Poster presentation, P58
Official XXIst International Pigment Cell Conference website - 21-24 Sept 2011, Bordeaux - France | updated: September 04 2011
Evidence for a local and systemic immune reaction against melanocyte differentiation antigens in a patient with regressing nevi without halo
| SPEAKER | R. Speeckaert #whois submiter ? |
| AUTHOR(s) | R. Speeckaert, N. Van Geel, R. Luiten, M. Van Gele, M. Speeckaert, J. Lambert, K. Vermaelen, E. Tjin, L. Brochez |
BACKGROUND AND OBJECTIVES: Regressing nevi are considered an example of an efficient early antitumoral immune response preventing the development of neoplasia. The underlying mechanism has not been elucidated although an immune-based destruction of melanocytes is supposed. The aim of this study was to provide evidence of an effective immunosurveillance of pigment lesions in a patient at high risk of melanoma. METHODS: A patient with the dysplastic nevus syndrome (> 100 nevi) and a history of melanoma (Breslow < 1 mm) in 1997 was included in this study. Since 2003, a marked regression of almost all nevi was observed without halo formation. Standard immunohistochemistry (CD3, CD4, CD8, CD1a, Foxp3) was performed on the regressing nevi. Flow cytometry with HLA-A2-peptide tetramers specific for Mart-1(26-35), gp100(280-288), gp100(209-217) and tyrosinase(369-377) was performed on peripheral blood mononuclear lymphocytes and lymphocytes isolated from a regressing nevus. A peptide-specific stimulation experiment with melanocyte antigen-specific peptides was carried out. RESULTS: Immunohistochemistry of the regressing nevi showed a strong infiltrate of CD3+, CD4+, CD8+ and CD1a+ cells with a low frequency of Foxp3+ cells. Flow cytometric analyses demonstrated the presence of a CD8 lymphocyte reaction against gp100(280-288) and Mart-1(26-35) both in peripheral blood and lesional lymphocytes. A moderate increase in proinflammatory cytokine production (TNF-γ, IFN-α, IL-4) after melanocyte specific peptide stimulation was observed. CONCLUSION: These findings indicate that an effective systemic immune reaction against melanocyte differentiation antigens can target specifically nevi without signs of vitiligo and suggests that boosting the anti-melanocyte immune response in patients at high risk for melanoma may prevent tumoral development at an early stage.
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