A blood test that screens for certain markers in the blood called “autoantibodies” is showing promise in diagnosing Alzheimer’s disease, researchers report. The blood test correctly detected Alzheimer’s disease in people already diagnosed with the devastating brain disorder with 96 percent accuracy, according to the researchers. The test could also distinguish who didn’t have the disease from a control group of non-affected adults with 92.5 percent accuracy. Though outside experts said the findings may be another step toward a quicker, easier way to diagnose Alzheimer’s, they cautioned that there’s still a long way to go.