PITTSBURGH, Sept. 11, 2014 /PRNewswire-iReach/ -- Today the FDA announced approval of PleximmuneTM, a blood test from the Pittsburgh-based biotech company Plexision. This test predicts acute cellular rejection of transplanted livers and intestines in children. PleximmuneTM is a first-in-class test to determine a personalized rejection-risk index using cell-based technology.