Early ReportQuantitative PCR of mycobacterial and propionibacterial DNA in lymph nodes of Japanese patients with sarcoidosis
Introduction
Sarcoidosis is a systemic granulomatous disease, the cause of which is unknown. There is some evidence that the epithelioid-cell granuloma formation of sarcoidosis is an immune response to an, as yet, unidentified agent.1 Clinical, histological, and immunological features common to sarcoidosis and tuberculosis suggest that mycobacteria may cause sarcoidosis, but a mycobacterium has been isolated from sarcoid lesions of only one patient to date.2 When PCR was used to search for mycobacterial DNA in tissue samples from patients with sarcoidosis, some investigators detected mycobacteria3, 4 and others did not.5, 6
About 15 years ago, Abe and colleagues7 reported that Propionibacterium acnes was the only bacterium isolated from biopsy samples of 31 (78%) of 40 lymph nodes from 40 patients with sarcoidosis. Indeed, P acnes is a strong adjuvant, causing granulomas when injected experimentally into sensitised rats.8 However, these findings were not conclusive, because this anaerobic bacterium is commonly isolated from healthy human skin and was isolated from lymph nodes of 38 (21%) of 180 patients with diseases other than sarcoidosis in that study.
We used quantitative PCR to search for bacterial genomes of P acnes and Mycobacteria tuberculosis in histological sections of lymph nodes from patients with sarcoidosis, tuberculosis, or gastric cancer.
Section snippets
Tissue samples
We examined samples obtained by biopsy of lymph nodes from 15 patients with sarcoidosis (11 scalene, two inguinal, one cervical, and one superclavicular lymph node) and from 15 patients with tuberculous lymphadenitis (ten cervical, three axillary, one superclavicular, and one pancreatic lymph node). As controls, we examined 15 lymph nodes without metastasis from 15 patients with gastric cancer undergoing surgery. Tissue blocks fixed with 10% neutral buffered formalin and embedded in paraffin
Results
With the primers and probe for P acnes, P avidum gave a single band in the same place as that of P acnes, and a quantitative PCR value as high as that of P acnes (table 1). However, after digestion with either of the restriction enzymes, P avidum gave two bands and P acnes gave one band. With the primers and probes for M tuberculosis and P granulosum, only the bacterium in question gave a band (single), and the quantitative PCR values were more than 20 times those of other bacteria.
M
Discussion
In tuberculosis, granulomas form in reaction to a well-known causative bacterium. Quantitative PCR showed many M tuberculosis genomes in all samples from patients with tuberculosis, and a few such genomes in samples from some patients without tuberculosis.
Results of earlier studies that used PCR for the detection of mycobacterial DNA in sarcoidosis were inconsistent. The method was not quantitative, and because of its sensitivity, small amounts of DNA probably unrelated to the disease-causing
References (12)
- et al.
Detection of mycobacterial DNA in sarcoidosis and tuberculosis with polymerase chain reaction
Lancet
(1992) - et al.
Frequent isolation of Propionibacterium acnes from sarcoid lymph nodes
Zbl Bakt Hyg
(1984) Etiology of sarcoidosis
Sarcoidosis
(1994)- et al.
Isolation of cell wall-defective acid-fast bacteria from skin lesions in patients with sarcoidosis
- et al.
DNA of Mycobacterium tuberculosis in formalin-fixed, paraffin-embedded tissue in tuberculosis and sarcoidosis detected by polymerase chain reaction
Am J Clin Pathol
(1994) - et al.
A search for mycobacteria DNA in granulomatous tissues from patients with sarcoidosis using the polymerase chain reaction
Am Rev Respir Dis
(1992)
Cited by (282)
Sarcoidosis
2021, Encyclopedia of Respiratory Medicine, Second EditionLung microbiome: new insights into the pathogenesis of respiratory diseases
2024, Signal Transduction and Targeted TherapyCardiac Sarcoidosis: A Comprehensive Clinical Review
2024, Reviews in Cardiovascular MedicineThe role of the host-microbiome and metabolomics in sarcoidosis
2023, American Journal of Physiology - Cell PhysiologyInterleukin-17A plays a key role in pulmonary fibrosis following Propionibacterium acnes–induced sarcoidosis-like inflammation
2023, Experimental Biology and Medicine