Detection of Mycobacterium tuberculosis in Paraffin-Embedded Pleural Biopsy Specimens by Commercial Ribosomal RNA and DNA Amplification Kits

摘要

Study objectives: To evaluate the utility of two gene amplification systems in historical paraffin-nembedded pleural biopsy (PEB) tissues from patients with pleural tuberculosis, and to comparenthe results to those obtained with conventional histologic and microbiological methods.nDesign: A retrospective study.nPatients and methods: Seventy-four formalin-fixed PEB tissues collected and stored over 12 yearsn(1984 through 1995) were retrieved. Gene amplifications were performed in 57 tissues fromnpatients with diagnoses of pleural tuberculosis and in 17 from patients with carcinoma as controls,nusing the first version of the Amplified Mycobacterium tuberculosis Direct Test (AMTDT;nGen-Probe; San Diego, CA) and the LCx Mycobacterium tuberculosis Assay (LCxMTB; AbbottnLaboratories; Abbott Park, IL).nResults: The sensitivities of the AMTDT and LCxMTB were 52.6% and 63.2%, respectivelyn(p 5 not statistically significant). The specificity of both tests was 100%. Twenty tissue samplesn(35.1%) were positive by both systems, and 10 tissues (17.5%) were positive only by the AMTDT,nwhile 16 tissues (28.1%) were positive only by the LCxMTB. Both tests gave negative results forn11 specimens (19.3%). When both tests were used, a positive diagnosis was achieved in 80.7% ofnthe samples. Diagnosis of 73.7% of patient conditions had previously been made by smearnexamination of pleural biopsy and sputum, pleural liquid, or biopsy culture. The overallndiagnostic yield with both culture and amplification techniques was 96.5% (55 of 57 patients) fornpleural tuberculosis, with amplification techniques adding 22.8% of the diagnoses.nConclusions: Amplification techniques are useful in archival PEB tissues, providing additionalndiagnoses beyond culturing, although the sensitivity should be improved, possibly by standard-nizing protocols. (CHEST 2000; 118:648–655)