Antitumour necrosis factor α treatment reduces retinol-binding protein 4 serum levels in non-diabetic ankylosing spondylitis patients

Increased cardiovascular (CV) mortality due to accelerated atherosclerosis occurs in ankylosing spondylitis (AS) patients.1 ,2 Beneficial effects of antitumour necrosis factor (anti-TNF)-α agents on disease activity and endothelial cell activation were reported in AS.3 ,4 Dramatic reduction of insulin resistance (IR) and improvement of insulin sensitivity after infliximab administration were also described in non-diabetic AS patients.5 We aimed to assess, for the first time, whether infliximab administration in AS patients may alter levels of retinol-binding protein 4 (RBP-4), a protein released from adipocytes, considered as an emerging cardiometabolic risk factor, which correlates with IR in individuals with obesity, impaired glucose tolerance or type 2 diabetes, and in non-obese subjects with or without family history of type 2 diabetes.6–⇓8 RBP-4 serum levels were measured by ELISA (Phoenix Pharmaceuticals, EK-028-28) in 30 consecutive non-diabetic and mostly non-obese AS patients without history of CV events before and after an infliximab infusion. Local institutional committee approval and patients’ informed consent were obtained. Information on blood sample determinations in this cohort was previously reported.9 Infliximab was given as an intravenous infusion in saline solution over 120 min.5 Measurements were made in …