Plateletpheresis in the Era of Automation: Optimizing Donor Safety and Product Quality Using Modern Apheresis Instruments

The increases in major surgeries, transplantations and speciality clinics have significantly increased the utilization of platelet concentrates including single donor platelets (SDP). The advantages of SDP or apheresis platelet have been discussed elaborately by previous authors as compared to random donor platelets. Here we share our experiences of plateletpheresis procedures using the modern apheresis machines with regards to product quality and donor safety. This study included 3016 procedures of plateletpheresis (1397 on Amicus and 1619 on Trima accel cell separators) on eligible donors using recommended apheresis kits. A target yield of 3 × 1011 was set as the end point of each procedure. Donor details, procedure details and donor adverse reactions if any were documented. Statistical analysis was done using the SPSS statistical package (version 13, USA). Of the total 6276 donors screened 2049 (32.6%) were deferred due to various reasons. Out of remaining 4227 eligible donors; 3016 (71.4%) underwent plateletphereis procedures based on the requirement of SDP by the patients. Mean pre-procedure platelet count and hematocrit in donors were 188.3 × 106/mL and 41.7% respectively. Mean procedure time in Amicus (76.6 min) was significantly more than the Trima accel (64.3 min) (p = 0.02). Platelet yield by Trima accel and Amicus was 2.96 × 1011 and 3.08 × 1011 respectively (p = 0.061). A total of 40 donors (1.33%) suffered adverse effect during or after apheresis procedures. While the modern plateletpheresis devices are both donor and user friendly at the same time they provide quality product consistently in lesser time.

A Study on Influence of Donor Hematocrit on the Procedural Parameters of Concentrated Single Donor Platelets Collected by Two Apheresis Devices

With improvements in apheresis collection, platelet additive solution (PAS) is steadily replacing plasma as the storage medium in single donor platelets (SDP). Concentrating platelets in SDP with one-third of plasma and two-thirds of PAS is referred as Concentrated-SDP (C-SDP). We studied the influence of donor hematocrit (Hct) in C-SDP procedures. A retrospective study, consisting of 124 and 95 plateletpheresis donors in MCS+ and Trima respectively. We compared two apheresis equipments MCS+ and Trima with regard to donor hematocrit on procedural parameters such as collection efficiency (CE), collection rate (CR), yield per hour (Y/H), yield per litre (Y/L) and percentage blood volume processed (%BV) during C-SDP procedures. Donors were categorized into two groups with Group A (Hct ≤ 46%) and Group B (Hct > 46%) based on mean baseline Hct of the study population. Among the 219 procedures, the overall CE was significantly higher for Trima over MCS+ equipment (77 vs 56, P < 0.001). However, there was no difference in procedural outcomes like CE, Y/L, Y/H, CR with MCS+ or Trima equipment between groups. %BV processed had a negative correlation with hematocrit in MCS+ (r = - 0.305, P = 0.001) and no difference was observed with Trima equipment. Donor Hct influences C-SDP collection only in processed blood volume with MCS+ equipment. Trima had statistically better performance over MCS+ equipments in all procedural parameters during C-SDP procedures. The data will guide apheresis centre to choose equipments based on donor characteristics.

Minor diurnal and activity-induced variations in daytime peripheral blood platelet counts do not have any major impact on platelet yield by platelet apheresis

Physical activity alters systemic levels of several angioregulatory cytokines that affect microvascular endothelial cells and can be assumed to influence vascular permeability. This may alter platelet release to the bone marrow microcirculation and thereby the levels of circulating platelets. We investigated effects of physical activity on angioregulatory chemokines (CXCL8, 9, 10 and 11) and peripheral blood platelet counts before and after intensive physical activity in young adults, and also compared platelet yields obtained by platelet apheresis performed in the morning and in the afternoon in 20 healthy donors. Physical activity increased serum CXCL10 levels and platelet counts but did not alter the other chemokine concentrations. In the apheresis donors, there was only a minor increase in platelet counts during the day, and the platelet yields did not differ significantly between platelet concentrates collected early in the morning and late in the afternoon. In conclusion, minor intra-individual variations in platelet counts do not seem to have major influence on platelet yields by platelet apheresis.

Complications of donor apheresis

A decreasing blood donor pool in the presence of increasing blood transfusion demands has resulted in the need to maximally utilize each blood donor. This has led to a trend in the increasing use of automated blood collections. While apheresis donation shares many reactions and injuries with whole blood donation, because of the differences, unique complications also exist. Overall, evidence in the literature suggests that the frequency of reactions to apheresis donation is less than that seen in whole blood donation, though the risk of reactions requiring hospitalization is substantially greater. The most common apheresis-specific reaction is hypocalcemia due to citrate anticoagulation, which, while usually mild, has the potential for severely injuring the donor. Other reactions to apheresis donation are uncommon (e.g., hypotension) or rare (e.g., air embolism). More worrisome, and in need of additional study, are the long-term effects of apheresis donation. Recent evidence suggests that repeated apheresis platelet donations may adversely effect thrombopoiesis as well as bone mineralization. Granulocyte donation has also been implicated in unexpected long-term consequences.

Effect of donor variables on yield in single donor plateletpheresis by continuous flow cell separator

The quality of single donor platelets (SDPs) in terms of yield influences platelet recovery in the recipient. Various donor factors such as pre-donation platelet count and hemoglobin (Hb) concentration affect the platelet yield. We studied the influence of pre-donation donor clinical and laboratory factors such as gender, age, weight of the donor, platelet count and Hb on the platelet yield. A total of 94 plateletpheresis procedures performed on continuous flow cell separator (CS3000, Baxter Healthcare, Round Lake, IL, USA) were evaluated for platelet yield. A relationship between pre-donation donor variables and yield of platelets was studied using the Pearson correlation. The mean platelet yield was 2.8+/-0.73x10(11). While a direct relationship was observed between pre-donation platelet count and yield (r=0.50, p<0.001), no such correlation was noticed with donor Hb concentration (r=-0.10, p>0.005). Similarly, no correlation was observed between gender (r=0.05), age (r=0.11) and weight (r=0.18) of the donor with yield. Optimization of platelet yield, which is influenced by pre-donation platelet count, is an emerging issue in blood transfusion services. Identification of such factors may help in selecting donors to obtain higher platelet yields and consequently better clinical outcome.

Factors influencing yield of plateletpheresis using intermittent flow cell separator

Platelet recovery in the recipient is influenced by the transfused dose of platelets, which in turn is dependent on the quality of single donor platelets (SDPs) in terms of platelet yield. Various donor factors such as predonation platelet count and Hemoglobin (Hb) concentration affect the platelet yield. A total of 61 plateletpheresis procedures performed on intermittent flow cell separator (MCS3p, Hemonetics) were evaluated for platelet yield. A relationship between predonation platelet count and Hb concentration with yield of platelets was studied using Pearson Correlation. The mean platelet yield was 2.9 +/- 0.64 x 10(11). While a direct relationship was observed between predonation platelet count and yield (r = 0.51, P < 0.001), no such correlation was noticed with donor Hb concentration (r = -0.05, P > 0.005). The yield was > or =3 x 10(11) in >80% of procedures when the predonation platelet count was > or =250 x 10(3)/mm. Optimization of platelet yield, which is influenced by predonation platelet count, is an emerging issue in blood transfusion services. However, further studies in this regard are needed using more advanced cell separators.

Quality systems in automated plateletpheresis in hospital-based blood transfusion service in north India

The issues of providing quality blood products and maintaining donor safety are primary aims of blood transfusion services. A comprehensive quality system should be in place to fulfill these aims, which can be attained through strict adherence to the established standard operating procedures (SOPs). The Drugs and Cosmetics Act of India, which controls the licensing of blood transfusion services, does not provide clear guidelines regarding plateletpheresis procedure. We, therefore, established our own SOP and operational flow chart for plateletpheresis that can be easily followed by other centers in India. A total of 100 plateletpheresis procedures performed using two cell separators (CS3000 Baxter Healthcare, Round Lake, IL; MCS3p, Haemonetics Corporation, Braintree, MA) were evaluated following our established SOP. The mean platelet yield in CS3000 was 2.9 +/- 0.84 x 10(11) and in MCS3p it was 2.88 +/- 0.75 x 10(11)per unit. However, only 4-7% of SDPs showed WBC levels <5 x 10(6) due to lack of appropriate methods to quantitate residual WBC counts. Six of 100 donors complained of hypocalcemic symptoms. The operational flow chart designed in this study was found to be simple and easy to adapt by blood transfusion services in this country.

Comparative study of plateletpheresis using Baxter CS 3000 plus and Haemonetics MCS 3P

Platelet concentrates made from cell separators are used more frequently due to less donor exposure and leucodepletion. This retrospective study was done to compare plateletpheresis done on two cell separators: Baxter CS 3000 plus and Haemonetics MCS 3p. Plateletpheresis procedures, done from January 1997 to April 2002, were included in the study. One hundred and seven procedures were done on Haemonetics MCS 3p using SDP protocol, 49 procedures were done on Haemonetics MCS 3p using PLP protocol, and 107 were done on Baxter CS 3000 plus. Pre-procedure donor's platelet count and haemoglobin were comparable in all the groups. Platelet yield was comparable in PLP (6.44 x 10(11) platelets) and SDP (5.27 x 10(11)) protocols, but significantly less in Baxter (4.05 x 10(11) platelets, P < 0.001 for PLP and P < 0.05 for SDP). Efficiency of platelet removal was statistically significantly different in all the groups (P < 0.0001), however it was more in PLP (PLP-55.02%, SDP-47.38%, Baxter 38.98%). A significant number of products (19.51%) of Baxter failed to comply platelet count of product < or = 2,435 x 10(9)/l compared to 5.13% in PLP and 1.23% in SDP group; 36.96% of units from PLP and 28% from SDP qualified for split products compared to 1.18% of Baxter. PLP protocol of Haemonetics MCS 3p gives better platelet yield compared to Baxter CS 3000 plus and SDP protocol of Haemonetics MCS 3p.

Calculated platelet dose: Is it useful in clinical practice?

The corrected count increment (CCI) can standardize assessment of platelet transfusions by correcting for patient's body surface area (BSA) and platelet dose (PD). By using a fixed CCI and a desired post-transfusion platelet count, CCI formula can be used to calculate PD. Our transfusion service has used the following formula since May 1990, to determine the number of platelet units to transfuse in non-bleeding patients: 1 where, 7,000 is expected platelet count increment per unit transfused, and 1.7 is BSA in square meters in a normal adult. To evaluate its usefulness, a retrospective review was performed of all 2,202 platelet transfusions at our level-one trauma center, between 1/1/98 and 12/31/00. Eighty-three transfusions in 69 adult patients, in which a calculated PD was determined prior to transfusion, were evaluated for platelet increments at 1, 1-18, or 18-24 hours post-transfusion. Transfusions that used the calculated PD (n = 49) were compared with those that were based on clinical judgment alone (n = 34). These two groups were comparable in their pre-transfusion platelet counts, ABO compatibility, and unit storage duration. The mean calculated PD transfused in the first group was 6 U +/- 1 standard deviation, which was not different from the second group (P = 0.2). There was no difference in the platelet count increments at 1, 1-18, or 18-24 hours post-transfusion. This study suggests that using a PD based on the CCI formula does not reduce platelet usage when the routine PD is six or less platelet concentrates.

Prophylactic platelet transfusions: which dose is the best dose? A review of the literature

Routine platelet transfusions for patients with acute leukemia were introduced in the early 1960s, and since then platelet use has increased steadily. Despite widespread use, good clinical evidence supporting prophylactic platelet transfusions is limited, and there are very few studies that have examined the dose for prophylactic platelet transfusions. Review of the platelet dose used in both early studies of routine platelet transfusions and more recent clinical trials of platelet transfusions shows wide variation in dosing, which is also reflected in clinical practice. As such, only limited recommendations for platelet dose have been forthcoming from consensus conferences or guidelines. The results from 3 recent clinical trials and a mathematical model examining the dose for prophylactic platelet transfusions suggest that lower dose transfusions may decrease the total number of platelets transfused; however, no definitive conclusions about the optimal platelet dose can be reached as these trials were not designed to evaluate bleeding outcomes or total platelet utilization. Future large clinical trials of platelet dose, which examine these critical outcomes, are required. Only with these results can the optimal platelet dose be determined.

Hemoglobin and platelet count effect on platelet yields in plateletpheresis

BACKGROUND

Platelet transfusion in thrombocytopenic patients, especially those with marrow failure, remains one of the most important support measures available. Treatment success depends on rational use of platelet transfusion. Platelet yield, reflected in transfused platelet dose, influences platelet recovery in the patient and allows prolonging intervals between transfusions. In this study, our main objective was to identify donor laboratory and clinical factors that showed some influence on platelet yield obtained by apheresis.

METHODS

Healthy donor laboratory and clinical data were analyzed prior to performing plateletpheresis. Platelet yield was quantified after plateletpheresis procedure was concluded in two different ways: a) prefixed volume of 5,000 mL processed, and b) volume determined according to manufacturer recommendations. Age, gender, hemoglobin concentration, platelet and leukocyte count, height, and weight were included as yield-predicting donor variables.

RESULTS

In group A, two variables were significant: donor platelet count and hemoglobin (Hb) concentrations with r = 0.554, and in group B, donor platelet count, Hb concentrations, and volume with r = 0.758.

CONCLUSIONS

Donor platelet count and hemoglobin concentrations influence platelet yield: higher platelet count corresponds to higher yield, while hemoglobin shows an inverse relationship, i.e., the lower the hemoglobin concentrations, the higher the platelet yield.

Altering interface detector positioning in combination with prestorage filtration to achieve a better quality of single donor platelet concentrates using the CS 3000 Plus blood separator

The interface detector (ID) is an optical density sensor that affects the quality of single donor platelet collection using the CS 3000 Plus blood separator. The purpose of this study was to evaluate the effect of altering ID position on platelet yields and the contamination of leukocytes (WBC) in platelet concentrates (PCs). Dual-needle apheresis procedures (n = 93) were performed using an A35 collection chamber. Plateletpheresis products were separated according to interface detector offset (IDO) positioning into four groups: A: IDO = 6 (n = 33), B: IDO = 10 (n = 28), C: IDO = 12 (n = 18), D: IDO = 18 (n = 14). For 32% of the collections, the closed system apheresis kit with integral Sepacell filter (Baxter) was used and 33% of them were leukodepleted using the LRP-6 (PALL) filter. Our results showed that: (1) Although the mean blood volume and the time of apheresis were significantly higher, the mean platelet (PLT) yields were significantly lower in PCs of group A as compared to all other groups (P < 0.0001). (2) The mean WBC content was significantly higher in PCs of group D as compared to all other groups (P < 0.0001). (3) With the LRP-6 filter, a significantly higher WBC reduction as well as PLT loss in PCs was observed as compared to Sepacell leukapheresis filter. A higher PLT loss was observed with both filters when leukoreduction was performed within the first 6 hours as compared to 24 hours after the procedure. Conclusively, an IDO setting of 10 or 12 results in better platelet yields in PCs without increasing the WBC contamination. An IDO positioning of 18 or higher must be avoided or should be always combined with PCs leukodepletion. Finally, the best timing for leukoreduction is 24 hours after the plateletpheresis.

Volunteer donor apheresis

Volunteer donor apheresis has evolved from early plasmapheresis procedures that collected single components into technically advanced multicomponent procedures that can produce combinations of red blood cells, platelets, and plasma units. Blood collection and utilization is increasing annually in the United States. The number of apheresis procedures is also increasing such that single donor platelet transfusions now exceed platelet concentrates from random donors. Donor qualifications for apheresis vary from those of whole blood. Depending on the procedure, the donor weight, donation interval, and platelet count must be taken into consideration. Adverse effects of apheresis are well known and fortunately occur in only a very small percentage of donors. The recruitment of volunteer donors is one of the most challenging aspects of a successful apheresis program. As multicomponent apheresis becomes more commonplace, it is important for collection centers to analyze the best methods to recruit and collect donors.

Generation of reticulated platelets in response to whole blood donation or plateletpheresis

BACKGROUND

There are few reports about thrombopoietic responses in whole blood (WB) and platelet-pheresis donors. This study compares the thrombopoietic responses of such donors and their platelet values.

STUDY DESIGN AND METHODS

The effect of WB donation or selective platelet loss (plateletpheresis) was evaluated prospectively. WB and platelet donor samples before donation and for 7 days thereafter were assessed for platelet count, mean platelet volume, and platelet reticulocytes.

RESULTS

Reticulated platelets appeared in the circulation of plateletpheresis donors by 24 hours. The proportion of reticulated platelets was highest on Day 2, and above-normal levels of reticulated platelets persisted until Day 7. The mean platelet volume was high on Days 2 and 3, which corresponded with the appearance of reticulated platelets. After plateletpheresis, platelet counts were higher than could be accounted for by new platelets, which suggested the release of sequestered platelets. WB donors manifested no changes in platelet counts but had a peak of circulating platelet reticulocytes 2 days after the donation.

CONCLUSION

The thrombopoietic peak in WB and plateletpheresis donors occurs 2 days after donation, and the response level is related to the amount of platelets lost. The impact of platelet loss on the number of circulating platelets is modulated by the release of platelets from the spleen.

Thrombopoietin therapy increases platelet yields in healthy platelet donors

The recombinant thrombopoietins have been shown to be effective stimulators of platelet production in cancer patients. It was therefore of interest to determine if one of these, pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), could be used to increase platelet counts and consequently platelet yields from apheresis in healthy platelet donors. In a blinded, 2-cycle, crossover study, 59 platelet donors were randomized to receive a single subcutaneous injection of PEG-rHuMGDF (1 microg/kg or 3 microg/kg) or placebo and 15 days later undergo platelet apheresis. Donors treated with placebo had a median peak platelet count after PEG-rHuMGDF injection of 248 x 10(9)/L compared with 366 x 10(9)/L in donors treated with 1 microg/kg PEG-rHuMGDF and 602 x 10(9)/L in donors treated with 3 microg/kg PEG-rHuMGDF. The median maximum percentage that platelet counts increased from baseline was 10% in donors who received placebo compared with 70% in donors who received 1 microg/kg and 167% in donors who received 3 microg/kg PEG-rHuMGDF. There was a direct relationship between the platelet yield and the preapheresis platelet count: Placebo-treated donors provided 3.8 x 10(11) (range 1.3 x 10(11)-7.9 x 10(11)) platelets compared with 5.6 x 10(11) (range 2.6 x 10(11)-12.5 x 10(11)) or 11.0 x 10(11) (range 7.1 x 10(11)-18.3 x 10(11)) in donors treated with 1 microg/kg or 3 microg/kg PEG-rHuMGDF, respectively. Substandard collections (<3 x 10(11) platelets) were obtained from 26%, 4%, and 0% of the placebo, 1 microg/kg, and 3 microg/kg donors, respectively. No serious adverse events were reported; nor were there events that met the criteria for dose-limiting toxicity. Thrombopoietin therapy can increase platelet counts in healthy donors to provide a median 3-fold more apheresis platelets compared with untreated donors.

Prophylactic platelet transfusions from healthy apheresis platelet donors undergoing treatment with thrombopoietin

Many patients receiving dose-intensive chemotherapy acquire thrombocytopenia and need platelet transfusions. A study was conducted to determine whether platelets harvested from healthy donors treated with thrombopoietin could provide larger increases in platelet counts and thereby delay time to next platelet transfusion compared to routinely available platelets given to thrombocytopenic patients. Community platelet donors received either 1 or 3 microg/kg pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) or placebo and then donated platelets 10 to 15 days later. One hundred sixty-six of these platelet concentrates were then transfused to 120 patients with platelets counts 25 x 10(9)/L or lower. Pretransfusion platelet counts (11 x 10(9)/L) were similar for recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Early after transfusion, the median platelet count increment was higher in patients receiving PEG-rHuMGDF-derived platelets: 19 (range, -12-66) x 10(9)/L, 41 (range, 5-133) x 10(9)/L, and 82 (range, -4-188) x 10(9)/L for placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. This difference was maintained 18 to 24 hours after transfusion. Transfusion-free intervals were 1.72, 2.64, and 3.80 days for the recipients of the placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. The rate of transfusion-related adverse events was not different in recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Therefore, when transfused into patients with thrombocytopenia, platelets collected from healthy donors undergoing thrombopoietin therapy were safe and resulted in significantly greater platelet count increments and longer transfusion-free intervals than platelets obtained from donors treated with placebo.

Platelet transfusion therapy

The relative merits of apheresis platelets and platelet concentrates are undergoing debate due to evolving issues of safety, inventory, and cost. The application of photochemical inactivation technology may eliminate any rationale for the use of apheresis platelets rather than pooled platelet concentrates, so that the relative merits of these two alternatives will be debated over costs and inventory. Doses of apheresis platelets are determined by donor platelet count and by platelet yield. The generation of a platelet apheresis inventory has been accompanied by a decline in whole blood inventory; research into the impact of these distinct donor pools on national blood policy is needed.

Economic consequences of alterations in platelet transfusion dose: analysis of a prospective, randomized, double-blind trial

BACKGROUND

In recent years, decreasing financial resources led to the use of lower-dose platelet components. However, the economic consequences of the use of such components have not been carefully studied.

STUDY DESIGN AND METHODS

A formal economic analysis was conducted of a recently reported, prospective, randomized, double-blind study examining the platelet dose-response relationship in nonrefractory patients. The economic analysis used a decision analysis model, conducted from the hospital's perspective and based directly on the observed clinical data and on institutional cost structures.

RESULTS

The decision analysis model estimated that a 38-percent reduction in mean platelet dose, within the commonly prescribed dose range, would result in the average patient's requiring approximately 60 percent more transfusions in the posttransplant period (8 vs. 5; p = 0.05), which would result in an estimated 60-percent increase in the median cost to the hospital ($4486/patient vs. $2804/patient [in 1996 US dollars], p = 0.05).

CONCLUSION

Efforts to decrease costs by utilizing lower-dose single-donor platelet transfusions are predicted to result in a disproportionate increase in the number of transfusions per patient, with a corresponding increase in overall hospital transfusion costs.

Comparison of plateletpheresis concentrates produced with Spectra LRS version 5.1 and LRS Turbo version 7.0 cell separators

BACKGROUND

The importance of transfusing WBC-reduced blood components is widely recognized, as it reduces the risk of alloimmunization and transfusion-transmitted CMV infections. The latest generation of cell separators allows the collection of WBC-reduced apheresis platelet concentrates (APCs).

MATERIALS AND METHODS

Consecutive APCs (n = 232) were retrospectively evaluated: 163 collected with the Spectra LRS [leukocyte-reduction system] Version 5.1 (Group A) and 69 with the LRS Turbo Version 7.0 (Group B) (both: COBE BCT). Donor peripheral blood count, procedure data, platelet yield, collection efficiency (CE), and residual WBC count in APCs were recorded.

RESULTS

The platelet yield was higher in Group B than in Group A: 5.5 +/- 1.4 versus 4.4 +/- 1.1, p<0.0001; residual WBCs were <5 x 10(6) in 99.4 percent of Group A APCs and in 97.1 percent of Group B APCs. CE was higher in Group B than in Group A: 51.4 +/- 8.7 versus 43.6 +/- 6.3, p<0.0001. Moreover, a correlation between predonation platelet count and platelet yield was observed in both groups. A double product (platelet yield >6.0 x 10(11)) was obtained in 28.9 percent of Group B APCs and in 9.2 percent of Group A APCs.

CONCLUSIONS

The Spectra LRS Turbo version 7.0 release showed a better CE and resulted in a higher platelet harvest than did the LRS version 5.1. High predonation platelet counts allow a higher platelet yield.