Diagnosis of Drug Allergy by Lymphocyte Stimulation Test with Ethidium Bromide Fluorescence Assay.

Lymphocyte stimulation test (LST) is one of the useful laboratory tests for identification of allergy to a specific drug.The present study was conducted to examine utility of LST using ethidium bromide (EB) fluorescence assay as a method for diagnosis of drug allergy.In a preliminary experiment, phytohemagglutinin (PHA) was used instead of suspected drugs.PHA at concentrations between 0.001-1.2% caused an activation of lymphocytes with elevation on stimulation index (SI).Interleukin 2 at concentrations between 1-100 ng/ml enhanced PHA-induced activation of lymphocytes. From these results, LST using EB fluorescence assay would be available for diagnosis of drug allergy.At first we carried out LST on 22 cases of suspicious drug-induced hepatitis.As a result, 9 cases were positive and 13 cases were negative.In order to analyze the relationship between background of the patients and LST, we studied transaminase (GOT and GPT) activities in the sera which were obtained from the patients in different states (remission and acute disease states). As a result, when LST was carried out in remission state, relatively high positive incidence (50%) was obtained.When LST was carried out in acute disease state, positive incidence of LST was low (25%).These results indicate that this method is useful for clinical diagnosis of drug allergy, And in the case of the diagnosis of drug-induced hepatitis, LST would be recommended to be carried out in remission state.