Institute for Neuro-Immune Medicine2026 SHIELD Conference Meeting

For the 2026 Sustained Homeostatic Imbalance due to Environmental Exposure Linked to Deployment (SHIELD) Conference, Dr. Lea Steele presents findings from a multi-site study examining how PON1 genetic variants interact with toxic exposures during the Gulf War to determine which veterans developed Gulf War illness. Dr. Steele reviews the three exposures most consistently linked to Gulf War illness across the literature — pesticides, pyridostigmine bromide (PB) pills, and chemical nerve agent exposure — and explains how the PON1 enzyme, which helps detoxify these compounds, comes in genetically distinct variants with very different capacities to neutralize each type of exposure. Drawing on a 398-veteran dataset from three existing cohorts across Boston, Houston, Miami, and San Francisco, she presents findings showing that veterans carrying the RR PON1 variant faced an 8.6-fold increased odds of Gulf War illness when exposed to nerve agents, while QQ and QR veterans showed elevated risk specifically from pesticide exposure. Exploratory analyses also suggest that PB pill use may have amplified risk substantially across genotype groups. Key points: 00:01 Introduction 01:32 Toxic exposures and Gulf War illness 03:16 The Kansas case definition symptom profile 04:29 Pesticides, PB pills, and chemical nerve agents 06:14 How the PON1 enzyme detoxifies organophosphates and nerve agents 08:18 PON1 genetic variants (QQ, QR, RR) 09:33 398 veterans across three cohorts 12:43 Pesticides, PB, and chemical alarms as top risk factors 13:50 RR veterans and nerve agent exposure 14:45 QQ and QR veterans and pesticide exposure risk 15:41 Exploratory PB interaction analysis 17:19 Complex exposure-gene interactions drive GWI susceptibility Watch Dr. Steele’s presentation, “GWI Population Research and What Has Been Learned About Associations with Exposures,” from the INIM 2025 SHIELD Conference on YouTube:    • Gulf War Illness Population Research & Wha...   Lea Steele, Ph.D. is a neuro and environmental epidemiologist and a professor at Baylor College of Medicine in Houston. She works in collaboration across the country with many investigators. Her current research includes studies of deployment factors that contributed to long-term health outcomes in veterans of the Persian Gulf War, as well as neurologic, immune, and genetic factors associated with Gulf War illness. Dr. Steele previously directed the Veterans Health Research program at Baylor University's Institute for Biomedical Studies. She served as scientific director of the Federal Research Advisory Committee on Gulf War Illness and was director of the Kansas Persian Gulf Veterans Health Initiative for the state of Kansas, which, by the way, gave us our case definition that we still lean heavily into today. She received her doctoral degree in epidemiology, and human ecology at the University of Texas School of Public Health, and investigated complex chronic illness as an epidemiology fellow at the Centers for Disease Control (CDC) in Atlanta. Learn more about the Institute for Neuro-Immune Medicine here. Website: https://www.nova.edu/nim/ Facebook:   / instituteforneuroimmunemedicine   Instagram:   / nsu_inim   Twitter:   / nsu_inim   #GulfWarIllness #ToxicExposure #VeteransHealth