Open Access Research

Chitotriosidase as a biomarker of cerebral adrenoleukodystrophy

Paul J Orchard1*, Troy Lund1, Wes Miller1, Steven M Rothman2, Gerald Raymond3, David Nascene4, Lisa Basso1, James Cloyd5 and Jakub Tolar1

Author Affiliations

1 Department of Pediatrics, Program in Blood & Marrow Transplantation, University of Minnesota, Minneapolis, USA

2 Department of Pediatrics, Program in Neurology, University of Minnesota, Minneapolis, USA

3 Department of Neurology, Kennedy Krieger Institute, Baltimore MD, USA

4 Department of Diagnostic Radiology, University of Minnesota, Minneapolis, USA

5 Department of Experimental and Clinical Pharmacology, Center for Orphan Drug Research, University of Minnesota, Minneapolis, USA

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Journal of Neuroinflammation 2011, 8:144  doi:10.1186/1742-2094-8-144

Published: 20 October 2011

Abstract

Background

Adrenoleukodystrophy (ALD) is an X-linked peroxisomal disorder characterized by the abnormal beta-oxidation of very long chain fatty acids (VLCFA). In 35-40% of children with ALD, an acute inflammatory process occurs in the central nervous system (CNS) leading to demyelination that is rapidly progressive, debilitating and ultimately fatal. Allogeneic hematopoietic stem cell transplantation (HSCT) can halt disease progression in cerebral ALD (C-ALD) if performed early. In contrast, for advanced patients the risk of morbidity and mortality is increased with transplantation. To date there is no means of quantitating neuroinflammation in C-ALD, nor is there an accepted measure to determine prognosis for more advanced patients.

Methods

As cellular infiltration has been observed in C-ALD, including activation of monocytes and macrophages, we evaluated the activity of chitotriosidase in the plasma and spinal fluid of boys with active C-ALD. Due to genotypic variations in the chitotriosidase gene, these were also evaluated.

Results

We document elevations in chitotriosidase activity in the plasma of patients with C-ALD (n = 38; median activity 1,576 ng/mL/hr) vs. controls (n = 16, median 765 ng/mL/hr, p = 0.0004), and in the CSF of C-ALD patients (n = 38; median activity 4,330 ng/mL/hr) vs. controls (n = 16, median 0 ng/mL/hr, p < 0.0001). In addition, activity levels of plasma and CSF chitotriosidase prior to transplant correlated with progression as determined by the Moser/Raymond functional score 1 year following transplantation (p = 0.002 and < 0.0001, respectively).

Conclusions

These findings confirm elevation of chitotriosidase activity in patients with active C-ALD, and suggest that these levels predict prognosis of patients with C-ALD undergoing transplantation.

Keywords:
biomarker; adrenoleukodystrophy; neuroinflammation; chitotriosidase