OBJECTIVE: To study the role of Mycobacterium tuberculosis in the pathogenesis of sarcoidosis. METHODS: Archival material of 22 patients with a histologic diagnosis of sarcoidosis were retrieved. Real-time fluorescent polymerase chain reaction (PCR) was used to detect DNA fragments of the complex-specific insertion sequence IS6110 of Mycobacterium tuberculosis in formalin-fixed and paraffin-embedded biopsy samples. RESULTS: Among the 22 samples studied, Mycobacterium tuberculosis DNA was detected in 11 cases. The sequence of PCR amplified IS6110 DNA fragments completely matched with the related sequence in Mycobacterium tuberculosis gene. CONCLUSIONS: Mycobacterium tuberculosis DNA is identified in a certain proportion of patients with a clinicopathologic diagnosis of sarcoidosis. Mycobacterium tuberculosis may be an important etiologic agent, at least in some of these patients.
OBJECTIVE: To study the role of Mycobacterium tuberculosis in the pathogenesis of sarcoidosis. METHODS: Archival material of 22 patients with a histologic diagnosis of sarcoidosis were retrieved. Real-time fluorescent polymerase chain reaction (PCR) was used to detect DNA fragments of the complex-specific insertion sequence IS6110 of Mycobacterium tuberculosis in formalin-fixed and paraffin-embedded biopsy samples. RESULTS: Among the 22 samples studied, Mycobacterium tuberculosis DNA was detected in 11 cases. The sequence of PCR amplified IS6110 DNA fragments completely matched with the related sequence in Mycobacterium tuberculosis gene. CONCLUSIONS:Mycobacterium tuberculosis DNA is identified in a certain proportion of patients with a clinicopathologic diagnosis of sarcoidosis. Mycobacterium tuberculosis may be an important etiologic agent, at least in some of these patients.