Thesis (M.Sc.)--Chulalongkorn University, 2009

The diagnosis and prevention of iodinated contrast media or radiocontrast media (RCM) hypersensitivity is still a major problem in clinical practice. At present, there are no alternative methods to diagnose RCM-induced hypersensitivity reaction other than history taking. Basophil activation test (BAT) by determining CD63 expression on basophil cell surface was demonstrated to correlate with hypersensitivity drug reactions. The purpose of this study, therefore, aims to explore the possibility whether BAT play a role in the diagnosis of patients with a history of RCM-induced immediate hypersensitivity reaction. Whole blood from 24 patients and 14 healthy donors were incubated in the presence or absence of 1:10 and 1:100 dilution concentrations of radiocontrast media. Levels of CD63 expressions on basophil surface were consequently determined by fluorescence staining and Flow cytometry analysis. The result from the study indicated that basophils from 13 out of 24 patients with a history of RCM reactions (54.17%) had increased CD63 expression and 11 out of 13 patients showed positive BAT result to both 1:10 and 1:100 concentrations of incubated RCM. Sensitivity and specificity of BAT were 54.17% and 92.86%, respectively. BAT results were not significantly different between skin test positive and skin test negative patients. In addition, BAT in combination with skin test results had increased sensitivity to 70.8%. In conclusion, basophil activation test (BAT) may be potentially useful in the diagnosis of patients with RCM-induced hypersensitivity reactions.