Distribution of complement regulators (CD46, CD55 and CD59) in skin appendages, and in benign and malignant skin neoplasms.

Immunohistochemical studies were performed to establish the distribution of membrane cofactor protein (MCP; CD46), decay-accelerating (DAF; CD55) and homologous restriction factor (HRF20; CD59), in normal skin appendages, and in benign and malignant skin neoplasms. At least two of these regulators were detected on normal eccrine glands, apocrine glands and sebaceous glands. They were also found in cellular naevi (CN), seborrhoeic keratoses (SK), basal cell carcinoma (BCC), Bowen's disease (BD), squamous cell carcinoma (SCC) and Paget's disease (PD). Although there were slight differences in their distribution, these regulators were found in all the cells examined, indicating that they are essential factors in human skin as well as other organs, and in neoplasms, in preventing autologous complement attack.