29) A 23-year-old man presents with diffuse bruising. He otherwise feels well. He takes no medications, does not use dietary supplements and does not use illicit drugs. His medical history is negative...

29) A 23-year-old man presents with diffuse bruising. He otherwise feels well. He takes no medications, does not use dietary supplements and does not use illicit drugs. His medical history is negative for any prior ilnesses. He is a college student and works as a Batista in a coffee shop. A blood count reveals an absolute neutrophil count of 780/ uL, hematocrit of 18% and platelet count of 21,000/uL. Bone marrow biopsy reveals hypocellularity with a fatty marrow. Chromosome studies of peripheral blood and bone marrow cells are performed that exclude Fanconi's anemia and myelodysplastic syndrome. The patient has a fully histocompatible brother. Which of the following is the best therapy? A Antithymocyte globulin plus cyclosporine B Glucocorticoids C Growth factors D Hematopoietic stem cell transplant E Red blood cell and platelet transfusion