مقایسه ارزش تشخیصی اسمیر و PCR شستشوی برونش ها در تشخیص سل ریوی

 Background: Tuberculosis (TB) is one the oldest known diseases in human. According to its high prevalence in Iran, using a diagnostic procedure with more rapid result than culture, more sensitive and specific than smear and near to culture can help us to diagnose and treat the disease rapidly and accurately, and thus control it in the community. So we decided to evaluate PCR for the diagnosis of Tuberculosis in Broncho-alveolar Lavage (BAL) and compare it with smear.  Methods: Patients who were admitted at Hazrat Rasoul Akram Hospital during 2 years of 2010-11 with the impression of tuberculosis and underwent bronchoscopy were included.  Their BAL was sent for smear, culture and PCR for tuberculosis diagnosis. Data were analyzed by mean and standard deviation and p Value under 0.05 was considered significant. Results: Forty seven patients with probable pulmonary tuberculosis underwent bronchoscopy. BAL cultures were positive in 6 (12.8%) patients, smears in 5 (10.6%) patients and PCR in 3 (6.4%) patients. According to this result smear had 83% sensitivity, 100% specificity, 100% PPV and 98% NPV. However PCR had 50% sensitivity, 100% specificity, 100% PPV and 93% NPV. Conclusion: Although PCR is a rapid and new tool for TB diagnosis, smear- which is an older way- is simpler has lower cost and is feasible in all points of Iran and still is a better method for TB diagnosis.