INTERLEUKIN-6 AND INTERLEUKIN-8 IN SERUM AND URINE IN PATIENTS WITH ACUTE PYELONEPHRITIS IN RELATION TO BACTERIAL-VIRULENCE-ASSOCIATED TRAITS AND RENAL-FUNCTION

Urine and serum concentrations of interleukin (IL)-6 and IL-8 were det ermined in 43 women with acute pyelonephritis caused by Escherichia co li. Urine and serum samples were also collected 2 weeks after the infe ction and during a subsequent episode of cystitis (n = 8) or asymptoma tic bacteriuria (n = 8). Concentrations of IL-6 and IL-8 were related to the expression of 5 virulence markers of E. coli and glomerular fil tration rate (GFR) after pyelonephritis. Patients with acute pyeloneph ritis had elevated urine and serum IL-6 and IL-8 levels as compared to 37 healthy women (IL-6:p < 0.001 in both cases, and IL-8: p < 0.001 i n both cases). Patients infected with E. coli producing hemolysin and/ or cytotoxic necrotizing factor (CNF) had significantly higher IL-6 le vels in serum during acute pyelonephritis as compared to patients infe cted with strains without the ability to produce these factors (p = 0. 0025 and p = 0.0154, respectively). Patients who had high concentratio ns of IL-8 in urine during acute pyelonephritis had lower GFR at follo w-up as compared to patients with lower levels of IL8 in urine (r = -0 .48, p = 0.0123). In conclusion, acute pyelonephritis is accompanied b y elevated urinary and serum IL-6 and IL8 levels. Bacteria producing h emolysin and CNF seem to induce higher concentrations of IL-6 in serum . The secretion of IL-8 from renal cells may participate in the initia tion and maintenance of renal inflammation which in turn may influence renal function.