Differences in cellular and inflammatory cytokine profiles in the bronchoalveolar lavage fluid in bagassosis and silicosis

BACKGROUND: Little is known about the crucial mediators involved in the inflammation and fibrogenesis in bagassosis. The aim of this study was to characterize the cellular and cytokine patterns in the airways of bagassosis and to compare these with silicosis subjects and controls. METHODS: Bronchoalveolar lavage (BAL) was performed in 11 patients with bagassosis, 16 cases with silicosis, and 8 controls. Differential cell counts, total protein concentration, TNF-alpha, IL-1beta, IL-5, IL-6, and IL-8 were analyzed in the bronchoalveolar lavage fluid (BALF). RESULTS: Bagassosis was characterized with hypercellularity with neutrophilia in BALF; while the predominant cell in the BALF in silicosis was macrophage. Compared with control subjects, increased TNF-alpha, IL-1beta, IL-8, and IL-6 levels were found in the BALFs in both bagassosis and silicosis. Furthermore, IL-6 levels in the BALF of silicosis subjects were significantly higher than that seen in bagassosis. In contrast, bagassosis had higher level of IL-8 in BALF than that in silicosis. Relationship among these parameters were found between IL-8 levels and neutrophils, lymphocytes and IL-1 beta in bagassosis, macrophages and IL-1beta in silicosis. No significant differences of total protein concentrations and IL-5 in BALF were found between controls or bagassosis, and silicosis. CONCLUSIONS: The findings of this study suggest that neutrophils, TNF-alpha, IL-1beta, IL-8, and IL-6 are involved in the pathogenesis in bagassosis. The mechanisms underline the different cellular and cytokine profiles in bagassosis and silicosis warrant further investigation.