An in vitro assay for radiographic contrast media idiosyncrasy.

Adverse reactions related to the use of iodine-containing radiographic contrast media (RCM) continue to present a significant problem in diagnostic radiology. This study was designed to test an in vitro assay that can probably be used before infusion of RCM to predict patients with high risk of developing contrast media reactions. Peripheral leukocytes of 23 patients with a positive history of RCM incompatibility or idiosyncrasy, 89 atopic individuals, and 49 normal, nonatopic volunteers were stimulated in vitro with three RCM in different concentrations, and the amount of histamine released was measured in the supernatant. There was a significant increase in histamine release induced by RCM in the majority of patients with RCM idiosyncrasy, and in patients with atopic disease. Normal leukocytes, when incubated with serum from high-releasing or atopic patients, did not show increased histamine release after stimulation with the respective RCM. The increased releasability of patients' leukocytes could not be transferred by serum. Our results show that leukocytes' histamine release is higher in patients with a positive history of RCM incompatibility and patients with atopic disease. This in vitro assay might be a useful diagnostic tool for detecting patients with a high risk of developing contrast media reactions.