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

Abstract

SUMMARY 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.