Non-allergic nature of docetaxel-induced acute hypersensitivity reactions

Based on observations of a discrepancy between ‘hypersensitivity’ reactions to docetaxel (DT) and the clinical features of allergic reactions, we explored the hypothesis that DT-induced acute hypersensitivity reactions (AHRs) have a non-allergic origin. Forty cancer patients receiving DT and 16 patients receiving other potentially allergenic chemotherapeutic agents were included in the study. All DT patients received standard pre- and post-medication. Before, during and after administration of the drugs, clinical symptoms and signs were recorded, and serial blood sampling was performed for the first 2 cycles for all patients or in all subsequent cycles in case of AHRs. Plasma histamine and serum tryptase, two established drug allergy markers, were measured. Seventy-five chemotherapy sessions were evaluable. Nine patients on DT, two on paclitaxel (PT) and one on pegylated doxorubicin experienced an AHR during the first course of chemotherapy. In all cases, heart rate remained stable or increased, while arterial pressure was unchanged or raised; no hypotension or bradycardia was noted. All episodes resolved with discontinuation of drug and did not reappear during a re-challenge with the same agent 30 min later. Tryptase levels were normal in all pre- and post-exposure samples (post-exposure11.32±35.63 μg/l, normal values