The Basophil Activation Test Can Be of Value for Diagnosing Immediate Allergic Reactions to Omeprazole

Publication date: Available online 12 January 2018
Source:The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Jose J. Laguna, Gador Bogas, Maria Salas, Cristobalina Mayorga, Javier Dionicio, Rosario Gonzalez-Mendiola, Adriana Ariza, Ruben Fernández-Santamaría, Isabel Olazabal, Inmaculada Doña, Tahia D. Fernandez, Maria J. Torres
BackgroundProton pump inhibitors (PPIs) are commonly used to treat gastrointestinal diseases. Incidence of hypersensitivity reactions to PPIs has risen, likely because of increased consumption. Their diagnosis is difficult, with skin tests (STs) presenting low sensitivity, making it necessary to perform drug provocation tests (DPTs). The value of in vitro tests for the diagnosis of immediate reaction to PPI is unclear.ObjectiveTo analyze the diagnostic value of the basophil activation test (BAT) in a group of patients diagnosed with immediate allergy to omeprazole.MethodsThe study included 42 patients with confirmed immediate allergic reactions to omeprazole confirmed by positive ST results or DPT results and 22 age- and sex-matched subjects tolerant to PPIs. BAT was performed with omeprazole, pantoprazole, and lansoprazole using CD63 and CD203c as activation markers.ResultsST sensitivity was 66.7% with a specificity of 100%. BAT using CD63 with a stimulation index of more than 2 as positive revealed a sensitivity of 73.8%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 66.7%. BAT was positive in 57.1% of patients with negative ST result, and thus by combining ST and BAT we can correctly diagnose 85.7% of patients with immediate allergy to omeprazole.ConclusionBAT represents a complementary tool for inclusion in the allergological workup for patients allergic to omeprazole. When combined with ST, it can be of value to guide the clinician as to whether to perform a DPT.