Obesity and response to biological therapy in rheumatoid arthritis: the role of body mass index and adipose tissue cytokines.

OBJECTIVES: To analyse the role of body mass index (BMI) in the clinical response to biologic dis-ease-modifying anti-rheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA). To per-form an in-depth analysis of the pathophysiology of obesity by assessing serum adipokine levels and their potential changes according to treatment. METHODS: This study involved 105 patients with RA starting tumour necrosis factor inhibitors (TNFi) or tocilizumab (TCZ). Patients were classified ac-cording to BMI as normal-weight and overweight/obesity. The clinical response to treatment was as-sessed by Clinical Disease Activity Index (CDAI) 6 months after initiation of bDMARDs. Serum adi-pokines (leptin and adiponectin) were determined using a commercial immunoassay kit in samples ob-tained before initiation of bDMARDs and after 6 months of treatment. RESULTS: A correlation was observed between BMI and disease activity and between BMI and serum adipokines. Sixty percent of patients achieved low disease activity (LDA)/remission: 45 patients in TNFi group (64.2%) and 18 (51.4%) in TCZ group. In TNFi group, patients who did not attain LDA/remission had a higher BMI (kg/m2) ([28.7±5.1] vs. [24.5±4.6], p=0.001) and baseline CDAI (26.3 [17.4-33.9] vs. 19.8 [14.0-28.8], p<0.03). However, no differences in BMI or baseline CDAI were observed between patients who achieved LDA after 6 months in TCZ group. CONCLUSIONS: Obesity influences the extent of LDA/remission in patients treated with TNFi, but not in patients treated with TCZ, probably because of underlying pathophysiological mechanisms intrinsic to the production of proinflammatory adi-pokines. Therefore, therapeutic strategies with a mechanism of action other than TNF inhibition would be more suitable for obese patients.

Asymmetric dimethylarginine but not osteoprotegerin correlates with disease severity in patients with moderate-to-severe psoriasis undergoing anti-tumor necrosis factor-α therapy.

Patients with psoriasis, in particular those with severe disease, have an increased risk of cardiovascular (CV) events compared with the general population. The aim of the present study is to determine whether correlation between asymmetric dimethylarginine (ADMA) and osteoprotegerin (OPG), two biomarkers associated with CV disease, and disease severity may exist in patients with moderate-to-severe psoriasis. We also aimed to establish if baseline serum levels of these two biomarkers could correlate with the degree of change in the clinical parameters of disease severity following the use of anti-tumor necrosis factor (TNF)-α therapy in these patients. This was a prospective study on a series of consecutive non-diabetic patients with moderate-to-severe psoriasis who completed 6 months of therapy with anti-TNF-α-adalimumab. Patients with kidney disease, hypertension or body mass index of 35 kg/m(2) or more were excluded. Metabolic and clinical evaluation was performed immediately prior to the onset of treatment and at month 6. Twenty-nine patients were assessed. Unlike OPG, a significant positive correlation between ADMA and resistin serum levels was found at the onset of adalimumab and also after 6 months of biologic therapy. We also observed a positive correlation between the percent of body surface area affected (BSA) and ADMA levels obtained before the onset of adalimumab and a negative correlation between baseline ADMA levels and a 6-month BSA change compared with baseline results. In patients with moderate-to-severe psoriasis, ADMA levels correlate with clinical markers of disease severity.