An amyloid levels test could help physicians predict who will develop Alzheimer’s disease, a study found.

German researchers collected spinal fluid samples from 58 individuals with minor memory or cognitive deficiencies and looked for remnants of a building block of beta amyloid called amyloid precursor protein. Within three years, 21 participants developed full-blown Alzheimer’s and 27 had mild cognitive impairment. Combined with other biomarkers for Alzheimer’s, the test predicted the eventual onset of the disease with an 80% accuracy rate.