Cystatin C: A Candidate Biomarker for Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurologic disease characterized by progressive motor neuron degeneration. Clinical disease management is hindered by both a lengthy diagnostic process and the absence of effective treatments. Reliable panels of diagnostic, surrogate, and prognostic biomarkers are needed to accelerate disease diagnosis and expedite drug development. The cysteine protease inhibitor cystatin C has recently gained interest as a candidate diagnostic biomarker for ALS, but further studies are required to fully characterize its biomarker utility. We used quantitative enzyme-linked immunosorbent assay (ELISA) to assess initial and longitudinal cerebrospinal fluid (CSF) and plasma cystatin C levels in 104 ALS patients and controls. Cystatin C levels in ALS patients were significantly elevated in plasma and reduced in CSF compared to healthy controls, but did not differ significantly from neurologic disease controls. In addition, the direction of longitudinal change in CSF cystatin C levels correlated to the rate of ALS disease progression, and initial CSF cystatin C levels were predictive of patient survival, suggesting that cystatin C may function as a surrogate marker of disease progression and survival. These data verify prior results for reduced cystatin C levels in the CSF of ALS patients, identify increased cystatin C levels in the plasma of ALS patients, and reveal correlations between CSF cystatin C levels to both ALS disease progression and patient survival

Vitamin D3 Deficiency Differentially Affects Functional and Disease Outcomes in the G93A Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by motor neuron death in the central nervous system. Vitamin D supplementation increases antioxidant activity, reduces inflammation and improves motor neuron survival. We have previously demonstrated that vitamin D3 supplementation at 10× the adequate intake improves functional outcomes in a mouse model of ALS

Urinary-excretion of Lead and Mercury After Oral-administration of Meso-2,3-dimercaptosuccinic Acid in Patients With Motor-neuron Disease

Amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) are progressive neurodegenerative disorders involving motor neurones. The aetiology of the non-familial forms is still unknown but it has been suggested that long-term exposure to heavy metals such as lead and mercury may play a role in the pathogenesis of these diseases. In 53 patients suffering from ALS (n = 42) and SMA (n = 9) the oral administration of dimercaptosuccinic acid (DMSA, 20 mg/kg) did not result in a greater mobilization of lead and mercury from peripheral depots than in control subjects. Although it cannot be excluded that the amount of lead or mercury excreted after DMSA administration may not be a reflection of the amount accumulated in the motor neurones, this study does not provide support for the hypothesis that heavy metals play a significant role in the occurrence of motor neurone diseases