[Antigenicity study of paclitaxel]

The antigenic property of paclitaxel was examined using its protein mixtures (paclitaxel + OVA, paclitaxel + GSA, paclitaxel + RSA) in guinea pigs and mice in comparison with ovalbumin (OVA) and the protein conjugate of 4-aminoantipriyne (AAP). The following results were obtained: 1. When guinea pigs were sensitized with paclitaxel or paclitaxel + OVA emulsified with Freund's complete adjuvant, none of active systemic anaphylaxis (ASA), passive cutaneous anaphylaxis (PCA) and Schultz-Dale reaction were induced by challenge with paclitaxel or paclitaxel + GSA (guinea pig serum albumin). In the observation of active cutaneous anaphylaxis (ACA), no changes were observed in animals treated with paclitaxel alone as a sensitizing and/or a challenging antigen under the condition where slight delayed type hypersensitivity was elicited in animals sensitized with paclitaxel + OVA and challenged with paclitaxel + GSA. 2. When mice were sensitized with paclitaxel or paclitaxel + OVA adsorbed to alum. sera of these animals revealed a negative reaction in PCA using rats by challenge with paclitaxel or paclitaxel + RSA (rat serum albumin). 3. Protein bindings of paclitaxel with the above albumins were more than 40%. As shown above, paclitaxel was considered not to possess antigenic property under the experimental condition. In addition, the dose levels of paclitaxel employed in the present experiment were confirmed not to suppress the immune response to OVA.