Basophil Histamine Release (HR) Activity and Disease Severity in Chronic Idiopathic Urticaria (CIU)

Abstract

RATIONALE: To assess CIU disease severity and activity in relation to basophil HR characteristics.METHODS: CIU subjects were recruited from university allergy and dermatology clinics. Subjects were excluded if they had recent use of systemic steroids or immunosuppressants. After being consented, subjects completed a disease severity questionnaire. Blood basophils of subjects were isolated by dextran sedimentation and stimulated for HR with polyclonal goat anti-human IgE. HR was measured by automated fluorimetry. Multivariable linear regression analyses were used to investigate the relationship between histamine release data and disease measures.RESULTS: Thirty-four subjects were enrolled with the following characteristics: mean age, 44 yrs; females, n = 27; Caucasian, n = 24; disease duration >4 years, n = 18; and family history of hives, n = 9. In the past year, 52% of subjects received > 1 steroid taper, 17% visited the ER for CIU and 62% reported > 1 d of work or school absence. The linear regression revealed a significant inverse relationship between current itch severity and blood histamine content (p = . 036), a measure of basophil presence in the circulation, after controlling for potential confounders such as race, gender, disease duration, family history and medications used.CONCLUSIONS: This study suggests CIU subjects have a significant disease burden. The inverse relationship between itch severity and blood histamine content identified supports prior observations that basopenia is linked to disease activity. Further, the reduction of blood basophils may indicate their recruitment to urticarial lesions as recently reported. RATIONALE: To assess CIU disease severity and activity in relation to basophil HR characteristics. METHODS: CIU subjects were recruited from university allergy and dermatology clinics. Subjects were excluded if they had recent use of systemic steroids or immunosuppressants. After being consented, subjects completed a disease severity questionnaire. Blood basophils of subjects were isolated by dextran sedimentation and stimulated for HR with polyclonal goat anti-human IgE. HR was measured by automated fluorimetry. Multivariable linear regression analyses were used to investigate the relationship between histamine release data and disease measures. RESULTS: Thirty-four subjects were enrolled with the following characteristics: mean age, 44 yrs; females, n = 27; Caucasian, n = 24; disease duration >4 years, n = 18; and family history of hives, n = 9. In the past year, 52% of subjects received > 1 steroid taper, 17% visited the ER for CIU and 62% reported > 1 d of work or school absence. The linear regression revealed a significant inverse relationship between current itch severity and blood histamine content (p = . 036), a measure of basophil presence in the circulation, after controlling for potential confounders such as race, gender, disease duration, family history and medications used. CONCLUSIONS: This study suggests CIU subjects have a significant disease burden. The inverse relationship between itch severity and blood histamine content identified supports prior observations that basopenia is linked to disease activity. Further, the reduction of blood basophils may indicate their recruitment to urticarial lesions as recently reported.