Plateletpheresis Donors Research Articles

The Impact of an Undergraduate Biology Class on Donor Recruitment at a Hospital-Based Blood Donor Center.

A biology class, BIOL 294H, taught undergraduates about platelet donation while partnering with the University of North Carolina's (UNC's) hospital-based Blood Donation Center to recruit apheresis platelet donors. We identified our platelet donors' demographics and learned how BIOL 294H affected recruitment. Every platelet donor presenting to the UNC Blood Donation Center from February 7, 2017, to March 10, 2017, was asked to complete an electronic 10-question survey. A total of 159 unique donors completed the survey; 64% were female and 75% were between ages 18 and 25 years. Overall, 70% were UNC undergraduate students. Over half (56%) reported first learning about platelet donation through word of mouth, and 22% cited specific efforts associated with BIOL 294H. Recruitment of undergraduate platelet donors primarily included BIOL 294H peer interactions and deliverables from the class, such as social media updates and events on campus. The sustained recruiting efforts of our students over many years contributed to recruitment of a majority of our platelet donors.

In Vitro Functionality of hiPSC Derived PLT+: The Utility of Microfluidic Assays in Determining Potency

Introduction: There is a growing shortage of platelets, the principal blood cells responsible for clot formation and blood vessel repair at sites of active bleeding. Platelet BioGenesis (PBG) is developing a commercial-scale, donor-free platelet (PLT+) production process using a cGMP-grade human induced pluripotent stem cell line (hiPSC) to address this issue. The PLT+ activity is being characterized extensively through multiple approaches that measure hemostatic function both in vitro and in vivo, with the ultimate goal of determining a clinical dose in humans. Alongside tests such as the current gold standard thrombin generation assay (TGA), we have developed an in-house microfluidic model to measure the ability of PLT+ to adhere to extracellular proteins under flow. The assay captures the surface receptor dynamics, as well as the ability of PLT+ to initiate coagulation. Materials and Methods: The thrombin generation assays are performed according to manufacturer's instructions. For the in-house microfluidic assay (MFA), fibrillar collagen, fibrinogen, or von Willebrand Factor is patterned in a commercial microfluidic device (Ibidi Slide VI 0.1). PLT+ (DNA-, calcein +, CD61+, CD42a+ cells from our bioreactor) are concentrated in normal pooled plasma, platelet additive solution, or platelet wash buffer to a normalized concentration of 1e8/mL, and are labeled with the mitochondrial dye DiOC6. Calcium chloride (7.5 mM) is added and the solution is perfused with a syringe pump at 50 1/s over the bioactive surface for 10 min. Images are captured every 10 seconds and quantified with ImageJ. After perfusion, the samples are fixed with 4% paraformaldehyde and can be stained for further characterization. Results and Discussion: PLTs+ are functionally non-inferior to human donor (blood) platelets and appear more active than Day 4/5 stored apheresis unit platelets. The TGA of PLT+ shows a more rapid generation of thrombin but similar total potential to donor platelets (Figure A). In the microfluidic assay, PLT+ (green DiOC6, red PAC1, figure B) adhere readily to the collagen surface under low shear flow, but do not adhere to non-functionalized surfaces, indicating GPVI functionality. As measured by surface coverage, the PLT+ resuspended in PAS adhere faster to the surface than either freshly washed donor platelets or apheresis platelets (p=0.01). When the PLT+ are preincubated in normal pooled plasma prior to perfusion, we observe fibrin formation and the aggregates show clot retraction, which supports the TGA results. Adhesion to surface bound fibrinogen and VWF is also comparable to donor platelets (GP IIb/IIa and GPIb function,). Combined, the TGA and MFA data reflect results of traditional more resource intensive assays, suggesting their viability as a rapid and flexible platform to study platelet function and function as release assays for in vitro generated PLTs+ Conclusion: Current work demonstrates that PLT+ are functional and a future alternative to donor derived platelet units. The MFA is a valuable tool for the characterization of this new therapeutic because of its specific control of surface protein-receptor interactions, shear forces, and flexibility to look at multiple markers. Alongside the TGA, the MFA will be a release assay for the PLT+. Figure Disclosures Lehmann: Platelet Biogenesis: Employment. Burton:Platelet Biogenesis: Employment. Szemethy:Platelet Biogenesis: Employment. Valdez:Platelet BioGenesis: Employment. Thon:Platelet BioGenesis: Employment.

Optimizing the Use of Platelets in a Single Oncology Center during Critical Shortages: Can Current Platelet Donations from Volunteer Donors be Sustained to Provide Adequate Platelet Inventories Long Term?

Introduction: The single largest use of platelets transfusions (PLT) are for patients with hematologic malignancies receiving Myeloablative chemotherapy or undergoing hematopoietic stem cell transplantation (HSCT). Patients routinely get prophylactically platelet transfusions at platelet counts ≤ 20 × 109/L at our institution per institutional guidelines. For this review we analyzed a two day period when a critical shortage of platelets occurred to illustrate how we managed the transfusion needs of our patients. Method All daily platelet orders are triaged. The orders are inclusive of patient demographics, indication(s) for transfusion and pertinent lab results (most recent H/H, PLT count, PT/INR/PTT, fibrinogen, D-Dimer, Creatinine and BUN). The location of the patient and indications (ICH Hemorrhage/coagulation abnormalities) further allows the Blood Bank to prioritize the release of platelets. The orders are sorted by counts ≤5K, 6-10K, 11-20K, 21-30K, 31-40K, 51-60K and >61K and then categorized by location (EC, Surgery/Outpatients and disease (Hematologic malignancies/HSCT/other neoplasms). A reduction of the Random Donor Platelet (RDP) inventory by 50% is considered critical especially when daily shipments from our contracted blood suppliers are delayed or reduced. Our regular platelet inventory consist mainly of RDPs with 5-10% of Single Donor Apheresis platelets (SDPs). Our daily transfusion needs consists of 400 to 700 RDPs with a reduction on weekends. Due to the volume of our daily platelet transfusion our needs cannot be met by SDPs only. Results: We received 269 platelet transfusion orders within the two day critical shortage period. The bulk of the orders were received between 4-10 am. The majority (93%) were from patients undergoing treatment for hematologic malignancies of which 18% were from HSCT patients. A total of 474 RDP were transfused to 176 (66%) patients, median of 3 (range 2-4 pooled RDPs), 57 (32%) received 2 pooled RDPs, 116 (66%) received 3 pooled RDPs and 3 (2%) patients received 4 pooled RDPs. Of the 269 patients 82 (30%) were transfused with SDPs. There were 2 duplicate orders and 9 (3.3%) patients did not receive platelets on the requested day. The majority of the platelet orders (85.5%) were for platelet counts =<20 K/uL, followed by Intracranial hemorrhage (4%), active bleeding (3.4%) and bone marrow biopsy (2.6%) and LP/Solid Organ biopsy/Spinal Surgery/Others (each <1%). The reduction in the number of pooled RDPs did not lead to adverse events. Discussion: When the platelet inventory is at par, patients receive 4 pooled RDP units as prophylactic transfusion for counts ≤ 20K. When the inventory falls to below 50% of par, the number of pooled RDPs is decreased to 3 for actively bleeding patients and for those with counts ≤10 K/L. The pools are further decreased to 2-3 RDP units for counts 11-20 K based on inventory. Electronic notification is sent to primary providers to call the Transfusion Medicine Physician when the reason for transfusion does not meet institutional guidelines. The current platelet stock management is heavily dependent on whole blood donations from which RDPs are processed. High school students currently contribute 10% of the US blood supply which may increase up to 20% during the spring/fall months. The most important question that needs to be discussed and addressed before it leads to a crisis is the sustainability of Platelets donations from volunteer donors. Donor Centers around the United States have seen a gradual decline in volunteer donors with aging of the volunteer donor pool. Only 4-6% of eligible donors in the US currently donate blood and this is projected to decrease in the next five years. The TRALI mitigation strategy eliminated many eligible females from donating whole blood/platelets and now the Iron mitigation strategy will also impact the volunteer donor pool. One avenue that could be explored for platelet acquisition would be to accumulate a dedicated pedigreed/trusted pre-screened repeat pool of paid donors similar to the concept used by US plasma centers. This will be a major paradigm shift, be problematic in the beginning as the model is not being used currently in the US for platelet donations. However, with the ever increasing need for platelet transfusion, altruistic appeals alone may be insufficient to meet the demands of blood and platelets. This concept may not be too farfetched in the near future and begs to be considered. Disclosures No relevant conflicts of interest to declare.

Determination of Appropriate Deferral Time for Repeat Apharesis Platelets Concentrate Donation in Abuja, Nigeria

Background: Plateletpheresis is the process by which a therapeutic adult dose of platelet concentrate is produced from a single donor using automated cell separator equipment. Recently, the demand for Apheresis Platelets concentrate transfusions has been increasing in our hospitals. This has been attributed to increased cases of malignancy associated bone marrow suppression and various other causes of thrombocytopaenia and thrombopathies. The Increasing use of myeloablative chemotherapy in treatment of haematological and other malignancies also results in transient severe fall in platelet count. The demand generally outstrips the supply necessitating the need to search for additional donor sources to increase the supply of platelets for transfusion. Is it therefore possible to reduce the time interval between plateletpheresis while maintaining donor safety? Aims and Objectives: The aim of the study was to determine the platelets recovery time after platelets concentrate donation with a view to determining the appropriate deferral time for repeat plateletpheresis Methods: The study was conducted at the National Hospital Abuja. Fifty seven healthy plateletpheresis donors were recruited over a period of seven months and their haematological parameters were analyzed on days 0, 2 and 7 post donation. We excluded donors whose pre-donation platelet count were less than 200 x 109/L Results and Analysis: Analysis was done in only forty eight (48) donors as nine (9) participants withdrew before the end of the study. The results show There was a significant decrease in the platelets counts (p <0.001), with subsequent good platelets recovery post donation (Pre: 259.83±44.61 x 109/L; Post - Day 0: 205.29±36.77 x 109/L, day 2: 216.88±32.71 x 109/L and day 7: 240.3±41.83 x 109/L). The apheresis donors recovered 64.29% of the lost platelets by day 2 of donation and subsequently attain 92.49% of pre-donation count within 7 days of donation. There was a statistically significant transient increase in the immediate post donation haemoglobin concentration (14.72±1.32)g/dL but this gradually reduced on day 2 (13.75±1.04)g/dL and 13.83±1.04g/dL on day 7 showing no significant different from the pre-donation Hb of 13.96±1.02g/dL Conclusion: This study has shown statistically significant platelets recovery 7 days after plateletpheresis making a 7 day deferral for repeat plateletpheresis feasible in our environment. The study also shows feasibility of a 2 days deferral as recommended by AABB. Strict monitoring and pre-donation evaluation of donors should be done to prevent any adverse events such as anaemia and thrombocytopenia. Disclosures No relevant conflicts of interest to declare.

Delayed adverse events in male plateletpheresis donors: Initial insights on donor safety.

Minimal information is available regarding delayed adverse donor events (D-ADEs) in plateletpheresis donors. Proactive follow up of donors for D-ADEs is not done routinely by BTS. The aim of this study was to analyze frequency and type of D-ADEs and its correlation with contributory factors if any. In this prospective observational study all eligible donors were contacted by telephone twice and asked about general wellbeing and questions specific to adverse donor events (ADEs). Donors were called at 24 hours and 2 weeks after donation. The ADEs were categorized in accordance with the International Society of Blood Transfusion standard guidelines. A total of 531 donors were analyzed in the study. D-ADEs were more common as compared to immediate ADEs (I-ADEs) (19.21% vs 5.46%, P < .0001). The most common D-ADEs were bruises (7.34%) and sore arms (3.58%). Localized D-ADEs in form of bruise and hematomas were more frequent as compared to systemic D-ADEs like fatigue and vaso-vagal reactions (16.01% vs 3.20% P < .0001). Repeat donors had a lower incidence of systemic D-ADEs (1.61% vs 6.96%, P = .001). Donors with weight ≤75 kg and platelet count ≤230 × 103 μL were more prone to systemic D-ADEs (P < .05). Citrate toxicity was more common in donors with weight ≤ 75 kg (P = .002). Plateletpheresis procedures are relatively safer without any sequelae. D-ADEs are more common than I-ADEs. Localized D-ADEs are more frequent than systemic D-ADEs. First-time donors are more prone to D-ADEs than repeat donors.

Analysis between Platelet Count and Blood Groups in Apheresis Platelet Donors with Demographic Features

Platelet transfusion is used to prevent bleeding in patients with thrombocytopenia or platelet dysfunction. Purpose of investigating demographic characteristics of eligible volunteers as platelet donors and of demonstrating the association of platelet counts with blood groups as well as other factors. We used data of individuals who referred to a blood center in our hospital. Age, body weight, body mass index (BMI), and gender were determined, and than hemogram values such as leukocyte, hemoglobin, hematocrit, and platelet and ABO blood types of those individuals were identified. A statistically significant difference determined for height, body weight, and BMI in both genders. Although BMI was lower in the group of platelet count ≤ 250, it was higher in a group of platelet count &gt; 250. Furthermore, platelet count was more moderate in blood group O Rh-positive but, no significant difference was group O Rh-negative. Platelet count was higher in other Rh-positive blood groups than Rh negatives. BMI is vital in apheresis donors, and individuals with higher BMI values may prefer in case of double dose or more apheresis need. The determination of platelet counts in Rh positives is more elevated than Rh negatives.

Efficacy of cross-match compatible platelets in multi transfused haemato-oncology patients refractory to platelet transfusion

BackgroundPlatelet refractoriness, which leads to platelet transfusion failure resulting in significant morbidity and long hospital stay, is routinely not investigated. AimsTo determine the efficacy of cross-match compatible platelets in multi-transfused alloimmunized hemato-oncological patients refractory to platelet transfusion. Materials and method149 ABO compatible single donor apheresis platelet transfusions given to 38 alloimmunized refractory patients. Corrected Count Increment (CCI) <5000 (1 h) was taken to define refractoriness. Solid-phase red cell adherence assay was used to determine the alloimmunization status and platelet cross-matching. Post Transfusion Platelet Increment, CCI and the Percentage Platelet Recovery were used to monitor the effectiveness of platelet transfusion. ANOVA test followed by Post hoc test Tukey HSD used to compare group means and classified into three groups depending upon the cross-matching and compatibility status. Categorical data was analysed for various outcomes using Pearson's chi square test or Fischer exact test. ResultPatients showed statistically significant recovery in terms of PPI, CCI and PPR at 1 h post SDAP transfusions when they received cross-matched compatible platelets. The one-hour CCI was significantly higher for cross-match-compatible platelets (19173 ± 2692) than for incompatible (5888 ± 1526) and for uncross-matched (8140 ± 1480). Forty four (97.8%) of 45 cross-matched compatible platelet transfusion episodes showed a satisfactory response in terms of PPI and CCI values as compared to 50 % and 53.9% in uncross-matched group respectively (p < 0.0001). ConclusionPlatelet cross-matching is an effective intervention in the management of multi-transfused alloimmunized Haemato-oncological patients, refractory to platelet transfusion.

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.

Comparison of efficacy of low and high dose prophylactic platelet transfusion therapy in thrombocytopenic haemato-oncology patients

IntroductionTo determine an optimal platelet dose in thrombocytopenic patients is important for their judicious use. Transfusing platelets in different doses and comparing their post transfusion response can achieve this. AimTo compare the efficacy of low and high dose single donor apheresis platelets (SDAP) with standard dose transfusions in terms of Corrected Count Increment (CCI), Percent Platelet Recovery (PPR) and transfusion free interval. MethodIt was a prospective case control study done from January 2016 to April 2017. Twenty-eight hemato-oncology patients with CCI ≥5000 at 20–24 hours after standard dose (3 × 1011/unit), received low dose (1.5 × 1011 platelets/unit) and high dose (>4 × 1011 platelets/unit) SDAP. CCI and PPR were calculated after 20 to 24 hours of transfusion. Transfusion free interval and bleeding episodes were also noted. Grading was done according to WHO bleeding scale. ResultThere was no statistical difference in CCI and PPR when standard dose was compared with low dose (CCI: p = 0.92, PPR: p = 0.89). When standard and high dose was compared, standard dose gave better results than the high dose in terms of CCI (p = 0.006) and PPR (p = 0.008) although the post transfusion increments were comparable (p = 0.938). High dose gave better (p = 0.005) platelet count increments than low dose but CCI (p = 0.04) and PPR (p = 0.05) was significantly less than the low dose. The difference in transfusion free intervals after three doses was not significant. Donor exposure to the patients was significantly (p = 0.000) reduced to 17.5%. ConclusionPossibility of low dose as an alternative to standard dose can be considered in view of comparable platelet response indicators and significantly reduced donor exposure.

Severe CD4+ T-cell lymphopenia is not observed in frequent plateletpheresis donors collected on the Fenwal Amicus.

In a recent study, we determined that 30% of frequent plateletpheresis donors collected using the Trima Accel Automated Blood Collection System (Terumo BCT) had a CD4+ T-cell count below 200 cells/μL. Whether CD4+ T-cell lymphopenia is associated with donation using other plateletpheresis instruments is unknown. We obtained blood samples from 30 current frequent Fenwal Amicus plateletpheresis donors. All participants had made 20 to 24 plateletpheresis donations in the most recent 365-day period, and all had previously donated over 50 times on the Fenwal Amicus instrument. Blood samples were analyzed to determine blood counts, including CD4+ and CD8+ counts. Of 30 study participants, none had a CD4+ count below 200 cells/μL. There was one participant with a CD4+ count between 200 and 300 cells/μL. This individual was over the age of 55 and had a history of more than 300 lifetime plateletpheresis sessions. One participant had a CD8+ count below the lower limit of normal (125 cells/μL) and a normal CD4+ count. We did not detect severe CD4+ lymphopenia in frequent platelet donors undergoing plateletpheresis with the Fenwal Amicus. Since the Fenwal Amicus does not incorporate a leukoreduction system chamber, this finding supports the hypothesis that such chambers-found in the Trima Accel instrument-contribute to CD4+ lymphopenia in frequent platelet donors.

Hepatitis C virus prevalence and incidence estimates among Chinese blood donors.

Hepatitis C virus (HCV) is an important transfusion-transmitted virus with global significance. The objective of this study was to evaluate the HCV prevalence and incidence among Chinese blood donors from 2013 to 2016. Whole blood and apheresis platelet donations collected from five Chinese blood centers from June 1, 2013, to December 31, 2016, were screened in parallel by two different enzyme-linked immunosorbent assays for anti-HIV 1/2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening-reactive samples were further confirmed by western blot. Confirmatory positive rates among first-time and repeat donors were used to estimate the prevalence and incidence rates. Multivariable logistic regression modeling was used to examine factors associated with HCV infection. A total of 1,276,544 donations were collected from five Chinese blood centers, of which an estimated 1203 were confirmed HCV positive. The overall HCV prevalence among first-time donors was 166.56 per 100,000 donors (95% confidence interval, 156.04-177.08). The HCV incidence rate was estimated to be 15.21 (95% confidence interval, 11.83-19.56) per 100,000 person-years among repeat donors. Multivariable logistic regression results showed that increased age, lower educational levels, ethnicity, and occupation were all important factors associated with HCV confirmatory status among first-time donors (p < 0.01). HCV infection is still an important concern for transfusion safety in China. Our findings indicate that continued strong efforts are needed to monitor and control the risk of transfusion-transmitted HCV infection in China. Moreover, to reduce unnecessary donor loss, HCV donor screening procedures should be improved by incorporating confirmatory testing into routine blood center operations.

Analysis of Iron Stores in the Plateletpheresis Donors

To understand the iron stores of the plateletpheresis donors, so as to provide some new experimental data for further exploration and more perfect health examination criteria of the plateletpheresis donors. A total of 297 plateletheresis donors conformed to standard in October 2018 were selected by the cross sectional study. The related factors affecting iron stores were analyzed; the effect of plateletpheresis times of donation on the levels of the hemoglobin(Hb) and serum ferritin(SF) as well as the iron deficency rate in the blood donors was also analyzed; the iron stores in the blood donors was evaluated. The SF level in plateletpheresis donors negatively correlated with annual plateletphersis times of donation（r=-0.416, P＜0.001）; The SF level decreased with the increase of annual times of donation（P＜0.05）; The iron deficiency rate in plateletpheresis donors showed the increase trend with the increase of annual times of donation. The iron deficiency rate in male and femal with 18-23 times of donation was 12.5%(8/64) and 40%(6/15) respectively. The blood center should reduce recruitment frequency and increase the testing of SF for regularly plateletpheresis donors.

Effect of Frequency of Platelet Apheresis on Coagulation Function in Donors: A Prospective Cohort Study

The maximum number of plateletpheresis donation was permitted up to 24 times every year for each donor in China. This study was investigated the effect of donation frequency on coagulation function of the plateletpheresis donors. A total of 96 plateletpheresis regular donors (splitted into A, B, C groups with 32 donors each group. A was 6–11 times donations, B with 12–17 times and C with 18–24 times) and 32 first time plateletpheresis donors (D group) were analyzed. The coagulation reaction time (R), blood clot formation time (K), α-Angle, normal maximum amplitude (MA) were tested using thromboelastography instrument. Platelet (PLT) count was measured using a hematology analyzer. The ratio of the male to female were 23:9, 24:8, 27:5 and 24:8, the mean age were 40.7 ± 7.6, 39.8 ± 8.3, 40.2 ± 7.9 and 37.0 ± 9.3, and the platelet collection amount were 1.55 ± 0.37 U, 1.58 ± 0.38 U, 1.61 ± 0.33 U and 1.46 ± 0.31 U in the A, B, C, D groups respectively. There were significant difference in the values of the R, K, α-Angle, MA and PLT count between before and after plateletpheresis donation in each group (p < 0.05). However, the values of R, K, α-Angle, MA and PLT count in the before donation were not difference among the A, B, C, D groups (p > 0.05). Similar results were found in the after plateletpheresis donation. The number of the PLT was significantly correlated with the values of the R, K, α-Angle and MA (p < 0.05). However, the frequency of plateletpheresis were not significantly correlated with R, k, α and MA parameters (p > 0.05) using Spearman correlation analysis. The regular donation of apheresis platelets and the frequency of annual blood donation had no adverse effect upon coagulation function of the donors in China.

Thromboelastography characterized CD36 null subjects as slow clot formation and indicative of hypocoagulability

BackgroundPlatelet CD36 is the receptor for oxidized low-density lipoprotein and collagen. The conventional platelet test cannot distinguish CD36-null subjects from normal expression subjects. Thromboelastography (TEG) testing can analyze global hemostasis. TEG testing data on CD36-null subjects are not available. MethodsOur subjects were 40 apheresis platelet donors, including 8 CD36-null individuals. We grouped the donors according to the platelet CD36 expression levels to assess the effects of platelet CD36 expression levels on TEG measurement variables. ResultsThe whole blood TEG test revealed that CD36-null subjects had prolonged reaction time of fibrin formation (TEG R time) and a slower rate to build up cross-linked fibrin (TEG α angle). The final maximal amplitudes of clot formation showed little difference between CD36-null individuals and normal expression individuals. Correlation analysis showed that CD36 expression levels were negatively correlated with TEG R time (r = −0.342, p = 0.031) and positively correlated with the TEG α angle (0.379, p = 0.016). TEG testing on apheresis platelet samples with diminished heterocellular interaction did not reveal differences between CD36-null and normal expression individuals. A subanalysis of the data of a group of healthy subjects showed that platelet CD36 levels correlated positively with platelet–monocyte aggregates (PMAs). Low PMA can diminish heterocellular interaction and likely explain the abnormal TEG results observed in CD36-null individuals. ConclusionTEG distinguishes CD36-null subjects from normal CD36 expression subjects as having a slower rate of fibrin formation and reassessment of TEG-based diagnostic monitoring is necessary for CD36 null subjects.

High-dose intravenous versus oral iron in blood donors with iron deficiency: The IronWoMan randomized, controlled clinical trial

Frequent blood donation often leads to iron deficiency and even anemia but appropriate strategies for detection and prevention are currently not mandatory. At the Medical University of Graz, we conducted a single-center prospective clinical trial to compare oral and IV iron supplementation in iron deficient blood donors including Austrian regular whole blood and platelet apheresis donors. We aimed to determine the difference of transferrin saturation between the treatment groups 8-12 weeks iron administration besides other parameters of iron status and blood count. 176 healthy male and female blood donors with iron deficiency (ferritin ≤30ng/mL) were randomized to either a single dose of IV ferric carboxymaltose (1000mg, n=86) or oral iron (II)fumarate (100 tablets of 100mg [10 per week], n=90). Between 2014 and 2016, 172 donors (137 women) completed the study; 4 in the oral group were lost to follow-up. At follow-up, median (IQR) transferrin saturation and ferritin were significantly higher in the intravenous group (27 [23-35]%, vs 21.0 [16-32]%; p<0.001 and 105 [75-145] ng/mL vs 25 [17-34] ng/mL; p<0.001, respectively) while median (IQR) hemoglobin levels were comparable (IV, 13.6 [13.0-14.4] g/dL vs oral, 13.6 [13.0-14.2] g/dL). The frequency of adverse effects was comparable (38% in both groups) and no serious adverse events occurred. A single dose of 1000mg of intravenous iron is highly effective to counteract iatrogenic iron deficiency in blood donors. Oral iron appears to be an acceptable alternative. The assessment of body iron stores should play a key role in maintaining blood donors' health. This trial was registered at www.clinicaltrials.gov as NCT01787526 on February 8, 2013 and at www.clinicaltrialsregister.eu (EudraCT identifier: 2013-000327-14) on September 24, 2013.

CD4+ T-cell lymphopenia in frequent platelet donors who have ceased platelet donation for at least 1 year.

We recently discovered that 30% of current frequent apheresis platelet donors in a study at our donor center had CD4+ counts below 200 cells/μL. How long CD4+ lymphopenia persists after ceasing plateletpheresis is unknown. Whether there are infectious or other complications in former frequent donors that could relate to CD4+ lymphopenia is also unknown. We mailed a letter to former frequent apheresis platelet donors who had not donated platelets for at least 12 months. Frequent donation was defined as 20 to 24 plateletpheresis sessions in at least one 365-day period starting in 2011. Donors who expressed interest in the study were contacted to schedule a study visit. Participants in the study provided a blood sample and completed a health questionnaire that included questions about opportunistic infections and malignancies. Of 50 potential study candidates who were mailed a letter, 15 participated in the study. There were 2 participants with CD4+ counts below 200 cells/μL, one of whom had prior counts that documented a small improvement with cessation of plateletpheresis. Three participants had counts between 200 and 300 cells/μL. No study participant had a history of an opportunistic infection or a malignancy associated with immune dysregulation. We detected CD4+ lymphopenia in former frequent apheresis platelet donors who had ceased platelet donation for more than 1 year. There was no evidence that the CD4+ lymphopenia predisposes to opportunistic infections or to malignancies associated with immune dysregulation.

Plateletpheresis-associated lymphopenia in frequent platelet donors

AbstractMore than 1 million apheresis platelet collections are performed annually in the United States. After 2 healthy plateletpheresis donors were incidentally found to have low CD4+ T-lymphocyte counts, we investigated whether plateletpheresis causes lymphopenia. We conducted a cross-sectional single-center study of platelet donors undergoing plateletpheresis with the Trima Accel, which removes leukocytes continuously with its leukoreduction system chamber. We recruited 3 groups of platelet donors based on the total number of plateletpheresis sessions in the prior 365 days: 1 or 2, 3 to 19, or 20 to 24. CD4+ T-lymphocyte counts were <200 cells per microliter in 0/20, 2/20, and 6/20 donors, respectively (P = .019), and CD8+ T-lymphocyte counts were low in 0/20, 4/20, and 11/20 donors, respectively (P < .001). The leukoreduction system chamber's lymphocyte-extraction efficiency was ∼15% to 20% for all groups. Immunophenotyping showed decreases in naive CD4+ T-lymphocyte and T helper 17 (Th17) cell percentages, increases in CD4+ and CD8+ effector memory, Th1, and regulatory T cell percentages, and stable naive CD8+ and Th2 percentages across groups. T-cell receptor repertoire analyses showed similar clonal diversity in all groups. Donor screening questionnaires supported the good health of the donors, who tested negative at each donation for multiple pathogens, including HIV. Frequent plateletpheresis utilizing a leukoreduction system chamber is associated with CD4+ and CD8+ T-cell lymphopenia in healthy platelet donors. The mechanism may be repeated extraction of these cells during plateletpheresis. The cytopenias do not appear to be harmful.

Size Estimation of HLA -Ⅰ class Typed Platelet Apheresis Donor Bank

To estimate the size of HLA -Ⅰ class typed platelet apheresis donor bank. A total of 16062 blood samples from Chinese Han voluntary unrelated marrow donors in Jiangsu were included in this study. Luminex-SSO was used to detect the HLA -Ⅰ class(A,B locus) antigens. The probability of finding at least one HLA matched unrelated donor was calculated based on the HLA -I class phenotype frequency. The population genetic data of HLA -Ⅰ class in Jiangsu were obtained, the optinal bans size in HLA typed apheresis plateler donor registry databane hrad been estimated by evaluating the population genetic data of HLA-1 class same donor. The establishment of HLA-1 class typed apheresis platelet donor bank with a total size of 1500 persons is acceptable, which can satisty the patients with phenotype freguency>0.002 to find at least 1 phenotype same donor in 95% probavility.

Effect of plateletpheresis on postdonation serum thrombopoietin levels and its correlation with platelet counts in healthy voluntary donors.

BACKGROUND:Thrombopoietin (TPO) is regulated by a feedback mechanism between megakaryocytes and platelets. This is important in plateletpheresis donors to compensate for donation-associated platelet loss.AIMS AND OBJECTIVES:The aim and objective of this study were to investigate changes in serum TPO levels in healthy plateletpheresis donors and its correlation with platelet recovery pattern.MATERIALS AND METHODS:Out of 50 plateletpheresis donors recruited in the study over 1 year, only 29 completed follow-up and were further analyzed. Plateletpheresis procedures were performed on two types of cell separators (TRIMA ACCEL®, Terumo BCT Lakewood Colorado and AMICUS®, Fresenius Kabi, Germany). Platelet parameters were estimated pre- and post-platelet donation, at 3rd- and 5th-day postdonation. Serum TPO levels were determined using quantitative sandwich enzyme-linked immunosorbent assay technique (Raybiotech, USA) as per the protocol of the manufacturer.RESULTS:The majority of donors (72%) in our study were first-time donors. The baseline platelet count was 226 ± 44 × 103/μl with a significant decline (30%; P < 0.001) in postdonation phase and remained below baseline on the 3rd and 5th day. The serum TPO levels increased significantly (P < 0.001) from a baseline of 227.81 (interquartile range [IQR]: 176.06) pg/ml to 269.94 (IQR: 110.68) pg/ml postdonation and remained elevated from baseline levels on the 3rd and 5th day. An inverse relation was observed between change in serum TPO levels and platelet count during postdonation phase which was not statistically significant (P > 0.05).CONCLUSION:Serum TPO levels increase significantly post plateletpheresis donation corresponding to decrease in platelet counts showing that TPO plays a vital role in compensatory mechanism after platelet loss.

A new insight into apheresis platelet donation by sickle cell trait carriers: evidences of safety and quality

A new insight into apheresis platelet donation by sickle cell trait carriers: evidences of safety and quality