Harvest of human bone marrow directly from bone

Harvest of human bone marrow directly from freshly resected bone provides purer preparations of marrow than can be obtained by the conventional technique of multiple aspirations from the iliac crests. In particular, directly harvested marrow is much less heavily contaminated with peripheral blood lymphocytes, a known source of mature T cells. Because of the possible relevance of these contaminating T cells for cadaveric bone marrow transplants, the best source of human marrow harvested directly from bone has been studied. Human bone marrow was harvested from 46 surgical specimens and 9 cadaveric tissue donors. Vertebral bodies provided the best source of bone marrow with average yields of 3.1 ± 1.6 × 10⁹ cells per vertebra. When entire ilia were removed and processed for marrow, an average of 1.6 ± 1.0 × 10⁹ cells was obtained. Surgically resected ribs yielded lower amounts of marrow with a mean cell number of 3.2 ± 2.6 × 10⁸ per rib. Isolation of bone marrowb mononuclear cells from these preparations by density gradient centrifugation resulted in a loss of 45% of the starting cells. Human bone marrow was found to contain 5–6% T cells before gradient separation and these cells were immunologically competent as measured in vitro by responses to mitogens and alloantigens. This technique may be useful in obtaining human bone marrow for both immunologic studies and allogeneic transplantation.