Single-donor Apheresis Platelets Research Articles

Isolated transfusion of leucocyte-depleted apheresis platelet concentrates and outcomes after cardiac surgery.

We investigated the association of isolated leucocyte-depleted single-donor apheresis platelet concentrate transfusion with short- and long-term outcomes of patients undergoing isolated or combined coronary artery bypass and valve surgery. Propensity score matching was used to compare the results of patients without blood product transfusion and patients with isolated platelet transfusion (n = 167 per group). The primary end-point was a composite of operative complications. Additionally, we assessed coronary reintervention and overall mortality over a follow-up period of 7.5 years. In the platelet- and platelet+ groups, the composite end-point was reached at 9.6% and 12.3%, respectively (P = 0.307). None of the patients died within 30 days. None of the patients needed coronary reintervention during follow-up. Long-term mortality was similar between groups (P > 0.05). Isolated leucocyte-depleted apheresis platelet transfusion does not appear to be associated with an increase in morbidity or mortality in non-complex cardiac surgery. However, larger studies are needed.

Analysis of platelet-reactive alloantibodies and evaluation of cross-match-compatible platelets for the management of patients with transfusion refractoriness.

Cross-match-compatible platelets can improve corrected count increments (CCIs) in alloimmunised patients with transfusion refractoriness. However, only a few studies mentioned that the specificities of platelet-reactive alloantibodies can predict high reactivity in cross-match assays among these patients. A total of 204 medical records of patients who were refractory to random single-donor apheresis platelets between January 2014 and December 2014 were enrolled. Platelet-reactive antibodies in patients' serum were screened by an enzyme-linked immunosorbent assay (ELISA).The platelet cross-match assays were performed by a solid-phase adherence assay. The specificities of human leukocyte antigen (HLA) class I and human platelet antigens (HPAs) alloantibodies were determined by Luminex Single Antigen and Monoclonal Antibody-specific Immobilization of Platelet Antigens (MAIPA) assays, respectively. Anti-HLA and anti-HPA alloantibodies were found in 114 of 204 (55.88%) patients, including 110 (96.49%) with anti-HLA alloantibodies only, 2 (1.75%) with anti-HPA alloantibodies (anti-GPIIb/IIIa) only and 2 (1.75%) with both anti-HLA and anti-HPA alloantibodies (anti-HPA-3a and anti-HPA-5b). The most common HLA class I alloantibody phenotypes in cross-match-incompatible patients were HLA-A23 (59.38%), -A24 (50.00%), -A02 (43.75%), -B27 (65.63%), -B40 (50.00%), -B18 (46.88%) and -B07 (43.75%). A total of 480 cross-matched platelet units were administered in 82 of 114 alloimmunised patients with a mean CCI of 7800 ± 5200, a significant improvement over random platelet units (P < 0.001). No development of additional platelet alloantibodies was observed during this platelet transfusion regiment. This study showed that transfusion of cross-match-compatible platelet units offers effective and safe management of platelet transfusion refractoriness (PTR). The finding of alloantibodies among cross-match-incompatible cases can be used as predictors for platelet donor selection.

Apheresis platelets in additive solution: Is it a good alternative to conventional group-specific apheresis platelets?

Introduction: India is among the medium developed countries with a population over 1.25 billion with areas of difficult terrains, landslides, and there is requirement of platelets for dengue outbreaks,cancer patients or patients needing intensive care. Use of nongroup-specific platelets is common and the incompatible plasma comes with complications at times. Thus, finding group-specific platelets have always been difficult. Arranging group-specific donor is really a challenge, especially in cases of international patients, outstation patients, and patients that require numerous platelet transfusions, more so in hospital-based blood banks that have limited voluntary apheresis blood donor registry. Materials and Methods: This study was conducted in multispecialty tertiary health-care hospital of Delhi/NCR where the majority of patients are from a different place or different state or a different country. To make do with the available donors who are often replacement donors of a group different from the patient, platelet additive solution (PAS) was used to replace the incompatible plasma. Use of PAS was implemented on all apheresis prepared using storage solution for platelets (SSP+, Macopharma, France) using apheresis platform. PAS was added after collection of hyperconcentrated platelets units. Control group (n = 10) included patients receiving group-specific platelets during the study. Results: A total of 130 apheresis units were prepared on PAS during the study. 126 units were issued to 77 patients. 99.2% of donors under study were male and 47.7% in age group 18–30 years and 31.5% of blood Group O positive. Final platelet volume prepared was 300 ± 20 ml. Mean platelet volume and product pH were within normal range. Conclusion: Use of PAS for apheresis platelets eliminates the need for group-specific platelets converting all single-donor apheresis platelets to universal platelets, thereby helping in better management without compromise in patient safety.

Utility of Fluorescence Cytometric Cross-Matched Platelets in Severely Alloimmunized Patients

▪Introduction:Platelet refractoriness due to alloimmunization (AI) is associated with increased bleeding, longer hospitalization, higher costs, and delay of therapy in oncologic patients. Platelet refractoriness in AI patients is traditionally managed by using commercially-available cross-match compatible and/or HLA-matched platelets. Our HLA laboratory has developed a fluorescence cytometric-based XM (FCXM) for patients with severe AI and platelet refractoriness for whom HLA compatible platelets were not available. We present a retrospective analysis of the utility of FCXM in oncologic patients who are refractory to random single donor apheresis platelet transfusions.Methods:Patients with platelet refractoriness during 2015 to 2016, as determined by platelet increments <10,000, and having HLA Class I antibodies with a Calculated Panel Reactive Antibody (cPRA) >90%, were selected for study. Data collected include gender, age, diagnosis, ongoing treatment and underlying medical illness during hospitalization, complications, time of release of unit from the Blood Bank, and time of platelet count post-transfusion. Platelet counts increments within 0-1 hour and 1-2 hours after transfusion were recorded. Platelet increments from random-donor platelet units served as controls for FCXM platelet unit increments for the same patient. Statistical analysis was performed using an unpaired t test.Results:We identified 36 patients with platelet refractoriness, of whom 5 met our study criteria (cPRA >90%): 4 female, 1 male. Median age was 67 years (range 48 to 78), with 4 Caucasians and 1 African American. Underlying diagnoses were multiple myeloma (2), colon cancer (1), acute myelocytic leukemia (1), and myelodysplastic syndrome (1). Two out of 5 patients had significant bleeding, 4 out of 5 had sepsis and mucositis (Table 1). All units were leukocyte-reduced, single donor apheresis platelets. The mean number of FCXM testing performed was 3 (8 units each, 24 total) with 13 and 9 units that were compatible and less compatible identified, respectively. The mean platelet increment within 0-1 and 1-2 hour of transfusion for FCXM vs non-FCXM were 9.5 and 7.2 (p= 0.78), and 8.4 vs 5.8 (p= 0.7), respectively. While a trend existed, the small numbers in the study were insufficient to demonstrate statistical significance (Table 2). One patient died during hospital admission due to diffuse pulmonary hemorrhage post induction chemotherapy. Although 1 other patient had significant bleeding, the remaining four patients were able to complete their planned chemotherapy.Conclusion:An overall increase in platelet counts occurs with FCXM identified compatible platelet units in severely AI patients who were refractory to random single donor apheresis platelet units. Although the mean increment using FCXM platelets was < 10,000 and did not differ statistically from the non-FCXM group, we were able to identify units to transfuse patients during chemotherapy and help prevent/treat major bleeding complication and death in 4/5 patients. FCXM testing may be a viable option for identifying compatible platelet units in severely AI patients. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Platelet Refractoriness Due to Anti-CD-36(NAKa) Ameliorated By Platelet Washing

▪Introduction:Platelet transfusion refractoriness in patients with hematological malignancies ranges from 7-34% (Blood 2015; 126:3484). The etiology of platelet refractoriness in this patient population is typically due to formation of HLA antibodies from pregnancy or previous transfusion. Although these patients receive leukoreduced products, alloimmunization is not completely prevented. We report platelet refractoriness in the setting of induction chemotherapy for acute myeloid leukemia (AML) from alloantibodies to NAKa antigen/CD-36/glycoprotein (GP) IV. We propose that washing platelets may be a potential strategy for treating platelet refractoriness in patients with NAKaantibodies as finding CD36 negative donors is extremely difficult and few blood banks in North America test donors for this antigen.Case:A 66 year old African American female presented with pancytopenia requiring transfusions. She was later diagnosed with AML with 70% circulating peripheral blasts and started on 7+3 regimen (Cytarabine for 7 days and Idarubicin for 3 days). She developed profound thrombocytopenia by day 7 and her platelet count was 0 by day 13. She was refractory to platelet transfusion from the outset. An Immucor ELISA assay was positive for anti-GPIV (NAKaantigen/CD-36). No antibody to GPIIb/IIIa, GPIa/IIa, GPIb/IX, and HLA Class I was present. Anti-GPIV was confirmed by Blood Center of Wisconsin utilizing monoclonal antibody MBC 131.7 (produced by Blood Center of Wisconsin) directed against CD36. Cross-matching was performed at our institution with multiple single donor apheresis platelets, all showing strong positive reactivity. Given the patient’s low platelet count and onset of urinary tract bleeding, an incompatible leukoreduced, irradiated, and washed single donor platelet unit was given. The patient tolerated the transfusion with no adverse events noted during or after transfusion. The patient’s platelet count rose from < 1 to 14,000/µL when measured 4 hours after the transfusion, and her count was sustained through the following day. Despite the strong, positive reactivity of this unit at crossmatch testing, this was the first successful response to multiple platelet transfusions. Unfortunately, her percentage of blasts in the peripheral blood increased and she maintained an absolute neutrophil count of 0. The patient and hematology team decided to switch to hospice as her AML was resistant to therapy and unfit for any other myelotoxic regimens. Her platelet count was checked the following week and it was 16,000/µL despite no transfusion support.Discussion:Platelet refractoriness in the setting of hematological malignancy has been well documented. Alloantibodies develop from prior pregnancy, prior transfusion or multiple transfusions in the setting of prolonged pancytopenia in hematological malignancies, especially AML. Typically, antibody develops against platelet membrane polymorphic structures including human platelet, ABO, HLA, and very rarely NAKa antigens on the CD36 glycoprotein molecule. CD36 is expressed in almost 100% of white Europeans and is not expressed by 2% of sub-Saharan Africans and 10% of Asians (Blood Transfus 2015: 13: 380). In screening of 871 US blood donors, Yamamoto et al. identified three platelet CD36 deficient individuals. Thus finding a CD36 negative platelet donor will most likely take an extended amount of time, which could be a challenge in these patients as bleeding risk is high during or after induction chemotherapy. CD36 is a soluble antigen and is expressed on various cells such as erythroblasts and monocytes. It has been proposed that when ABO mismatched platelets are transfused, circulating immune complexes may form between the soluble ABH antigens and the transfused antibody. Platelets may then be destroyed by binding of immune complexes to the Fc and C1q receptors. We speculate that a similar pathophysiology may occur in CD36 deficient patients as circulating anti-CD36 forms immune complexes with donor soluble CD36 antigen. Washing will remove most soluble CD36 and potentially mitigate the effect of immune complex formation. Based upon the limited experience with this patient, we suggest that washing in this setting may be beneficial and yield a sustained, incremental response in the platelet count in patients with platelet refractorinesssecondary to anti-NAKa. DisclosuresBlumberg:Biomet/Citra Labs: Consultancy, Honoraria.

Blood Utilization and Quality Indicators - Trend at a Super Specialty Hospital in Northern India

Blood components are a scarce and expensive resource. Therefore, there is a need to continuously monitor blood utilization and audit the transfusion practices to identify key areas of concern for blood usage. We assessed the transfusion data for the patients requiring blood transfusion at our hospital for a period of one year from January 2015 to December 2015 using patient transfusion requisition forms, crossmatch and issue records. A total of 2434 blood transfusion requisitions were received by the Department of Transfusion Medicine for 3621 (49.69%) packed red cells (PRBC) units, 2140 (27.59%) fresh frozen plasma (FFP), 1923 (24.80%) random donor platelet concentrates (RDP), 15 (0.19%)whole blood units and 55 (0.56%) single donor apheresis platelet concentrates (SDP).The overall average CT Ratio (1.57), Transfusion probability (79.0%) and Transfusion index (1.18) demonstrated that there is efficient blood utilization at our hospital.

To study the effects of gamma irradiation on single donor apheresis platelet units by measurement of cellular counts, functional indicators and a panel of biochemical parameters, in order to assess pre-transfusion platelet quantity and quality during the shelf life of the product

BackgroundThe occurrence of transfusion associated graft versus host disease can be prevented by gamma irradiation of blood components. This study was undertaken to assess the effects of gamma irradiation on single donor platelet (SDP) concentrate units. MethodSDPs were collected by a continuous flow apheresis technique (n=400). The SDPs from each donor were divided into two parts, one gamma-irradiated with 25Gy and the other used as a non-irradiated control. Swirling and morphological features, cellular counts, biochemical parameters including blood gas analysis, and platelet activation levels (CD62P: p-selectin) by flow cytometry were analyzed on Day 1 and on Day 5. ResultsSwirling and morphology were maintained in all products, in both the groups throughout the shelf life. No significant change was seen in both groups, on the first and fifth day, as far as pO2, pCO2, Na+, K+, HCO3− & Ca2+ were concerned. However, lactate increased and glucose decreased significantly in irradiated products over 5-day storage period. A small but significant decrease in pH and platelet count was found in the irradiated PCs after 5-day storage. The mean proportion of platelets expressing CD62P over 5-day storage increased significantly. ConclusionAfter an overall assessment of all our in vitro parameter results and observations, a few of which were significant, while most were not significant, we concluded that a well-preserved quality of gamma irradiated apheresis platelets is maintained throughout the entire 5-day shelf life of the platelet product, with minimal difference compared to non-irradiated platelets.

North American Cooperative Group Members' Patterns of Blood Products Transfusion for Patients with Acute Leukemia

Background. Transfusion of blood products is an integral component of the management of patients with acute leukemias. However, high-quality evidence and clinical trial data to support specific practices of blood product transfusion in this population are limited. We hypothesized that there is wide variation in blood product transfusion practices among providers in North America who manage patients with acute leukemia.Methods. A 30-question web-based survey about transfusion practices was emailed to members of the Eastern Cooperative Oncology Group (ECOG)-ACRIN Cancer Research Group, Alliance for Clinical Trials in Oncology (Alliance), and the Southwest Oncology Group (SWOG), and the Cancer Trials Support Unit (CTSU) on 7/6/2015 with 4 subsequent weekly reminders. The distribution list included 9,859 recipients, of whom at least 741 were providers who treated patients with acute leukemia. Responses were anonymous, and the survey distribution was approved by the respective cooperative group chairs. Descriptive statistics were used to analyze the data.Results. Of 254 responses received, 113 were excluded as they were returned by recipients not directly treating patients with acute leukemia. Another 30 responses were excluded due to incomplete data, leaving 111 responses (43.7%) eligible for the primary analysis. Of those, 109 responders were from North America representing 83 institutions in 33 states and the province of Ontario. Eighty-four of the included responders (75.7%) were physicians, and 44 (39.6%) were females. Median age of responders was 44 years (range, 26-76). A hemoglobin (Hb) level of ≤7 g/dL was the most commonly used threshold (44%) for red blood cell (RBCs) transfusions to asymptomatic stable hospitalized patients, followed closely by 8 g/dL (38%) (Figure 1). In the outpatient setting, the most commonly reported threshold was 8 gm/dL (49%) (Figure 1). Most providers reported that they "always" use leukocyte-reduced (93%) and irradiated (79%) RBCs. A platelet level of 10,000/µL was the threshold for platelet transfusions in the stable non-bleeding hospitalized patients cited by the majority of responders (76%) (Figure 2). This platelet level remained the most common threshold for platelet transfusions for non-bleeding patients in the outpatient setting (49%), although 31% of responders reported a higher threshold of 20,000/µL. A preference for single-donor apheresis platelets was reported by 81% respondents, and 57% use these products exclusively. Most providers (70%) reported always using irradiated platelets. With respect to cryoprecipitate and plasma infusions, nearly half of the respondents reported a threshold fibrinogen level of 100 mg/dL as a trigger for administering a product to a stable non-bleeding patient (Figure 3). The most commonly reported platelet threshold for performing a bone marrow biopsy (BMB) was 10,000/μL (69% of responders), followed by 20,000 (21%), 50,000 (6%), and 30,000 (4%). Therapeutic anticoagulation was held by most responders (80%) before performing a BMB. Most responders (73%) reported a platelet level of 50,000/µL as the lowest level for performing a lumbar puncture (LP) without prophylactic platelet transfusion.Conclusions. This survey demonstrates wide variability in blood product transfusion patterns among providers who treat patients with acute leukemias. A platelet level of 10,000/µL is the most common trigger for platelet transfusions for stable non-bleeding patients in both inpatient and outpatient settings. This, along with a platelet threshold of 50,000/µL for performing an LP, appear to be most widely accepted practices. Our findings emphasize the need to obtain high-quality data to develop consensus evidence-based guidelines for transfusion practices in acute leukemia with the goal of limiting unnecessary transfusions without compromising patient outcomes. [Display omitted] [Display omitted] [Display omitted] DisclosuresSekeres:TetraLogic: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Steensma:Onconova: Consultancy; Incyte: Consultancy; Amgen: Consultancy; Celgene: Consultancy. Prebet:CELGENE: Research Funding. Komrokji:Celgene: Consultancy, Research Funding; Incite: Consultancy; Novartis: Speakers Bureau; GSK: Research Funding. Stone:Merck: Consultancy; AROG: Consultancy; Celgene: Consultancy; Sunesis: Consultancy, Other: DSMB for clinical trial; Abbvie: Consultancy; Novartis: Research Funding; Juno: Consultancy; Amgen: Consultancy; Roche/Genetech: Consultancy; Celator: Consultancy; Agios: Consultancy; Karyopharm: Consultancy; Pfizer: Consultancy. Erba:GlycoMimetics; Janssen: Other: Data Safety & Monitoring Committees; Sunesis; Pfizer; Daiichi Sankyo; Ariad: Consultancy; Millennium/Takeda; Celator; Astellas: Research Funding; Seattle Genetics; Amgen: Consultancy, Research Funding; Novartis; Incyte; Celgene: Consultancy, Patents & Royalties. Barbarotta:Celgene, BMS, Novartis: Speakers Bureau. Gore:Celgene: Consultancy, Honoraria, Research Funding.

Abstract 15635: Consumption of Aspirin and Naproxen by Platelet Donors and the Quality of Platelet Transfusion

Over-the-counter pain killers are amongst the most frequently consumed drugs world-wide. Individuals who self-report ingesting aspirin or aspirin containing drugs within the preceding 48-72 hours - depending on regional practice - are excluded from platelet donation, given the assumed platelet functional inhibition due to irreversible acetylation of platelet cyclooxygenase-1 (COX-1) by aspirin and the consequent suppression of thromboxane formation. Other nonsteroidal anti-inflammatory drugs, which bind COX-1 tightly enough to cause long acting platelet inhibition, such as naproxen, may also impact the quality of platelet preparations for transfusion but are not typically exclusionary. The prevalence of functionally relevant exposure of platelet donors to aspirin and naproxen is unknown. We used sensitive and specific mass spectrometry methods to quantitate the acetylation of platelet COX-1 by aspirin and platelet protein binding of naproxen in platelet transfusion units as indices of donor exposure to these drugs. Platelet thromboxane formation was assessed as a functional parameter. We screened single-donor apheresis platelet units transfused at the Hospital of the University of Pennsylvania. Over 30 % (71 out of 235) of the analyzed platelet units showed evidence of aspirin exposure ranging from residual COX-1 acetylation after an appropriate washout period to complete acetylation suggestive of recent aspirin exposure. Approximately 7% (16 out of 235) of the platelet units showed complete COX-1 acetylation and inhibition of thromboxane formation. More than 15% (22 out of 143) of analyzed platelet units showed high naproxen concentrations that were associated with depression of thromboxane formation. The prevalence of aspirin and naproxen consumption by platelet donors is as high as would be expected in the general population and results in transfusion of inhibited platelets with suppressed thromboxane formation.

What is new in the blood bank for trauma resuscitation.

The aim of the present review was to describe recent changes in blood banking thinking, practice, and products that affect trauma care. Prompt balanced hemostatic resuscitation of major hemorrhage from trauma improves outcome and reduces blood use. New blood processes and products can help deliver appropriate doses of procoagulant plasma and platelets quicker and more safely. New processes include holding larger inventories of thawed plasma with risk of wastage and rapid plasma thawers. New products in the blood bank include group A or group A low-titer B thawed plasma and AB or A liquid (never-frozen) plasma for resuscitation, prepooled cultured whole blood-derived platelets in plasma, and prepooled cryoprecipitate in varying pool sizes. Single-donor apheresis or pooled whole blood-derived platelets in additive solution, designed to reduce plasma-related transfusion reactions, are also increasingly available but are not an appropriate blood component for hemorrhage control resuscitation because they reduce the total amount of administered plasma coagulation factors by 10%. Early initiation of balanced massive transfusion protocols leading to hemostatic resuscitation is lifesaving. Changing blood product availability and composition will lead to higher complexity of massive transfusion. It is critical that anesthesiologists understand the composition of the available new blood products to use them correctly.

Namibia's transition from whole blood-derived pooled platelets to single-donor apheresis platelet collections.

Few African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT availability while reducing exposure to multiple donors via pooling. This study describes the impact this transition had on PLT availability and safety in Namibia. Annual national blood collections and PLT units issued data were extracted from a database maintained by the Blood Transfusion Service of Namibia (NAMBTS). Production costs and unit prices were analyzed. In 2006, NAMBTS issued 771 single and pooled PLT doses from 3054 whole blood (WB) donations (drawn from 18,422 WB donations). In 2007, NAMBTS issued 486 single and pooled PLT doses from 1477 WB donations (drawn from 18,309 WB donations) and 131 single-donor PLT doses. By 2011, NAMBTS issued 837 single-donor PLT doses per year, 99.1% of all PLT units. Of 5761 WB donations from which PLTs were made in 2006 to 2011, a total of 20 (0.35%) were from donors with confirmed test results for human immunodeficiency virus or other transfusion-transmissible infections (TTIs). Of 2315 single-donor apheresis donations between 2007 and 2011, none of the 663 donors had a confirmed positive result for any pathogen. As apheresis replaced WB-derived PLTs, apheresis production costs dropped by a mean of 8.2% per year, while pooled PLT costs increased by an annual mean of 21.5%. Unit prices paid for apheresis- and WB-derived PLTs increased by 9 and 7.4% per year on average, respectively. Namibia's PLT transition shows that collections from repeat apheresis donors can reduce TTI risk and production costs.

Risk Assessment of Single-Donor (Apheresis) Platelet Concentrates and Pooled Whole-Blood-Derived Platelet Concentrates

According to the risk estimates of the Robert-Koch-Institute (RKI) and the Paul Ehrlich-Institute (PEI) an equivalence cannot be assumed to exist between the two different platelet preparations. Differences between single-donor (apheresis) platelet concentrates (ATK) and pooled whole-blood-derived platelet concentrates (PTK) result from donor populations, donation intervals, and preparation techniques. There are no prospective randomized studies with regard to the clinical efficacy, which would unambiguously demonstrate equivalence of the therapeutic efficacy of PTK (buffy coat method) in comparison to ATK. The German Association of Blood Transfusion Services (StKB) points out that, due to the non-equivalence of PTK and ATK, it is incumbent on the transfusion physician to select the platelet concentrate, make the appropriate disclosures, and assume treatment responsibility. Proper compensation for ATK and PTK must be ensured by the health insurance companies, whereby a special indication for the selection of either PTK or ATK is not given. Exceptions are patients with known HLA antibodies in which only selected platelet concentrates may be administered. Otherwise, no indication exists in the selection of the different platelet concentrates (Article is in German).

Defining an appropriate leucoreduction strategy by serial assessment of cytokine levels in platelet concentrates prepared by different methods.

Background and Objectives:Different methods of platelet concentrate preparations leave behind certain number of residual leukocytes, accounting for most of the febrile nonhemolytic transfusion reactions, especially in multitransfused patients. Various inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 are generated during storage and have been implicated for these adverse effects. We have studied the levels of these cytokines and their correlation with leucocyte contents in platelet concentrates prepared by three different methods.Study Design and Methods:Five pools of platelet rich plasma platelet concentrates (PRP-PC) and buffy-coat platelet concentrates (BC-PC) each were prepared and divided into two halves. One half of the pool was leucofiltered (LF), whereas the other half was stored as such. Ten apheresis units were also included in the study. All the platelet concentrates were assessed for leucocyte load and cytokine content (IL-1β, IL-6, and TNF-α) on different days of storage (0, 3, and 5) using Nageotte chamber and commercially available immunoassays respectively.Results:There was a statistically significant rise in cytokine levels (IL-1β, IL-6, and TNF-α) in nonleucofiltered (NLF) random donor platelet concentrates (RDPs) (PRP-PC and BC-PC) during storage (day 3 and 5) whereas LF RDP concentrates (PRP-PC and BC-PC) and apheresis platelet concentrates (AP-PC) did not show any significant rise in cytokine levels (on day 3 and 5) over the baseline values at day 0.Conclusion:This data suggests that although AP-PCs are superior to PRP-PC (NLF) and BC-PC (NLF) in terms of in vitro quality control parameters and cytokine generation during storage, BC-PC mode of platelet preparation followed by leucofiltration is the best method to store platelets and minimise the cytokine accumulation. This strategy is best suited for transfusion in multitransfused hematooncologic patients, who cannot afford single donor apheresis platelets.

Atrial Fibrillation Due to Acute Myocarditis During Dengue Haemorrhagic Fever.

Atrial Fibrillation Due to Acute Myocarditis During Dengue Haemorrhagic Fever.

Prevalence of platelet-specific antibodies and efficacy of crossmatch-compatible platelet transfusions in refractory patients.

The development of specific antibodies against human leukocyte antigen (HLA) and/or human platelet antigen (HPA) could induce platelet transfusion refractoriness especially in patients receiving multiple platelet transfusions. A retrospective analysis was conducted to evaluate the prevalence of platelet-specific antibodies and the efficacy of crossmatch-compatible platelet transfusions in these recipients. All enrolled patients were refractory to random single-donor apheresis Platelet (PLT) units. Enzyme-linked immunosorbent assay (ELISA) was used to detect anti-HLA and anti-HPA antibodies in serum. For those patients with antibodies, the PLT crossmatch assays were performed to select the compatible PLTs with a commercial solid-phase adherence kit. A total of 193 patients were included and 29.02% of which was HLA and/or HPA antibody-positive. There were no significant differences in antibody-positive rates among AML/CML, ALL/CLL, MDS, SAA and ITP groups, but they are statistically significantly higher than other groups (P = 0.0035). Of those antibody-positive patients, there were 41 (73.21%) patients with only HLA antibodies, 11 (19.64%) patients with only HPA antibodies and 4 (7.14%) patients with both HLA and HPA antibodies. A total of 43 random PLT units and 88 crossmatch-compatible PLT units were administered. The mean (± SD) corrected count increment (CCI) was 8700 (± 4500) after crossmatch-compatible unit transfusion, significantly higher than 3600 (± 2400) for random PLT units (P < 0.001). HLA and/or HPA alloimmunisation is an important factor to cause refractoriness to platelet transfusions. Crossmatch-compatible platelet transfusion is an effective method in those patients refractory to random platelet transfusions.

Critical Issues in Management of Dengue Outbreak with Single Donor Apheresis Platelets: Experience from a Tertiary Care Hospital of North India

Background: Dengue fever (DF) going into dengue shock syndrome (DSS) and dengue hemorrhagic fever (DHF) has challenged the blood transfusion services in the form of urgent requirement of platelets. Single donor apheresis platelets technology has helped the transfusion services that would have otherwise to arrange a large inventory of random donor platelets. Aim: To analyze the critical issues in the management of dengue outbreak during the year 2012 at a tertiary care institute. Study Design and Method: This is a retrospective study of records of the 186 serology proven dengue patients' requisitions, who received SDAP transfusion support from our department and analyses of the critical issues faced in managing the dengue patients. Results: A total of 239 single donor apheresis platelets (SDAP) procedures were done for 186 patients with serology proven dengue infection. Total 139(58.15%) SDAP requisitions were received from our own institution while 100(41.84%) requisitions were from other hospitals in the region. We observed that 20.43% SDAP requisitions did not qualify either prophylactic or therapeutic criteria for platelet transfusion according to the current guidelines. A total of 205 voluntary SDAP donors are registered in our emergency donor panel for plateletpheresis, out of this only 29 (14.14%) responded for SDAP donation during the dengue outbreak. Conclusions: Following appropriate guidelines for prophylactic and therapeutic blood and blood components transfusions and a well-planned emergency donor panel registry are essential pre- requisites for successful

Hemostatic Function and Transfusion Efficacy of Apheresis Platelet Concentrates Treated with Gamma Irradiation in Use for Thrombocytopenic Patients

Background: During the transfusion of blood components, the transfer of allogeneic donor white blood cells (WBCs) can mediate transfusion-associated graft-versus-host disease (TA-GVHD). To minimize the reaction, exposure of blood products to gamma irradiation is currently the standard of care. The aim of our study was to evaluate and compare hemostatic function, transfusion efficacy, and safety of gamma-irradiated single-donor apheresis platelet concentrates (PCs) and of conventional non-irradiated PCs in patients with chemotherapy-induced thrombocytopenia. Methods: 20 double-dose single-donor leukoreduced PCs were split in two identical units; one was gamma-irradiated with 25 Gy (study arm A) and the other remains non-irradiated (study arm B). Both units were stored under equal conditions. Hematologic patients were randomly assigned to receive gamma-irradiated or conventional non-irradiated PCs. Hemostatic function was evaluated by thrombelastography (TEG). TEG measurements were taken pre transfusion and 1 and 24 h post transfusion. TEG profiles were measured, noting the time to initiate clotting (R), the angle of clot formation (α), and the maximum amplitude (clot strength (MA)). Whole blood samples were collected from these thrombocytopenic patients at 1 and 24 h for PLT count increments (CIs) and corrected count increments (CCIs) with assessments of transfusion efficacy. Time to next PLT transfusion, transfusion requirement of RBCs, active bleeding, and adverse events (AEs), were analyzed. Results: No differences could be found in hemostatic function parameters (MA, R, and α) between study arms A and B (all p values > 0.096) pre transfusion as well as 1 and 24 h post transfusion. No differences between study arms A and B were observed for mean (± standard deviation (SD)) 1-hour CCI (12.83 ± 6.33 vs. 11.59 ± 5.97) and 24-hour CCI (6.56 ± 4.10 vs. 5.76 ± 4.05). Mean 1-hour CI and 24-hour CI were not significantly different in both study arms (p = 0.254 and p = 0.242 respectively). Median time to the next PC transfusion after study PC was not significantly different between groups: (2.4 vs. 2.2 days, p = 0.767). No differences could be found in transfusion requirement of red blood cells (p = 0.744) between both study arms. There were also no regarding bleeding, adverse events, and acute transfusion reaction(s). Conclusions: This study confirms safety of gamma-irradiated PCs for treatment thrombocytopenia. Hemostatic function, transfusion efficacy, bleeding, and safety of single-donor apheresis PCs treated with gamma irradiation versus untreated control PCs are comparable.

Feasibility of applying the 2 day deferral for repeat plateletpheresis: Indian perspective

As the use of single donor apheresis platelets and plateletpheresis procedures done steadily increases in India, the plateletpheresis donors are at an increased risk of postpheresis anemia and thrombocytopenia. This study was planned in order to evaluate the effect of plateletpheresis on the hematological parameters in the local donor population and to evaluate the possibility of following the 2day deferral for repeat plateletpheresis. A total of 60 plateletpheresis procedures performed over a period of 1year with CS 3000 Plus Baxter Fenwal were evaluated. All the post-donation hematological parameters showed a significant decrease from the pre-donation values (p<0.001). Post-donation hemoglobin <12g, which is defined by WHO as anemia irrespective of the gender occurred in 25% (n=15) of the donors. The post-donation platelet count was less than 100×109/L in 16.6% (n=10) of the procedure. The ability of these donors to serve as repeat plateletpheresis donor after 2days as recommended by AABB needs to be evaluated by further studies done post donation. Keeping in view the hematological profile of our donor population we recommend that donors who already have a low or borderline pre-donation platelet count and hemoglobin should be assessed and monitored post-donation for decrements in these parameters. While serving as repeat donors, their pre donation hemoglobin and platelet counts should be tested again.

Approach to a Child with Bleeding in the Emergency Room

A bleeding child is a cause of great concern and often, panic, for parents and pediatricians alike. Causes of bleeding could be trivial or secondary to an underlying bleeding disorder or a potentially serious systemic illness. Based on etiology, they can be categorized into disorders affecting platelets or the coagulation cascade and can be inherited or acquired. A systematic approach with relevant clinical history and examination along with appropriate laboratory investigations aid in reaching the diagnosis promptly. Indication and administration of blood products including fresh frozen plasma, cryoprecipitate, random donor and single donor apheresis platelets is elaborated. Management of hemophilia, Von Willebrand disease, disseminated intravascular coagulation and bleeding in cyanotic congenital heart disease, among other causes is outlined. Role of antifibrinolytic therapy, desmopressin and recombinant factor VIIa is briefly described. The review outlines the approach to a bleeding child in the emergency room. Practical points in history, examination, investigations and management are discussed. Management in resource constraint setting of developing countries is addressed.

Platelet transfusions: treatment options for hemorrhage secondary to thrombocytopenia

To review current human and veterinary protocols for platelet transfusion triggers, available platelet transfusion products to support veterinary thrombocytopenic patients, and the advantages and disadvantages of each product. Data from human and veterinary literature. Prophylactic and therapeutic platelet transfusions are instrumental in managing human patients with thrombocytopenia. The platelet transfusion products used in human medicine consist of platelet concentrates, derived from pooled random donor platelets, or single-donor apheresis platelets. Historically, platelet transfusions in human medicine have been prophylactic in nature; however, recent research suggests changing from a prophylactic transfusion strategy to a therapeutic transfusion strategy may be safe for most patients. The optimal platelet transfusion trigger and the use of prophylactic verses therapeutic platelet transfusions are ever changing in human medicine. There have been many advances in platelet transfusion products, but fresh whole blood remains the most commonly used platelet transfusion product in veterinary medicine. New products such as lyophilized platelets and cryopreserved platelets offer the benefits of long shelf life, immediate availability, and higher concentration of platelets at smaller doses. Veterinary platelet transfusion guidelines are mostly extrapolated from human literature because data on veterinary platelet transfusions are lacking. In veterinary medicine the most commonly available product for platelet transfusions is fresh whole blood, because of availability of blood donors and lack of a cost effective easily obtainable alternative. Cryopreserved and lyophilized platelets are promising new products being used in the treatment of hemorrhaging patients with thrombocytopenia. These products offer increased platelet concentrations at decreased volumes, longer storage shelf life, and decreased exposure to whole blood products. With the development of newer readily available products, platelet transfusion parameters, to include dose, platelet count trigger, presence of disease, and clinical signs, should be further evaluated in veterinary medicine.