Three Blood Biomarkers Together Predict ALS Progression and Survival, Study Finds

Amyotrophic lateral sclerosis remains one of the most feared diagnoses in neurology, a disease in which motor neurons steadily fail while the mind often stays intact. Patients and clinicians alike have long wished for a way to read the disease’s trajectory from a simple blood test: how fast will it progress, and how long might a given patient live? A new study published in Annals of Clinical and Translational Neurology brings that goal closer, showing that three serum biomarkers drawn from distinct biological pathways—lipid peroxidation, systemic inflammation, and axonal injury—can be measured together to discriminate rapid progression and poor survival with striking accuracy.

The research team, based at Houston Methodist Hospital’s MDA/ALSA ALS clinic, took advantage of a longitudinal serum repository collected between January 2018 and December 2022. From 352 patients with stored, immediately frozen samples, the investigators used a computer-generated random sampling process to select 100 patients for exploratory analysis. Each patient contributed between four and eleven blood draws, averaging six per person, spanning the full arc of disease from diagnosis to samples taken at or near end stage. One hundred age- and gender-matched healthy controls, typically spouses and friends of the patients, provided comparison samples. Only about five percent of the cohort carried known ALS mutations such as C9orf72 or a family history, making the group overwhelmingly representative of sporadic disease.

The three biomarkers were chosen for their biological coherence with what is known about ALS pathophysiology. 4-hydroxy-2-nonenal, or 4-HNE, is a toxic product of lipid peroxidation, the chemical assault on cell membranes that follows when dysfunctional mitochondria churn out reactive oxygen species. Lipopolysaccharide binding protein, or LBP, is synthesized and secreted by hepatocytes in the liver as part of the acute phase response, the innate, nonspecific first reaction of the body to immunological stress; it binds bacterial lipopolysaccharide and presents it to immune receptors such as CD14 and Toll-like receptor 4, amplifying inflammatory signaling. Neurofilament light chain, or NfL, is a structural protein released when axons degenerate, and it has already emerged as one of the most scrutinized fluid markers in neurodegeneration. All three were quantified by standard enzyme-linked immunosorbent assays, the kind of procedure routinely available in clinical diagnostic laboratories.

The cross-sectional findings immediately set ALS apart from other neurodegenerative diseases. Rapidly progressing patients, defined as those losing one or more points per month on the revised ALS Functional Rating Scale, showed significantly higher 4-HNE than both healthy controls and slowly progressing patients. LBP was elevated in rapid progressors compared with slow progressors and controls, and even slow progressors had higher LBP than controls. NfL followed a similar pattern, higher in rapid progressors than in slow ones and controls. Crucially, 4-HNE and LBP showed no such elevations in patients with Parkinson’s disease or mild cognitive impairment and Alzheimer’s disease, whereas NfL rose in those conditions as expected. This dissociation suggests that oxidative stress and systemic inflammation are not generic accompaniments of neurodegeneration but are specifically intensified in ALS.

The longitudinal data revealed a compelling divergence in how the three markers behave over time. At diagnosis, NfL showed the largest elevation relative to controls, roughly 3.3-fold, with LBP at about 1.6-fold and 4-HNE at a modest 1.3-fold. Yet from diagnosis to the last available sample, the picture inverted: 4-HNE climbed 177 percent and LBP rose 80 percent, while NfL increased only 27 percent, effectively plateauing. In other words, axonal injury as reflected by NfL is largely front-loaded into the early disease course, whereas lipid peroxidation and systemic inflammation escalate continuously as the disease advances. This temporal architecture helps explain why NfL did not correlate with ALSFRS-R scores in this cohort, since the functional scale kept declining steadily while NfL had already peaked.

The correlation analyses underscored the primacy of the inflammatory and oxidative markers. LBP at diagnosis showed the strongest negative correlation with ALSFRS-R score at diagnosis (r = −0.688) and the strongest correlation with survival from diagnosis to death (r = −0.773), along with the strongest link to progression rate (r = 0.668). 4-HNE tracked closely behind, correlating with survival at r = −0.661 and with progression rate at r = 0.589. NfL, by contrast, correlated only weakly with survival (r = −0.325) and progression rate (r = 0.274). The biomarkers also correlated with one another, moderately so between LBP and 4-HNE and between NfL and 4-HNE, painting a picture of interacting pathways in which oxidative damage, inflammation, and axonal breakdown feed one another. As expected clinically, older age at diagnosis and faster progression each correlated with shorter survival.

Site of disease onset added further biological texture. Among the 97 patients with either bulbar or limb onset, those with bulbar onset survived significantly shorter periods. Their mean 4-HNE levels were approximately 1.5-fold higher and LBP levels approximately 1.7-fold higher than in limb-onset patients, yet NfL levels did not differ between the two groups. This pattern implies that the worse prognosis of bulbar-onset ALS is driven not by greater axonal injury per se but by a more intense burden of oxidative stress and systemic inflammation, consistent with the idea that these pathways accelerate the pace of the disease rather than merely marking it.

The centerpiece of the study was a series of receiver operating characteristic analyses testing how well each biomarker, alone and in combination, could discriminate poor survival and rapid progression. Individually, 4-HNE and LBP performed well, with area under the curve values of 0.78 and 0.75 for poor survival and 0.83 and 0.74 for rapid progression, while NfL was more modest at 0.66 and 0.61. Pairwise combinations improved performance, and the three-marker panel achieved the best results: an AUC of 0.86 for poor survival and 0.84 for rapid progression, both highly significant. For third-quartile progression rates, the three-biomarker combination again reached an AUC of 0.86. Because post hoc ROC analyses risk overfitting, the team performed internal validation using bootstrap resampling with 2000 iterations. The optimism estimates were small, below 0.02, and the optimism-adjusted AUCs closely mirrored the apparent ones, with the three-marker survival model holding at an adjusted AUC of 0.85, indicating stable and robust discriminative performance.

The authors are candid about the limitations. The study was retrospective and single-center, drawing 100 patients from a larger repository, which may limit generalizability, though computer-generated random sampling minimized systematic selection bias and potential confounders including age, sex, genetic status, onset site, and disease duration were accounted for in the design. The ROC analyses lack independent prospective validation, which the bootstrap procedure only partially addresses. The study was explicitly framed as exploratory. Still, the practical appeal of the approach is considerable: unlike multi-protein panels discovered through untargeted proteomics and machine learning, these three biomarkers were selected on biological grounds, target three distinct and interacting pathways, and can be measured with standardized ELISA kits already familiar to clinical laboratories.

The findings also open a therapeutic horizon. Plasma NfL has already been validated as a pharmacodynamic marker through its reduction in association with tofersen-mediated slowing of disease progression in SOD1-mediated ALS. Whether LBP and 4-HNE can similarly serve as readouts of treatment response remains an open question, and the authors highlight prospective therapeutic studies as the necessary next step. If the escalating oxidative and inflammatory burden measured in this cohort truly reflects the engine of disease acceleration, then serial monitoring of these markers could one day tell clinicians whether a therapy is working months before functional scales register a difference. For a disease in which every point on the ALSFRS-R matters, a three-protein blood panel that discriminates fast from slow trajectories with an AUC near 0.86 is a meaningful step toward personalized prognosis and, ultimately, more responsive care.

Subject of Research: Longitudinal serum biomarkers for predicting ALS disease progression and survival

Article Title: Longitudinal Assessment of Biomarkers in ALS: Discriminative Biomarkers for Disease Progression and Survival

Article References: Beers, D. R., Lin, Y.-Y., Thonhoff, J. R., Thome, A. D., Faridar, A., Zhao, W., Wen, S., & Appel, S. H. (2026). Longitudinal Assessment of Biomarkers in ALS : Discriminative Biomarkers for Disease Progression and Survival. Annals of Clinical and Translational Neurology, 13(10), 2102-2113. https://doi.org/10.1002/acn3.70381

Image Credits: AI Generated

DOI: 10.1002/acn3.70381

Keywords: ALS, biomarkers, 4-HNE, lipopolysaccharide binding protein, neurofilament light chain, lipid peroxidation, systemic inflammation, axonal injury, survival, disease progression, ROC analysis, neurodegeneration