Marcucci F, Sensi L, Di Cara G, Gidaro G, Incorvaia C, Frati F
Department of Obstetric, Gynaecologic and Pediatric Sciences, University of Perugia-Policlinico Monteluce, Via Brunamonti, 06122 Perugia, Italy.
Int J Immunopathol Pharmacol. 2006 Jan-Mar;19(1):141-8.
Oral Allergy Syndrome (OAS) in patients with pollen-induced rhinoconjunctivitis is caused by specific IgE recognizing cross-reacting epitopes of fruits and plants, which were clearly shown in vitro, but failed to be demonstrated in vivo by cross-challenges in the target organs. Considering the hypothesis of degradation of such epitopes in natural extracts, challenges with recombinant pollen allergens were done to evaluate the reactivity of the oral mucosa in OAS patients. Seventeen patients with OAS and rhinitis from birch (10) and grass pollen (7) and 10 non-atopic controls were studied by skin prick tests (SPT), allergen specific nasal challenges (ASNC) and allergen specific sublingual challenges (ASSC) with birch and timothy extracts and with rBet v1 and rPhl p1 at increasing concentrations from 1 to 1000 mcg/ml. None of the healthy subjects in the control group had any positive test for birch and timothy extracts or for recombinant allergens. In the OAS group the following results were observed: SPTs with recombinant allergens were positive in all patients, mostly at 10 mcg/ml concentration; ASNC with rBet v1 were positive in all patients, mostly at 100 mcg/ml; ASSC with natural pollen extracts were positive in only 2 of 17 patients, but in 15 of 17 with rBet v1 and rPhl p1, mostly at 500 mcg/ml and 1000 mcg/ml. ASSC with rBet v1 and rPhl p1 were positive with a mean concentration of 677 and 533 mcg/ml, respectively. The results of sublingual challenges with rBet v1 and rPhl p1 showed the in vivo cross-reactivity between pollens and foods in patients with OAS, but high concentrations of the recombinant allergens were needed to reproduce oral symptoms, thus explaining the failure of challenges performed with natural extracts, which have concentrations of major allergens lower than 50 mcg/ml. This indicates that sublingual mucosa is much less reactive to allergens than other surfaces, such as skin and nasal mucosa, probably because of its anatomic and immunologic peculiarity.
花粉诱导的鼻结膜炎患者的口腔过敏综合征（OAS）是由识别水果和植物交叉反应表位的特异性IgE引起的，这在体外已得到明确证实，但在体内通过靶器官的交叉激发未能得到证实。考虑到天然提取物中此类表位会降解的假说，采用重组花粉变应原进行激发试验，以评估OAS患者口腔黏膜的反应性。对17例来自桦树（10例）和草花粉（7例）的OAS和鼻炎患者以及10例非特应性对照者进行了研究，采用皮肤点刺试验（SPT）、变应原特异性鼻激发试验（ASNC）和变应原特异性舌下激发试验（ASSC），使用浓度从1至1000μg/ml递增的桦树提取物、梯牧草提取物、重组Bet v1和重组Phl p1。对照组的健康受试者对桦树提取物、梯牧草提取物或重组变应原均无阳性试验结果。在OAS组观察到以下结果：所有患者对重组变应原的SPT均为阳性，大多在10μg/ml浓度时；所有患者对重组Bet v1的ASNC均为阳性，大多在100μg/ml时；17例患者中仅有2例对天然花粉提取物的ASSC为阳性，但17例中有15例对重组Bet v1和重组Phl p1的ASSC为阳性，大多在500μg/ml和1000μg/ml时。对重组Bet v1和重组Phl p1的ASSC阳性的平均浓度分别为677μg/ml和533μg/ml。重组Bet v1和重组Phl p1的舌下激发试验结果显示，OAS患者体内花粉与食物之间存在交叉反应性，但需要高浓度的重组变应原才能重现口腔症状，这就解释了使用主要变应原浓度低于50μg/ml的天然提取物进行激发试验失败的原因。这表明舌下黏膜对变应原的反应性远低于其他表面，如皮肤和鼻黏膜，这可能是由于其解剖学和免疫学特性所致。
