Discuss Of Predictive Ability Of Leukocyte Esterase To Detect Urinary Tract Infection Of Ureteric Calculus

Objective:To evaluate the diagnostic value of leukocyte esterase in patients who suffered from both ureteral calculus and urinary tract infection.Methods:A retrospective analysis of the clinical data of 269 patients with Ureteric calculus between 2006.1 and 2009.10. All urine specimens for urinalysis and culture were obtained by the mid-stream clean catch method, collected under aseptic conditions.Results:1. Of 134 male cases investigated, 16 were judged to have positive urine culture. 83 showed positive leukocyte esterase results,65 showed positive microscopic examination results,8 showed positive nitrite reductase results. The dipstick leukocyte esterase had a sensitivity of 93.8% and a specificity of 42.4%.There was a potential overtreatment rate of 91.9%and a undertreatment rate of 12.0% for male cases. Of 135 female cases investigated,28 were judged to have positive urine culture. 107 showed positive leukocyte esterase results,87 showed positive microscopic examination results,17 showed positive nitrite reductase results. The dipstick leukocyte esterase had a sensitivity of 89.3% and a specificity of 23.4%.There was a potential overtreatment rate of 76.6%and a undertreatment rate of 10.7% for female cases.The specificity of leukocyte esterase to female ureteral calculus was higher than male's while the sensitivities were equivalent.2. The lagest Youden index was 0.762.When the result of leukocyte esterase test≥+1 was regarded as positive results, the leukocyte esterase had a better ROC curve. Compared with previous study about uncomplicated UTI, the positive predictive value of leukocyte esterase to ureteral calculus was low and the negative predictive value was equivalent.3. RBC and WBC in urine had no correlativity no matter the patient with ureteral calculus whether suffered an UTI.Conclusions:1. Compared with previous study about uncomplicated UTI, positive predictive value of leukocyte esterase to ureteral calculus was low, the negative predictive value was equivalent.2. When the result of leukocyte esterase test≥+1 was regarded as positive results, the leukocyte esterase had a better ROC curve.