Search

Platelets collected by using a two-stage automated blood cell separator were evaluated after 5 days of storage. The procedure caused no unanticipated physiologic changes in donors and produced greater than 3 x 10(11) intact platelets in 200 mL of plasma, plus an additional 400 mL of plasma with intact coagulation factors. Posttransfusion recovery of autologous radiolabeled platelets was comparable to that seen in platelets prepared by manual centrifugation techniques. Corrected count increments in 14 patients showed results similar to those with control transfusions. This device, which involves a collection time of less than 90 minutes, provides an option for platelet-pheresis in a variety of settings including blood mobiles.

Incubation of stored platelet concentrates (PCs) at 37 degrees C for 1 hour has been reported to result in a better morphology score and improved platelet recovery. A study was conducted in adult patients with leukemia to determine whether incubation of stored PCs results in an improved platelet recovery as measured by 10-minute posttransfusion corrected count increments (CCI). Eligible patients had platelet counts of less than 30,000 per microL and were clinically stable. Patients were transfused with 6 to 10 units of PC stored for 3 days (15 studies) or 4 days (5 studies). Platelets were pooled and then split in two equal volumes so that each patient received two sequential half-transfusions, one incubated at 37 degrees C for 1 hour and the other kept at 22 degrees C for 1 hour. Patients were randomized as to which half-transfusion was received first. The mean CCI of the incubated half-transfusions was 13.6 x 10(3) when they were given first and 14.5 x 10(3) when given second; this was not significantly different from the mean CCI of the nonincubated half-transfusions: 13.8 x 10(3) when they were given first and 13.8 x 10(3) when given second. In contrast to earlier reports, it can be concluded that incubation of pooled PCs does not improve platelet recovery.

It is generally felt that increments in platelet counts following platelet transfusions to patients with splenomegaly are severely reduced as a result of splenic sequestration. The results of 631 random-donor platelet transfusions administered to 66 thrombocytopenic patients with palpable splenomegaly were analyzed. Increasing splenomegaly had a significant effect on corrected count increments (CCIs), with the greatest deterioration occurring in patients whose spleens were palpable greater than 2.0 cm below the left costal margin. A similar trend was noted when the percentage of transfusions with satisfactory CCIs was compared, although it should be noted that 42 percent of the transfusions produced CCIs greater than 7500, and a large proportion produced clinically helpful absolute increments. Splenomegaly also had an effect on platelet survival: in patients with CCIs greater than 7500, the mean ratio of 24-hour CCIs to 1-hour CCIs was 0.29 to 0.47 in patients with various degrees of splenomegaly, as compared to an expected value of 0.6 to 0.7. Sixteen patients, most with spleens palpable less than 5.0 cm below the left costal margin, consistently had CCIs greater than 7500. A significant fraction of patients with splenomegaly can benefit from platelet transfusion, and thus splenomegaly should not preclude intensive therapeutic approaches.