HUMAN MACROPHAGE RESPONSE TO RETRIEVED TITANIUM-ALLOY PARTICLES IN-VITRO

Titanium alloy particles were isolated from membranes obtained at revi sion arthroplasty. Addition of these retrieved particles to human mono cytes/macrophages in cell culture resulted in morphologic change and m etabolic activation. Cells exposed to these particles actively phagocy tized the metallic debris, resulting in an increase in cytoplasm and a polarization of ingested metal. The metabolic response of the macroph ages included increased release of prostaglandin E(2), interleukin-1 b eta, interleukin-6, and tumor necrosis factor-alpha, and increased hex osaminidase activity. Increased release of interleukin-1 beta was maxi mal 6 to 12 hours after particle exposure. These data show that retrie ved titanium alloy particles activate macrophages in vitro in an analo gous fashion to that observed around failed arthroplasties.