Evaluation of light-chain neurofilaments (NfL) and heavy-chain (NfH) neurofilaments as biomarkers of neuroaxonal damage in an animal model for Amyotrophic Lateral Sclerosis (ALS) and Guillain-Barré Syndrome (GBS)

The dog is considered a useful animal model for studying two human diseases: Amyotrophic lateral sclerosis (ALS) and Guillain-Barré syndrome (GBS). Degenerative myelopathy (DM) and Acute canine polyradiculoneuritis (ACP) are canine analogous of ALS and GBS, respectively. These diseases are characterised by neuroaxonal damage, and the aim of the research was to evaluate a biomarker that correlates well with this damage. Neurofilaments (Nf) are recognized biomarkers of neuroaxonal damage. In particular, the concentration of neurofilament heavy chain (NfH) and neurofilament light chain (NfL) has been evaluated as diagnostic and prognostic biomarkers in various human neurological diseases, including ALS and GBS. In literature, the concentration of serum NfL and NfH in ALS and GBS patients is greater than in healthy control groups. Analogous findings were reported for DM in dogs, no study had evaluated the concentration of serum Nf in dogs affected by ACP. This study aimed to evaluate the concentration of Nf in dogs with ACP and DM, and to compare these concentrations with those of a group of unaffected dogs (ACP and DM control group respectively). Two different analytical methods were used. Factors that can affect Nf serum concentration were also evaluated. No statistically significant differences were found between the concentration of NfH and NfL between ACP/DM group and the respective control group. Numerous elements can affect Nf serum concentrations (e.g. sample quality, comorbidities), so further studies are needed to better evaluate these factors to try to achieve more significant results. By including more cases and selecting control groups more rigorously, we can verify whether these methods can be used for clinical and research purposes. Furthermore, it will be possible to confirm the increase in serum Nf concentration observed in patients with ACP, which has never been demonstrated previously.