The effect of heat-inactivated Helicobacter pylori on the blastogenic response of peripheral blood mononuclear cells of patients with chronic urticaria

Background: Helicobacter pylori, the most important etiologic factor of gastritis and peptic ulcer, has recently been associated with several extradigestive diseases. Previous studies reported conflicting results on H. pylori eradication in chronic urticaria, in that some studies showed a benefit, while others found no effect. Methods: Peripheral blood mononuclear cells of 24 chronic urticaria patients (13 seropositive/11 seronegative for H. pylori) and 18 healthy controls (9 seropositive/9 seronegative) were stimulated with whole heat-inactivated H. pylori (8 x 10(5), 8 x 10(6) and 8 x 10(7) bacteria/well), phytohemagglutinin (2 mug/ml) and pokeweed mitogen (5 mug/ml). The proliferative response was determined by H-3-thymidine incorporation. Helicobacter-specific IgG antibody response was determined by ELISA. Results: There were significantly higher proliferative responses to various concentrations of whole heat-inactivated H. pylori antigen in 6- to 7-day cultures of peripheral blood mononuclear cells of chronic urticaria patients compared to healthy controls. We found a tendency to exhibit a higher proliferative response to either Helicobacter antigens or mitogens in seropositive compared to seronegative patients. Conclusion: Our results support the hypothesis that there is an increased lymphocyte reactivity in chronic urticaria, perhaps further enhanced by the presence of H. pylori which, therefore, may be involved as a trigger in the pathogenesis of chronic urticaria. Copyright (C) 2001 S. Karger AG, Basel.