Human leucocyte antigen class I and class II antigen expression in malignant fibrous histiocytoma, fibrosarcoma and dermatofibrosarcoma protuberans is significantly downregulated.

BACKGROUND: Abnormalities in the expression of human leucocyte antigens (HLA) by tumour cells impair cellular immune responses promoting immune evasion and tumour survival. To date, studies analysing HLA class I and class II expression levels in malignant fibrous histiocytomas, fibrosarcomas and dermatofibrosarcoma protuberans are limited. AIMS: Therefore, we investigated the in vivo expression profile of HLA class I and class II antigens in 99 malignant fibrous histiocytomas, 20 fibrosarcomas and 34 dermatofibrosarcoma protuberans from different anatomical sites.
MATERIAL AND METHODS: Immunohistochemistry using monoclonal antibodies to HLA class I and class II antigens was used to define the expression levels of these antigens on respective tumour samples.
RESULTS: Frequent loss or downregulation of HLA class I and class II expression in malignant fibrous tumours was observed for the different types of tumours examined. DISCUSSION: The data presented suggest for the first time a high frequency of HLA class I and class II abnormalities in malignant fibrous histiocytomas, fibrosarcomas and dermatofibrosarcoma protuberans in vivo.
CONCLUSION: This information might be useful in the practical and clinical design of tumour vaccination strategies.