 Researchers also note higher levels of chronic pain reported by female family members of combat-exposed service women. And scientists at Northwestern University say for the first time they've discovered a possible cause of lupus. Researchers identified a molecular defect that impacts the body's immune system, and they believe it could lead to targeted treatments. Lupus affects more than 1.5 million people in the U.S. and can damage organs like the kidneys, brain, and heart.