Tumour necrosis factor soluble receptors I and II and interleukin-1 receptor antagonist in acute pyelonephritis in relation to bacterial virulence-associated traits and renal function

Urinary tract infections activate both mucosal and systemicinflammatory responses reflected by elevation of cytokine concentrationsin serum and urine. We determined urine and serum concentrationsof tumour necrosis factor soluble receptors I and II (sTNFRI and sTNFR II) and interleukin-1 receptor antagonist (IL-1ra)in 41 women with acute pyelonephritis caused by Escherichiacoli, 2 weeks after the infection, during a subsequent episodeof cystitis or asymptomatic bacteriuria and also later whenthe same patients were free from bacteriuria. Concentrationsof sTNFR I, sTNFR II and IL-1ra were related to the expressionof five virulence markers of E. coli, glomerular filtrationrate (GFR) and to the concentration of C-reactive protein (CRP)in serum. Patients with acute pyelonephritis had elevated serumconcentrations of sTNFR I and sTNFR II compared to healthy women(P<0.001 for both comparisons). The concentrations of sTNFRI and sTNFR II in urine were significantly higher in patientswith acute pyelonephritis compared to controls (P<0.001 inboth cases). The concentration of sTNFR II in urine was higherin patients infected by E. coli producing haemolysin (P=0.05)and in patients infected by E. coli expressing hydrophobic properties(P=0.05) compared to patients infected by strains without thesevirulence traits. Patients who had high concentrations of sTNFRII in serum during acute pyelonephritis had lower GFR at follow-up(r=–0.48, P=0.05). Patients who responded with a markedincrease in CRP had higher sTNFR I and sTNFR II in urine (r=0.58,P<0.01 and r=0.48, P<0.01, respectively). The concentrationsof sTNFR I and sTNFR II in serum and urine decreased duringfollow-up and were lower 2 weeks after the infection when allpatients were free from bacteriuria. IL-1ra in serum was elevatedduring pyelonephritis (P<0.001) while that in urine was significantlylower compared to controls (P<0.001). It is concluded thatthe