The IL-6 −174G/C polymorphism and renal scarring in children with first acute pyelonephritis

Urinary tract infections (UTI) are common in infants and children and may result in serious complications, such as renal scarring, hypertension, and renal failure. Identification of the new markers in relation to acute pyelonephritis (APN) and its treatment is essential for designing interventions that would minimize tissue damage. This prospective study investigated the first UTI infection in 71 children (age range: 1–24 months) in respect to interleukin-6 (IL-6) −174G/C polymorphism and renal scarring. The patients were divided into an APN group and a lower UTI group according to dimercaptosuccinic acid (DMSA). The IL-6 −174G/C genotypes were determined by tetra-primer ARMSPCR. Serum IL-6 was significantly higher in the APN group than in the group with lower UTI (p < 0.05). In both groups, the −174G/C genotype and allele frequencies did not differ significantly from the control group. The highest white blood cell (WBC) count was observed in the CC genotype (p < 0.05). A non-significant trend toward higher serum IL-6 was observed in children with CC genotype. On follow-up DMSA imaging performed 6 months later, renal scarring was detected in 36.9% of APN children. We did not find the significant association of IL-6 −174G/C polymorphism with APN and/or postinfectious renal scarring. These results indicate that serum IL-6 concentrations were significantly higher in children with APN than in patients with lower UTI.