Ferastraoaru Denisa, Jordakieva Galateja, Jensen-Jarolim Erika
Department of Internal Medicine/Allergy and Immunology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA.
Department of Physical Medicine, Rehabilitation and Occupational Medicine, Medical University of Vienna, Vienna, Austria.
World Allergy Organ J. 2021 Feb 6;14(1):100505. doi: 10.1016/j.waojou.2020.100505. eCollection 2021 Jan.
Since the discovery of IgE, almost all attention was given to conditions with elevated specific or total IgE levels such as atopy, type I hypersensitivity reactions, or parasitic infestations. Recent prospective and retrospective studies show that having very low IgE levels, such as those seen in IgE deficiency (IgE<2.5 kU/L), is not without clinical consequences. Patients with ultra-low IgE levels have an elevated risk of cancer of any type. These results are in agreement with murine models research which demonstrated that grafted tumors grow faster and bigger on an IgE knockout background. The novel finding that IgE deficiency is a susceptibility factor for cancer, fits very well with the AllergoOncology concept. The reports on a beneficial, cytotoxic function of IgE, in cooperation with its high (FcεRI) and low (FcεRII, CD23) affinity IgE receptors resulting in tumor cell phagocytosis, propose a role of IgE in cancer surveillance. It appears that not only deficiency of serum IgE, but also lack of tissue-bound IgE is important in malignancy susceptibility in these patients. As such, IgE deficient individuals with absent serum and cell-bound IgE as suggested by negative type I hypersensitivity skin tests, are at the highest risk for a malignancy diagnosis. In contrast, IgE deficient individuals with cell-bound IgE depicted through positive type I hypersensitivity skin tests, have lower rates of malignancy diagnosis. The present report discusses the evidence and potential role of ultra-low IgE as a novel biomarker for cancer susceptibility.
自发现免疫球蛋白E（IgE）以来，几乎所有的注意力都集中在特异性或总IgE水平升高的情况，如特应性、I型超敏反应或寄生虫感染。最近的前瞻性和回顾性研究表明，IgE水平极低，如在IgE缺乏症（IgE<2.5 kU/L）中所见，并非没有临床后果。IgE水平超低的患者患任何类型癌症的风险都会升高。这些结果与小鼠模型研究一致，该研究表明移植的肿瘤在IgE基因敲除背景下生长得更快、更大。IgE缺乏是癌症易感性因素这一新发现，与过敏肿瘤学概念非常契合。关于IgE与其高亲和力（FcεRI）和低亲和力（FcεRII，CD23）IgE受体协同发挥有益的细胞毒性功能导致肿瘤细胞吞噬的报道，提示了IgE在癌症监测中的作用。似乎不仅血清IgE缺乏，而且组织结合型IgE的缺乏对这些患者的恶性肿瘤易感性也很重要。因此，I型超敏皮肤试验阴性提示血清和细胞结合型IgE均缺乏的IgE缺乏个体，患恶性肿瘤的风险最高。相比之下，I型超敏皮肤试验阳性显示有细胞结合型IgE的IgE缺乏个体，患恶性肿瘤的诊断率较低。本报告讨论了超低IgE作为癌症易感性新型生物标志物的证据和潜在作用。
