Exploring clinical chemistry markers in amyotrophic lateral sclerosis: insights into survival and disease trajectories

Abstract

Objective Commonly measured clinical chemistry markers might be indicative of survival and disease progression in amyotrophic lateral sclerosis (ALS). Methods In a cohort study of 270 ALS patients diagnosed from April 2014 to May 2021 in Stockholm, Sweden, we examined the link between 29 clinical chemistry markers at diagnosis and mortality risk at 6 months, 1 year, and 3 years after diagnosis. Summary variables from exploratory factor analysis (EFA) assessed the markers’ collective impact on survival. We integrated ALS functional rating scale-revised (ALSFRS-R) scores with survival data using a joint latent class model to identify patterns of functional decline. Multinomial logistic regression determined how the EFA-derived factors predicted the decline trajectories post-diagnosis. Results Higher levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B, and albumin at diagnosis were linked to lower mortality in ALS patients, while increased neurofilament light chain (NfL), leukocyte count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and carbon dioxide (CO2) levels indicated higher mortality. The ‘Red blood cell profile’ factor, derived from EFA, emerged as a significant predictor of survival, independent of other prognostic indicators. The joint latent class model identified three distinct patient groups based on functional decline, with ‘Red blood cell profile’ suggesting a lower likelihood of being in the groups with slower progression. Conclusion Clinical chemistry markers, including NfL, lipids, albumin, leukocyte count, MCV, MCH, CO2, and the ‘Red blood cell profile,’ were associated with ALS survival. As these markers represent broader bodily functions, integrating them in ALS patient care could improve disease management.