IMMUNOHISTOCHEMICAL DETECTION OF CD44V EX PRESSION IN PRENEOPLASTIC AND NEOPLASTIC LESIONS OF THE VULVA

Purpose: The cell surface glycoproteins of the CD44 family are divided into standard CD44 (CD44 s) and splice variants of CD44 (CD44v). In n ormal human tissues CD44v expression is mainly restricted to certain e pithelia. Its expression could also be demonstrated in human gynaecolo gical malignancies by immunohistochemistry and semi-quantitative rever se transcription PCR. In this study we investigated the expression of CD44v epitopes encoded by the variant exons v5, v6 and v3 to v10 in pr eneoplastic and neoplastic lesions of the vulva. Method and material: We investigated the expression of CD44v in biopsies of 30 patients wit h VIN and 11 patients with vulval carcinoma by immunohistochemical APA AP staining. In addition HPV-DNA was tested using PCR on 10 mu m thick paraffin sections. We examined samples for HPV 6 and 11 as well as fo r 16 and 18. Results: In normal vulval keratinocytes CD44v5, CD44v6 an d CD44v3-v10 is present in the membranes of the lower two thirds of th e epithelium. The same distribution pattern of CD44v is seen in mild a nd moderate intraepithelial neoplasia of the vulva (VIN I/II). In seve re intraepithelial neoplasia of the vulva (VIN III) we observed altera tions in the CD44v expression in comparison to normal vulval tissue. T he detection of CD44v isoforms is reduced. In squamous cell carcinoma of the vulva CD44v5, CD44v6 and CD44v3-v10 is present in the membranes of carcinoma cells in non-keratinizing areas. In poor differentiated areas of squamous cell carcinoma we found a loss of CD44v expression. CD34v expression is independent of age, histological subtype of VIN II I or vulval carcinoma and detection of HPV-DNA type 6/11, 16 and 18. C onclusion: According to our first immunohistochemical results, CD44v e xpression is not correlated to poor clinical outcome of patients with preneoplastic and neoplastic diseases of the vulva.