Association between Helicobacter pylori infection and fibromyalgia syndrome

Abstract

Dear Editor, In the paper by Akkaya N, et al., Helicobacter pylori (H. pylori) infection was evaluated in 65 patients with fibromyalgia syndrome (FM) and in 41 healthy controls, using two different serological methods [1]. In particular, the authors used anti-H. pylori IgA antibodies, a serological test with unacceptably low sensitivity (63.4%) and specificity (67.6%), yielding a poor overall accuracy of 67.2% in all ages [2]. Furthermore, it was demonstrated that this test possesses an even lower overall accuracy rate in the ages over 18 years (51.8%) [2], thereby rendering it practically useless and a waste of time and resources for the patients evaluated in the study by Akkaya N, et al. [1]. Therefore, this comes to no surprise why the authors found no significant difference in the prevalence of H. pylori IgA antibodies between their FM patients and controls (p=0.169) [1]. It would be interesting to know why the authors chose this particular test for their study in spite of its poor performance shown before. On another aspect, the authors reported that they found no statistically significant differences regarding mainly the clinical features (sleep disturbance, fatigue, stiffness, headache, subjective soft-tissue swelling, paresthesia, dysmenorrhea, female urethral syndrome, irritable bowel syndrome, and anxiety), anxiety and depression subscale of Fibromyalgia Impact Questionnaire, history of depression, and previous treatment for depression between the two study groups (FM patients and controls) [1]. We believe that this is a paradox, since one would expect that FM patients with a higher prevalence of H. pylori infection (according to the H. pylori IgG serology) should present with more profound clinical features compared with a group of healthy controls. This paradox, however, can be explained by the fact that although this serological test establishes the presence of previous H. pylori infection, it does not discriminate between current and old infections. Such a distinction is crucial because only current H. pylori infection induces both humoral and cellular immune responses that cross-react with host components, owing to the sharing of homologous epitopes (molecular mimicry), thereby contributing and/or perpetuating tissue damage [3], and possibly, the development of the clinical features of FM; immunological (cellular/humoral) responses are increasingly recognized as being essential in the initiation and progression of FM syndrome [4]. Moreover, eradicating H. pylori infection might delay the progression of this disease, particularly at earlier stages. Thus, it would be interesting to know why the authors chose a serological IgG test, instead of histology, the practical gold standard for the diagnosis of current H. pylori infection, or at least the C-urease breath test, the noninvasive test of choice for H. pylori infection. Although the latter test requires fasting, false-negative results may occur if antibiotics have been used within the previous 4 weeks and false-positive results can occur from urease present in the mouth [5], this is considered a reliable alternative to the histologic method for the detection of H. pylori infection. By using these two methods signifying active H. pylori infection, the authors C. Zavos : J. Kountouras : P. Katsinelos : S. A. Polyzos : G. Deretzi :N. Zavos : E. Gavalas : I. Pilpilidis :D. Tzilves Department of Gastroenterology, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece