O066. Kynurenine pathway metabolites in cluster headache

In this preliminary study we enrolled 14 cluster headache patients (CH, 13 males) and 15 age-matched healthy controls (HC, 14 males). We developed a HPLC tandem mass spectrometry method to assess the serum concentrations of KYNA, QUINA, Anthranilic acid and Kynurenine. Kynurenine serum levels resulted not significantly different between the groups (HC 0.33±0.1 and CH 0.35±0.14; Z= -0.53, p = 0.597), while both QUINA, KYNA and Anthranilic Acid were significantly reduced in cluster headache patients with respect to healthy controls (QUINA: HC 18.94±5.24 and CH 3.14±4.87; Z= -4.38, p < 0.001; KYNA: HC 3.53±1.33 and CH 2.53±1.20; Z= -12.45, p = 0.041; Anthranilic Acid: HC 1.28±1.14 and CH 0.17±0.06; Z= -4.46, p < 0.001). These results highlight that the endogenous regulation of the glutamatergic transmission in cluster headache might play an important role in its pathophysiology. Written informed consent to publication was obtained from the patient(s).