Crystal Arthropathies

Abstract

A group of diseases, fast expanding, are marked by the deposition in tissue of crystals which appear to produce tissue destruction by a common mechanism. Either they are ingested by, or nucleation occurs within the cytoplasm of, polymorphonuclear leucocytes. There is abundant evidence that the white cell responds by trying to digest or destroy these crystals. The rate of all measured metabolic processes of these cells increases, neutral and acidic proteinases are formed within the primary and secondary lysosomes of these cells and these and other products of the cells leak into the extracellular fluid, reducing the local pH. Potentially toxic products of oxygen metabolism and products of cell membrane lysis such as prostaglandins, leukotrienes, interleukins and superoxides are released and an acute inflammatory reaction ensues which may limit or promote further destruction according to local circumstances. In the past individual crystals have been linked to different diseases. Recently it has been appreciated that the position may be considerably more complex.