Serum concentrations of VEGF and bFGF in the course of propranolol therapy of infantile hemangioma in children: Are we closer to understand the mechanism of action of propranolol on hemangiomas?

BACKGROUND: Propranolol has become the treatment of choice for infantile hemangiomas (IH). Neither the pathogenesis of IH nor the mechanism of action of propranolol on them are well understood. Possible explanations include the inhibition of angiogenesis by decreasing vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), induction of vascular endothelial cell apoptosis and vasoconstriction.

OBJECTIVES: The aim of the study was to assess serum concentrations of VEGF and bFGF in the course of propranolol therapy of IH in children, and to assess their clinical implications.

MATERIAL AND METHODS: The study included 51 children with IH treated with propranolol. The participants were assessed before, during and after the therapy with Hemangioma Activity Score (HAS), Doppler ultrasound (US) of the lesions, as well as VEGF and bFGF serum concentrations.

RESULTS: All children showed clinical improvement measured in the HAS. A complete involution of the IH was reported in 32 (63%) children at the time of decision of the gradual withdrawing of propranolol, and in 28 (61%) patients at the end of the treatment (out of 46 patients present at the follow up after 1.5 months). Doppler US at the follow-up showed a complete disappearance of the blood flow in the lesion in 24 (52%) children and its reduction in 12 (26%) children. There was a significant decrease in VEGF and bFGF during and after treatment compared to pretreatment values. There was a correlation between the outcome of the Doppler US and changes in bFGF during and after treatment. Changes in VEGF during treatment did not correlate with changes in the Doppler US.

CONCLUSIONS: Serum concentrations of VEGF and bFGF decreased during the propranolol treatment of IH, which may indicate the effect of propranolol on both. However, the statistical analysis showed their low prognostic value as biochemical markers of propranolol treatment. Clinical evaluation combined with Doppler US is the most valuable method of monitoring the therapy.