IMMUNOHISTOCHEMICAL DETECTION OF MYCOBACTERIAL ANTIGEN IN TUBERCULOUS LYMPHADENITIS

摘要

Background: Early detection of active tuberculosis is important for effective chemotherapy. The diagnosis of tuberculosis depends upon identifying the infecting organism. Various techniques are available for the purpose, each of which has its own advantages and disadvantages. Immunohistochemical staining methods are simple, sensitive and practical for definitive disease diagnosis.Methods: The study population comprised 50 cases of tuberculous lymphadenitis and 10 cases of non-tuberculous lymph node and other lesions. Biopsy sections from these cases were subjected to Hematoxylin and Eosin(H&E), Ziehl Neelsen(ZN) and Immunohistochemical (1HC) staining using polyclonal anti-BCG antibody and a comparative analysis of the results was made. Cases of lepromatous leprosy were used as positive controls and non-tuberculous granulomas as negative controls.Results: Acid fast bacilli were identified by ZN stain in 44% of the cases studied (22/50). IHC stains identified 74%(37/ 50) cases and the non-mycobacterial granulomas were not positive with either stain. The sensitivity of the IHC test was 74% and specificity was 100%.Conclusion: The procedure can be useful in the definitive diagnosis of tuberculous granuloma.