In vitro properties of concentrated canine platelets stored in two additive solutions: a comparative study

Platelet storage: Progress so far

There is a crucial need for platelet transfusion during an emergency-surgery and treatment of platelet disorders. The unavailability of donors has furthermore increased the demand for platelet storage. Platelets have limited shelf life due to bacterial contamination and storage lesions. Temperature, materials, oxygen availability, media, platelet processing and manufacturing methods influence the platelet quality and viability during storage. The conception of various platelet additive solutions along with the advent of plastic storage during the 1980s led to enormous developments in platelet storage strategies. Cold storage of platelets gained attention despite its inability to contribute to platelet survival post-transfusion as it offers faster haemostasis. Several developments in platelet storage strategies over the years have improved the quality and shelf-life of stored platelets. Despite the progress, the efficacy of platelets during storage beyond a week has not been achieved. Antioxidants as additives have been explored in platelet storage and have proven to enhance the efficacy of platelets during prolonged storage. However, the molecular interactions of antioxidants in platelets can provide a better understanding of their mechanism of action. Optimization of dosage concentrations of antioxidants is also a critical parameter to be considered as they tend to exhibit toxicity at certain levels. This review provides comprehensive insights into the critical factors affecting platelet storage and the evolution of platelet storage. It also emphasizes the role of antioxidants as additives in platelet storage solutions and their future prospects towards better platelet banking.

The effects of additive solutions on the development of storage lesions in stored canine platelet concentrates

OBJECTIVE

To determine if platelet additive solutions (PAS) decrease the occurrence and degree of platelet storage lesions, maintain platelet function, and extend storage time in vitro beyond 5 days at 22°C when compared to platelets stored in plasma only.

DESIGN

Prospective, ex vivo experimental controlled study.

SETTING

Research laboratory in a school of veterinary medicine.

ANIMALS

Twelve units of canine platelet concentrate prepared from fresh whole blood donations.

INTERVENTIONS

Platelet concentrates were aliquoted into 4 units and stored at room temperature (22°C) under constant agitation in either 100% plasma (control) or 35% plasma and 65% of 1 of 3 different PAS (Plasma-Lyte A, Isoplate, and InterSol) for 7 days. At days 0, 3, 5, and 7, samples were analyzed for presence of swirling, degree of aggregate formation, platelet count, platelet indices, glucose, lactate, lactate dehydrogenase, Pvo₂ , and Pvco₂ concentrations, aggregation via light aggregometry, and activation percentage based on flow cytometric measurement of surface P-selectin. Bacterial cultures were performed on days 0, 5, and 7.

MEASUREMENTS AND MAIN RESULTS

Isoplate had a higher incidence of aggregate formation on day 0 (n = 2), and Plasma-Lyte A had a higher incidence of loss of swirl on day 7 (n = 5). Plasma-stored samples had significantly higher platelet counts (P < 0.001), pH (P < 0.05), Pvco₂ (P < 0.001), and lactate (P < 0.001), and significantly lower lactate dehydrogenase (P < 0.05) as compared to all PAS. The mean pH remained above 7.2 in PAS and plasma. There was no difference in platelet activation between plasma and PAS. Changes in platelet indices, glucose consumption, and maximum aggregation varied by storage solution. There was no bacterial growth seen in any samples.

CONCLUSIONS

The 3 PAS performed similarly and could all be considered as potential replacements for plasma during the room temperature storage of canine platelet concentrate for up to 7 days.

Quality control in veterinary blood banks: evaluation of canine platelet concentrates stored for five days

Background

Platelets undergo structural, biochemical and functional alterations when stored, and platelet storage lesions reduce platelet function and half-life after transfusion. The objective of this study was to evaluate stored canine platelet concentrates with platelet aggregation, flow cytometry and biochemistry assays. Twenty-two bags of canine platelet concentrates were obtained by the platelet-rich plasma method and were assessed on days 1, 3 and 5 after collection. Parameters such as platelet counts, residual leukocytes, platelet swirling, glucose, lactate, pH, CD62P expression (platelet activation), JC-1 (mitochondrial function) and annexin V (apoptosis and cell death) were assessed.

Results

Over the five days of storage there was a significant decrease in glucose, HCO₃, pCO₂, ATP, pH, swirling and mitochondrial function, associated with a significant increase in lactate levels and pO₂. At the end of storage pH was 5.9 ± 0.6 and lactate levels were 2.8 ± 1.2 mmol/L. Results of the quality parameters evaluated were similar to those reported in human platelets studies. The deleterious effects of storage were more pronounced in bags with higher platelet counts (> 7.49 × 10¹⁰/unit), suggesting that canine platelet concentrates should not contain an excessive number of platelets.

Conclusions

Quality parameters of canine platelets under standard storage conditions were similar to those observed in human platelets. Our results have potential to be used for the routine evaluation and quality control in veterinary blood banks.

Platelet Function and Therapeutic Applications in Dogs: Current Status and Future Prospects

Significant progress has been made in the functional characterization of canine platelets in the last two decades. The role of canine platelets in hemostasis includes their adhesion to the subendothelium, activation, and aggregation, leading to primary clot formation at the site of injury. Studies on canine platelet function and advancements in laboratory testing have improved the diagnosis and understanding of platelet-related disorders as well as the knowledge of the mechanisms behind these diseases. This review focuses on the most recent discoveries in canine platelet structure, function, and disorders; and discusses the efficacy of various tests in the diagnosis of platelet-related disorders. With the relatively recent discovery of angiogenetic and reparative effects of growth factors found in platelets, this review also summarizes the use of canine platelet-rich plasma (PRP) alone or in association with stem cells in regenerative therapy. The characterization of proteomic and lipidomic profiles and development of platelet gene therapy in veterinary species are areas of future study with potential for major therapeutic benefits.