Abstract: Wang Duoqin*, Tang Hui, Shen Yanyun, Xu Jinhua. *Department of Dermatology, Huashan Hospital, Fudan University, Shanghai 200040, China Corresponding author: Xu Jinhua, Email: xjhhuashan@yahoo.com 【Abstract】 Objective To measure the levels of plasma D-dimer, activated coagulation factor Ⅶ （FⅦa） and activated clotting factor Ⅻ （FⅫa） in patients with chronic urticaria （CU）, and to investigate their relationship with the occurrence of CU. Methods Venous blood samples were collected from 50 patients with CU and 50 healthy human controls. Dry-column immune scattering chromatography was performed to detect the plasma level of D-dimer, and enzyme-linked immunosorbent assay （ELISA） to measure the levels of FⅦa and FⅫa. In addition, autologous plasma skin test （APST） was conducted in 43 patients with CU, and autologous serum skin test （ASST） in 41 patients with CU. A correlation analysis was carried out between the above three parameters and disease severity as well as between the results of APST and ASST and plasma level of D-dimer. Results The levels of plasma D-dimer and FⅦa were significantly higher in patients with CU than in healthy human controls （both P < 0.05）, while no significant difference was found in FⅫa level between the two groups （P > 0.05）. Moreover, the degree of increase in D-dimer plasma level was positively correlated with disease severity in the patients with CU. The plasma level of D-dimer was significantly higher in APST-positive patients than in APST-negative patients （P < 0.05）, but not significantly different between ASST-positive and -negative patients （P > 0.05）. Conclusions Coagulation mechanism, especially the extrinsic coagulation pathway, is related to the occurrence of CU. Studies on coagulation mechanism are beneficial to the evaluation of severity, and clinical treatment, of CU.

Key words: Urticaria, Factor Ⅶa, Factor Ⅻa