Abstract
Four patients with nonβHodgkin lymphoma and two with acute lymphocytic leukemia (ages 4 years 4 months to 16 years 6 months) exhibited a unique reaction to intravenously administered cytosine arabinoside (AraβC) given alone as a part of the previously reported LSA~2~βL~2~ treatment protocol. The syndrome was characterized by fever, myalgia, bone pain, and occasionally by chest pain, maculopapular rash, and conjunctivitis. Each of the eleven episodes of this syndrome occurred within 6β12 hours of drug infusion and always abated after cessation of AraβC. Prior to the reaction, patients had been on therapy for an average of 13.5 months during which they were exposed to 2298β5387 mg/m^2^ (mean of 3200 mg/m^2^) of AraβC.
The high incidence of this syndrome (50% of our patients on the LSA~2~βL~2~ regimen and 33% of those receiving AraβC) has not been previously reported. Considering the prolonged exposure to AraβC and our inability to document infections in the patients or pyrogens contaminating the drug lots, the most likely explanation for this syndrome is a hypersensitivity reaction to AraβC. Prevention of these symptoms with corticosteroids supports this contention and provides a reasonable alternative to discontinuing AraβC.