Neuropeptides in saliva of subjects with burning mouth syndrome: a pilot study

A neuropathic basis has been suggested for burning mouth syndrome (BMS) and an altered concentration of neuropeptides has been reported in lingual oral mucosa and saliva in this disease. The aims of this study were to compare the levels of nerve growth factor (NGF), substance P (SP) and degranulation products from mast cells and neutrophils in the saliva of BMS subjects with those of control subjects.

Salivary flow rate, protein concentration, NGF peptide and mRNA, SP, mast cells tryptase, neutrophil myeloperoxidase and calprotectin were analyzed in saliva of 20 BMS subjects and of 20 age- and gender-matched healthy subjects.

NGF peptide and tryptase activity were shown to be significantly and persistently higher in saliva of BMS subjects, with respect to control values. Conversely the salivary levels of SP were shown to be significantly lower, while neutrophil markers didn't show any change. We conclude that the neuropathic origin of the disease is confirmed at salivary level. Furthermore, the higher tryptase activity indicates a possible involvement of mast cells. The salivary neuropeptide concentration in BMS subjects, together with mast cell derived compounds, could be useful biomarkers for diagnosis and monitoring of this disease.