Mononuclear cell-surface antigens during storage of banked blood

The surface antigens present on lymphocyte subpopulations and monocytes in whole blood stored under standard blood bank conditions were analyzed with a series of monoclonal antibodies and a fluorescence-activated cell sorter. During the first week of storage, the percentage of viable cells bearing T lymphocyte markers declined from 66% to 29% (P less than 0.001). Within the T cell subset, there was a disproportionate decrease in the percentage of cells reacting with anti-Leu 3a (a helper T cell marker) resulting in a reduction in the measured ratio of helper-to-suppressor T cells (P less than 0.01). The relative percentage of cells bearing B lymphocyte markers increased from 11% to 31% (P less than 0.001). The proportion of HLA-DR-positive cells that were B cells increased during the first week of storage from 38% to 65% (P less than 0.01). The degree of residual antigen expression as measured by the remaining median intensity of fluorescence was significantly greater for B cell and HLA-DR antigens as compared with T cell antigens. The measured changes during storage in the relative proportions of mononuclear cells expressing cell-surface antigens probably result from a combination of differential residual antigen expression and differential survival of mononuclear subpopulations. The presence of adenine in the anticoagulant-preservative solution had no measurable effect. Storage at 4 C, however, was shown to result in a 70% decrease in the proportion of antigen-bearing T cells, even as early as 24 hr of storage. The findings may have bearing on the beneficial effect of blood transfusion in renal transplant recipients, as well as on experimental models of the immune response to transfusion.