CD28 and triple-A syndrome: Baseline aPL positive AAA patients had higher serum levels of neopterin [14 ng/ml (7.7–30.4) versus 6.8 ng/ml (3.2–43.6), p = 0.017] as well as increased prevalences of circulating CD4+CD28− T-cells [6.4% (2.3–30.2) versus 4.4% (0.1–33.8), p = 0.037] compared to aPL negative patients (see Figures 1B and 1C, respectively).