No abstract

Plasmapheresis was performed in normal blood donors using simple plastic equipment. Removal of plasma in amounts up to 1.0 liter at a single venipuncture proved feasible and produced no major changes in the donor’s blood counts and serum protein levels. Chronic plasmapheresis for periods up to 23 weeks with maximal rates not exceeding 1.5 liters of plasma withdrawn per week, produced no changes in formed elements and only minor changes in serum protein levels. Five donors were subjected to acute plasmapheresis with removal of 5 liters of plasma in 5 days. In this group, serum protein depletion was observed with particular depletion appearing at the end of the 5-day period. From calculations of protein replacement, the presence of a ready extravascular protein reserve, of a size somewhat less than the intravascular pool, was suggested. An average maximal protein replacement of 49 Gm. per day was observed during the most intensive plasmapheresis, and the data suggest that protein withdrawals should not exceed this amount if serum protein levels are to be maintained. Although no rebound of serum protein was observed, recovery after depletion required at least 2 to 4 weeks.

Repeated plasmapheresis with simple plastic equipment was performed on six normal donors for the purpose of obtaining platelet-rich-plasma. Plasmapheresis was performed at rates of up to 1000 ml. of plasma per week for periods up to three months. The six donors produced a total of 26.5 liters of platelet-rich-plasma, an amount which would have requried 106 separate blood donations had conventional means been used. No significant changes in hemoglobin, platelets or white cells were observed in the donors and serum protein depletion was minimal. No reactions to intensive plasmapheresis were encountered even when the procedure was abruptly terminated. Repeated donor plasmapheresis is a convenient method for producing large amounts of platelet-rich-plasma and affords a practical means of controlling donor factors in platelet transfusion studies.