Abstract
Tuberculous lymphadenitis is the most common cause of extra-pulmonary tuberculosis (TB) in developing countries. Lymphadenitis caused by non-tuberculous mycobacteria (NTM) requires consideration, particularly in immunocompromised patients and children in developed countries. Fine-Needle Aspiration Biopsy (FNAB) offers a valuable specimen collection technique, but culture confirmation, mycobacterial speciation and drug resistance testing (if indicated) is often unavailable in TB endemic areas and result in unacceptable diagnostic delay. We evaluated the diagnostic value of high-resolution DNA melting (HRM) analysis in the diagnosis of mycobacterial lymphadenopathy using FNAB and an inexpensive transport medium. Specimens were collected from patients referred to the FNAB Clinic at Tygerberg Hospital (June 2007-May 2008) with clinical mycobacterial lymphadenitis. Cytology, culture, and HRM were performed on all specimens. The reference standard for disease was defined as positive cytology (morphological evidence plus mycobacterial visualization) and/or a positive culture. Specimens were collected from 104 patients and mycobacterial disease was confirmed in 54 (51.9%); 52 Mycobacterium tuberculosis, 1 Mycobacterium Bovis BCG and 1 NTM. Cytology was positive in 83.3% (45/54) and culture in 72.2% (39/54) of patients. HRM identified 57.4% (31/54) of cases. By using the defined reference standard, we recorded 94.0% specificity and 51.9% sensitivity (positive predictive value 90.3%) with HRM analysis.HRM analysis allowed rapid and species specific diagnosis of mycobacterial lymph adenitis in the majority of patients, permitting early institution of appropriate therapy. Optimization of this technique requires further study.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.