive assessment of active inflammation in at least a number of common acute and chronic conditions.