Abstract: Objective  To investigate the application value of real-time fluorescent quantitative polymerase chain reaction(FQ-PCR) technique in pathological diagnosis of renal tuberculosis. 
Methods  We retrospectively analyzed 55 patients with paraffin-embedded specimens after retroperitoneoscopic or open nephrectomy in Department of Urology of our hospital. Taking the results of preoperative urine Mycobacterium tuberculosis culture results as the gold standard, combined with the results of postoperative pathological diagnosis, the subjects were divided into tuberculos nephropathy group(positive group, n=25) and non-tuberculous nephropathy group(negative group, n=30). Each paraffin-embedded tissue specimen was detected using TaqMan-probe real-time FQ-PCR technique and and acid-fast staining technique, and the diagnostic efficiency of the two detection techniques in the pathological diagnosis of renal tuberculosis was compared and analyzed. A recevier operating characteristic(ROC) curve was drawn to evaluate the value of the two methods in the pathological diagnosis of renal tuberculosis. 
Results  The sensitivity of real-time FQ-PCR and acid-fast staining was 80.0%(20/25) and 48.0%(12/25) respectively; the sensitivity of the former was higher by 32.0% than that of acid-fast staining,with significant difference(χ2=5.556， P=0.018). The specificity，the positive predictive value and the negative predictive value of real-time FQ-PCR were higher than that of acid-fast staining, but there was no significant difference between them（P＞0.05）. The accuracy of real-time FQ-PCR was higher than that of acid-fast staining（89.1% vs. 72.7%）, and there was significant difference between them（χ2=4.767， P=0.029）. The Kappa values of the two techniques for detecting pathogens in renal tuberculosis tissue specimens which were consistent with results of urine Mycobacterium tuberculosis culture were 0.777 and 0.429, respectively. ROC curve analysis showed that area under ROC curve(AUC)of real-time FQ-PCR technique and acid-fast staining technique was 0.883 and 0.707 respectively; the former was higher than the latter by 0.177, and the difference was statistically significant(Z=3.502, P＜0.05). 
Conclusion  Real-time FQ-PCR technique is simple and has higher sensitivity and accuracy in the detection of pathogens in renal tuberculosis tissue, as compared with acid-fast staining technique. Real-time FQ-PCR technique shows good application value in pathological diagnosis of renal tuberculosis.

Key words: tuberculosis, renal, real-time Polymerase chain reaction, histocytological preparation techniques