Platelets Stored in a Glucose‐Free Additive Solution or in Autologous Plasma – An Ultrastructural and Morphometric Evaluation

Background: By inhibiting nucleic acids, photochemical treatment (PCT) using amotosalen hydrochloride (S-59) in combination with UVA light provides a new method for the inactivation of pathogens and leukocytes, potential contaminants of platelet concentrates (PCs). Material and Methods: We evaluated the effect of PCT on function and viability of PCs derived from apheresis over a storage period of 5 days. Double-dose PCs containing 6.5–7.0 × 10¹¹ platelets (n = 8) were collected in 600 ml of approximately 35% autologous plasma and 65% platelet additive solution. Each collection was split into two equal-sized portions for paired analysis. One day after collection, test PCs were mixed with 15 ml of 3 mmol/l S-59 and illuminated with UVA light for 3 min, followed by a 6- to 8-hour incubation in a compound adsorption device (CAD) for the reduction of residual S-59 and unbound photoproducts. In vitro platelet function measurements included platelet count, pH, lactate dehydrogenase (LDH), β-thromboglobulin (β-TG), hypotonic shock response (HSR), extent of shape change (ESC) and the expression of p-selectin. Platelet morphology and ultrastructure were analyzed by light and electron microscopy (EM). Results: We found no statistically significant differences on day 5 of the storage between the control and test platelets for pH, platelet count, p-selectin, ESC, HSR, morphology, and the percentage of lysed platelets analyzed by EM. The level of β-TG was reduced in the test units by the CAD step. Significant differences (p < 0.05) were observed for LDH and HSR immediately after PCT, indicating a slight platelet activation. Until the end of the storage period, LDH increased further in control and test platelets, but the quantitative difference between both products did not vary upon further storage. The effect for HSR was transient as no differences between treated and untreated PCs were detected at the end of the storage period. Conclusion: These in vitro results indicate that PCT with amotosalen and UVA light is applicable for split double-dose platelets derived from apheresis as it leads only to a transient activation of platelets immediately after the procedure, without affecting the function and structure of PCs over the 5-day storage period.

Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Storage Characteristics of Split Double-Dose Platelet Concentrates Derived from Apheresis and Treated with Amotosalen Hydrochloride and UVA Light for Pathogen Inactivation

Janetzko¹,

Klinger²,

Mayaudon³

et al. 2002

“…On the other hand, depletion of glucose and, in the next step, significantly reduced levels of adenine nucleotides have been associated with loss of platelet viability [1,21,22]. In a study by Klinger et al [23] focusing on morphological changes, PCs prepared by apheresis were stored in either plasma or PAS-2 with a very limited plasma carryover (10%). In PAS-2, glucose was consumed after 3 days of storage which was associated with a decrease in the relative volume fraction of alpha granules of platelets, an increase in the fraction of platelet open canalicular system, and an almost total lysis of platelets after 8 days.…”

Section: Effects Of Glucosementioning

confidence: 99%

Storage of Platelets for Transfusion in Additive Solutions: Effects of Different Factors and Compounds

Gulliksson¹

2000

Platelet-additive solution (PAS) can be used as a substitute for plasma for the storage of platelet concentrates (PCs) in order to improve storage conditions, to recover plasma for other purposes, to avoid transfusion of large volumes of plasma to patients, and to make possible photochemical treatment for viral inactivation of PCs. For this reason, PAS should have a great potential for wide use in transfusion medicine. In the studies cited in this review, PCs were prepared from units of whole blood either by the platelet-rich plasma method or the buffy coat method. In some studies, PCs prepared by apheresis were used. The composition of the PASs used varied. The effects on platelet metabolism associated with different factors and compounds in PAS are only partly known. Available studies suggest that: 1) Presence of glucose in the platelet storage medium during the entire storage period is necessary for platelet metabolism. 2) Acetate is used as an additional substrate for platelet metabolism. Acetate also reduces the production of lactate by platelets, and by the formation of bicarbonate it maintains stable pH levels during storage. 3) The fall in pH can be rapid in PAS-containing media due to the very limited buffering capacity of PAS compared with that of plasma. 4) Platelets stored in PAS at a citrate concentration of 8 mmol/l produce only half the quantity of lactate as that of platelets at 14–26 mmol/l of citrate. 5) Free fatty acids from plasma can be used as substrate for platelet metabolism and are supposed to be made available by the hydrolysis of plasma triglycerides. 6) For PCs prepared by apheresis with ACD anticoagulant, presence of phosphate in PAS seems to be a critical factor to avoid low adenine nucleotide levels during storage.

“…It is worthy of note that a preferential secretion from selected types of granules may be induced by different kinds of stimulation [14,15], and recently the main molecular elements of the selective exocytosis machinery were identified [16]. The fusion of granInfusionsther Transfusionsmed 1999;26: [20][21][22][23][24][25] Platelets Are Circulating Stores 21 ules with the OCS is an energy-dependent process which becomes obvious in stored platelets after metabolic exhaustion: These platelets are severely damaged but still contain substantial amounts of intact α-granules [17]. After fusion of granules and OCS, the granular contents become diluted within the OCS and possibly bind to the OCS membrane or reach the extracellular space.…”

Section: Exocytosis and Endocytosis In Plateletsmentioning

confidence: 99%

Blood Platelets Are Circulating Stores for Adhesive Proteins, Inflammatory Mediators, and Immunoglobulins – Role in Nonhemolytic Transfusion Reactions

Klinger¹,

Klüter²

1999

Objective: Blood platelets store within their α-granules a variety of substances that are involved in blood clotting, inflammation, and repair processes after a lesion of the vessel wall. Not all of these substances are synthesized within the megakaryocytes or platelets themselves, but some of them are taken up from the blood plasma by the circulating platelet. This article summarizes recent investigations on the internalization capabilities of platelets and the mechanism of endocytosis. Results: By means of immunoelectron microscopy and by incubations with gold-labeled peptides the uptake of fibrinogen, IgG, IgE, and the chemokine RANTES by the platelet can be demonstrated. Two different mechanisms of internalization are discerned: In resting platelets, the gold-labeled peptides are endocytosed and transferred to α-granules, whereas in platelets stimulated by ADP or thrombin the gold particles appear within the open canalicular system and not within granules. Conclusion: Platelets store and release not only proinflammatory mediators that are typical for the megakaryocyte-platelet lineage, but also blood-borne substances from other cellular sources. Due to activation and disintegration of platelets that are stored as concentrates for usage in transfusion medicine, these substances can accumulate in the platelet concentrate and might be responsible for transfusion-associated reactions. Further investigation in this field of platelet immunobiology is warranted.