A comparison of platelet production methods suitable for a service-oriented blood donor center

In vitro study of immunologic changes in long-term cytapheresis donors

Several in vitro measurements of immune function were examined retrospectively in a population of active long-term cytapheresis donors (group I; n = 50) and the results were compared to age- and sex-matched controls (group II; n = 50) who had donated only whole blood. In group I, significantly different mean absolute lymphocyte counts (P = .0025), total T-cells (P = .0026) and T-helper cells (P less than .0001), and helper-to-suppressor ratios (P = .0279) were present. No differences were noted between the two groups for peripheral blood mean B-cell count, T-suppressor numbers, lymphocyte responsiveness to mitogens or alloantigen, and serum immunoglobulin level. The reduced mean absolute lymphocyte count in group I was due to the reduction in T-helper cell numbers and accounted for the imbalance in the helper-to-suppressor ratio. These disturbances are currently unexplained and, while no clinical consequences have so far become evident, there is a need to continuously monitor the immunologic status of cytapheresis donors. It is also important to determine whether reversal of the defects occurs and, if so, over what time interval.

Plateletpheresis experience with the Haemonetics Blood Processor 30, the IBM Blood Processor 2997, and the Fenwal CS-3000 Blood Processor

Comparisons were made of the apheresis instruments Haemonetics Blood Processor 30, IBM Blood Processor 2997 and Fenwal CS-3000, for collection of platelets from normal donors. With each instrument the mean recovery was at least 4 x 10(11) platelets per procedure, and each instrument afforded a safe and reliable collection. The Haemonetics Blood Processor gave the lowest recovery of platelets per minute per procedure. The IBM Blood Processor 2997 required the longest time for set-up and priming and processed 1.5 liters more donor blood per collection than the other instruments. The Fenwal CS-3000, which is a computer-controlled instrument, was the least time consuming. The donor suffered a significantly greater drop in platelet count after collection with the IBM Blood Processor 2997 (31%) than after collection with the other instruments (19%), and we were unable to account for this observation.

The safety of weekly plateletpheresis: effect on the donors' lymphocyte population

Ten normal donors were monitored before, during, and after ten weekly donations of platelet concentrates prepared using the Haemonetics Model 30 blood processor. Analysis of these data indicates about a 20 per cent decrease of lymphocytes, with B cells being significantly decreased in half of these patients. While coincident immunoglobulin deficiencies did not develop in this short-term study, it is presumed that these would occur with a prolongation of platelet donations, as has been noted in previous studies. Additional studies are indicated to further delineate the lymphocyte depletion in normal platelet donors.

Cost accounting in plateletpheresis: comparison of two techniques

Cost comparison of two comparably effective techniques of plateletpheresis, a manual method and an automated discontinuous flow centrifugation technique, is presented using a hypothetical model. The former procedure costs $62.48 per pheresis for disposables and labour as opposed to $78.32 per pheresis for disposables and labour for the latter. The annual volume of plateletpheresis at which the accumulated costs equal the total charges, i.e. the 'break-even' point, is calculated and found to be 63.7 for the automated technique and 10.9 for the manual method, if the charge for each is $200.00. For the manual method at a current charge of $80.00, the break even point is 85.8. The assumptions underlying this hypothetical model are examined, and the effects of deviation from these assumptions are analyzed in terms of the break even point. Cost accounting of plateletpheresis is shown to be dependent upon the choice of approach to allocation of costs, the assumptions of the cost accounting model, and the selection of an appropriate charge.

Efficacy of platelets collected by semi-continuous flow centrifugation (Haemonetics Model 30)

The viability of both autologous and donor platelets collected by means of a semi-continuous flow centrifuge (Haemonetics Model 30) was measured. Radiochromium labelled pooled platelets harvested from six passes and reinfused into their normal donors showed recoveries and survivals of 58% +/- 8 and 9.6 d +/- 0.8 compared with normal values of 65% and 9.5 d +/- 0.6, respectively. When the viability in aplastic thrombocytopenic recipients of platelets collected from normal donors by the Haemonetics Model 30 was compared with that of platelets collected from the same donors by multiple bag plateletpheresis the results were very similar: recoveries of 82% +/- 18 and 80% +/- 25 and survivals of 3.9 d +/- 2.0 and 3.8 d +/- 1.3, respectively. The in vitro function of the collected platelets in response to aggregating agents was normal when measured within 60 min of collection at pH 7.4. The relationship between bleeding time and post-transfusion platelet count in aplastic, thrombocytopenic patients showed that in vivo function was maintained.