HLA-B and Alzheimer disease: Of the 17 studies, only three had more than 60 AD cases: one Japanese study [18] (122 AD cases) and two Caucasian, Middleton et al 1999 [19] (95 AD cases) and our previous study [9] (299 AD cases from three cohorts; however, full HLA-B &C typing was only performed in the OPTIMA cohort, with 55 AD cases).