NESTED POLYMERASE-CHAIN-REACTION FOR MYCOBACTERIUM-TUBERCULOSIS IS6110 SEQUENCE ON FORMALIN-FIXED PARAFFIN-EMBEDDED TISSUES WITH GRANULOMATOUS DISEASES FOR RAPID DIAGNOSIS OF TUBERCULOSIS

We evaluated the sensitivity and specificity of a nested polymerase ch ain reaction (PCR) to the Mycobacterium tuberculosis IS6110 sequence o n formalin-fixed pariffin-embedded tissue samples from patients with t ubercular and other granulomatous lesions. Five groups of patients and samples were studied: (1) 28 samples from HIV-positive patients with tuberculosis, (2) 8 samples from HIV-negative patients with histologic ally suspected tuberculosis (confirmed by culture in 5 cases), (3) lym ph nodes from 5 HIV-positive patients with Mycobacterium avium-intrace llulare infection, (4) lymph nodes from 30 patients with sarcoidosis, and (5) specimens from 17 patients with other granulomatous diseases. The DNA was extracted from sections with a total thickness of 60 mu m, and PCR amplified an internal fragment of 123 base pairs. All of the cases with M tuberculosis infection were PCR-positive, although this s ensitivity was partially related to the initial concentration of the D NA used for amplification. Two of the group 4 samples also were repeat edly positive, thus reducing the specificity of the method. All of the cases with granulomatous diseases other than sarcoidosis were negativ e. We propose a simplified and highly sensitive nested PCR for the dia gnosis of RI tuberculosis infection on archived material in HIV-positi ve and HIV-negative patients.