Cerebrospinal fluid metabolomic pattern of different pituitary stalk lesions.

OBJECTIVES: To describe cerebrospinal fluid (CSF) metabolomic pattern of pituitary stalk lesions.

METHODS: CSF was collected from patients with different pituitary stalk lesions (germ cell tumor (GCT), n = 27; hypophysitis, n = 10; Langerhans cell histiocytosis (LCH) or Erdheim-Chester disease (ECD), n = 10) treated at Peking Union Medical College Hospital. CSF metabolome profiling was characterized through Liquid Chromatography-Mass Spectrometer (LC-MS).

RESULTS: 44 metabolites were significantly different between GCT and hypophysitis patients (P < 0.05). When comparing GCT (CSF beta subunit of human chorionic gonadotrophin (β-hCG) < 5 mIU/ml) with hypophysitis patients, there were 15 differential metabolites (P < 0.05, fold change > 1.5 or < 1/1.5). All the metabolites had the AUC (area under the curve) above 0.7. Besides, 9 metabolites were significantly different between GCT and LCH + ECD patients (P < 0.05) and 7 metabolites had significant differences between GCT (CSF β-hCG < 5 mIU/ml) and LCH + ECD patients (P < 0.05, fold change > 1.5 or < 1/1.5). 6 metabolites were significantly different between hypophysitis and LCH + ECD patients (P < 0.05) and 5 of them had fold change more than 1.5 or less than 1/1.5. Three metabolites, 5-deoxydiplosporin, cloversaponin I and phytosphingosine, showed excellent capabilities to differentiate three diseases. Furthermore, we determined 67 metabolites associated with clinical test results (ρ > 0.2, P < 0.05) and 29 metabolites showed strong correlation (ρ > 0.4, P < 0.05).

CONCLUSIONS: Our study is the first to systematically investigate the metabolomics of CSF in different pituitary stalk lesions. CSF metabolomics is a useful strategy for biomarker discovery.