Open Access Research
H. pylori infection and rheumatoid factor: a possible immunopathological association
Raghdah Naser Mohsin1,*
, Rand Hatam Kalo2, Naseer Jumaa Abdulhasan3, Sabreen Hammoudi Hamzah4, Zahraa Khalid Salih5
1Department of Medical Laboratory Techniques, College of Health and Medical Techniques, Al-Bayan University, Baghdad, Iraq
2Department of Medical Laboratory Techniques, Ibn Khaldoun University College, Baghdad, Iraq
3Department of Medical Laboratory Techniques, Ibn Khaldoun University College, Baghdad, Iraq
4Department of Medical Laboratory Techniques, Ibn Khaldoun University College, Baghdad, Iraq
5College of Science for Women, University of Baghdad, Baghdad, Iraq
*Corresponding author: Raghdah Naser Mohsin, Department of Medical Laboratory Techniques, College of Health and Medical Techniques, Al-Bayan University, Baghdad, Iraq; Tel.: +9647721049270; e-mail: raghdah.n@albayan.edu.iq
Download PDF
Published: 2026 ; https://doi.org/10.61873/
Abstract
Background: Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonises the gastric mucosa and is a well-established cause of chronic gastritis and peptic ulcer disease. Chronic infection triggers persistent immune activation and has been proposed as a potential contributor to systemic autoimmune responses, including the production of rheumatoid factor (RF). The immunopathological mechanisms potentially involved include molecular mimicry, polyclonal B-cell activation, and sustained pro-inflammatory cytokine release. However, the evidence linking H. pylori infection to RF positivity remains inconclusive. Aim: To investigate the prevalence of H. pylori infection using a two-step serological screening and stool antigen confirmation approach, and to assess RF positivity among confirmed-positive patients presenting with gastrointestinal complaints in Baghdad, Iraq. Methodology: A cross-sectional study was conducted on 84 adult patients presenting with mild-to-severe gastrointestinal symptoms at internal medicine clinics across several districts of Baghdad. All 84 patients underwent serological screening for H. pylori infection using a rapid serum antibody test. The 33 seropositive patients subsequently underwent confirmatory stool antigen testing (HIGHTOP One Step Rapid Test, HP AG), all of whom were confirmed to have active H. pylori infection. RF testing was then performed on these 33 confirmed-positive patients. The 51 seronegative patients did not undergo further testing, which represents a limitation of the study design. Results: Of the 84 patients screened serologically, 33 (39.3%) were seropositive and subsequently confirmed antigen-positive. Among these 33 patients, 7 (21.2%) were RF-positive (≥ 8 IU/mL) and 26 (78.8%) were RF-negative. As RF was not tested in the seronegative group, no between-group statistical comparison was performed. Conclusion: RF positivity was detected in a subset of patients with confirmed active H. pylori infection identified by a two-step testing approach. As RF was not assessed in the seronegative group, no definitive conclusion regarding an association between H. pylori infection and RF positivity can be drawn. Further controlled studies are required.
Keywords: rheumatoid factor (RF), Helicobacter pylori, stool antigen test, autoimmune response, Iraqi patients
Please cite as: Mohsin R. N., Kalo R. H., Abdulhasan N. J., Hamzah S. H., Salih Z. K.: H. pylori infection and rheumatoid factor: a possible immunopathological association. Epitheorese Klin. Farmakol. Farmakokinet. xx(xx): xx-xx (2026). DOI: 10.61873/XXXXXXX
pISSN 1011-6575 • eISSN 2945-1914