• Posted November 1, 2023

Blood Test Measures ALS Risk From Environmental Toxins

Amyotrophic lateral sclerosis, better known as ALS, is debilitating and has no cure.

Now, researchers at the University of Michigan have developed an environmental risk score that will allow them to assess a person's risk for developing ALS, as well as their survival after diagnosis.

Toxins such as pesticides and carcinogenic PCBs affect a person's risk of developing and dying from ALS.

The risk score uses samples of patients' blood.

“For the first time, we have a means collecting a tube of blood and looking at a person's risk for ALS based on being exposed to scores of toxins in the environment,” said study first author Dr. Stephen Goutman. He is director of the Pranger ALS Clinic at the University of Michigan in Ann Arbor.

To study this, the researchers obtained more than 250 blood samples from people in Michigan both with and without ALS.

The investigators calculated individual risk and survival models using 36 organic pollutants. Several of those pollutants were significantly associated with ALS risk.

Risk for developing ALS was most strongly seen with a mixture of pesticides in the blood. Someone with the highest exposure had double the risk compared to someone in the lowest group of exposure.

“Our results emphasize the importance of understanding the breadth of environmental pollution and its effects on ALS and other diseases,” senior author Dr. Eva Feldman said in a university news release. She is director of the NeuroNetwork for Emerging Therapies at Michigan Medicine.

Previous research by this team had found elevated levels of pesticides in the blood of patients with ALS, commonly referred to as Lou Gehrig's disease.

The team later showed that exposure to organic pollutants advances ALS progression and contributes to worse outcomes.

“When we can assess environmental pollutants using available blood samples, that moves us toward a future where we can assess disease risk and shape prevention strategies,” Feldman said.

“Environmental risk scores have been robustly associated with other diseases, including cancers, especially when coupled with genetic risk," she added. "This is a burgeoning application that should be further studied as we deal with the consequences of pollutants being detected throughout the globe.”

The findings were recently published in the Journal of Neurology, Neurosurgery and Psychiatry.

The research was supported by the National ALS Registry/Agency for Toxic Substances and Disease Registry at the U.S. Centers for Disease Control and Prevention, the U.S. National Institutes of Health and others.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more on ALS.

SOURCE: Michigan Medicine -- University of Michigan, news release, Oct. 30, 2023