Certain medications can potentially lead to false positive results. For example, the heart medication Entresto (sacubitril/valsartan) affects the Aβ42/40 ratio — someone taking it could have a lower ratio, potentially leading to a false positive, with changes three times larger than what scientists expect to see when a healthy person begins developing Alzheimer’s. Chronic kidney disease also elevates various blood biomarkers, making test interpretation more challenging.