A comparative study of plateletpheresis using Baxter Autopheresis C and Haemonetics PCS Plus

SUMMARY. This study compared plateletpheresis on the Haemonetics PCS Plus (PCS Plus) and the Baxter Autopheresis C (Auto C) using the same 100 selected donors. The number of packs meeting UK BTS/NIBSC specification (>2.2 times 10¹¹ platelets per pack) was achieved by 99% of PCS Plus and 82% of Auto C procedures. The positive correlation found between donor precount and final platelet yield was better for the PCS Plus. Both machines met U.K. specification for white-cell contamination but this was significantly greater for the Auto C. Plasma yields were similar.
As a result of this study we chose to use the PCS Plus for routine plateletpheresis in our unit. This has enabled us not only to comply with UK BTS/NIBSC specifications for apheresis platelets easily and cost effectively but also to meet our own higher specification (2.75 times 10¹¹ platelets per pack) using existing staff and without extending the working day.     

Endogenous serum levels of thrombopoietic cytokines in healthy whole-blood and platelet donors: implications for plateletpheresis

Serum concentrations of the thrombopoiesis-enhancing cytokines thrombopoietin (TPO), erythropoietin (EPO), interleukin (IL)-6 and IL-11 were determined in 119 healthy whole-blood (WBD) and 101 platelet donors (PD) prior to donation. The 90% TPO reference interval in WBD of 64-867 pg/ml (median 163, 100% range 45-7572) was significantly higher than in PD of 56-524 (median 122, range 44-801, P = 0.004), whereas their platelet counts were lower (P < 0.001). EPO levels were not different (WBD 7.7 +/- 3.8, PD 8.0 +/- 4.9 IU/l), IL-6 and IL-11 were below the detection limit in >/=90% of cases (IL-6 < 3.2 pg/ml, IL-11 < 31.2 pg/ml). None of the cytokines correlated with platelet counts, other blood parameters, or in the PD group with the frequency of platelet donations within the last 6 months. We conclude that plateletpheresis does not lead to a lasting increase of thrombopoietic cytokines and provide reference data for potential platelet mobilization strategies with recombinant growth factors.     

The effects of platelet apheresis in total hip replacement surgery on platelet activation

BACKGROUND: Autologous platelet rich plasma (PRP) harvest with autotransfusion devices has been used for 10 years in cardiac surgery and recently in orthopedics as a blood saving method. The quality of the harvested platelets has not been adequately examined, in part because of methodological difficulties in studying platelet function during surgery. METHODS: Twenty patients undergoing primary total hip replacement (THR) were studied. Ten patients underwent an immediate preoperative platelet apheresis to obtain concentrated platelet rich plasma (c-PRP). The other 10 patients not undergoing apheresis were allocated to a control group. Platelet activation was evaluated as the population expressing P-selectin on the surface of platelets in the c-PRP and in blood samples collected pre-, per- and postoperatively. The method used was flow cytometry. RESULTS AND CONCLUSIONS: A minor population of activated platelets was found to be circulating in the patients' blood, with a highly significant difference between patients (P = 0.005), and with a range of 1-23% in peroperative activation. PRP harvest did not significantly alter platelet activity. The platelet apheresis procedure did not inhibit platelet function in the c-PRP, as judged by a high proportion of platelets that could be activated in ADP stimulation experiments (mean value +/- SD 86% +/- 7.5%).     

Peripheral blood lymphocyte numbers, lymphocyte proliferative responses in vitro, and serum immunoglobulins in regular hemapheresis donors

Selected tests of lymphoid function were used to screen a population of volunteer hemapheresis donors. Testing included: 1) absolute lymphocyte numbers, and percentage of T-cell, B-cell, and mononuclear phagocytes, 2) serum immunoglobulins, and, 3) in vitro proliferative responses to lectin mitogens (phytohemagglutinin, concanavalin A, and pokeweed mitogen), soluble antigens (staphylococcal filtrate, candida, and streptococcal varidase), and cell-bound alloantigens (mixed lymphocyte culture). A control population of first-time plateletpheresis donors was examined similarly. Regular donors manifested a small but statistically significant decrease in absolute lymphocyte counts (p less than 0.02), and IgM (p less than 0.02) compared to controls. Leukapheresis donors also manifested significant decreases in percentage of T cells (p less than 0.02). These findings are qualitatively similar to changes reported following intensive lymphocytapheresis and indicate the need for conservative policies regarding donation frequency in hemapheresis programs.     

Combination of acute preoperative plateletpheresis, cell salvage, and aprotinin minimizes blood loss and requirement during cardiac surgery

Acute preoperative plateletpheresis (APP), cell salvage (CS) technique, and the use of aprotinin have been individually reported to be effective in reducing blood loss and blood component transfusion while improving hematological profiles in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this prospective randomized clinical study, the efficacy of these combined approaches on reducing blood loss and transfusion requirements was evaluated. Seventy patients undergoing primary coronary artery bypass grafting (CABG) were randomly divided into four groups: a control group (group I, n = 10) did not receive any of the previously mentioned approaches. An APP and CS group (group II, n = 20) experienced APP in which preoperative platelet-rich plasma was collected and reinfused after reversal of heparin, along with the cell salvage technique throughout surgery. The third group (group III, n = 22) received aprotinin in which 5,000,000 KIU Trasylol was applied during surgery, and a combination group (group IV, n = 18) was treated with all three approaches, i.e., APP, CS, and aprotinin. Compared with group I (896+/-278 mL), the postoperative total blood loss was significantly reduced in groups II, III, and IV (468+/-136, 388+/-122, 202+/-81 mL, respectively, p < 0.05). The requirements of packed red blood cells in the three approached groups (153+/-63, 105+/-178, 0+/-0 mL, respectively) also were reduced when compared with group I (343+/-118 mL, p < 0.05). In group I, six patients (6/10) received fresh-frozen plasma and three patients (3/10) received platelet transfusion, whereas no patients in the other three groups required fresh-frozen plasma and platelet. In conclusion, both plateletpheresis concomitant with cell salvage and aprotinin contribute to the improvement of postoperative hemostasis, and the combination of these two approaches could minimize postoperative blood loss and requirement.     

C-PG血小板聚集试验在单采血小板捐献者筛查中的应用

本研究探讨以阳离子没食子酸丙酯（C-PG）为激活剂的血小板聚集试验用于单采血小板捐献者筛查的可行性,并调查血小板献血者血小板功能缺陷的发生率.测定不同浓度C-PG诱导的健康献血者的血小板聚集率,以确定C-PG的最适应用浓度;检测30名志愿者服用阿司匹林前和服药24小时后的血小板聚集率,以确定血小板功能不良的筛查界点值;检测483例血小板捐献者的C-PG诱导的血小板聚集率,并对聚集功能不良者进行活化血浆凝固时间（APCT）测定.结果表明：血小板聚集率随C-PG浓度的增加而升高,当C-PG浓度达200μmol/L时,血小板聚集率达最高;服用阿司匹林24小时后的血小板聚集率与服药前相比,均表现明显减低（P＜0.001）,但以C-PG诱导180秒时的血小板聚集率减低最显著.血小板功能不良的筛查界点值确定为C-PG诱导180秒时的血小板聚集率小于20%;在483例血小板捐献者中,检出25例有血小板聚集功能不良,其中有11例表现为血小板促凝血活性减低.结论：C-PG诱导的血小板聚集试验能有效的检出血小板功能不良者,适用于血小板捐献者血小板功能的筛选;在血小板献血者中,血小板功能缺陷者的检出率大约为5%.