Helicobacter pylori--a trigger of reactive arthritis?

Four cases of reactive arthritis (ReA) related to Helicobacter pylori (HP) are presented. These were identified by IgG, IgM and IgA ELISA tests performed on sera obtained from a 2-year prospective study on 186 patients with a clinical picture suggesting ReA as a possible diagnosis. If anti-HP IgM and IgA or IgG were positive, the case was considered related to HP. Three out of four HP ReA patients were originally classified as "possible ReA", i.e. having a clinical picture of ReA but without any identified triggering microorganism. IgG antibodies against cagA and vacA were detected in three and two cases respectively. The HP ReA patients did not present with typical clinical or laboratory features differentiating them from ReA induced by Chlamydia trachomatis (N = 25) or enteropathogenic bacteria (N = 27). However, compared to findings in patients with ReA due to enteropathogenic bacteria the number of active joints was higher (six versus two), duration of arthritis longer (3.9 weeks versus 2 weeks) and the CRP (C-reactive protein) lower (43 versus 59). Our findings suggest that HP may be included in the list of possible arthritis triggering microbes.