Tocilizumab Increases Serum Adiponectin and Reduces Serum Fatty Acid Binding Protein 4 in Patients With Rheumatoid Arthritis

Abstract

Background: Recently tocilizumab, a humanized anti-interleukin-6 receptor antibody (IL-6R Ab), was clinically demonstrated to ameliorate metabolic syndrome. However, it is unknown whether blocking the IL-6R with tocilizumab directly impacts the adiponectin and fatty acid-binding protein 4 (FABP4) levels. Methods: In this study, we measured the serum adiponectin and FABP4 levels in 18 patients with rheumatoid arthritis (RA) 3 months after treatment with tocilizumab. Results: Our study revealed that treatment with tocilizumab decreased serum FABP4 levels and increased serum adiponectin levels in patients with RA. We also assessed the production of adipocytokines stimulated by IL-6R Ab using adipocyte precursors obtained from human fat tissue. Tocilizumab did not increase local adiponectin levels; however, the suppression of adiponectin secretion by IL-6 was completely abolished. Tocilizumab also directly suppressed FABP4 in human adipocytes. Conclusion: This suggests that treatment with tocilizumab may be a novel approach to coordinately regulate adiponectin and FABP4 levels. J Endocrinol Metab. 2014;4(5-6):143-147 doi: http://dx.doi.org/10.14740/jem251w