COMPARISON OF PCR, CULTURE, AND HISTOPATHOLOGY FOR DIAGNOSIS OF TUBERCULOUS PERICARDITIS

Nucleic acid amplification techniques for the diagnosis of tuberculosi s (TB) are rapidly being developed, Scant work, however, has focused o n pericardial TB. Using cryopresered specimens from a prior study of p ericarditis, we compared PCR to culture and histopathology for the dia gnosis of tuberculous pericarditis in 36 specimens of pericardial flui d and 19 specimens of pericardial tissue from 20 patients, Fluid and t issue were cultured on Lowenstein-Jensen and Middlebrook solid media a nd in BACTEC radiometric broth, Tissue specimens were stained with hem atoxylin-eosin, Ziehl-Neelsen, auramine O, and Kinyoun stains and were examined for granuloma formation and acid-fast bacilli, PCR was perfo rmed with both fluid and tissue with IS6110-based primers specific for the Mycobacterium tuberculosis complex by published methods. Sixteen of the 20 patients had tuberculous pericarditis and 4 patients had oth er diagnoses, TB was correctly diagnosed by culture in 15 (93%) patien ts, by PCR in 13 (81%) patients, and by histology in 13 of 15 (87%) pa tients, PCR gave one false-positive result for a patient with Staphylo coccus aureus pericarditis. Considering the individual specimens as th e unit of analysis, M. tuberculosis was identified by culture in 30 of 43 specimens (70%) from patients with tuberculous pericarditis and by PCR in 14 of 28 specimens (50%) from patients with tuberculous perica rditis (P > 0.15). The sensitivity of PCR was higher with tissue speci mens (12 of 15; 80%) than with fluid specimens (2 of 13; 15%; P = 0.00 2), Ln conclusion, the overall accuracy of PCR approached tile results of conventional methods, although PCR was much faster, Therefore, PCR merits further development in this regard, The sensitivity of PCR wit h pericardial fluid was poor, and false-positive results with PCR rema in a concern.