Hydroxyapatite phagocytosis by human polymorphonuclear leucocytes

Abstract

Hydroxyapatite crystals were incubated with human polymorphonuclear leucocytes and samples examined by light and electron microscopy after 3, 8, 30, and 120 minutes' incubation. Phagocytosis of crystals occurred at 3 minutes and increased with incubation. Degranulation of neutrophils, loss of cytoplasmic density, and cell necrosis were greatest in cells mixed with apatite and increased with time. Avid in vitro phacotysosis of hydroxyapatite crystals lends further support to the potential of these crystals as causes of human arthritis.