[Detection of mycobacterium tuberculosis DNA using nested polymerase chain reaction in lymph nodes with sarcoidosis,...

An involvement of mycobacteria in the pathogenesis of sarcoidosis has often been hypothesized, but not confirmed reproducibly. In this study we applied a nested Polymerase Chain Reaction (PCR) to the insertion sequence IS6110 for detection of Mycobacterium tuberculosis (MT) DNA in formalin-fixed and paraffin-embedded tissues from patients with sarcoidosis, with tuberculosis and atypical mycobacteriosis confirmed by culture, and from negative control samples. MT-DNA could be detected in 2/30 samples of sarcoidosis, in 10/10 tuberculoses, in 0/5 atypical mycobacterioses and in 0/10 negative controls. Nested PCR confirmed its high sensitivity and specificity in detecting MT-DNA on archival histopathological specimens. From our results we conclude that in the granulomatous lesions of sarcoidosis MT-DNA is only sporadically demonstrable and probably it doesn't play a role in the pathogenesis of this disease.