title: Protein expression of MMP-13, uPA, and PAI-1 in pseudocapsular and interface tissue around implants of loose artificial hip joints and in osteoarthritis.
abstract: Matrix metalloproteinase 13 (MMP-13), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1) have been reported to be involved in aseptic loosening of artificial hip joints. This study for the first time presents the protein levels of all of these factors in synovial-like interfaces between bone and prosthesis and in pseudocapsular tissues surrounding the artificial joint in patients with aseptic loosening (n=17) measured by ELISA. No differences were observed in the antigen expression of MMP-13, uPA, and PAI-1, comparing interface and pseudocapsular tissue. Also, no significant correlation between the protein expression of these factors and years from arthroplasty to revision or to type of fixation (cemented vs. cementless) was observed. As control, MMP-13, uPA, and PAI-1 antigen levels were also determined in the synovium of patients with osteoarthritis (n=10). Yet, the antigen levels of MMP-13, uPA, and PAI-1 in tissue specimens from patients with aseptic loosening of artificial hip joints were significantly higher compared to their expression in synovial capsular tissues obtained from patients with osteoarthritis. In conclusion, this study shows that elevated protein levels of uPA, PAI-1, and MMP-13 in periprosthetic pseudocapsular and interface tissues from patients after total hip replacement due to aseptic loosening seem not to be associated with the patient outcome.
authors.affiliation: Department of Orthopaedic Surgery, Technical University of Munich, D-81675 München, Germany. p.diehl@lrz.tum.de
authors.forename: Peter
authors.initials: P
authors.lastname: Diehl
authors.forename: Bernd
authors.initials: B
authors.lastname: Hantke
authors.forename: Michael
authors.initials: M
authors.lastname: Hennig
authors.forename: Harald
authors.initials: H
authors.lastname: Tschesche
authors.forename: Wolfram
authors.initials: W
authors.lastname: Mittelmeier
authors.forename: Manfred
authors.initials: M
authors.lastname: Schmitt
authors.forename: Bernd
authors.initials: B
authors.lastname: Muehlenweg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D017364:Collagenases / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D006622:Hip Prosthesis; D006801:Humans; D017746:Joint Capsule / Q000378:metabolism*; D008297:Male; D053509:Matrix Metalloproteinase 13; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D011475:Prosthesis Failure; D012086:Reoperation; D016896:Treatment Outcome; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D014568:Urokinase-Type Plasminogen Activator; D017364:Collagenases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13