Official Journal of the British Blood Transfusion Society
| ORIGINAL ARTICLE
Clinical and quality evaluation of apheresis vs random-donor platelet concentrates stored for 7 days E. Hussein Clinical Pathology Department, Transfusion Medicine Division, Cairo University, Cairo, Egypt Received 13 April 2014; accepted for publication 8 March 2015
SUMMARY Background and Objectives: The clinical efficacy of different types of platelets remains under debate. We conducted a pilot study to prospectively evaluate the impact of subsequent storage on the in vitro quality and post-transfusion outcome of apheresis prepared platelets (APCs) vs random donor platelets (RDPs). Materials and Methods: We studied 30 units of APCs, and 30 units of RDPs. We performed assays on days 1, 3, 5 and 7, evaluating ADP aggregation, platelet count and pH. Fifteen thrombocytopenic patients with haematologic conditions were evaluated. Each patient received prophylactic transfusions of both components, and their post-transfusion platelet increments were compared. Twenty-five transfusions were apheresis prepared, and 35 transfusions were received as RDPs. None of the RDPs were leukoreduced. Results: The median platelet counts for APCs on days 1, 3, 5 and 7 were; 2070, 1990, 1680 and 1240 × 103 μL−1 , respectively, and were; 1290, 850, 499 and 284 × 103 μL−1 , respectively for RDPs. The pH of all units was more than 6·2. Both groups demonstrated a significant decrease of ADP aggregation after 3 days of storage (P < 0·05). However, APCs provided satisfactory increments for 90·9% of transfusions. On the sixth and seventh days of storage, APCs provided significantly higher platelet increments (18·7 × 103 μL−1 ) compared with RDPs (3·20 × 103 μL−1 ) (P < 0·05). Significantly longer transfusion intervals were also achieved with APCs (P < 0·05). Conclusion: Although other variables may have confounded the results, subsequent storage of APCs appeared to provide higher increments with longer intervals of transfusion compared with RDPs. Future prospective studies are needed, adjusting for other possible confounding variables.
Key words: apheresis platelets, platelet aggregation, platelet increments, random donor platelets. Prophylactic platelet transfusions are crucial to avoid catastrophic bleeding in patients on intensive chemotherapy (Stanworth et al., 2005; Wandt et al., 2012; Stanworth et al., 2013). The demand for platelet transfusions continues to grow exceeding the available supply (Yazer & Triulzi, 2007; Estcourt, 2014). Because of concerns over possible bacterial contamination, platelet storage in the United Sates is limited to 5 days. In other countries, platelets storage can be extended to 7 days after bacterial screening. Because of Egypt’s constrained economy, extending platelet storage beyond 5 days may be potentially beneficial. Many studies have addressed the impact of extended storage on platelet recovery and survival in vivo. Most of these studies lacked data such as collection procedure and transfusion intervals. Due to these limitations and the small number of trials, definite conclusions could not be drawn (Heddle et al., 2008). Platelets can be prepared from single donor via apheresis (APCs), or from whole blood (WB) via the buffy coat method or the platelet rich plasma (PRP) method. The clinical efficacy of different types of platelets remains under debate (Heddle et al., 2008). We conducted a pilot study to investigate the impact of subsequent storage on the in vitro quality of APCs vs random donor platelets (RDPs). Another objective of our study was to assess the impact of collection procedure and storage days on the post-transfusion outcome, by evaluating time to next transfusion and measuring platelet increments, following transfusion of both products into the same group of haematology-oncology patients.
MATERIALS AND METHODS Correspondence: Eiman Hussein, MD, Clinical Pathology Department, Transfusion Medicine Division, Cairo University, 6 Hussein Elezaby St, Higazy St, Cairo Alexandria Desert Road, Cairo, Egypt. Tel.: +011201 001549621; fax: +011202 23689683; e-mail: [email protected]
First published online 24 March 2015 doi: 10.1111/tme.12187
We designed and performed the study according to the tenets of the Declaration of Helsinki. The study protocol was approved by the institutional committee for the protection of human subjects. We performed in vitro studies for 30 units of leukoreduced APCs prepared via COBE Spectra machine (Gambro BCT, Lakewood, CO, USA) vs 30 units of RDPs prepared via PRP method. Platelet units were stored under standard blood
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Single vs random donor platelets banking conditions, at 22 ∘ C with horizontal agitation. None of the RDPs units were leukoreduced, and all were stored individually. Units were stored up to 2 days beyond the fifth day of outdating and were used if no other suitable units were available.
Collection and preparation of platelets Platelet units were collected from donors, who all met the American Association of Blood Banks (AABB) eligibility criteria for donation. Donors were recruited from the Blood Bank and the Apheresis unit at Cairo University Hospital.
Evaluation of ADP aggregation Platelet aggregation was determined via optical aggregation method (Kandice, 2009), using a single ADP agonist at the final concentration of 50 μmol mL−1 . Platelet count in PRP was adjusted with PPP to 250 × 109 ± 50 × 109 , following manufacturer’s recommendations (DiaMed, Cressier sur Morat, Switzerland).
Evaluation of platelet count Samples were diluted 1 : 5 and platelet count was measured with a calibrated cell counter (Cobas Micros, F. Hoffman La Roche, Ltd., Basel, Switzerland).
Manual platelet preparation RDPs were prepared by PRP method within 8 h of WB donation. We collected 450 ± 20 mL of WB in triple bags, containing citrate phosphate dextrose adenine (CPD-A) anticoagulant solution. WB was centrifuged using the Thermo Scientific centrifuge (Thermo Fisher Scientific GmbH, Ulm, Germany), at a low centrifugal speed (soft spin) for 8 min at 22 ∘ C to obtain PRP. This PRP was centrifuged again, for another 8 min at a high speed (hard spin) to concentrate platelets. The supernatant platelet poor plasma (PPP) was expressed into a separate bag for the preparation of fresh frozen plasma, leaving a small volume of approximately 50–70 mL of plasma in which platelets were re-suspended. RDPs were divided by a sterile tubing welder machine. RDPs had the same ABO and Rh group as the recipient.
COBE Spectra apheresis protocol for platelet collection We performed apheresis by a double-needle procedure using the COBE Spectra machine. APCs are automatically leukoreduced to reach a target residual leucocyte count below 1 × 106 and a product equivalent to 6–18 RDPs units. APCs were suspended in approximately 300 mL of plasma.
Sampling procedures and in vitro platelet analysis The standard technique for donor’s arm scrubbing in our centre is to scrub with alcohol for 10 s. After mixing the unit, samples of approximately 5 mL are collected anaerobically from units immediately after collection on day 1 and then subsequently on days 3, 5 and 7. We performed in vitro assays of ADP aggregation, platelet count, glucose and pH using standard procedures. Culture for aerobes and anaerobes was done using a 20 gauge syringe swabbed with alcohol and platelet were transferred into a sterile bottle after the cap was swabbed with alcohol. Bottles were sent to the microbiology laboratory (Department of Clinical Pathology) and incubated at 37 ∘ C for up to 7 days or until positive. Aerobic and anaerobic culture for 7 days was performed on day 5 using Blood agar, Chocolate agar and MaConkey agar plates. Bacterial growth was identified by colonial morphology, Gram stain reaction, standard biochemical reactions and sugar fermentation test (Collee et al., 1996).
© 2015 British Blood Transfusion Society
Evaluation of pH and glucose They were measured with strips of Multistix R 10 SG (Bayer, Elkhart, IN, USA).
In vivo platelet analysis We prospectively evaluated a total of 60 irradiated platelet transfusions in 15 patients, of whom 9 were males and 6 were females. Their mean age was 29·4 ± 6·36 year, and their average weight was 60 ± 7 kg. Table 1 provides a summary of the patients’ characteristics and number of transfusions with both components. Patients were transfused prophylactically when their platelet count fell below 20 × 109 L−1 . All thrombocytopenic patients were being treated for haematologic disorders, and had anaemia (Hematocrit Hct less than 21%) following chemotherapy. Each patient received 1–2 units of red blood cells (RBCs) during the period of thrombocytopenia. None of our patients received haemostatic agents or anti-platelet drugs at time of platelet transfusion. Each patient received prophylactic transfusions of both components. Twenty-five platelet transfusions were apheresis prepared and 35 transfusions were received as RDPs. Ten patients received two transfusions each of APCs, and two transfusions each of RDPs. Five patients received three RDPs transfusions and five patients received 1 unit of APCs. All patients received a standard platelet dose of 2·5–3 × 1011 platelets (equivalent to 5–6 units of RDPs) per transfusion. They received a volume of 10–15 mL kg−1 . Out of group APCs were used for eight transfusions (13·3%). None of the patients had coagulopathy. Patients with platelet refractoriness and/or bleeding were excluded from the study. Refractoriness is often defined as an inadequate increase in patient’s platelet count (usually less than 10 × 109 L−1 ) following transfusion of an appropriate dose of fresh ABO compatible platelets on at least two consecutive occasions. We drew peripheral blood samples from thrombocytopenic patients 18–24 h after transfusion and assessed their platelet counts, using the Cobas Micros calibrated cell counter. The platelet increment was estimated as the difference between pre-transfusion and post-transfusion counts. Post-transfusion increments were considered acceptable when greater than
Transfusion Medicine, 2015, 25, 20–26
Table 1. Patient characteristics
Diagnosis Acute Myeloid Leukemia AML Aplastic anaemia Waldenstrom macroglobulinemia Liver Cancer with metastasis Acute Lymphoblastic leukemia ALL Aplastic anaemia Aplastic anaemia Aplastic anaemia Aplastic anaemia Chronic lymphocytic leukemia CLL Aplastic anaemia ALL Multiple myeloma Cancer breast with metastasis Aplastic anaemia
1 2 3
40 31 35
Male Female Male
6 7 8 9 10
21 23 22 24 37
Male Female Male Male Male
11 12 13 14 15
34 30 34 25 27
Male Female Male Female Female
Days of thrombocytopenia
Number of ABO incompatible APCs
Number of APCs transfusions
Number of RDPs transfusions
No No No
7 5 8
0 1 0
1 1 1
2 2 2
No No No No No
10 8 14 9 7
1 1 1 0 1
2 2 2 2 2
3 3 2 3 2
Yes No No No No
17 10 8 9 14
0 0 1 0 1
2 2 2 2 2
2 2 3 2 3
Table 2. Changes in platelet aggregation of APCs and RDPs over 7 days of storage Aggregation (%) APCs Storage days Day 1 Day 3 Day 5 Day 7
68·5 65·0 26·3 12·9
65·6 ± 9·23 60·0 ± 16·2 25·0 ± 11·50 13·5 ± 7·70
40·4–73·0 29·3–67·5 9·80–46·4 4·50–25·5
37·4 27·3 11·5 8·20
35·0 ± 10·0 25·2 ± 6·23 10·9 ± 5·45 6·71 ± 5·21
15·3–40·0 10·2–33·3 4·80–19·9 0–14·7