ABSTRACT
BACKGROUND: No available test diagnoses allergic reactions to radiocontrast media (RCM). The basophil activation test (BAT) has been introduced for the diagnosis of both immunoglobulin (Ig) E and non-IgE-dependent mast cell degranulation, but its value to diagnose immediate RCM reactions is still unknown. OBJECTIVE: This study aims to evaluate the diagnostic value of BAT in immediate RCM hypersensitivity. METHODS: The BATs were performed in 26 patients with immediate RCM reactions and in 43 specimens from healthy volunteers. The sample's whole blood was incubated with the responsible RCM and % activated (CD63+/CCR3+) basophils were analyzed by flow cytometry. Receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cutoff value of activated basophils to diagnose patients with RCM hypersensitivity. RESULTS: The incubation of blood with RCM yielded significantly higher activated basophil percentages in patients with a history of immediate RCM reactions than in normal controls with both 1:100 and 1:10 dilutions (13.11% vs. 2.71%, P value = .01; and 19.23% vs. 3.73%, P = .001, respectively). Both % activated basophils and stimulation index (SI) had acceptable discrimination powers to diagnose RCM hypersensitivity. The area under the curve was 0.79 (95% CI 0.67-0.91, P = .000) by using SI as the diagnostic criteria with 1:100 dilution of RCM. The specificity of the test ranged from 88.4% to 100%. CONCLUSION: Our study demonstrated the potential of BAT as a diagnostic tool for an immediate RCM hypersensitivity, particularly as a confirmation test. Further studies are required to confirm the test accuracy and identify a patient's predisposing factors.
