RESUMO
OBJECTIVE: Urinary tract infection occurs in 1.8-6.6% of children under 6 years old. The aim of this study was to assess the urinary concentrations of matrix metalloproteinase 9 (MMP9) and tissue inhibitor of metalloproteinase 1 (TIMP1), in children with acute pyelonephritis (APN) and the potential to develop renal scarring. MATERIAL AND METHODS: Children who had experienced an episode of APN were divided into 2 groups. Group 1 included children with APN who exhibited scarring and group 2 included children with APN who had a normal 99mTechnetium dimercaptosuccinic acid scan. Urinary levels of MMP9 and TIMP1 were measured in the acute phase of infection. A receiver operating characteristic curve was generated to allow calculation of cut-off values. RESULTS: Sixty-one children were enrolled across the 2 groups: group 1 contained 16 patients (all female); group 2, 38 children (36 female and 2 male). Urinary levels of MMP9 and TIMP1 were significantly higher in group 1 than in group 2 (p=0.037 and 0.022 respectively). For comparison of groups 1 and 2, the cut-off values were measured as 75.5 ng/mL (sensitivity 62.5%, specificity 71.1%, positive predictive value, PPV, 48%, negative predictive value, NPV, 82%), 16.1 ng/mL (sensitivity 75%, specificity 55.3%, PPV 41%, NPV 84%), and 1310.7 ng/mL (sensitivity 75% specificity 60.5%, PPV 44%, NPV 85%) for MMP9, TIMP1, and MMP9×TIMP1 levels, respectively. CONCLUSION: Evaluation of urinary MMP9 and TIMP1 levels may help to identify children with APN who are at risk of developing renal scarring.
RESUMO
INTRODUCTION: Urinary tract infections (UTIs) are the most serious common bacterial infections among young children. It may affect kidneys that classified as acute pyelonephritis (APN) and may lead to renal parenchymal involvement and scarring with high prevalence rate (15%-60%) among children. This study aimed to assess the urinary concentration of neutrophil gelatinase-associated lipocalin (NGAL) in patients with APN to diagnose those with potency to scar formation. PATIENTS AND METHODS: Children who were admitted with a diagnosis of APN were enrolled and divided into two groups; APN with scar and APN without scar. Urinary levels of NGAL and its ratio to creatinine (Cr) levels were measured in the acute phase of infection. A receiver operating characteristic (ROC) curve was generated to allow calculation of cut-off values. RESULTS: Fifty-four children were enrolled across the 2 groups: group 1 consisted of 16 patients (all female); group 2 consisted of 38 children (36 female and 2 male). Urinary levels of NGAL were significantly higher in APN with scar than in APN without scar (P = 0.037). For comparison of groups 1 and 2, the cut-off values were measured as 7.32 ng/ml, sensitivity; 81.3% and specificity; 66%. CONCLUSION: Evaluation of urinary NGAL levels may help us to identify children with APN who are at risk of developing renal scarring.
