AUTHOR=Manera Umberto , Grassano Maurizio , Matteoni Enrico , Bombaci Alessandro , Vasta Rosario , Palumbo Francesca , Torrieri Maria Claudia , Cugnasco Paolo , Moglia Cristina , Canosa Antonio , Chiò Adriano , Calvo Andrea 

TITLE=Serum chloride as a respiratory failure marker in amyotrophic lateral sclerosis

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 15 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2023.1188827

DOI=10.3389/fnagi.2023.1188827

ISSN=1663-4365

ABSTRACT=Respiratory failure is the most common cause of death in patients with Amyotrophic Lateral Sclerosis (ALS) and occurs with a great variability among patients according to different phenotypic features. Early predictors of respiratory failure in ALS are important to start non-invasive ventilation (NIV). Venous serum chloride values correlates with carbonate (HCO3-) blood levels, reflects metabolic compensation of respiratory acidosis. Despite its wide availability and low cost, few data on serum chloride as a prognostic marker exists in ALS literature. In the present study, we evaluated serum chloride values at diagnosis as prognostic biomarker for overall survival and non-invasive ventilation adaptation in a retrospective center-based cohort of ALS patients. We collected all ALS patients with serum chloride assessment at diagnosis, identified through the Piemonte and Valle d’Aosta Register for ALS, evaluating the correlations among serum chloride, clinical features and other serum biomarkers. Then, time-to-event analysis were modelled to predict overall survival and NIV start. Significant correlation between serum chloride and inflammatory status markers, serum sodium, forced vital capacity (FVC), ALS functional rating scale-revised (ALSFRS-R) item 10 and 11, age at diagnosis and weight loss. Time-to-event analysis confirmed both in univariate analysis and after multiple confounders’ adjustment that serum chloride value at diagnosis significantly influenced survival and time to NIV start. According to our analysis, we found that serum chloride analyzed at diagnosis is a low-cost marker of impending respiratory decompensation. In our opinion, it should be added among the prognostic biomarkers able to stratify patients into different prognostic categories