CD4 and thromboangiitis obliterans: Blood routine information was collected from 135 TAO patients, 95 Grave’s disease without TAO (GD) patients, and 116 normal controls (NC), while surface marker expression of PMN and the level of CD4+T cell and B cell subsets in peripheral blood from 40 TAO patients, 17 GD patients, and 45 NC was assessed by flow cytometry.