Role of interleukin-35 in rheumatoid arthritis pathogenesis and its relation to disease activity and joint damage

Abstract

Aim This study aimed to discuss the role of interleukin-35 (IL-35) in the pathogenesis of rheumatoid arthritis (RA) and its relation to disease activity and radiological severity. Patients and methods Thirty patients diagnosed with RA were selected from the outpatient clinic and inpatient unit of Physical Medicine, Rheumatology and Rehabilitation Department, Tanta University Hospitals fulfilling the American College of Rheumatology/European League Against Rheumatism 2010 criteria for the diagnosis of RA, and 20 apparently healthy individuals who were matched in age and sex participated as controls. Patients with other autoimmune diseases, malignancy, or any current infections were excluded. Disease activity score in 28 joints was assessed for all patients. Rheumatoid factor, anticyclic citrullinated peptide, complete blood count, erythrocyte sedimentation rate and C-reactive protein and serum level of IL-35 measured by enzyme-linked immunosorbent assay were evaluated. The degree of joint destruction was assessed by Larsen score. Results Of the RA patients, 73.3%showed low serum levels of IL-35 with significant difference compared with controls, and its levels showed negative association with disease activity. IL-35 serum levels were significantly correlated with hemoglobin level, erythrocyte sedimentation rate, C-reactive protein, and rheumatoid factor and not correlated with anticyclic citrullinated peptide antibodies. Also IL-35 serum levels significantly correlated with radiological disease severity were assessed by Larsen score. Conclusion IL-35 had an immunoregulatory role in RA pathogenesis as its serum level is significantly low in RA patients and correlated with different parameters of disease activity and radiological severity.

Keywords

• disease activity and severity
• interleukin-35
• pathogenesis
• rheumatoid arthritis