IN VITRO APPROACH TO PROBLEMS OF CLINICAL ALLERGY

在美国，所有有昆虫叮咬过敏史和毒液皮肤试验阳性的成年患者都会使用全身提取物进行治疗。我们已经证明，与昆虫叮咬过敏的标准治疗相反，毒液免疫疗法是有效的。最近，荷兰的研究人员发现，如果刺痛病史呈阳性的皮试阳性患者，超过70%的患者没有反应，他们认为，不需要治疗。美国不完整的研究发现，受到挑战的非反应堆较少。无论是美国还是荷兰的调查人员，都未能开发出诊断参数来预测哪些患者会对叮咬做出反应，哪些患者不会。目前的建议是基于这样一个假设，即欧洲的研究在一定程度上是正确的，没有必要治疗像我们现在这样多的患者。我们将重复他们的工作，重点放在反应较轻的患者身上，并解决该研究中的一个缺陷，即是否一次叮咬就能预测对后续叮咬的反应。我们还假设，临床预防过敏原免疫治疗的结果是一种与免疫球蛋白阻断抗体无关的免疫机制。用变应原多肽进行免疫治疗会导致再次接触变应原时不那么直接的过敏反应。我们将用主要的黄夹克蛇毒变应原抗原5的多肽来免疫患者。使用蛇毒蛋白的标准免疫疗法会导致频繁的大范围局部反应，并在较少的情况下导致全身过敏反应。多肽免疫疗法不会立即引起任何反应，但经常会有延迟的、轻微的“过敏样”反应，我们认为这是由于HRF样细胞因子的产生。我们已经制定了一项详细的协议，以确定这一反应的性质。最后，这些研究的主要目标是使用100或更多患者的叮咬来开发参数，预测哪些人会对叮咬有反应。在目前的工作中，我们不仅计划研究免疫球蛋白水平，还计划研究炎症细胞激活、细胞因子产生、血和尿组胺水平以及类胰蛋白酶水平。此外，在早期研究结果的基础上，我们还将研究激动素凝血通路的激活状态。毒液免疫治疗(VIT)是基于认为未来全身反应(SR)的高风险(&gt；50%)、对SR恶化的恐惧以及缺乏特定的预后测试而推荐的。这项刺痛挑战计划旨在确定与SR病史和毒液皮肤试验(VST)阳性患者的SR风险较低相关的临床和实验室特征。在监测的临床环境中实施昆虫叮咬，并观察患者的SR的客观体征和主观症状。自上一次进度报告以来，通过电话筛选了603名对我们广告的应答者，但在本研究年度只有102人愿意并有资格接受门诊评估，其中37名新患者在1998年夏天完成了刻意的刺痛挑战。在这些患者中，23名(62%)对挑战没有反应，另有7名(19%)临床反应可疑(仅主观症状)。目的：7例(19%)患者出现全身反应，其中轻度5例，中度2例，无严重反应。这一相对较低的反应率与1997年在我们的第一批58名患者中的结果相似，可能与这些志愿者的不太严重的病史有关，以及我们没有叮咬最严重的患者的事实。结果证实，轻度到中度反应堆的风险低于重度反应堆(p&lt；0.03)。到目前为止，还没有发生过挑战反应比之前的全身刺痛反应更糟糕的情况。去年和今年的患者都进行了重复刺痛，总共有95名患者参与(接受了160次刺痛)，总体反应率为20%。到目前为止的结果支持了我们的假设，即目前符合毒液免疫治疗(VIT)条件的大多数患者可能不需要治疗。我们的结果也让我们初步确认，我们已经适当地推动了这项研究，以确保有意义的结果，因为一些结果已经具有统计意义，而另一些结果正在接近重要。现有的计划是在未来18个月内为许多类型的患者提供额外的刺痛挑战，这将提供分析许多不同临床和实验室参数的作用的能力。

In the United States, all adult patients with a history of anaphylaxis in insect sting and a positive venom skin test are treated with whole body extracts. We have shown that, contrary to this standard treatment for insect sting allergy, venom immunotherapy is effective. Recently, investigators in Holland have found that if they sting history-positive skin test-positive patients, more than 70% have no reaction, and they contend, need no therapy. Incomplete US studies found fewer non-reactors on challenge sting. Neither the US nor the Dutch investigators have been able to develop diagnostic parameters to predict which patients will react to sting and which will not. The current proposal is based on the hypothesis that the European studies are, in part, correct and that it is unnecessary to treat as many patients as we do now. We will repeat their work focusing on patients with milder reactions, and address a flaw in that study, i.e., the question of whether a single sting predicts the reaction to subsequent stings. We also hypothesize that clinical protection from allergen immunotherapy results from a mechanism of immunization unrelated to IgG blocking antibodies. Immunotherapy with allergen peptides leads to a lesser immediate allergic response on re-exposure to allergen. We will immunize patients with peptides from antigen 5, the major yellow jacket venom allergen. Standard immunotherapy with venom proteins leads to frequent large local reactions and, less often, to systemic anaphylaxis. Peptide immunotherapy does not cause any immediate reactions, but there is often a delayed and mild "anaphylactic-like" response which we believe is due to the generation of an HRF-like cytokine. We have developed a detailed protocol to ascertain the nature of this response. Finally, the major goal of these studies is to use the stings of a hundred or more patients to develop parameters which predict which individuals will have a reaction to a sting. In the current work, we plan to study not only immunoglobulin levels, but also inflammatory cell activation, cytokine production, blood and urine histamine levels and tryptase levels. Further, based on the results of earlier studies, we will also study the state of activation of the kinin coagulation pathways. Venom immunotherapy (VIT) is recommended based on perceived high risk (>50%) of future systemic reaction (SR), fear of worsening SR and lack of specific prognostic test. This sting challenge program seeks to define clinical and laboratory characteristics associated with lower risk of SR in patients with SR history and positive venom skin tests (VST). Insect stings were performed in a monitored clinical setting and patients were observed for objective signs and subjective symptoms of SR. Since the last progress report, 603 respondants to our advertisements have been screened by telephone, but only 102 were willing and eligible for in- clinic evaluations in this study year, of whom 37 new patients completed a deliberate sting challenge during the summer of 1998. Of these patients, 23 (62%) had no reaction to the challenge and another 7 (19%) had questionable clinical responses (subjective symptoms only). Objective evidence of systemic reaction occurred in 7 (19%) patients, with 5 mild, 2 moderate and no severe reactions. This relatively low reaction rate is similar to the results in our first 58 patients in 1997, and probably related to the somewhat less severe histories in these volunteers, and the fact that we did not sting the most severe patients. The results confirm that mild to moderate reactors are at a lower risk than severe reactors (p<0.03). Thus far, no case has occurred in which the challenge reaction was worse than the previous systemic sting reaction. Patients from last year and this year have had repeat stings performed, with a total of 95 patients participating (receiving 160 stings), and an overall reaction rate of 20%. The results to date support our hypothesis that the majority of patients currently eligible for venom immunotherapy (VIT) may not need treatment. Our results also give us early confirmation that we have powered this study appropriately to ensure significant results, since some results are already statistically significant and others are approaching significance. The existing plan for additional sting challenges of many patient types over the next 18 months will provide the power to analyze the role of many different clinical and laboratory parameters.