Kwaasi A A, Harfi H A, Parhar R S, Collison K S, Al-Sedairy S T, Al-Mohanna F A
Department of Biological and Medical Research, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
Int Arch Allergy Immunol. 2000 Oct;123(2):137-44. doi: 10.1159/000024432.
Date fruits are allergenic and standardized extracts are required for diagnosis and therapy of this allergy. Since there are several cultivars of dates, this study was carried out to assess the allergenicity of different cultivars in order to select suitable source material for standardization.
The protein profiles of 18 of the most commonly sold varieties were compared by SDS-PAGE and their relative allergenicity assessed by SPT and IgE-based ELISA and immunoblotting. Thirty-two date fruit-sensitive patients were skin tested with a pooled extract from all the cultivars. Six of the patients with high SPT results (> or =3+) who volunteered were further tested with the 18 cultivars and their sera used in ELISA and immunoblotting.
Six of the cultivars gave high SPT-positive reactions in > or =4 of patients. Five of these high SPT-reactive cultivars gave high IgE ELISA scores (> or =0.58) but individual cultivars varied in their number of IgE immunoblot bands. Cultivar-specific IgE-binding patterns indicated that only certain cultivars bound IgE at molecular weights of < or =14.3 and 27-33 kDa whilst all cultivars bound to a 54-58 kDa doublet. Cultivars that bind to the < or =14.3 and 27-33 kDa bands appeared to form the majority of the high SPT-reactive cultivars. When individual sera of 24 of the 32 SPT-positive patients were used in IgE immunoblots with the pooled cultivar extract, all sera bound IgE at < or =14.3 and 27-33 kDa and about 60% of sera bound to a 54-58 kDa doublet bands.
These results indicate that allergenicity of date fruits is a cultivar-specific phenomenon. Sixty to 100% of sera from date fruit-allergic patients bind IgE to three major allergens of < or =14.3, 27-33 and 54-58 kDa. Five of the cultivars that evoke high SPT reactions, high IgE ELISA scores and bind IgE to the major allergens, can be selected for the preparation of 'in-house' allergen extracts and for allergen standardization.
海枣果实具有致敏性，诊断和治疗这种过敏需要标准化提取物。由于海枣有多个品种，本研究旨在评估不同品种的致敏性，以便选择合适的原料进行标准化。
通过SDS-PAGE比较18种最常销售品种的蛋白质谱，并通过皮肤点刺试验（SPT）、基于IgE的酶联免疫吸附测定（ELISA）和免疫印迹法评估其相对致敏性。用所有品种的混合提取物对32名对海枣果实敏感的患者进行皮肤试验。6名皮肤点刺试验结果较高（≥3+）的志愿者患者进一步用这18个品种进行测试，并将他们的血清用于ELISA和免疫印迹法。
6个品种在≥4名患者中产生了较高的皮肤点刺试验阳性反应。其中5个皮肤点刺试验反应高的品种在IgE ELISA中得分较高（≥0.58），但各个品种的IgE免疫印迹条带数量有所不同。品种特异性IgE结合模式表明，只有某些品种在分子量≤14.3 kDa和27 - 33 kDa时结合IgE，而所有品种都与54 - 58 kDa的双峰结合。与≤14.3 kDa和27 - 33 kDa条带结合的品种似乎构成了大多数皮肤点刺试验反应高的品种。当用32名皮肤点刺试验阳性患者中的24名患者的个体血清与混合品种提取物进行IgE免疫印迹时，所有血清在≤14.3 kDa和27 - 33 kDa时都结合IgE，约60%的血清与54 - 58 kDa的双峰条带结合。
这些结果表明海枣果实的致敏性是品种特异性现象。60%至100%的海枣果实过敏患者血清将IgE结合到≤14.3 kDa、27 - 33 kDa和54 - 58 kDa的三种主要过敏原上。可以选择5个引起高皮肤点刺试验反应、高IgE ELISA得分并将IgE结合到主要过敏原上的品种来制备“内部”过敏原提取物和进行过敏原标准化。
