Bone-marrow aspiration

Standardization of the processing of human bone marrow for allogeneic transplantation

Allogeneic bone marrow transplantation has been undertaken within this centre on 62 patients with acute or chronic leukaemia. Employing the standard separation protocol described, all bone marrows were processed on the 2991 Blood Cell Processor to isolate the 'buffy coat' cells and subsequently the mononuclear cell component using a density separation medium of Ficoll-metrizoate. Following the mononuclear cell separation, the cells were identified for their T lymphocyte component using a combination of two murine monoclonal antibodies, MBG6 reacting with a pan T cell antigen (CD6) and RFT8 detecting the 'cytotoxic/supressor' cell antigen (CD8). The numerical results for nucleated cells, red blood cells, T lymphocytes and colony forming units-granulocyte macrophage are presented.

Use of anti-T-cell monoclonal antibody OKT3 to prevent acute graft-versus-host disease in allogeneic bone-marrow transplantation for acute leukaemia

Seventeen patients who received allogeneic bone-marrow transplants from matched or slightly mismatched (in four patients) siblings were observed for at least 60 days or until acute graft-versus-host disease (GvHD) developed. All donor marrows after preliminary manipulation were incubated with 1 mg of the murine monoclonal antibody OKT3 before infusion in an attempt to deplete them of immunocompetent T lymphocytes (opsonisation). In three of the seventeen patients acute GvHD of grade II or greater developed. Two of these patients died, but they had disseminated cytomegalovirus infection as well as GvHD. Eleven patients showed no evidence of acute GvHD, and four had transient limited skin rashes (grade I GvHD). Opsonisation of T lymphocytes has reduced the incidence of severe acute GvHD in this unit from 79% in an earlier group of 14 patients to 18% when added to prophylactic methotrexate.