Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
*Corresponding author: Prof. S. Anupurba (MD), Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. Email: shampa_anupurba@yahoo.co.in
Online published on 17 June, 2017.
Tubercular lymphadenitis (TBLN) is the most common manifestations of extra-pulmonary tuberculosis (EPTB) accounting for 30–40% of cases with multiple discrepancy in diagnosis. Rapid diagnosis and timely initiation of anti-tubercular therapy (ATT) is the key for successful clinical effects. This study was carried out to evaluate multiplex polymerase chain reaction (MPCR) using MTP40, IS6110, 32 kD-alpha antigen encoding gene, and mycobacterial specific genes (rpoB, katG & inhA promoter region), and compare with the conventional methods for rapid diagnosis of TBLN.
Lymph node aspirates samples were collected and analyzed from a total of 48 TB lymphadenitis cases and 20 non-TB controls. Each specimen was subjected to Ziehl-Neelsen (ZN) staining, culture on Lowenstein– Jensen (LJ) medium, cytological examination and multiplex PCR using MTP40, IS6110, 32 kD-alpha antigen encoding gene sequences and mycobacterial specific genes (rpoB, katG & inhA promoter region) as a primer.
In total, 29.2% of the samples were positive for ZN staining, 31.2% of the samples were positive for TB by culture and 89.6% by MPCR assay. The sensitivity of ZN staining method was the lowest (29.2%) while sensitivity of MPCR assay was the highest (89.6%). In the control group, all the tests were found to be negative, thus giving a specificity of 100%.
Multiplex PCR assay is rapid, cost effective, highly sensitive and specific technique for the diagnosis of tubercular lymphadenitis.
Cytological examination, Tubercular lymphadenitis, Multiplex PCR
