ORIGINAL ARTICLE 675 P J M H S Vol. 7, NO. 3, JUL – SEP 2013 Accuracy of Urinary PCR as Compared with Urine Culture for Early Diagnosis of Genitourinary Tuberculosis FAZAL-UR-REHMAN KHAN, FARHAN ARSHAD CHEEMA, MOHAMMAD USMAN KHAN ABSTRACT Objective: To determine the sensitivity and specificity of PCR in early diagnosis of genitourinary tuberculosis when compared with urine culture for detection of genitourinary tuberculosis. Patient and methods: This observational cross-section study was conducted from December 2011 to May 2012 at Shaikh Zayed Hospital, Lahore in the in the Department of Urology It is a prospective study of 50 patients to evaluate various modes of presentation of genitourinary tuberculosis and efficacy of various diagnostic tests currently available. Results: The patients age range from 20-67 (38.23±13.27 years). Male to female ratio was 1:1.16. Nineteen patients (100%) had growth of mycobacterium tuberculosis on routine culture on Lowenstein Jensen (LJ) medium (Gold standard) and were considered positive for tuberculosis. Thirteen patients showed acid fast bacilli in their urine on ZN staining (sensitivity 51.5%, specificity 94.6%). Eighteen (18) patients showed acid fast bacilli in their urine on PCR, out of which 16 patients showed growth on LJ medium with a sensitivity of 88.6% and specificity of 96.5% (positive predictive value 95.3% and negative predictive value 92.4%). Conclusion: Genitourinary tuberculosis remains the most common form of extrapulmonary tuberculosis. Polymerase chain reaction (PCR) is a very sensitive, specific and rapid diagnostic test and the only disadvantage is that it can not differentiate between the live and dead bacteria. Keywords: Genitourinary tuberculosis, Urinary polymerase chain reaction, Early diagnosis, Lower urinary tract symptoms, Urine culture. INTRODUCTION The World Health Organization (WHO) estimates that one third of the world's population is infected with mycobacterium tuberculosis and there are 8 to 10 million new active cases of tuberculosis (TB) diagnosed each year. 1 Tuberculosis of kidney and urinary tract is like other forms of the disease, caused by member of mycobacterium tuberculosis complex. By far the most common causative organism is the human Tubercle Bacillus, Bovine Tubercle Baccilus, Mycobacterium Bovis Bacillus can occasionally be responsible as well 2 . The infecting organism reaches the genitourinary organs by the hematogenous route from the lungs 3 . Urinary tuberculosis is a disease of young adults (60% of patients are between the ages of 20 and 40) and is more common in males than in females 4 . Genitourinary tuberculosis (GUTB) is commonest form of extrapulmonary TB and has been reported in 8-10% of all cases of tuberculosis in developed countries and about 20% cases in under developed countries 5 . The primary site of involvement of TB is lungs, the leading secondary site of involvement is the as genitourinary tract. ----------------------------------------------------------------------- Department of Urology, Shaikh Zayed Hospital Lahore. Corresponding to Dr. Fazal-ur-Rehman Khan, email: drfazaln@gmail.com Presentation of genitourinary tuberculosis is usually with vague symptoms. Urinary frequency is the most common symptoms in both genders 5 . Sterile pyuria, gross or microscopic hematuria, a non-tender, enlarged epididymis with a beaded or thickened vas, a chronic draining scrotal sinus, or induration or nodulation of the prostate and thickening of one or both seminal vesicles are few of the presenting features 6 . Genitourinary tuberculosis presents as a diagnostic dilemma especially in the early disease and many cases remain undiagnosed or misdiagnosed. Diagnosis of GUTB depends upon the demonstration of mycobacterium tuberculosis through smear Zheil Nelson (ZN) staining of AFB, culture on solid or liquid media of early morning urine specimens 7 . Mycobacterial components including DNA can be detected by polymerase chain reaction (PCR) 8 . The polymerase chain reaction is a technique that can be used to amplify a specific DNA genomic sequence, whereby the presence of an extremely small number of bacteria can be detected 9 . The method relies on thermal cycling, consisting of cycles of repeated heating and cooling of the reaction for DNA melting and enzymatic replication of the DNA. Primers (short DNA fragments) containing sequences complementary to the target region along with a DNA polymerase (after which the method is named) are