Pooled platelet concentrates: an alternative to single donor apheresis platelets?

Are Buffy-coat Pooled Platelet Concentrates an Effective Alternative to Apheresis Platelet Concentrates? An In vitro Analysis at a Tertiary Care Center in Northern India

Background

There is a need for platelet products to have the best quality. Apheresis platelet concentrates (PCs) obtained from single-donors PCs (SD-PCs) are considered best but have issues such as feasibility and cost. Buffy-coat pooled PCs (BCP-PCs) are considered an alternative to SD-PCs. This study compares BCP-PCs and SD-PCs for in vitro quality parameters and their changes during storage.

Materials and Methods

Fifteen units of BCP-PCs and 15 units of SD-PCs were prepared. In this study, a pool of five buffy coats was prepared. Fifteen units of BCP-PCs were analyzed on day 1 and day 5 of storage, while 15 SD-PCs were analyzed on day 1 while ten units on day 5. The parameters analyzed were volume, hematological parameters, pH, swirling, and sterility.

Results

The mean platelets count of SD-PCs was found to be significantly higher as compared to BCP-PCs. White blood cells (WBCs) contamination was significantly lower in BCP-PCs as compared to SD-PCs. The mean pH and mean platelet volume of SD-PCs were significantly lower than BCP-PCs. During storage, the mean platelets count of BCP-PCs was decreased significantly while that of SD-PCs nonsignificantly. The mean WBCs count and pH decreased in both BCP-PCs and SD-PCs significantly. All units in both types of PCs were sterile.

Conclusion

Platelet yield was significantly better in SD-PCs, while mean WBCs contamination was significantly lower in BCP-PCs. BCP-PCs may be preferred in place of SD-PCs in case of nonavailability of apheresis, difficulty in finding a willing donor, or when the cost is of consideration.

Biomarkers of complement and platelet activation are not correlated with the one or twenty-four hours corrected count increments in prophylactically platelet transfused hematological patients: a prospective cohort study

Platelet transfusion refractoriness is a serious clinical concern that complicates the management of thrombocytopenic patients. Previous studies have suggested a potential role for both complement and platelet activation based on in vitro analyses of platelet concentrates. In this study, the post-transfusion platelet response, as indicated by the corrected count increment at 1 and 24 h after prophylactic platelet transfusions, respectively, was correlated with the 1 h post-transfusion Δconcentration (1 h post-transfusion - pretransfusion) of complement and platelet activation biomarkers. The study was registered as a clinical trial at ClinicalTrials.gov (identifier: NCT02601131) and patients were recruited during inpatient care in the hematological department. Soluble terminal complement complexes, soluble P-selectin and soluble CD40 ligand were analyzed. Confirmed alloimmunized patients were excluded. Included subjects were either given platelet transfusions (n = 43) and categorized into four clinical study groups or included in a non-transfused control group (n = 10). In total, 54 transfusions were included. No transfusion-mediated complement activation was observed. The transfusions were associated with a significant increase in the concentration of soluble P-selectin (p < .001), primarily corresponding to the passive infusion of soluble P-selectin-containing plasma residuals. The Δconcentration of soluble P-selectin was, however, not significantly correlated with the corrected count increments. Thus, significant correlations between biomarkers of complement and platelet activation and the post-transfusion platelet response could not be demonstrated in this study.

Platelet Transfusion: And Update on Challenges and Outcomes

Platelet transfusion is a common practice in onco-hematologic patients for preventing or treating hemorrhages. Platelet concentrates can be transfused with therapeutic or prophylactic purposes. With the aim to help clinicians to take the decisions on platelet transfusion, some guidelines have been developed based on the current scientific evidence. However, there are some controversial issues and available scientific evidence is not enough to solve them. There is little information about what is the best platelet product to be transfused: random platelets or single donor apheresis platelets, and plasma-suspended or additive solution suspended platelets. Platelets are often transfused without respecting the ABO compatibility, but influence of this practice on platelet transfusion outcome is not well established. In the prophylactic platelet transfusion set there are some questions unsolved as the platelet threshold to transfuse prior to specific procedures or surgery, and even if platelet transfusion is necessary for some specific procedures as autologous hematopoietic stem cell transplantation. A challenging complication raised from multiple platelet transfusions is the platelet transfusion refractoriness. The study and management of this complication is often disappointing. In summary, although it is a widespread practice, platelet transfusion has still many controversial and unknown issues. The objective of this article is to review the current evidence on platelet transfusion practices, focusing on the controversial issues and challenges.

Pooled platelet product using the Acrodose plus system: evaluation of feasibility, safety and efficacy

BACKGROUND

Pooling of whole blood-derived platelets is not practiced in India. Currently available data shows that pooled platelets are equivalent in quality and less costly when compared with apheresis platelets.

AIM

To evaluate feasibility, safety and efficacy of pooled platelets using the Acrodose Plus system.

MATERIAL AND METHODS

Standardization of platelet pooling procedure was done. Sterile docking device was used to maintain closed system. Pools of ABO compatible platelets (N=40) as well as ABO incompatible (N=10) pooled platelets were studied. ABO antibody titers were studied before and after pooling in case of ABO incompatible platelet pools. Corrected count increments (CCIs) (at 1h and 24h) were noted after transfusion of pooled platelets and Apheresis platelets in matched patient groups.

RESULTS

Loss of platelet product due to pooling and leucodepletion was not statistically significant (p=0.23). Leucodepletion >3 log was achieved in all pooled platelets. The total platelet content, time taken for procedure and pH were within acceptable limits. There were no issues related to platelet availability and turn around time during the study period. There was a reduction in the ABO antibody titers after pooling in case of the ABO incompatible pools. None of the pooled platelets showed evidence of bacterial contamination on testing with eBDS system at 18 h and 24h intervals after pooling. CCI with pooled platelets was equivalent to that with apheresis platelets at 1h (p=0.36) and 24h (p=0.15).

CONCLUSION

Whole blood derived platelets can be pooled safely using closed system without altering the platelet quality in vitro as well as in vivo survival post transfusion. Pooled platelets can be a cost effective and safe alternative to thrombocytopenic patients whose transfusion requirements cannot be fulfilled with apheresis platelets alone.

Quality control of leucocyte-depleted platelet concentrates obtained by buffy-coat method

OBJECTIVES

Quality control results on leukoreduced buffy-coat platelet pools during the 7-year period (2005-2011) are presented with the aim to assess their overall quality and trends recorded during the study period.

METHODS

Data of the Quality Assurance Department, Croatian Institute of Transfusion Medicine were used in the study. Measurement results of all study parameters are presented for the entire study period, while the rate of controlled platelet pools consistent with the specified quality requirements is additionally presented for each study year.

RESULTS

The mean component volume was 50 ± 9 mL per 6 × 10(10) platelets (91.5% of conformable results), mean platelet count 7.81 ± 1.26 × 10(10) per single unit equivalent (97.5% of conformable results), mean leucocyte count 0.01 ± 0.08 × 10(6) per single unit equivalent (99.6% of conformable results), and mean pH 7.45 ± 0.16 (99.4% of conformable results). Bacteriologic testing showed negative result in 99.8% of tested components.

CONCLUSION

Study results indicated the results of platelet pool quality control to be highly conformable with the specified quality requirements. It is illustrated how simple interventions in the preparation process can have significant impact on product quality improvement and thus on redefining quality requirements.

Clinical observation of factors in the efficacy of blood component transfusion in patients following hematopoietic stem cell transplantation

BACKGROUND

Factors affecting the efficacy of platelet and red blood cell (RBC) transfusion in patients undergoing hematopoietic stem cell transplantation (HSCT) have not been studied extensively. We aimed to evaluate platelet and RBC transfusion efficacy by measuring the platelet corrected count increment and the hemoglobin increment, respectively, 24 h after transfusion in 105 patients who received HSCT.

METHODOLOGY/PRINCIPAL FINDINGS

Using retrospective analysis, we studied whether factors, including gender, time of transplantation, the compatibility of ABO group between HSC donors and recipients, and autologous or allogenic transplantation, influence the efficacy of blood component transfusion. We found that the infection rate of HSCT patients positively correlated with the transfusion amount, and the length of stay in the laminar flow room was associated with transfusion. We found that platelet transfusion performed during HSCT showed significantly better efficacy than that performed before HSCT. The effect of platelet transfusion in auto-transplantation was significantly better than that in allo-transplantation. The efficacy of RBC transfusion during HSCT was significantly lower than that performed before HSCT. The efficacy of RBC transfusion in auto-transplantation was significantly higher than that in allo-transplantation. Allo-transplantation patients who received HSCs from compatible ABO groups showed significantly higher efficacy during both platelet and RBC transfusion.

CONCLUSIONS

We conclude that the efficacy of platelet and RBC transfusions does not correlate with the gender of patients, while it significantly correlates with the time of transplantation, type of transplantation, and ABO compatibility between HSC donors and recipients. During HSCT, the infection rate of patients positively correlates with the transfusion amount of RBCs and platelets. The total volume of RBC units transfused positively correlates with the length of the patients' stay in the laminar flow room.

Platelet transfusion alters CD40L blood level and release capacity in patients suffering from thrombocytopenia

BACKGROUND

Platelet (PLT)-derived cytokines, such as soluble CD40 ligand (sCD40L), play an important role in the development of adverse transfusion reactions associated with the administration of PLT products. In this study, we determined sCD40L concentration and release capacity in patients with thrombocytopenia before and after receiving a PLT transfusion.

STUDY DESIGN AND METHODS

The study included 12 patients suffering from chemotherapy-induced thrombocytopenia. sCD40L levels and release capacity were measured in plasma samples of the patients before and after PLT administration as well as in the respective plateletpheresis concentrates by enzyme-linked immunosorbent assay. Sixteen healthy blood donors served as a control group.

RESULTS

In PLT concentrates, elevated sCD40L levels (2567±134 pg/mL) were observed in comparison to plasma sCD40L levels in controls (238.4±35.3 pg/mL). sCD40L plasma concentration of patients with thrombocytopenia was significantly reduced (86.3±16.7 pg/mL) before transfusion and increased to nearly normal levels (204.4±24.8 pg/mL) after PLT administration. In parallel, the sCD40L release capacity per PLT showed no significant difference between controls and patients with thrombocytopenia before transfusion (33.3±2.6 and 29.3±4.6 ag/PLT, respectively) but was significantly reduced after PLT transfusion (22.4±2.7 compared to 29.3±4.6 ag/PLT).

CONCLUSIONS

In patients with thrombocytopenia, sCD40L levels were clearly influenced by PLT transfusions: PLT administration led to a normalization of sCD40L plasma concentration. Nevertheless, adverse transfusion reactions did not occur in these patients. The sCD40L release capacity was enhanced by PLT administration dependent on the increase in the amount of PLT count.

[Techniques of preparation and indications of labile blood products]

Labile blood products are obtained from samples of whole blood or aphaeresis. The techniques of preparation evolve with technological advances, which allow both an increasing automation and an intensification of the sanitary safety of the blood products. Over the last ten years, thanks to the availability of new technologies, several measures have been introduced in order to reduce the risk of transmission of pathogens and prevent the onset of transfusion-related acute lung injury (TRALI): leukoreduction, use of platelet storage solutions, inactivation of plasma and presumably of platelets in a very near future. The control of transfusion risk also depends on proper use of labile blood products. To assist the prescriber in his treatment options and to standardize practices, the French Agency for Sanitary Safety of Health Products has issued recommendations in terms of utilization of blood products that are detailed in this review of major labile blood products available.