Obesity in autoimmune diseases: Not a passive bystander

• Published in: Autoimmunity reviews Vol. 13; no. 9; pp. 981 - 1000
• Main Authors: Versini, Mathilde, Jeandel, Pierre-Yves, Rosenthal, Eric, Shoenfeld, Yehuda
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2014
• Subjects: Adipokines; Allergy and Immunology; Animals; Autoimmune diseases; Autoimmune Diseases - complications; Autoimmune Diseases - immunology; Autoimmunity; Humans; Inflammation - immunology; Obesity; Obesity - complications; Obesity - immunology; Overweight; Risk Factors; Thyroid Gland - immunology; White adipose tissue; CRP; RR; Autoimmunity; TNFα; Anti-Tg; T1D; iNK cells; HR; IBD; WAT; HT; ACPA; SLE; UC; Overweight; CSF; BMI; Th17 cells; IFNγ; Anti-TPO; CD; Obesity; PASI; IL; OR; White adipose tissue; AIM; ESR; MS; T2D; EAE; TSH; Adipokines; CCL; PBMC; RA; ACR; HAQ; NLRP3-inflammasome; Treg cells; Foxp3; HLA; Autoimmune diseases; TAI; PsA; C-reactive protein; anti-thyroglobulin antibodies; invariant natural killer T cells; odds ratio; Psoriasis Area and Severity Index; Health Assessment Questionnaire; cerebro-spinal fluid; experimental autoimmune encephalomyelitis; Forkhead box protein 3; ulcerative colitis; interferon gamma; human leukocyte antigen; body mass index; thyroid autoimmunity; chemokine ligand; rheumatoid arthritis; inflammatory bowel disease; relative risk; Anti-citrullinated protein antibodies; psoriatic arthritis; white adipose tissue; apoptosis inhibitor of macrophage; NOD-like receptor protein 3-inflammasome; systemic lupus erythematosus; tumor necrosis factor alpha; American College of Rheumatology; interleukin; T-helper 17 cells; erythrocyte sedimentation rate; T-regulatory cells; type-2 diabetes; multiple sclerosis; Crohn's disease; thyroid-stimulating hormone; Hashimoto thyroiditis; hazard ratio; anti-thyroperoxydase antibodies; type-1 diabetes; peripheral blood mononuclear cell
• ISSN: 1568-9972; 1873-0183
• DOI: 10.1016/j.autrev.2014.07.001

In the last decades, autoimmune diseases have experienced a dramatic increase in Western countries. The involvement of environmental factors is strongly suspected to explain this rise. Particularly, over the same period, obesity has followed the same outbreak. Since the exciting discovery of the secretory properties of adipose tissue, the relationship between obesity and autoimmunity and the understanding of the underlying mechanisms have become of major interest. Indeed, the fat tissue has been found to produce a wide variety of “adipokines”, involved in the regulation of numerous physiological functions, including the immune response. By conducting a systematic literature review, we extracted 329 articles regarding clinical, experimental and pathophysiological data on the relationship between obesity, adipokines – namely leptin, adiponectin, resistin, visfatin – and various immune-mediated conditions, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), multiple sclerosis (MS), type-1 diabetes (T1D), psoriasis and psoriatic arthritis (PsA), and thyroid autoimmunity (TAI), especially Hashimoto thyroiditis (HT). The strongest levels of evidence support an increased risk of RA (OR=1.2–3.4), MS (OR=2), psoriasis and PsA (OR=1.48–6.46) in obese subjects. A higher risk of IBD, T1D and TAI is also suggested. Moreover, obesity worsens the course of RA, SLE, IBD, psoriasis and PsA, and impairs the treatment response of RA, IBD, psoriasis and PsA. Extensive clinical data and experimental models demonstrate the involvement of adipokines in the pathogenesis of these autoimmune diseases. Obesity appears to be a major environmental factor contributing to the onset and progression of autoimmune diseases.