[Detection of mycobacterium tuberculosis DNA using nested polymerase chain reaction in lymph nodes with sarcoidosis, fixed in formalin and embedded in paraffin].

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.