Characterization of mode II – wear particles and cytokine response in a human macrophage – like cell culture / Charakterisierung von Mode II – Abriebpartikeln und der Zytokinantwort in einer humanen Makrophagen – ähnlichen Zellkultur

Informations about wear particles in metallosis (mode II wear) and their effects in vitro and in vivo are limited. The aim of this study was to characterize wear particles obtained intraoperatively and to analyse their effects on cytokine response in an established human macrophage-like cell culture model [15]. Method: Wear particles were obtained intraoperatively from four patients with metallosis resulting from CrCoMo/PE/TiAlV-implants (mode II wear) (3 knee, 1hip prosthesis). After purification, particles were characterized regarding to their composition and size (particle size analyser, electron microscopy, edx-analysis, histological slices). The effects of particles on the release of cytokines (PDGF, IL-1β, IL-8, TNF α) were determined in an established human macrophage-like cell culture system by ELISA-assays. Results: The metal wear particles consisted of TiAlV with a mean size of 0,1± 0,15 μm, independent of the prosthesis location. CrCoMo particles could not be detected. In the cell culture model 1456 × 108 particles per 1 × 106 macrophages released maximum amounts of TNFα (8-fold) and IL-8 and IL-1ß (5-fold) while the survival rate of the cells was more than 90 percent. A particle-dependent increase of PDGF-levels could not be detected. Conclusion: As already shown for mode I wear particles (contact between primary bearing surfaces), also mode II wear particles cause release of bone resorbing cytokines in a macrophage-like cell culture model. Because their local and systemic effects in vivo are still not completely understood, we recommend a complete removal of wear particles in cases of metallosis to avoid possible immunological reactions of the body as well as periprosthetic osteolysis. Informationen über Abriebpartikel in Fällen von Metallose (Mode IIAbrieb) und über deren Effekte in vitro und in vivo sind limitiert. Ziel dieser Studie war die Charakterisierung von intraoperativ gewonnenen Abriebpartikeln und die Analyse ihrer Effekte auf die Zytokinausschüttung in einem etablierten, humanen Makrophagen-ähnlichen Zellkulturmodell [15]. Methode: Bei vier Patienten resultierte eine Metallose aufgrund pathologischen Abriebs von CrCoMo/PE/TiAlV – Implantaten (Mode IIAbrieb, 3 Knie, 1 Hüftprothese). Die intraoperativ gewonnenen Abriebpartikel wurden aufgereinigt und bezüglich ihrer Zusammensetzung und Größe charakterisiert (particle size analyser, Elektronenmikroskopie, Edx-Analyse, Histologie). Die Effekte der Partikel auf die Freisetzung von Zy