The predictive value of Gen-Probe's amplified Mycobacterium tuberculosis direct test compared with culturing in paraffin-embedded lymph node tissue exhibiting granulomatous inflammation and negative acid fast stain

• Main Authors: Wasim F. Raslan (Author), Ali Rabaan (Author), Jaffar A. Al-Tawfiq (Author)
• Format: Book
• Published: Elsevier, 2014-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Summary: Background and objectives: The diagnosis of granulomatous inflammation with possible tuberculosis (TB) infection in histopathology is often difficult. There is a need for a rapid and reliable diagnostic test. Thus, we evaluated the performance of the Mycobacterium tuberculosis direct (MTD) test in specimens with granulomatous lymphadenitis and negative acid fast stains. Methods: The M. tuberculosis direct (MTD) test by Gen-Probe was performed on 45 formalin-fixed paraffin-embedded tissue samples including 34 lymph nodes. We measured the predictive values of the MTD test in specimens with granulomatous lymphadenitis and negative acid fast stains. Results: The overall test sensitivity was 73.9%, and specificity was 95.4%. The MTD test sensitivity and specificity for lymph node tissue were 72.7% and 91.67%, respectively. In the presence of granulomatous inflammation, the MTD test sensitivity and specificity were higher than those for all tissue samples, at 75% and 100%, respectively. Conclusion: Based on this study, the MTD test should be used as a supportive test in addition to conventional histochemical or immunological staining methods when evaluating lymph node tissue with a granulomatous inflammation to deliver stronger evidence to support clinical decisions at a much earlier time than a culture would allow. Keywords: Tuberculosis, Molecular testing, Granuloma, Mycobacterium tuberculosis direct (MTD) test, Gen-Probe

Item Description

1876-0341
10.1016/j.jiph.2013.11.002