Comparison of two immuno-mechanical methods of T-cell depletion of human bone-marrow for prevention of graft-versus-host disease: soybean lectin agglutination and sheep erythrocyte rosette depletion versus triple rosette depletion.

Depletion of T-lymphocytes from HLA-mismatched donor bone marrow can be accomplished by either triple neuraminidase-treated sheep erythrocyte depletion (3En) or soybean agglutination and sheep erythrocyte depletion (SBA/E/En). T-lymphocyte depletion by 3En resulted in higher yields of all marrow precursor phenotypes (studied by a battery of monoclonal antibodies) than did SBA/E/En depletion. While both procedures enriched for some early precursor cells (e.g., HLA-DR and/or terminal deoxynucleotidyl transferase (TdT) positive cells), greater numbers of these cells were available after 3En. Clinical benefits which may be derived from the larger inoculum of T-depleted bone-marrow cells available after 3En treatment remain to be studied.