Cystathionine Levels in Patients With Huntington Disease

Background: Recently a profound depletion of cystathionine γ-lyase (CSE), the principal enzyme involved in the generation of cysteine from cystathionine, was shown in Huntington disease (HD) patients and several transgenic HD mouse models. We therefore hypothesized that blood and urine cystathionine levels may be increased in HD patients and that this increase might correlate with disease progression. Methods: We measured concentrations of cystathionine as well as 22 other amino acids in fasting plasma and 24-h urine samples of nine early-stage HD patients and nine age, sex, and body mass index matched controls. Results: There were no significant differences in the plasma or urine concentrations of cystathionine or any other amino acid between HD patients and controls. Conclusion: We found no evidence for changes in plasma or urine concentrations of cystathionine in early-stage HD patients. Therefore, cystathionine levels are unlikely to be useful as a state biomarker in HD.