Monocytes, macrophages, and their diseases in man.

Mononuclear phagocytes are a widely distributed system of cells involved in host defense functions, immunologic reactions, disposal of unwanted organic and inorganic materials, and synthesis of biologically active compounds such as complement components and prostaglandins. The system includes early precursor cells in the bone marrow, blood monocytes, alveolar and peritoneal macrophages, sinusoidal lining cells in the spleen, and Kupffer cells in the liver. We have recently come to understand the biology of these interesting cells and the diseases they produce.