Expression of CD9, CD11b, CD18, CD52 and PDGFR-beta in the interface membrane of loose endoprostheses

The number of endoprosthesis revision operations is increasing. In a previous analysis using cDNA microarrays, differentially expressed genes were detected in the wear-particle-induced membrane and in the infectious periprosthetic membrane. This study aims at validation of these gene expression profiles in order to find genes that are potentially relevant for the pathogenesis, diagnosis, or therapy of endoprosthesis loosening. Tissue samples from 16 wear-particle-induced and 20 infectious periprosthetic membranes were analyzed by reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry with regard to the expression of CD9, CD11b, CD18, CD52, and platelet-derived growth factor (PDGFR)-beta. RT-PCR demonstrated cd9, cd11b, cd18, cd52, and pdgfr-beta RNA in all samples. Macrophages and multinuclear giant cells in the wear-particle-induced membranes showed intense immunohistochemical staining for CD9, CD11b, and CD52. The staining of PDGFR-beta was stronger in the infectious membranes, whereas there were no differences for CD18. Using RT-PCR and immunohistochemical analysis, the cDNA-microarray data of cd9, cd11b, cd52, and pdgfr-beta could be validated, whereas the differential expression of cd18 was not confirmed. The potential relevance of these genes for prosthesis loosening is discussed.