A longitudinal observation of Brain-Derived Neurotrophic Factor mRNA levels in patients with Relapsing-Remitting Multiple Sclerosis

This report is part of a 2-year study assessing the functional effect of Brain-Derived Neurotrophic Factor (BDNF) and its Va166Met polymorphism on a selected population of Relapsing-Remitting Multiple Sclerosis (RRMS) patients from Southern Italy. For this purpose, we measured the peripheral BDNF expression in ARMS patients compared to healthy controls. The influence of concomitant IFN beta therapy was also evaluated. Thirty-six inactive ARMS patients and 37 healthy controls were genotyped for BDNF Va166Met, and total RNA was extracted at time-points 0-24 months. The BDNF level was quantified by ABI Prism 7900 HT Sequence Detection System, and its relative expression was calculated by the comparative method of 2-(Delta Delta Ct). At baseline and after 24 months, the BDNF levels of ARMS patients resulted significantly higher than controls (p=0.001), independently of the concomitant IFN beta treatment; no correlations were found with the investigated clinical and MRI features of MS. Otherwise, carriers of the Met-allele showed significantly higher levels of BDNF in ARMS patients than healthy controls (p=0.005). These data was replicated after a 24-month interval. The present study confirms the increased levels of peripheral BDNF levels in ARMS, even during the inactive phase of the disease. Although with caution due to the small sample size, it also underscores the potential role of the Va166Met polymorphism on the peripheral BDNF expression in ARMS. Functional studies are needed to better clarify this issue. (C) 2008 Elsevier B.V. All rights reserved.