Autoantibody production in chronic idiopathic urticaria is not associated with Helicobacter pylori infection.

Chronic idiopathic urticaria (CIU) is a dermatological syndrome, characterized by raised erythematous skin lesions, that affects 20% of the general population and has been associated with autoimmunity. However, some reports have also suggested a close relationship between CIU and Helicobacter pylori infection, which is endemic in developing countries and associated with chronic gastritis, peptic ulcer disease, and gastric carcinoma. In the present study, we investigated the occurrence of autoantibodies in sera from 23 CIU subjects infected with H. pylori and from 23 CIU subjects without this infection. The presence of anti-thyroid antibodies was determined by indirect hemagglutination assay and the presence of autoantibodies to IgE and C1INH was determined by ELISA. Antibodies to thyroid antigens were detected at low titers from 100 to 400 in three of 23 (13%) CIU-infected subjects and in four of 23 (17%) CIU-noninfected subjects. The titers of anti-IgE autoantibodies were similar in these CIU groups, presenting absorbances of 1.16 +/- 0.09 and 1.07 +/- 0.16, respectively, while a titer of 1.14 +/- 0.15 was detected in the healthy control group. The concentration of anti-C1INH autoantibodies was the same in the CIU-infected and -noninfected subjects (7.28 +/- 1.31 and 7.91 +/- 2.45 ng/ml, respectively), and was 7.20 +/- 2.25 ng/ml in the healthy control group. However, the serum levels of complexed anti-C1INH antibodies were increased in CIU-infected subjects compared to CIU-noninfected subjects and healthy controls with an absorbance of 1.51 +/- 0.21 vs 1.36 +/- 0.16 and 1.26 +/- 0.23, respectively (P<0.05), indicating an impaired clearance of immune complexes in CIU-infected patients. In conclusion, no correlation was observed between H. pylori infection and autoantibody production in CIU patients consistent with reports of clinical studies.