Elevation of Proenkephalin 143-183 in Cerebrospinal Fluid in Moyamoya Disease

Background: In moyamoya disease (MMD), the causes of differences in clinical features between children and adults and of the dramatic temporal changes in moyamoya vessels are poorly understood. We previously discovered elevated levels of m/z 4588 and m/z 4473 peptides in cerebrospinal fluid (CSF) in patients with MMD. This study examined the amino acid sequences of these peptides and quantified in specimens.

Methods: The m/z 4588 and m/z 4473 peptides in CSF from patients with MMD were purified and concentrated by high-performance liquid chromatography and ultrafiltration. Liquid chromatography coupled with tandem mass spectrometry analysis was performed to identify the amino acid sequences of these peptides. We quantified these peptides in samples using sandwich enzyme-linked immunosorbent assay, and concentrations in CSF were compared between MMD (n = 40, 19 male; median age, 37 years) and non-MMD intracranial disease (n = 40, 19 male; median age, 39 years) as controls.

Results: These peptides were identified as proenkephalin 143-183 (PENK 143-183). The concentration of PENK 143-183 was significantly greater in patients with MMD (median, 8,270 pmol/L) than control patients (median, 3,760 pmol/L; P < 0.001) and decreased in an age-dependent manner in MMD (r = -0.57; P < 0.001). The area under the receiver operating characteristic curve in children (age <18 years) was 0.885 (95% confidence interval 0.741-1). The correlation between proenkephalin concentration and temporal changes in moyamoya vessels was suggested.

Conclusions: Proenkephalin 143-183 in CSF may offer a helpful diagnostic biomarker in pediatric MMD. The effect of enkephalin peptides through opioid growth factor receptor or delta opioid receptor might be associated with the pathophysiology of MMD.