Chow J M, Moncada J, Brooks D, Bolan G, Shaw H, Schachter J
University of California, San Francisco, USA.
J Clin Microbiol. 1996 Mar;34(3):534-6. doi: 10.1128/jcm.34.3.534-536.1996.
We evaluated the use of the leukocyte esterase test (LET) on first-catch urine specimens from women as a screening test to predict infection with Chlamydia trachomatis. For diagnosis, we used Abbott's ligase chain reaction (LCR) on urine specimens and isolation by tissue culture (TC) on cervical brushes. Of 4,053 women attending sexually transmitted disease and family planning clinics, 4.3% (n = 174) were positive by TC and 5.9% (n = 239) were positive by LCR. When LET was compared to TC, the sensitivity, specificity, positive predictive value, and negative predictive value were 54.0, 67.0, 6.8, and 97.0%, respectively. The corresponding performance of LET versus LCR was 53.1, 67.3, 10.1, and 95.8%. Almost half of the laboratory-confirmed chlamydial infections were negative by LET. The low specificity probably reflects multiple causes of pyuria in women and results in a low positive predictive value. LET is neither sensitive nor specific as a predictor of chlamydial infection and cannot be recommended for use as a screening test for C. trachomatis with first-catch urine samples from females from low- or moderate-prevalence populations.
我们评估了利用白细胞酯酶试验（LET）检测女性首次晨尿样本，以此作为预测沙眼衣原体感染的筛查试验。诊断时，我们对尿液样本采用雅培连接酶链反应（LCR），并通过宫颈刷进行组织培养（TC）分离。在4053名前往性传播疾病和计划生育诊所就诊的女性中，174人（4.3%）经TC检测呈阳性，239人（5.9%）经LCR检测呈阳性。将LET与TC进行比较时，其敏感性、特异性、阳性预测值和阴性预测值分别为54.0%、67.0%、6.8%和97.0%。LET与LCR比较的相应表现为53.1%、67.3%、10.1%和95.8%。经实验室确诊的衣原体感染病例中，近一半经LET检测呈阴性。低特异性可能反映了女性脓尿的多种病因，导致阳性预测值较低。LET作为衣原体感染的预测指标，既不敏感也不特异，不建议将其用于低或中等流行率人群中女性首次晨尿样本的沙眼衣原体筛查试验。
