石棉纤维被铁和钙包裹，这就是采用铁染色法染色发现含铁体的原因。当这些纤维被巨噬细胞吞噬时会发生纤维增生反应，此反应通过成纤维细胞释放能促进胶原沉积的生长因子来实现。
The asbestos fiber becomes coated with iron and calcium, which is why it is often referred to as a "ferruginous body" as seen here with an iron stain. Ingestion of these fibers by macrophages sets off a fibrogenic response via release of growth factors that promote collagen deposition by fibroblasts.
