AN EVALUATION OF SPONTANEOUS HISTAMINE RELEASE AND THE LOW RESPONDERS IN A BASOPHIL HISTAMINE RELEASE TEST

We evaluated the clinical significance of the spontaneous histamine release ratio (SHR/T) and low responders in the automated basophil histamine release test (AllerportⓇ HRT).This study analyzed the outcomes of 101 oral food challenges (OFC) with egg, milk or wheat (challenge-positive: n=79) in relation to the SHR/T. The traditional HRT low responders (n=27) were separated into two groups:"LOW"responders (n=10), who showed a ≥10% concentration-dependent maximum histamine release in response to the anti-human IgE stimulation, and"NON"responders who did not fulfill the criteria (n=17).Among the 34 patients with ≥20% SHR/T, 32 patients (94%) had a positive OFC with a low threshold dose which provoked severe symptoms. Among the"LOW"responders, four cases showed ≥10% allergen-specific maximum histamine release. On the other hand, concentration-dependent histamine release was not seen in the"NON"responders, suggesting the basophil function was not detected in this subgroup.The present study suggested that SHR/T could be an indicator of basophil activation and hypersensitivity in vivo. We also suggested that significant basophil functions might be detected among the "LOW"responders, but not among the"NON"responders.