尿液中肝素结合蛋白和白介素6及白细胞计数水平对细菌性尿路感染诊断的应用价值

Diagnositic value of urine heparin-binding protein, interleukin-6 and white blood cell in bacterial urinary tract infection

目的探讨尿液中肝素结合蛋白(U-HBP)和白介素6(U-IL-6)及白细胞计数(U-WBC)对细菌性尿路感染(UTI)的辅助诊断价值。方法病例对照方法。收集2017年9月至2018年3月于中南大学湘雅三医院收治的157例UTI患者、61例非UTI患者以及40名健康体检者的尿液标本,采用酶联免疫吸附法检测U-HBP;发光法检测U-IL-6;细菌定量培养鉴定病原菌种类;全自动尿沉渣分析仪及其配套试剂检测U-WBC、尿白细胞酯酶(U-LE)、尿亚硝酸盐(U-NIT)含量。对非正态分布的连续变量(定量资料和等级资料),两独立样本间的非参数检验采用Mann-WhitneyU检验,各组总体水平差异采用Kruskal-WallisH检验。对二分类的定性资料,两组之间和多组之间比较使用卡方检验。建立受试者工作特征曲线(ROC曲线)分析U-HBP、U-IL-6及U-WBC对细菌性UTI的临床诊断价值,并确定U-HBP、U-IL-6及U-WBC对诊断细菌性UTI的最佳截断值。结果UTI组、非UTI组和健康对照组U-HBP的水平分别为513.43(50.45~644.40)ng/ml、55.65(20.43~314.55)ng/ml、4.83(3.28~12.63)ng/ml;U-IL-6的水平分别为5.72(3.84~9.02)pg/ml、5.31(4.31~6.39)pg/ml、5.06(4.56~6.18)pg/ml;U-WBC水平分别为205(24~754)个/μl、34(13~117)个/μl、0(0~0)个/μl。3组之间U-HBP、U-WBC比较,差异有统计学意义(HU-HBP=83.192,HU-WBC=100.416,P<0.05);U-IL-6比较,差异无统计学意义(HU-IL-6=2.585,P>0.05)。U-HBP和U-WBC诊断细菌性UTI最大约登指数分别为0.475和0.441,最佳截断值分别为64.35ng/ml和119.25个/μl。结论检测尿液中HBP对由细菌感染引起的尿路感染的辅助诊断具有重要意义,而U-IL-6对细菌性尿路感染的诊断无显著意义。

Objective To evaluate the diagnostic values of urinary heparin-binding protein (HBP), interleukin-6 (IL-6) and white blood cell (WBC) levels in bacterial urinary tract infection (UTI). Methods A case-control method was used. Urine of 157 cases of bacterial UTI, 61 cases of non-infection, and 40 cases of normal controls were collected in the Third Xiangya Hospital of Central South University from September 2017 to March 2018. U-HBP levels were measured in duplicate using a commercial HBP ELISA, U-IL-6 concentrations were analyzed with an up-conversion luminescence. The method of quantitative culture of bacteria was used to identify pathogenic species. Rapid dipstick tests and urinary sediment analyses were detected by FUS-2000 Urinalysis Hybrid. For continuous variables with skewed distributions, comparisons among the three groups were performed using the nonparametric Kruskal-Wallis test, and Mann-Whitney U test was used to further evaluate the difference between two groups. The Chi-square test was applied to analyze dichotomous. Receiver operating characteristic curve (ROC curve) was constructed to analyze the clinical diagnostic values of U-HBP, U-IL-6 and U-WBC for bacterial UTI. Results The levels of U-HBP in UTI group, non-UTI group and control group were 513.43 (50.45-644.40) ng/ml, 55.65 (20.43-314.55) ng/ml and 4.83 (3.28-12.63) ng/ml. The scores of U-IL-6 were 5.72 (3.84-9.02) pg/ml, 5.31 (4.31-6.39) pg/ml and 5.06 (4.56-6.18) pg/ml. The scores of U-WBC were 205 (24-754) cells/μl, 34 (13-117) cells/μl and 0 (0-0) cell/μl. There were statistically significant differences of U-HBP and U-WBC among the three groups (HU-HBP=83.192, HU-WBC=100.416, P<0.05), but no significant difference for U-IL-6 (HU-IL-6=2.585, P>0.05). The best Youden indexes of U-HBP and U-WBC diagnosing bacterial UTI were 0.475 and 0.441, respectively. The best cut-off level of U-HBP and U-WBC was 64.35 ng/ml and 119.25 cells/μl, respectively. Conclusions Testing the level of U-HBP was important for auxiliary diagnosing bacterial UTI, but testing U-IL-6 wasn′t.