Traditional biomarkers in narcolepsy: experience of a Brazilian sleep centre.

UNLABELLED: This study was thought to characterized clinical and laboratory findings of a narcoleptic patients in an out patients unit at São Paulo, Brazil.

METHOD: 28 patients underwent polysomnographic recordings (PSG) and Multiple Sleep Latency Test (MSLT) were analyzed according to standard criteria. The analysis of HLADQB1*0602 allele was performed by PCR. The Hypocretin-1 in cerebral spinal fluid (CSF) was measured using radioimmunoassay. Patients were divided in two groups according Hypocretin-1 level: Normal (N) - Hypocretin-1 higher than 110 pg/ml and Lower (L) Hypocretin-1 lower than 110 pg/ml.

RESULTS

Only 4 patients of the N group had cataplexy when compared with 14 members of the L group (p = 0.0002).

DISCUSSION: This results were comparable with other authors, confirming the utility of using specific biomarkers (HLA-DQB1*0602 allele and Hypocretin-1 CSF level) in narcolepsy with cataplexy. However, the HLADQB1*0602 allele and Hypocretin-1 level are insufficient to diagnose of narcolepsy without cataplexy.