Evidence for rapid mobilization of platelets from the spleen during intensive plateletpheresis.
The role of the spleen as a reservoir capable of adding platelets to the circulating blood cells has been well documented in animals but poorly documented in humans. As part of a program of platelet cryopreservation, we have intensively plateletpheresed a group of patients with acute leukemia in remission who had undergone splenectomy. The results of the 64 plateletphereses in these 11 patients (average platelet yield 4.2 X 10(11) +/- 2.4, range 1.2-12.4) were compared with 50 consecutive plateletphereses in nonsplenectomized leukemia patients (average yield 4.9 X 10(11) +/- 3.2, range 2.1-18.3) and 50 consecutive plateletphereses in normal donors (average yield 3.8 X 10(11) +/- 1.4, range 1.7-7.6). There was no difference in the prepheresis platelet counts among the three groups. Plateletphereses were done in 1.5-3 hr by intermittent flow differential cell centrifugation technique. The expected platelet yield was calculated by multiplying the pre-platelet count - (pre-hct/post-hct X post plt count) by the estimated blood volume (70 ml/per kg body weight). The mean ratios of the observed platelet yield to expected platelet yield were similar for the nonsplenectomized leukemia patients (mean ratio = 1.32 +/- 0.50, range 0.73-3.04) and normal donors (mean ratio = 1.31 +/- 0.49, range .52-2.9), implying mobilization of platelets from outside of the blood pool. In contrast, in the splenectomy group, the mean ratio (0.76 +/- 0.32, range 0.31-2.9) was significantly lower (p less than .001). These data indicate that there is replenishment of the circulating platelet pool by the spleen in response to the rapid removal of platelets.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000502:physiology*; D001793:Blood Preservation; D002465:Cell Movement; D002469:Cell Separation; D005260:Female; D006801:Humans; D007938:Leukemia / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D010983:Plateletpheresis; D013154:Spleen / Q000166:cytology*; D013156:Splenectomy