A Kind of IgE-Independent Chronic Urticarial Mediated by MRGPRX2

Concentration of serum substance P (SP) were confirmed higher in chronic urticaria (CU) patients. Subsequently, SP was verified to induce pseudo-allergic reactions via MRGPRX2. To confirm that IgE-independent CU was connected with MRGPRX2, a single-center, case-control study was adopted. A total of 353 residual peripheral blood samples from clinical examinations were collected, including the patient groups (150 CU specimen, 68 acute urticarial (AU) specimen, and 135 control specimen of healthy people who underwent physical examinations. Transcripts of MRGPRX2 were detected by RT-PCR and recorded as log copy number (LCN), while serum SP was detected using ELISA Kits. Data analyses were performed by R project software package. The results showed that MRGPRX2 expressed in peripheral blood basophils and levels of MRGPRX2 transcripts, as well as serum SP concentration, were higher in the CU group. IgE levels in these patients were particularly low and the scores of wheal and itch were lighter. MRGPRX2 receptor mediates a kind of CU which is IgE-independent. Trial Registry Number: This study was registered at Chinese Clinical Trail Registry, and the registration number is ChiCTR-DDD-17013003. Funding Statement: This work was supported by the National Natural Science Foundation of China (Grant Number: 81230079 and 81872837). Declaration of Interests: The authors declare no competing financial interests. Ethics Approval Statement: The ethical approval was approved by Ethics Committee at Xi’an Jiaotong University and conformed to the ethical standard. All the specimen in this study had signed informed consent.