Patients with steroid-refractory GVHD required more transfusions than patients with steroid-dependent or steroid-responsive GVHD. Platelet and pRBC transfusions administered in the first 4 weeks after endoscopy for GI GVHD symptoms are shown. Steroid-refractory GVHD patients required more platelets and pRBCs than either steroid-dependent or steroid-responsive GVHD patients. The increased transfusion requirement supports our hypothesis that steroid-refractory GVHD patients may have concurrent TA-TMA explaining their lack of response to increasing immune suppression.