Role of immunochromatographic test in the diagnosis of tuberculous lymphadenitis

Background: Tuberculosis has been declared a global emergency. The mainstay for its control is the rapid and accurate identification of infected individuals. Tuberculous lymphadenitis is one of the most common extrapulmonary forms of tuberculosis. To improve the diagnosis, rapid diagnostic techniques such as antibody detection method using immuno chromatographic test methods (ICT-TB) have been developed. Objectives : This study was designed to evaluate the role of ICT-TB in the diagnosis of tuberculous lymphadenopathy. Methods : This study was carried out on 55 patients of lymphadenopathy reffered to the department of cytopathology, JJM Medical College, Davangere, from September 2005 to April 2007. Two ICT kits from different manufacturers were used on all cases of cytologically proven tuberculous lymphadenopathy cases. Results: Out of 685 lymphnode aspirates in the study period tuberculous lymphadenoapthy features were seen in 234 cases. 55 cases were selected from this group for present study. ICT test was positive in overall 21.82% cases. High positivity was seen in age group of 25 and above, when the duration of illness was more than 6 months and when lymphnodes were multiple and matted. ICT positivity was also significant when cytology showed caseous necrosis as the predominant pattern. ICT positivty was more in AFB positive cases but few cases showed positivity even on AFB negative smears. Conclusion : Our results suggest that ICT TB rapid test can be used as additional diagnostic modality and not as a sole diagnostic method. FNAC can still be considered a highly diagnostic for tuberculous lymphadenopathy.