Blood Tests Highly Accurate in ALS Diagnosis, Prognosis

TOPLINE:

Four serum neurofilament light chain (NfL) tests showed high accuracy in diagnosing and predicting progression of amyotrophic lateral sclerosis (ALS) in a new study. Investigators said the findings also offer diagnostic and prognostic cutoff values and lay the foundation for future use of the tests in clinical practice.

METHODOLOGY:

• This study included 139 patients with ALS (mean age, 67.3 years; 50% women) and 70 individuals without ALS (mean age, 63.8 years; 41% women).
• Researchers conducted a head-to-head comparison of four technologies for NfL measurement: Ultrasensitive Simoa, microfluidic Ella platform, and clinical-grade Lumipulse and Elecsys platforms.
• Additionally, they used Elecsys to evaluate the performance of two serum substances: Glial fibrillary acidic protein (GFAP) and phosphorylated tau 181 (pTau181).
• The mean follow-up duration was 42 months for the ALS group and 141.6 months for the non-ALS group.

TAKEAWAY:

• A strong correlation was observed among the four NfL methods (correlation coefficient, 0.939-0.963; P < .0001 for all).
• All four showed favorable diagnostic performances, but the area under the curve (AUC) was significantly lower for Simoa (0.889) vs Ella (0.906; P = .02), Lumipulse (0.912; P = .008), and Elecsys (0.910; P = .008). Ella, Lumipulse, and Elecsys did not differ significantly from each other.
• Serum pTau181 and GFAP showed poor diagnostic abilities (AUC, 0.565; and 0.546, respectively).
• Hazard ratios were significant for all NfL assays (4.4-5.4). Patients with ALS with NfL levels above prognostic cutoffs had near-zero survival rates at 50 weeks, whereas those with levels below cutoffs had 40%-50% survival probability.

IN PRACTICE:

“These tests can be useful in confirming a diagnosis in rare cases where it is uncertain. We propose diagnostic and prognostic cutoffs for serum NfL measured on these 4 platforms. This information can serve as a basis for implementing these tests in other laboratories,” the investigators wrote.

SOURCE:

This study was led by Etienne Mondesert, CHU Montpellier, Montpellier, France. It was published online on February 26 in Neurology.

LIMITATIONS:

Participants were exclusively from southern France, which may have introduced geographical bias and limited the generalizability of the results to other populations.

DISCLOSURES:

This study was funded by Fondation pour la Recherche Médicale and the AXA mécénat program through the INTERVAL project. The investigators reported having no potential conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.