In vivo treatment with atorvastatin and NAC improved the number and function of either precultivated or cultivated BM EPCs from corticosteroid-resistant ITP patients. The effects of atorvastatin and NAC treatment on the (A) platelet counts, (B) percentages, (C) ROS levels, (D) double-positive–stained cells (per well), (E) apoptosis rates, (F) migration, (G) p-p38, and (H) p-Akt of BM EPCs were compared pre- and posttreatment from corticosteroid-resistant ITP patients who achieved response (R) or CR (left panel) and NR (right panel). (I) Mouse anti-human CD34 (green) and rabbit anti-human CD133 (red) were incubated to identify the BM EPCs. DAPI (blue) was used to stain the nucleus. In situ histological analyses of the BMBs showed that the frequency of the double-positive–stained (merged in yellow) EPCs with CD34 (green) and CD133 (red) was increased in corticosteroid-resistant ITP patients posttreatment compared with pretreatment according to immunofluorescent staining (scale bars, 50 μm). Subject variables were compared using the Mann-Whitney U test for continuous variables. All P values <.05 were considered significant and were provided in the figure. ST, atorvastatin.