β-glucan in Lymph Nodes in Sarcoidosis Patients

Abstract

SESSION TITLE: Sarcoidosis SESSION TYPE: Original Investigation Slide PRESENTED ON: Wednesday, October 26, 2016 at 07:30 AM - 08:30 AM PURPOSE: Previous studies have demonstrated a relation between fungal exposure at home and the risk of sarcoidosis. Β-glucan, a cell wall agent in fungi, was present in BALF of patients with sarcoidosis and at higher levels, there was a suppression of iNKT-cells and IL-10 and a relation to the severity of granuloma infiltration. The present study was undertaken prospectively to investigate the presence of β-glucan in lymph nodes of patients with sarcoidosis. The amount was also measured in Kveim’s agent. METHODS: TBNA lymph node aspiration by flexible fiberoptic bronchoscopy in regions R4 or R7 was performed in 40 patients with newly diagnosed sarcoidosis, stages II and I. The samples were treated to retrieve the non-soluble part of β-glucan and analysed using a Limulus based assay. Different CFUs/mL of Propionibacterium acnes and Mycobacterium gordonii in 1 ml of saline solution, as well as samples of Kveim’s agent were also analysed. RESULTS: The levels of ß-glucan in the lymph node samples ranged from 90 to 8350 pg/mL with a mean of 763 and SEM of 196. There was a significant relationship between the amount of non-soluble β-glucan in lymph nodes and the extent of granuloma formation in lung parenchyma (r = 0.8456 p<0.0001) and the size of lymph nodes in mediastinum (r=0.742; p<0.0001). The samples of Kveim’s agent contained high levels of non-soluble β-glucan, mean 3900 pg/mL, range 2500 to 5400 pg/mL. Different CFUs/mL of Propionibacterium acnes also contained different levels of β-glucan as did those of Mycobacterium gordonii although at lower levels. CONCLUSIONS: The results support a conclusion that non-soluble β-glucan and thus a higher level of fungal exposure is involved in the pathogenesis of sarcoidosis in susceptible patients. CLINICAL IMPLICATIONS: β-glucan should thus be recognized as a causative agent for sarcoidosis. It is likely that other microbial agents, not yet defined, have the same effect. DISCLOSURE: The following authors have nothing to disclose: Marjeta Tercelj-Zorman, Barbara Salobir, Ragnar Rylander No Product/Research Disclosure Information