Anti-TNF-α therapy reduces retinol-binding protein 4 serum levels in non-diabetic patients with psoriasis: a 6-month prospective study

Background Retinol-binding protein-4 (RBP4), an adipokine considered as an emerging cardiometabolic risk factor, is increased in patients with moderate-to-severe psoriasis. Objective In this study, we aimed to establish the effect of anti-TNF-alpha therapy on RBP4 levels in patients with moderate- to-severe psoriasis. We also assessed if RBP4 levels correlate with metabolic syndrome features and disease severity in these patients. Methods Prospective study on a series of consecutive non-diabetic patients with moderate-to-severe psoriasis who completed 6 months of therapy with adalimumab. Patients with kidney disease, hypertension or body mass index >= 35 kg/m(2) were excluded. Metabolic and clinical evaluation was performed at the onset of treatment (time 0) and at month 6. Results Twenty-nine patients were assessed. Statistically significant reduction (P = 0.0001) of RBP4 levels was observed after 6 months of therapy (RBP4 at time 0: 55.7 +/- 21.4 mu g/mL, vs. 35.6 +/- 29.9 mu g/mL at month 6). No significant correlation between basal RBP4 levels and metabolic syndrome features or disease severity was found. Nevertheless, although RBP4 levels did not correlate with insulin resistance, a negative and significant correlation between RBP4 levels obtained after 6 months of adalimumab therapy and other metabolic syndrome features such as abdominal perimeter and body mass index were observed. At that time, a negative and significant correlation between RBP4 levels and disease activity scores and ultrasensitive CRP levels was also disclosed. Conclusion Our results support an influence of the anti-TNF-alpha blockade on RBP4 serum levels. This finding is of potential relevance due to increased risk of cardiovascular disease in patients with psoriasis.