| Abstract: | We have investigated the natural killer (NK) cell activity in peripheral blood and in bone marrow of nine normal donors. It was found that Ficoll-Hypaque (FH)-separated cells from the bone marrow collected in small (1 ml) aliquots had very low NK activity compared with normal activity in the peripheral blood of the same donor (mean +/- SD: 4.2% +/- 2.5% vs 25.1% +/- 15%, P less than 0.01). This difference was maintained for cells bearing receptors for sheep erythrocytes (E+) in both tissues (4.3% +/- 2.37% vs 15%+/-12.6%, P less than 0.01) or E- cells (2.5% +/- 2.86% vs 20.4% +/- 19.5%, P less than 0.01). Also, in bone marrow cells with Fc receptors for IgG (Fc gamma+) neither E+ nor E- had significant NK activity, in contrast to the peripheral blood, where significant NK cell activity was detectable in the Fc gamma + cells, either E+ or E- (1.9% +/- 1.2% and 1.3% +/- 1.4% vs 16.1% +/- 10.3% and 12.8% +/- 7.4%, respectively, P less than 0.01 for both). Our data indicate that bone marrow obtained with a low degree of blood contamination from normal donors has very low NK activity with no significant increase in any of the several fractions tested. |
