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Simultaneous labeling of mast cell proteases and protease mRNAs at the bone–implant interface of aseptically loosened hip implants
Author(s) -
Qiu J.,
Beckman M. J.,
Qian J.,
Jiranek W.
Publication year - 2005
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1016/j.orthres.2005.04.008
Subject(s) - proteases , protease , implant , mast cell , dentistry , chemistry , medicine , surgery , biochemistry , enzyme , immunology
Human mast cells (MC) exhibit two distinct phenotypes based on the protease content of their secretory granules. MC TC cells express tryptase, chymase, cathepsin G, and mast cell carboxypeptidase, while MC T cells express only tryptase. Both mast cell phenotypes were assessed near regions of osteolysis in uninfected failed joint implants by immunohistochemistry with antibodies to tryptase and chymase, and by in situ hybridization with anti‐sense RNA probes for the respective mRNA molecules. Specimens from the interface membrane of 32 aseptically loosened total hip implants were studied, 28 of which had mast cells of the MC TC type. Most of these mast cells were aligned along the bone–prosthesis interface adjacent to loosened implants, suggesting involvement in the chronic inflammatory response that leads to bone resorption. Further ultrastructural evidence of mast cells in tissues from failed joint interface membranes was shown by transmission electron microscopy, and detection by staining after magnetic activated cell sorting. The presence of MC at the periprosthetic interface of eroded bone suggests MC degranulation and activity are associated with osteolysis in failed joint prostheses. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.