Relationship between differing volumes of bone marrow aspirates and their cellular composition.

We compared the cellular composition of the first 1.0 ml volume bone marrow aspirate with that of an aliquot from the total bone marrow harvest at the end of the procedure in 17 healthy bone marrow donors. Each sample was assayed for its content of red blood cells, nucleated cells, CD2+, CD4+, CD8+, CD19+, HLA-DR+, CD56+, CD13+, CD33+, CD34+ and KiM8+ cells and CFU-GM. On the basis of data obtained, we estimated that the first 1.0 ml samples had 8.0 +/- 5.2% (SD) and the transplant samples 20.8 +/- 8.5% contamination with nucleated blood cells. The calculation revealed that both types of bone marrow samples had 100% volume contamination with peripheral blood, i.e. that bone marrow cells were aspirated within blood fluid volume. Nucleated cell concentration was 3-fold, and CFU-GM concentration 10-fold lower in the transplant than in the first-puncture 1.0 ml bone marrow samples. Various marker-positive cells appeared in transplant samples in concentrations that depended on their abundance in the first-puncture 1.0 ml and blood samples. Taken together, our data suggest that bone marrow harvesting would be substantially improved if individual aspirates were small in volume and taken from bone puncture sites as distant as possible.