Objective:

The aim of the study was to determine clusterin levels in cerebrospinal fluid (CSF) in patients with amytrophic lateral sclerosis (ALS), to compare them with healthy controls and to assess whether clusterin CSF levels differ depending on the form, stage and overall duration of the disease.

Background:

Clusterin is a chaperone protein involved in proteostasis. It is thought to protect against misfolding of the TDP-43 (43 kDa TAR DNA binding) protein, which is a major component of pathological inclusions present in brain tissue and spinal cord in patients with ALS.

Design/Methods:

CSF clusterin levels were compared between 19 patients with ALS and 18 age-matched controls. Furthermore, a comparison of CSF clusterin levels between patients with bulbar form of ALS (n = 14) and patients with onset of the disease in the limbs (n = 30) and an evaluation of the dependence of CSF clusterin levels on the phase and overall duration of the disease (n = 34) were performed.

Results:

A significantly higher CSF clusterin level (median 4650 vs. 1838 μg/l; p <0.0001) was demonstrated in the group of patients with ALS compared to the control group. There was no significant difference in CSF clusterin levels between patients with initial bulbar symptoms and patients with disease onset in the limbs (median 2086 vs. 2321 μg/l; p = 0.296). There was no significant relationship between CSF clusterin level and disease phase (r = -0.102) or between CSF clusterin level and total disease duration (r = 0.088).

Conclusions:

Clusterin could be one of the potential CSF biomarkers of ALS.  Its level does not correlate with the stage or form of the disease, so it could be used in diagnostic doubts at any stage and clinical manifestations. Further studies on a larger number of patients will be needed to confirm the findings.