Molecular analysis of sarcoidosis tissues for mycobacterium species DNA

Abstract

We performed polymerase chain reaction analysis, for Mycobacterium species 16S rRNA, rpoB, and IS6110 sequences, on 25 tissue specimens from patients with sarcoidosis and on 25 control tissue specimens consisting of mediastinal or cervical lymph nodes and lung biopsies. Mycobacterium species 16S rRNA sequences were amplified from 12 (48%) rpoB sequences and from 6 (24%) of the sarcoidosis specimens. In total, 16S rRNA or rpoB sequences were amplified from 15 sarcoidosis specimens (60%) but were not detected in any of the control tissues (p=0.00002, chi square). In three specimens, the sequences resembled Mycobacterium species other than M. tuberculosis. All specimens with sequences consistent with M. tuberculosis were negative for IS6110. We provide evidence that one of a variety of Mycobacterium species, especially organisms resembling M. tuberculosis, is found in most patients with sarcoidosis.

Figure

Analysis of 16S rRNA sequences from nine Mycobacterium species and from 12 patients with sarcoidosis. Phylograms based on nucleotide alignments were generated with HKY85 distances matrices using Paup 4.0b10 (Sinauer Associates, Sunderland MA). Bootstrap values >50 (based on 500 replicates) are represented at each node, and the branch length index is represented below the phylogram. For eight patients, the 16S rRNA sequence was identical to M. tuberculosis, and for one patient (patient 24) was identical to M. gordonae. For patient 15, the sequence was closely related to M. tuberculosis; for patient 19, the sequence was closely related to M. duvalii and M. gordonae; for patient 7, the sequence was less closely related to M. leprae.