Lymphocyte collection for donor leucocyte infusion from normal donors: estimation of the minimum processed blood volume and safety of the procedure

BACKGROUND AND OBJECTIVES: To estimate the minimum volume of processed blood necessary for the purpose of donor leucocyte infusion (DLI), we determined the number of CD3+ cells harvested by apheresis from normal donors and examined adverse events during the procedure. MATERIALS AND METHODS: Leukapheresis utilizing the COBE Spectra' was performed a total of 24 times from 12 normal donors. Blood counts were obtained and the number of CD3+ cells was evaluated before and after apheresis and in the peripheral blood products. Complications associated with the procedure were documented. RESULTS: Blood products contained, on average, 51.1% CD3+ cells. A linear correlation was found between the number of CD3+ cells collected and the processed blood volume, up to 12 000 ml (r = 0.930, P < 0.001). Cytoreduction was observed in all donors after apheresis. In particular, the platelet and lymphocyte values decreased to approximately 70% of the preapheresis value. Two donors reported adverse effects: one was a mild vaso-vagal reaction and the other was citrate-related lip paresthesia. These symptoms were mild and disappeared spontaneously. CONCLUSIONS: We found a linear correlation between the number of CD3+ cells collected and the processed blood volume, which enabled us to estimate the minimum volume of processed blood necessary for DLI. The adverse events observed were acceptable.