Application of a glycinated bile acid biomarker for diagnosis and assessment of response to treatment in Niemann-pick disease type C1.

Abstract

Niemann-Pick disease type C (NPC) is a neurodegenerative disease in which mutation of NPC1 or NPC2 gene leads to lysosomal accumulation of unesterified cholesterol and sphingolipids. Diagnosis of NPC disease is challenging due to non-specific early symptoms. Biomarker and genetic tests are used as first-line diagnostic tests for NPC. In this study, we developed a plasma test based on N-(3β,5α,6β-trihydroxy-cholan-24-oyl)glycine (TCG) that was markedly increased in the plasma of human NPC1 subjects. The test showed sensitivity of 0.9945 and specificity of 0.9982 to differentiate individuals with NPC1 from NPC1 carriers and controls. Compared to other commonly used biomarkers, cholestane-3β,5α,6β-triol (C-triol) and N-palmitoyl-O-phosphocholine (PPCS, also referred to as lysoSM-509), TCG was equally sensitive for identifying NPC1 but more specific. Unlike C-triol and PPCS, TCG showed excellent stability and no spurious generation of marker in the sample preparation or aging of samples. TCG was also elevated in lysosomal acid lipase deficiency (LALD) and acid sphingomyelinase deficiency (ASMD). Plasma TCG was significantly reduced after intravenous (IV) 2-hydroxypropyl-β-cyclodextrin (HPβCD) treatment. These results demonstrate that plasma TCG was superior to C-triol and PPCS as NPC1 diagnostic biomarker and was able to evaluate the peripheral treatment efficacy of IV HPβCD treatment.

• Authors: Rohini Sidhu, Pamela Kell, Dennis J Dietzen, Nicole Y Farhat, An Ngoc Dang Do, Forbes D Porter, Elizabeth Berry-Kravis, Janine Reunert, Thorsten Marquardt, Roberto Giugliani, Charles M Lourenço, Raymond Y Wang, Nina Movsesyan, Ellen Plummer, Jean E Schaffer, Daniel S Ory, Xuntian Jiang
• Journal: Molecular genetics and metabolism (Mol Genet Metab) Vol. 131 Issue 4 Pg. 405-417 (12 2020) ISSN: 1096-7206 [Electronic] United States
• PMID: 33257258 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 Elsevier Inc. All rights reserved.

Chemical References

• Bile Acids and Salts
• Biomarkers
• Intracellular Signaling Peptides and Proteins
• NPC1 protein, human
• NPC2 protein, human
• Niemann-Pick C1 Protein
• Vesicular Transport Proteins
• 2-Hydroxypropyl-beta-cyclodextrin
• Glycine

Topics

• 2-Hydroxypropyl-beta-cyclodextrin (administration & dosage)
• Bile Acids and Salts (blood)
• Biomarkers (blood)
• Female
• Glycine (analogs & derivatives, blood, isolation & purification)
• Humans
• Intracellular Signaling Peptides and Proteins (genetics)
• Male
• Niemann-Pick C1 Protein
• Niemann-Pick Disease, Type C (blood, drug therapy, genetics, pathology)
• Tandem Mass Spectrometry
• Vesicular Transport Proteins (genetics)