A38 and A43 do not differentiate between Alzheimer's disease and cerebral amyloid angiopathy

Differential diagnosis between Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA) using cerebrospinal fluid (CSF) biomarkers is challenging. A recent study suggested that the addition of A beta 38 and A beta 43 to a standard AD biomarker panel (A beta 40, A beta 42, t-tau, p-tau) to improve the differential diagnosis. We tested this hypothesis in an independent German cohort of CAA and AD patients and controls using the same analytical techniques. We found excellent discrimination between AD and controls and between CAA and controls, but not between AD and CAA. Adding A beta 38 and A beta 43 to the panel did not improve the discrimination between AD and CAA.