Chemotactic factor generation by asbestos. Fibre type differences and the effects of leaching.

The generation of chemotactic factors in normal human serum by treatment with chrysotile and crocidolite asbestos was investigated using the Boyden chamber method. Both types of asbestos produced chemotactic activity but not to the same extent. The two fibre types also produced different levels of complement activation as measured by C3 conversion using two dimensional immunoelectrophoresis. While there was a simple correlation between fibre concentration and C3 conversion the production of chemotactic activity declined at high doses of chrysotile. Phosphate buffer treatment reduced the differences between fibre types. The possible role of these phenomena in asbestos-associated disease is discussed.