Detection of endogenous cytokines in sera or in lymph nodes obtained from patients with sarcoidosis

Abstract

To investigate the possible role of endogenous cytokines in the immunopathogenesis of sarcoidosis, a study of cytokines in lymph nodes obtained from patients with active pulmonary sarcoidosis was carried out using immunoperoxidase staining and radioimmunoassays (RIA). Cells stained for inlerfcron‐y (IFN‐γ) and tumour necrosis factor‐α (TNF‐α), which appeared to be CD3+ cells and CD14+ cells, respectively, were seen scattered around granulomas. In contrast, cells positive for intcrlcukin‐1β (IL‐1β) were located in CD11c+ cells within granulomas. Lymph nodes of patients with sarcoidosis contained significantly higher amounts of IFN‐y, TNF‐a and IL‐1β than control lymph nodes. The levels of IFN‐γ and TNF‐α in extracts of lymph nodes were correlated with the histological status of the granulomas. IFN‐γ was delected in all stages, while the highest level of TNF‐α was obtained from lymph nodes containing many active granulomas. The level of serum IFN‐γ was always lower than in lymph node extract and correlated significantly with either serum angiotensin‐converting enzyme or serum lysozyme. Patients with positive gallium‐67 uptake or bilateral hilar lymphadenopathy had high levels of either serum IFN‐γ or lysozyme. These results suggest that quantitative analyses of IFN‐γ and TNF‐α in sera and lymph nodes may serve to elucidate the pathophysiology of sarcoidosis. Copyright © 1991, Wiley Blackwell. All rights reserved