Significance of joint detection of serum cystatin C, procalcitonin, and urine N-acetyl-β-D-glucosaminidase combined detection on localization diagnosis of the urinary tract infection in children

Abstract

Objective To explore the differences of biological markers level between upper urinary tract infection(UUTI) and lower urinary tract infection(LUTI) in children for providing help for localization diagnosis of urinary tract infection(UTI). Methods One hundred and nine children with UTI hospitalized in Children's Hospital of Tianjin from May 2010 to Jan.2012 were divided into UUTI group (18 cases) and LUTI group (91 cases). The clinical information (sex, age, onset symptoms), laboratory test including blood urea nitrogen and creatinine, biological markers including serum cystatin C(CysC), procalcitonin(PCT), β2-microglobulin (β2-MG), urine microalbumin(mAlb), transferrin(TF), α1-microglobulin(α1-MG), β2-MG and N-acetyl-β-D-glucosaminidase(NAG)were recorded. Then SPSS 17.0 software was used to analyze the data. Results UUTI children showed higher level of serum CysC, PCT, urine mAlb, TF, α1-MG, β2-MG and NAG than LUTI children did.The area under ROC curve of the 7 biological markers were all between 0.71 and 0.87.Logistic regression test was used to do multiple regression analysis and establish the multiple regression model.The standard of eliminating or screening variables was 0.05.CysC, PCT, NAG were identified as influence factors.Combining test result of CysC, PCT, NAG could improve diagnostic value so that the sensitivity could reach 90%and the specificity could reach 88.9%. Conclusions Both of serum CysC, PCT and urine mAlb, TF, α1-MG, β2-MG, NAG can be used for the positioning diagnosis of UTI, and the diagnostic value of joint test of serum change of CysC, PCT, urine NAG is higher than any single biological marker. Key words: Urinary tract infection; Cystatin C; Procalcitonin; N-acetyl-β-D-glucosaminidase; Early renal damage; Localization diagnosis