Abstract

Background: Granulomatous lesions occur in tuberculosis (TB), other infections, toxic, allergic, and autoimmune diseases among others. In absence of a an acid-fast bacilli (AFB) con rmation of TB is necessary. Objective: To assess the ef cacy of PCR for TB detection and to correlate with granuloma histology and AFB staining. Meth- ods: We analyzed 380 xed paraf n-embedded tissues (PETs) of granulomas with and without caseous necrosis; suppurative; sarcoidal; or of chronic nonspeci c nature. Nested PCR-IS6110 for Mycobacterium tuberculosis complex (MTB) and a nested pan-Mycobacterium for the hsp65 gene were used for Mycobacterium spp detection. Results: PCR was more sensitive than AFB staining for all ve catageories of granulomas: G1: PCR 71%, AFB staining 28%. G2: PCR 37%, AFB 8%. G3: PCR 17%, AFB staining 7%. G4: PCR 8%, AFB staining 4%. G5: PCR 6%, AFB staining 0%. Conclusions: Molecular diagnosis of TB using PCR-based testing is a fast, ef cacious and sensitive method that increased the accuracy of PET histological diagnosis associated with granulomatous lesions.