Phosphorylated tau in plasma could be a biomarker of lower motor neuron impairment in amyotrophic lateral sclerosis.

Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2023 Oct

filter terms:

Plasma levels of phosphorylated tau (P-tau181) have been recently reported to be increased in amyotrophic lateral sclerosis (ALS) and associated with lower motor neuron (LMN) impairment. We quantified plasma P-tau181 (pP-tau181) in a cohort of 29 deeply phenotyped ALS patients using the new fully automated Lumipulse assay and analysed phenotype-biomarker correlations. pP-tau181 levels correlated positively with a clinical LMN score (r = 0.3803) and negatively, albeit not significantly, with a composite index of muscle strength (r = - 0.3416; p = 0.0811), but not with Penn Upper Motor Neuron (UMN) Score. Accordingly, pP-tau181 correlated with electromyographic indices of spinal active and chronic denervation (r = 0.4507 and r = 0.3864, respectively) but not with transcranial magnetic stimulation parameters of UMN dysfunction. pP-tau181 levels did not correlate with those in the cerebrospinal fluid (CSF), serum NFL, serum GFAP, CSF/serum albumin ratio, or estimated glomerular filtration rate, but correlated with plasma creatine kinase levels (r = 0.4661). Finally, while not being associated with neuropsychological phenotype, pP-tau181 correlated negatively with pH (r = - 0.5632) and positively with partial pressure of carbon dioxide (PaCO2; r = 0.7092), bicarbonate (sHCO3-; r = 0.6667) and base excess (r = 0.6611) on arterial blood gas analysis. pP-tau181 has potential as ALS biomarker and could be associated with LMN impairment. Its raised levels might reflect pathophysiological processes (tau hyperphosphorylation and/or release) occurring in the axons of LMNs distantly from the CNS and the CSF. pP-tau181 could also be associated with respiratory dysfunction. © 2023. Fondazione Società Italiana di Neurologia.

Citation

Federico Verde, Ilaria Milone, Eleonora Colombo, Alessio Maranzano, Antonella Dubini, Claudia Colombrita, Francesco Gentile, Alberto Doretti, Silvia Torre, Stefano Messina, Claudia Morelli, Erminio Torresani, Barbara Poletti, Alberto Priori, Luca Maderna, Antonia Ratti, Vincenzo Silani, Nicola Ticozzi. Phosphorylated tau in plasma could be a biomarker of lower motor neuron impairment in amyotrophic lateral sclerosis. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. 2023 Oct;44(10):3697-3702