Quantitative spectroscopic imaging predicts outcome in MLD patients
Use of proton magnetic resonance spectroscopic imaging at baseline predicts clinical course of patients with metachromatic leukodystrophy (MLD) and helps identify those eligible for haematopoietic cell transplantation (HCT), according to a retrospective study.
Sixteen of 21 patients with baseline scans (five with good, three with moderate and eight with poor outcome) met the inclusion criteria and were compared with 16 controls in the same age group.
There were significant differences for all metabolite concentrations in white matter for all groups (p<0.001). Patients with MLD, compared with controls, had reduced N-acetylaspartate and glutamate, as well as increased myo-inositol and lactate, which was most pronounced in those with poor outcome (p<0.05 for all posthoc).
Logistic regression demonstrated complete data separation. Creatinine could distinguish poor from moderate and good outcome. The sum of glutamate and glutamine could differentiate from moderate and poor outcome. In addition, N-acetylaspartate could characterize all outcome groups.
The authors evaluated one or more follow-up examinations for 13 patients (eight with baseline scans), which showed stabilization or even partial normalization of metabolites among those with moderate and good outcome, clearly visible in the ratio of choline/N-acetylaspartate.
Of the 21 patients with juvenile or adult MLD included in this study, 12 were HCT-treated. The authors determined clinical outcome as good, moderate or poor. They also quantified metabolites in white matter and examined the significance of metabolite concentrations at baseline for outcome prediction using logistic regression analysis. Evolution of metabolic changes were assessed for patients with follow-up examinations.
MLD is an inherited white matter disorder that can be treated with HCT, according to the authors.