Abstract
Abstract: :
Purpose: Chemoattractant cytokines or chemokines have many differing properties, including angiogenesis and angiostasis. The «ELR» CXC chemokines and CCL2 (also known as MCP-1) possesses angiogenic properties, whereas CXCL10 and CCL21 (SLC) , possess angiostatic properties. This study was undertaken to investigate whether chemokines can be detected on paraffin-embedded sections of choroidal neovascular membranes (CNVM) and to define differences between CNVMs of differing aetiologies. Methods: CNVM were excised following vitrectomy. Membranes were fixed in 4% formaldehyde and stored until they were cut into 4µ sections onto charged slides. Immunohistochemical analysis of serial sections from each patient was performed using a highly sensitive catalysed signal amplification system and antigen retrieval (DAKO), with biotinyl tyramide acting as a signal amplifier. Clinical features were correlated with the immunohistochemical results. Results: By using antigen retrieval and catalysed signal amplification we were able to detect the expression of a number of molecules on paraffin-embedded specimens. In all membranes cytokeratin and von Willebrand Factor staining allowed identification of epithelial and endothelial structures, respectively. CCL2 was strongly expressed on the endothelial vessels of a single diabetic membrane, yet CNVMs of unknown aetiology showed only minimal neovascularisation and only a few scattered cells had strong CCL2 expression. Conclusion: We describe a technique by which chemokines and other molecules may be detected in paraffin-embedded CNVMs. Our initial results suggest that retinal neovascularisation from different aetiologies may show distinct patterns of CCL2 expression.