Increased nerve growth factor serum levels in top athletes.

OBJECTIVE: The nerve growth factor (NGF) is the main neurotrophin, which, besides being an important growth factor for nerves, plays an important role as a mediator of inflammation. Nerve growth factor has been shown to increase in relation to stress stimuli and in allergic diseases in humans as well as after physical exercise in animal models. This study aims at evaluating NGF serum levels in top athletes, a population sample in which allergic and neuro-immune diseases are reported with a significantly increased prevalence. DESIGN: Observational, cross-sectional, multicenter study. SETTING: Institutional, tertiary care. PARTICIPANTS: Ninety-six Italian pre-Olympic athletes (44 allergic and 52 nonallergic) and 49 matched controls selected within the Italian National Olympic delegation (n = 435). INDEPENDENT VARIABLES: Nerve growth factor serum levels determined through an enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: Parametric or nonparametric tests were used for comparing NGF serum levels among different study groups depending on value distributions. RESULTS: Nerve growth factor serum levels were significantly higher in athletes than in controls independently from the presence of allergy. Nerve growth factor mean values were 368.3 ± 776.3 pg/mL in the sample of athletes and 174.1 ± 483.7 pg/mL in the control group (P < 0.001). CONCLUSIONS: This is the first study showing that intense and prolonged physical exercise is associated with an increase of NGF serum levels in athletes. Whether the increased NGF production might be linked to the prevalent Th2 response observed in allergic diseases and after physical exercise and whether it might be related to the patophysiology of neuro-immune disorders as such amyotrophic lateral sclerosis, reported with a higher prevalence in athletes, should deserve further investigations.

Urinary profile of methylprednisolone acetate metabolites in patients following intra-articular and intramuscular administration.

A study on urinary metabolites of methylprednisolone acetate (MPA) has been performed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in precursor ion scanning (PIS) and neutral loss (NL) modes. Patients suffering from joint inflammation have been treated with Depo-Medrol® (MPA marketed suspension, 40 mg) intra-articularly (IA) and after a wash-out period, intramuscularly (IM) at the same dose. Urine samples have been collected after both the administration routes. Metabolites were identified in PIS mode by setting the fragment ion at m/z 161 which is specific for MPA, methylprednisolone (MP), methylprednisolone hemisuccinate, and in NL mode by selecting the losses of 54, 72, 176 and 194 Da. The MP-related structure of each target ion detected in both the MS modes was then confirmed by MS/MS acquisitions, and by accurate mass experiments. By using this approach, 13 MPA metabolites (M1-M13) have been identified, nine already reported in the literature and four unknown and for which the chemical structures have been proposed. No differences in the metabolic pattern of MPA when administered IM or IA were observed. The relative abundances of metabolites compared with the internal standard (MP-D2) were monitored by multiple reaction monitoring analysis for 19 days after both the administration routes.