Autologous WB induces a modest immunomodulation, but this effect is not observed upon transfusion of autologous blood components.

In the perioperative setting, a specific cellular immune response to autologous transfusion is not detectable.

The variations in plasma erythropoietin (EPO) concentration during preoperative deposit of autologous blood were studied in 12 patients (8 men, 4 women). Four donations were scheduled at weekly intervals. A predonation hemoglobin concentration of 11 g per dL (110 g/L) was required. Hemoglobin concentration decreased from 14.3 ± 1.1 g per dL (143 ± 11 g/L) (mean ± SD) before the first donation to 11.7 ± 0.7 g per dL (117 ± 7 g/L) on Day 22 (p<0.0001). Reticulocyte counts increased from a median of 31,800 (range, 4900-95,000) per \xL (median, 32 x 10 9 /L [range, 5-95 x 10 9 /L]) to 93,800 (16,800-194,900) per \iL (median, 94 x 10 9 /L [range, 17-195 x 10 9 /L]) on Day 28 (p<0.01). Plasma EPO concentration was 17.8 ± 5.1 mU per mL prior to the first donation and displayed a small and transient peak after each donation. A sustained elevation followed each peak. Although plasma EPO concentration differed significantly from the baseline value after the first donation, only the peak concentrations after the second (35.5 ± 15.5 mU/mL), third (38.0 ± 14.5 mU/ mL), and fourth (36.1 ±11.0 mU/mL) donations exceeded the normal range. The moderate, biphasic increase in plasma EPO concentration and the moderate increase in erythropoiesis suggest two strategies in autologous blood donation that should be investigated with respect to efficiency and safety: 1) more aggressive donation schemes, which reduce donation intervals and/or the minimum hemoglobin concentration and 2) the administration of recombinant human EPO. TRANSFUSION 1991;31:650-654. Abbreviations: EPO = erythropoietin.THE IMMUNOLOGIC AND INFECTIOUS risks of transfusion 1,2 can be minimized by the use of autologous blood. Preoperative autologous blood donation considerably reduces homologous transfusion requirements in surgery. 3 " 8 Frozen storage of red cells allows the preoperative deposit of a large number of blood units, but it is costly and time-consuming. On the other hand, liquid storage is limited to 5 weeks for whole blood and 7 weeks for packed red cells. 9,10 The efficiency of preoperative deposit in the liquid state thus depends on the rate of recovery from blood loss, that is, on the degree of stimulation of erythropoiesis.Erythropoietin (EPO) is the primary humoral regulator of erythropoiesis. 11 Increasing the availability of EPO may therefore enhance the efficiency of preoperative donation programs. This increased availability of EPO may be achieved by allowing the modulation of donation schemes (shorter donation intervals, lower minimum