Persistent environmental pollutants like pesticides are associated with amyotrophic lateral sclerosis (ALS) and may represent modifiable ALS disease risk factors, according to a study published online in JAMA Neurology, titled “Association of Environmental Toxins With Amyotrophic Lateral Sclerosis.”
ALS is a progressive, fatal neurodegenerative disease. Persistent exposure to environmental toxins, combined with a genetic susceptibility, may trigger motor neuron degeneration as explained in the gene-time-environment hypothesis.
To evaluate the association between occupational exposures and environmental toxins on the odds of developing ALS, Eva Feldman, MD, PhD, with the University of Michigan in Ann Arbor, and colleagues studied occupational exposures and environmental factors in Michigan.
Researchers evaluated assessments of environmental pollutants in the blood, and detailed exposure reporting through a survey. The study involved 156 patients with ALS and 128 control participants. Of these, 101 ALS patients and 110 controls had complete demographic and pollutant data. Participants completed a survey assessing occupational and residential exposures. Blood concentrations of 122 persistent environmental pollutants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs), were measured using gas chromatography-mass spectrometry.
Using survey data and blood measurements, the team found that pesticide exposure was associated with an increased risk of ALS.
“[A]s environmental factors that affect the susceptibility, triggering and progression of ALS remain largely unknown, we contend future studies are needed to evaluate longitudinal trends in exposure measurements, assess newer and nonpersistent chemicals, consider pathogenic mechanisms, and assess phenotypic variations,” the researchers concluded.
During the Drug Company Working Group session at the recent American Academy of Neurology annual meeting in Vancouver, Canada, a top researcher from Cytokinetics gave an update on a new Phase 3 study of tirasemtiv as a potential treatment for amyotrophic lateral sclerosis (ALS), and another from Biogen talked about a new trial to assess outcome measures in ALS patients.
Origent Data Sciences’ chief scientific officer also presented a “machine learning” method of predicting ALS progression, which may one day replace placebo control groups in these trials, according to an ALS Association release on the session.