Proteins Bound to Polyethylene Components in Patients Who Have Aseptic Loosening After Total Joint Arthroplasty. A Preliminary Report*

Abstract

Background: Immunological responses to proteins that adhere to ultra-high molecular weight polyethylene have not, to our knowledge, been examined previously in patients who have aseptic loosening. In the current study, polyethylene components from fortynine failed prostheses recovered during revision procedures were examined for the presence of antibodies that were bound to the polyethylene surface or that were reactive with other proteins that were bound to the polyethylene surface. Methods: The polyethylene components consisted of thirty acetabular cups recovered during revision total hip arthroplasties and nineteen tibial components recovered during revision total knee arthroplasties. After extensive washing, bound proteins were extracted from the polyethylene components with use of 0.1molar glycine-hydrogen chloride solution followed by four-molar guanidine hydrochloride solution. Results: Sufficient protein for analysis was recovered from forty-two polyethylene components. Polyacrylamide gel electrophoresis demonstrated a minimum of one and a maximum of twelve protein bands, with molecular weights ranging from thirteen to 231 kilodaltons. Immunoblotting revealed the presence of type-I collagen in most (thirty-four) of the forty-two explants, whereas aggrecan proteoglycans were detected in eight samples. Immunoglobulin also was detected in most (thirty-three) extracts, whereas type-II collagen was consistently absent. The presence of autologous antibodies directed against polyethylenebound proteins in sera drawn at the time of the revision was investigated. Antibodies that were reactive against the ultra-high molecular weight polyethylene-bound

Human serum opsonization of orthopedic biomaterial particles: Protein‐binding and monocyte/macrophage activation in vitro

“…36 The major proteins identified in this study may bind and instantaneously opsonize wear particles in vivo because particles are generated in the presence of plasma, clotting factors, and other immunologic components. 54,55 Protein binding may also occur on prosthetic biomaterials before generation of the particulate debris. 56 -58 In vivo, opsonization of particles likely involves multiple protein species that may be more efficacious in monocyte/macrophage activation than binding of a single protein, as examined in this study.…”

Accumulation of LPS by polyethylene particles decreases bone attachment to implants

“…5,6 Besides molecules of host origin, molecules of microbial origin such as LPS may also bind to these particles and contribute to the inflammatory reaction. 7 LPS, the classical bacter-ial endotoxin, is a component of the outer membrane of Gram-negative bacteria, and is released during bacterial growth or upon bacterial lysis.…”

In situ complement activation by polyethylene wear debris

“…Because of this, complement activation could be a mechanism whereby wear debris triggers early events in aseptic loosening. 13 We therefore studied the ability of polyethylene, a biomaterial component of orthopaedic hip and knee implants, to activate the complement cascade. The results demonstrate in vitro and in situ alternative complement pathway activation, as well as binding of complement components to polyethylene wear debris.…”