Detection of mycobacterial DNA directly from FNAC samples of tuberculous lymphadenopathy using real-time PCR: A preliminary study.

ABSTRACT

Background: Fine needle aspiration cytology (FNAC) is most commonly used in first line investigation for tuberculous lymphadenopathy (TBLAP). Real-time polymerase chain reaction (PCR) an extremely versatile technique is being used for diagnosis and follow up of patients with infectious diseases. It can also be used for detecting Mycobacterium tuberculosis (Mtb) DNA in FNAC samples of TBLAP for rapid diagnosis and treatment. Aim: Detection of Mtb DNA on FNAC samples of tuberculous lymphadenopathy using Real-time PCR. Material and Methods: Twelve clinico-cytologically diagnosed TBLAP cases and five controls were included in the study. FNA samples were used for studying morphology, AFB demonstration, culture and for detecting Mtb DNA using Real-time PCR. Results: Mtb DNA was detected in ten cases (83.33 %) by Real-time PCR. ZN stain was positive in eight cases and culture in six cases. Conclusion: Detection of Mtb DNA in FNAC samples using Real-time PCR is a time saving, logical, economical approach over the culture based method.