Utility of cartridge based nucleic acid amplification test in diagnosis of tubercular lymph nodes on fine needle aspiration and its comparison with zeihl-neelsen staining and concentration bleach method

Abstract

Tuberculosis (TB) is one of the oldest disease known to humanity and among the deadliest epidemics and is in the top 10 causes of death worldwide. The incidence of tuberculosis in India has dramatically increased and contributing to it is Human Immunodeficiency Virus (HIV). Various diagnostic methods are available for detection of tubercular bacilli. Only full proof criteria for diagnosis of TB is to demonstrate the bacilli from affected tissue. This study was planned in extra pulmonary tuberculosis cases to evaluate different staining methods for demonstration of mycobacterium on FNAC material. To evaluate efficacy of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) in the initial cytodiagnosis of Tubercular Lymphadenitis 147 clinically suspected cases of extra pulmonary tuberculosis mainly TB lymphadenitis who attended cytology OPD were selected irrespective of age and sex. FNAC was performed. Slides stained for PAP, ZN and concentration bleach. Material remained in hub was sent for CBNAAT. PAP stained slides were observed for various morphological pattern.Six morphological patterns were observed. Positivity for acid fast bacilli by ZN staining, concentration bleach method and CBNAAT were compared. Detection of acid-fast bacilli by CBNATT was found more as compared to ZN and Concentration bleach method.