Effects of platelet concentrate storage time reduction in patients after blood stem cell transplantation

Platelet storage duration and its clinical and transfusion outcomes: a systematic review

Background

Platelets (PLTs) are usually stored for up to 5 days prior to transfusion, although in some blood services the storage period is extended to 7 days. During storage, changes occur in both PLT and storage medium, which may lead to PLT activation and dysfunction. The clinical significance of these changes remains uncertain.

Methods

We performed a systematic review to assess the association between PLT storage time and clinical or transfusion outcomes in patients receiving allogeneic PLT transfusion. We searched studies published in English between January 2000 and July 2017 identified from MEDLINE, Embase, PubMed and the Cochrane Libraries.

Results

Of the 18 studies identified, five included 4719 critically ill patients (trauma, post-cardiac surgery and a heterogeneous population of critically ill patients) and 13 included 8569 haematology patients. The five studies in critically ill patients were retrospective and did not find any association between PLT storage time when PLTs were stored for up to 5 days and mortality. There was also no association between older PLTs and sepsis in the two largest studies (n = 4008 patients). Of the 13 studies in haematology patients, seven analysed prolonged storage time up to 6.5 or 7 days. Administration of fresh PLTs (less than 2 or 3 days) was associated with a significant increase in corrected count increment (CCI) compared to older PLTs in seven of the eight studies analysing this outcome. One single centre retrospective study found an increase in bleeding events in patients receiving older PLTs.

Conclusions

PLT storage time does not appear to be associated with clinical outcomes, including bleeding, sepsis or mortality, in critically ill patients or haematology patients. The freshest PLTs (less than 3 days) were associated with a better CCI, although there was no impact on bleeding events, questioning the clinical significance of this association. However, there is an absence of evidence to draw definitive conclusions, especially in critically ill patients.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2114-x) contains supplementary material, which is available to authorized users.

Platelet Storage Lesions: What More Do We Know Now?

Platelet concentrate (PC) transfusions are a lifesaving adjunct to control and prevent bleeding in cancer, hematologic, surgical, and trauma patients. Platelet concentrate availability and safety are limited by the development of platelet storage lesions (PSLs) and risk of bacterial contamination. Platelet storage lesions are a series of biochemical, structural, and functional changes that occur from blood collection to transfusion. Understanding of PSLs is key for devising interventions that prolong PC shelf life to improve PC access and wastage. This article will review advancements in clinical and mechanistic PSL research. In brief, exposure to artificial surfaces and high centrifugation forces during PC preparation initiate PSLs by causing platelet activation, fragmentation, and biochemical release. During room temperature storage, enhanced glycolysis and reduced mitochondrial function lead to glucose depletion, lactate accumulation, and product acidification. Impaired adenosine triphosphate generation reduces platelet capacity to perform energetically demanding processes such as hypotonic stress responses and activation/aggregation. Storage-induced alterations in platelet surface proteins such as thrombin receptors and glycoproteins decrease platelet aggregation. During storage, there is an accumulation of immunoactive proteins such as leukocyte-derive cytokines (tumor necrosis factor α, interleukin (IL) 1α, IL-6, IL-8) and soluble CD40 ligand which can participate in transfusion-related acute lung injury and nonhemolytic transfusion reactions. Storage-induced microparticles have been linked to enhanced platelet aggregation and immune system modulation. Clinically, stored PCs have been correlated with reduced corrected count increment, posttransfusion platelet recovery, and survival across multiple meta-analyses. Fresh PC transfusions have been associated with superior platelet function in vivo; however, these differences were abrogated after a period of circulation. There is currently insufficient evidence to discern the effect of PSLs on transfusion safety. Various bag and storage media changes have been proposed to reduce glycolysis and platelet activation during room temperature storage. Moreover, cryopreservation and cold storage have been proposed as potential methods to prolong PC shelf life by reducing platelet metabolism and bacterial proliferation. However, further work is required to elucidate and manage the PSLs specific to these storage protocols before its implementation in blood banks.

Storage time of platelet concentrates and risk of a positive blood culture: a nationwide cohort study

BACKGROUND

Concern of transfusion-transmitted bacterial infections has been the major hurdle to extend shelf life of platelet (PLT) concentrates. We aimed to investigate the association between storage time and risk of positive blood cultures at different times after transfusion.

STUDY DESIGN AND METHODS

We performed a nationwide cohort study among PLT transfusion recipients in Denmark between 2010 and 2012, as recorded in the Scandinavian Donations and Transfusions (SCANDAT2) database. Linking with a nationwide database on blood cultures (MiBa), we compared the incidence of a positive blood culture among recipients of PLTs stored 6 to 7 days (old) to those receiving fresh PLTs (1-5 days), using Poisson regression models. We considered cumulative exposures in windows of 1, 3, 5, and 7 days.

RESULTS

A total of 9776 patients received 66,101 PLT transfusions. The incidence rate ratio (IRR) of a positive blood culture the day after transfusion of at least one old PLT concentrate was 0.77 (95% confidence interval [CI], 0.54-1.09) compared to transfusion of fresh PLT concentrates. The incidence rate of a positive blood culture was lower the day after receiving one old compared to one fresh PLT concentrate (IRR, 0.57; 95% CI, 0.37-0.87). Three, 5, or 7 days after transfusion, storage time was not associated with the risk of a positive blood culture.

CONCLUSION

Storage of buffy coat-derived PLT concentrates in PAS-C up to 7 days seems safe regarding the risk of a positive blood culture. If anything, transfusion of a single old PLT concentrate may decrease this risk the following day.

Age of platelet concentrates and time to the next transfusion

BACKGROUND

Storage time of platelet (PLT) concentrates has been negatively associated with clinical efficacy outcomes. The aim of this study was to quantify the association between storage time of PLT concentrates and interval to the next PLT transfusion for different types of PLT components, stored for up to 7 days and transfused to transfusion-dependent hematooncology patients with thrombocytopenia.

STUDY DESIGN AND METHODS

From a cohort of patients from 10 major Dutch hospitals, patients were selected whose transfusion patterns were compatible with PLT transfusion dependency due to hematooncologic disease. Mean time to the next transfusion and mean differences in time to the next transfusion for different storage time categories (i.e., fresh, <4 days; intermediate, 4-5 days; and old, >5 days) were estimated, per component type, using multilevel mixed-effects linear models.

RESULTS

Among a cohort of 29,761 patients who received 140,896 PLT transfusions we selected 4441 hematooncology patients who had received 12,724 PLT transfusions during periods of PLT transfusion dependency. Transfusion of fresh, compared to old, buffy coat-derived PLTs in plasma was associated with a delay to the next transfusion of 6.2 hours (95% confidence interval [CI], 4.5-8.0 hr). For buffy coat-derived PLTs in PAS-B and -C this difference was 7.7 hours (95% CI, 2.2-13.3 hr) and 3.9 hours (95% CI, -2.1 to 9.9 hr) while for apheresis PLTs in plasma it was only 1.8 hours (95% CI, -3.5 to 7.1 hr).

CONCLUSION

Our results indicate that the time to the next transfusion shortens with increasing age of transfused buffy coat-derived PLT concentrates. This association was not observed for apheresis PLTs.

Duration of platelet storage and outcomes of critically ill patients

BACKGROUND

The storage duration of platelet (PLT) units is limited to 5 to 7 days. This study investigates whether PLT storage duration is associated with patient outcomes in critically ill patients.

STUDY DESIGN AND METHODS

This study was a retrospective analysis of critically ill patients admitted to the intensive care unit (ICU) of two hospitals in Australia who received one or more PLT transfusions from 2008 to 2014. Storage duration was approached in several different ways. Outcome variables were hospital mortality and ICU-acquired infection. Associations between PLT storage duration and outcomes were evaluated using multiple logistic regression and also by Cox regression.

RESULTS

Among 2250 patients who received one or more PLT transfusions while in the ICU, the storage duration of PLTs was available for 64% of patients (1430). In-hospital mortality was 22.1% and ICU infection rate 7.2%. When comparing patients who received PLTs of a maximum storage duration of not more than 3, 4, or 5 days, there were no significant differences in baseline characteristics. After confounders were adjusted for, the storage duration of PLTs was not independently associated with mortality (4 days vs. ≤3 days, odds ratio [OR] 0.88, 95% confidence interval [CI] 0.59-1.30; 5 days vs. ≤3 days, OR 0.97, 95% CI 0.68-1.37) or infection (4 days vs. ≤3 days, OR 0.71, 95% CI 0.39-1.29; 5 days vs. ≤3 days, OR 1.11, 95% CI 0.67-1.83). Similar results were obtained regardless of how storage duration of PLTs was approached.

CONCLUSIONS

In this large observational study in a heterogeneous ICU population, storage duration of PLTs was not associated with an increased risk of mortality or infection.

Aging of platelets stored for transfusion

A goal of platelet storage is to maintain the quality of platelets from the point of donation to the point of transfusion - to suspend the aging process. This effort is judged by clinical and laboratory measures with varying degrees of success. Recent work gives encouragement that platelets can be maintained ex vivo beyond the current 5 -7 day shelf life whilst maintaining their quality, as measured by posttransfusion recovery and survival. However, additional measures are needed to validate the development of technologies that may further reduce the aging of stored platelets, or enhance their hemostatic properties.

A randomized noninferiority crossover trial of corrected count increments and bleeding in thrombocytopenic hematology patients receiving 2- to 5- versus 6- or 7-day-stored platelets

BACKGROUND

Bacterial screening offers the possibility of extending platelet (PLT) storage to Day 7. We conducted a noninferiority, crossover trial comparing PLTs stored for 6 or 7 days versus 2 to 5 days.

STUDY DESIGN AND METHODS

Stable hematology patients were allocated to receive blocks of 2- to 5- and 6- or 7-day PLTs in random order. The primary outcome was the proportion of successful transfusions during the first block, defined as a corrected count increment (CCI) of more than 4.5 at 8 to 24 hours posttransfusion.

RESULTS

Of 122 patients with an evaluable first block, 87 (71%) and 84 (69%) had successful transfusions after 2- to 5- and 6- or 7-day PLTs of mean (SD) ages of 3.8 (1.0) and 6.4 (0.5) days, respectively. Six- or 7-day PLTs were declared noninferior to 2- to 5-day PLTs since the upper confidence interval (CI) limit was less than the predefined noninferiority margin of 10% (95% CI, -14.0% to 9.1%; p = 0.766). Logistic regression analysis gave an adjusted odds ratio of 0.86 (95% CI, 0.47-1.58; p = 0.625). Mean (SD) 8- to 24-hour CCIs were 9.4 (7.9) and 7.7 (7.1) after transfusion with 2- to 5- or 6- or 7-day PLTs (95% CI, -3.31 to 0.03; p = 0.054). The proportions of days with bleeding scores of WHO Grade 2 or higher were 13% (38/297 days) and 11% (32/296 days; 95% CI, -3.2 to 7.2; p = 0.454). Median interval to next PLT transfusion (2 days) was unaffected (95% CI, -10.5 to 5.4; p = 0.531).

CONCLUSION

In hematology patients, there was no evidence that 6- or 7-day PLTs were inferior to 2- to 5-day PLTs, as measured by proportion of patients with successful transfusions, bleeding events, or interval to next transfusion.

Metabolomic analysis of platelets during storage: a comparison between apheresis- and buffy coat-derived platelet concentrates

BACKGROUND

Platelet concentrates (PCs) can be prepared using three methods: platelet (PLT)-rich plasma, apheresis, and buffy coat. The aim of this study was to obtain a comprehensive data set that describes metabolism of buffy coat-derived PLTs during storage and to compare it with a previously published parallel data set obtained for apheresis-derived PLTs.

STUDY DESIGN AND METHODS

During storage we measured more than 150 variables in 8 PLT units, prepared by the buffy coat method. Samples were collected at seven different time points resulting in a data set containing more than 8000 measurements. This data set was obtained by combining a series of standard quality control assays to monitor the quality of stored PLTs and a deep coverage metabolomics study using liquid chromatography coupled with mass spectrometry.

RESULTS

Stored PLTs showed a distinct metabolic transition occurring 4 days after their collection. The transition was evident in PLT produced by both production methods. Apheresis-derived PLTs showed a clearer phenotype of PLT activation during early days of storage. The activated phenotype of apheresis PLTs was accompanied by a higher metabolic activity, especially related to glycolysis and the tricarboxylic acid cycle. Moreover, the extent of the activation differed between bags resulting in interbag variability in the storage lesion of apheresis-prepared PLTs. This may be related to donor-related polymorphism.

CONCLUSION

This study demonstrated two discrete metabolic phenotypes in stored PLTs prepared with both apheresis and buffy coat methods. PLT activation occurs during the first metabolic phenotype and might lead to a low reproducibility of the apheresis PCs.

Comprehensive metabolomic study of platelets reveals the expression of discrete metabolic phenotypes during storage

BACKGROUND

Platelet (PLT) concentrates are routinely stored for 5 to 7 days. During storage they exhibit what has been termed PLT storage lesion (PSL), which is evident by a loss of hemostatic function when transfused into patients. The overall goal of this study was to obtain a comprehensive data set describing PLT metabolism during storage.

STUDY DESIGN AND METHODS

The experimental approach adopted to achieve this goal combined a series of standard assays to monitor the quality of stored PLTs and a deep-coverage metabolomics study using liquid chromatography coupled with mass spectrometry performed on both the extracellular and the intracellular environments. During storage we measured 174 different variables in 6 PLT units, collected by apheresis. Samples were collected at eight different time points resulting in a data set containing more than 8000 measurements.

RESULTS

Stored PLTs did not undergo a monotonic decay, but experienced systematic changes in metabolism reflected in three discrete metabolic phenotypes: The first (Days 0-3) was associated with active glycolysis, pentose phosphate pathway, and glutathione metabolism and down regulation of tricarboxylic acid (TCA) cycle. The second (Days 4-6) was associated with a more active TCA cycle as well as increased purine metabolism. A third metabolic phenotype of less clinical relevance (Days 7-10) was associated with a faster decay of cellular metabolism.

CONCLUSION

PSL is not associated with a linear decay of metabolism, but rather with successive metabolic shifts. These findings may give new insight into the mechanisms underlying PSL and encourage the deployment of systems biology methods to PSL.