Diagnosis of immediate reactions to amoxicillin: Comparison of basophil activation markers CD63 and CD203c in a prospective study

Allergy. 2023 Oct;78(10):2745-2755. doi: 10.1111/all.15610. Epub 2022 Dec 17.

Abstract

Background: Amoxicillin (AX) combined or not with clavulanic acid (CLV) is frequently involved in IgE-mediated reactions. Drug provocation test (DPT) is considered as the gold standard for diagnosis, although contraindicated in high-risk patients. Basophil activation test (BAT) can help diagnose immediate reactions to beta-lactams, although controversy exists regarding the best activation marker. We have performed a real-life study in a prospective cohort to analyze the real value of BAT as diagnostic tool and the best activation marker, CD63 and CD203c, for the evaluation of immediate reactions to these drugs.

Methods: We prospectively evaluated patients with a clinical suspicion of immediate reactions after AX or AX-CLV administration during a 6-year period. The allergological work-up was done following the EAACI recommendations. BAT was performed in all patients using CD63 and CD203c as activation markers.

Results: In AX-allergic patients, both activation markers, CD63 and CD203c, showed similar SE values (48.6% and 46.7%, respectively); however, specificity was of 81.1% and 94.6%, respectively, with CD203c showing good positive predictive value and like-hood ratio. In CLV-allergic patients, CD203c showed higher SE (50%) than CD63 (42.9%), maintaining the same value of SP (80%). Combining the results of both markers can slightly increase the sensitivity (51.4% for AX and 54.8% for CLV), although decreasing the specificity (79.7% and 73%, respectively). Interestingly, all patients with an anaphylactic shock showed a positive BAT to CLV using CD203c.

Conclusions: BAT using CD203c showed a good confirmatory power, especially for AX allergy. Placing BAT as a first step in the diagnostic procedure can help reduce the need of performing a complete allergological work-up in 46.6% of patients, diminishing the risk of reinducing allergic reactions.

Keywords: amoxicillin; basophils; clavulanic acid; drug allergy; immediate reactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin / adverse effects
  • Anaphylaxis* / diagnosis
  • Anaphylaxis* / etiology
  • Basophil Degranulation Test / methods
  • Basophils
  • Clavulanic Acid
  • Humans
  • Hypersensitivity, Immediate* / diagnosis
  • Prospective Studies
  • Tetraspanin 30

Substances

  • Amoxicillin
  • Clavulanic Acid
  • Tetraspanin 30
  • CD63 protein, human