Molecular analysis of sarcoidosis lymph nodes for microorganisms: a case–control study with clinical correlates

Robinson, Lary A; Smith, Prudence; SenGupta, Dhruba J; Prentice, Jennifer L; Sandin, Ramon L

Perhaps the most intriguing findings came from correlation of the PCR findings with the clinical information. All patients with lymph nodes containing bacteria DNA on presentation were also highly symptomatic and 75% of them had the poorer-prognosis radiographic stage II findings. Moreover, after a median 4 years follow-up, all bacterial DNA-positive patients were still highly symptomatic. This striking correlation strongly suggests that demonstration of bacterial DNA by PCR in lymph nodes on initial presentation is an adverse prognostic factor and makes it unlikely that these patients will have a spontaneous remission. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 specimens. 16 Of note, the only 3 sarcoidosis lymph nodes positive for mycobacteria in our study were less than 3 years old when evaluated by PCR. Had we used fresh lymph node tissue like Drake and associates 16 who found 60% PCR positive for mycobacteria species, there may have been a much higher rate of positive bacterial DNA results (particularly mycobacteria) in our study.