There is growing evidence suggesting that in a subset of patients with severe chronic urticaria [CSU] mast cells are activated via mechanisms that bypass the high affinity IgE receptor. This might explain why some patients do not respond at all to anti-IgE therapy [omalizumab]. The present article reviews the pathogenic mechanisms able to lead to histamine release from mast cells described so far in patients with CSU. These include the activation of the coagulation cascade, the activation of the complement system, the activation of the MRGPRX2 receptor, and the platelet activating factor vicious circle. The article suggests some possible interpretations for the clinical events occurring in this specific subset of patients.

越来越多的证据表明，在一部分患有严重慢性荨麻疹 [CSU] 的患者中，肥大细胞通过绕过高亲和力 IgE 受体的机制被激活。这可能解释了为什么有些患者对抗 IgE 疗法 [omalizumab] 根本没有反应。本文综述了迄今为止在 CSU 患者中描述的能够导致肥大细胞释放组胺的致病机制。这些包括凝血级联的激活、补体系统的激活、 MRGPRX2受体的激活以及血小板激活因子恶性循环。该文章对这一特定患者亚群中发生的临床事件提出了一些可能的解释。