Threshold for basophil activation test positivity in neuromuscular blocking agents hypersensitivity reactions

Area of Science:

• Immunology
• Allergy and Clinical Immunology
• Pharmacology

Background:

• The Basophil Activation Test (BAT) is used to diagnose hypersensitivity reactions to Neuromuscular Blocking Agents (NMBAs).
• Previous studies have employed various criteria for BAT positivity, leading to inconsistencies in diagnostic accuracy.
• Establishing standardized thresholds for BAT positivity is crucial for reliable NMBA allergy diagnosis.

Purpose of the Study:

• To determine optimal thresholds for BAT positivity, using both stimulation index (SI) and percentage of activated basophils.
• To evaluate the sensitivity and specificity of the BAT for diagnosing NMBA hypersensitivity reactions.

Main Methods:

• The study included 22 adult patients with a history of NMBA hypersensitivity reactions and 34 control subjects.
• BAT was performed using the Flow2Cast technique, measuring CD63 marker upregulation on basophils.
• Receiver operating characteristics (ROC) curve analysis was used to identify optimal diagnostic thresholds.

Main Results:

• ROC analysis identified an SI threshold of 1.76 (AUC 0.81) and activated basophils >5.01% (AUC 0.84) as optimal criteria.
• Using both thresholds (SI ≥ 1.76 and activated basophils >5.01%), BAT demonstrated 68.18% sensitivity and 100% specificity.
• No control subjects met both positivity criteria, confirming high specificity.

Conclusions:

• The study established specific thresholds for BAT positivity in diagnosing NMBA hypersensitivity.
• The BAT, with an SI ≥ 1.76 and activated basophils >5.01%, offers a highly specific diagnostic tool (100%) with good sensitivity (68.18%) for NMBA allergies.