Retinol Binding Protein 4 in children with Inflammatory Bowel Disease: a negative correlation with the disease activity.

Objectives: Retinol Binding Protein-4 (RBP-4), the action of which was initially thought to be only the transport of vitamin A, is a major circulating adipocytokine involved in the inflammation. We evaluated the serum RBP-4 levels in children with inflammatory bowel disease (IBD) and correlated them with transthyretin (TTR), inflammation markers, disease activity, and body mass index (BMI).

Design: In 41 children of mean age 11.9 ± 3.6 years (range 5-17.7 y) with IBD (19 with Crohn's disease (CD) and 22 with Ulcerative colitis (UC) serum RBP-4, TTR, Amyloid A (SAA), C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR), disease activity and BMI were prospectively determined and compared with those of 42 matched controls.

Results: No difference in the RBP-4 and TTR serum levels, between patients and controls as well as between active and remission state of the disease was noticed. A negative correlation of serum RBP-4 with the disease activity, SAA and ESR and a positive correlation with TTR was found, but no significant correlation with CRP or BMI was found. Inflammation markers were significantly increased in patients compared to controls and had a positive correlation with the disease activity.

Conclusions: RBP-4 negatively correlated with disease activity of children with IBD probably indicating a protective anti-inflammatory mechanism of action in addition to transport of vitamin A.