Impact of high dose vitamin C on platelet function

Area of Science:

• Hematology and Transfusion Medicine
• Biochemistry and Molecular Biology
• Clinical Pharmacology

Background:

• Vitamin C (VitC) is an essential nutrient with antioxidant properties.
• High-dose intravenous VitC is used in clinical settings, but its effects on blood components like platelets (PLTs) are not fully understood.
• Understanding VitC's impact on PLT function is crucial for transfusion medicine and patient safety.

Purpose of the Study:

• To investigate the effects of high concentrations of VitC on human platelets (PLTs) ex vivo.
• To assess changes in PLT function, coagulation parameters, and lipid metabolism following VitC exposure.

Main Methods:

• Human platelet concentrates were exposed to normal saline (control), low-dose VitC (0.3 mmol/L), or high-dose VitC (3 mmol/L).
• PLT function was assessed using Thromboelastography (TEG), aggregometry, and flow cytometry over 8 days.
• Intracellular VitC levels, plasma coagulation tests (PT, PTT, fibrinogen), and lipidomics were analyzed.

Main Results:

• High-dose VitC significantly increased intracellular PLT ascorbic acid levels.
• After 8 days, high-dose VitC exposure led to significantly altered TEG parameters (increased R and K times, decreased α-angle) and reduced maximum amplitude.
• High-dose VitC induced the release of specific eicosanoids and lipoxygenase pathway products.

Conclusions:

• Prolonged exposure to high-dose VitC (3 mmol/L) ex vivo significantly alters human platelet function.
• These findings suggest that caution is warranted with prolonged intravenous administration of high-dose VitC due to potential impacts on hemostasis.
• Further research is needed to elucidate the clinical implications of these ex vivo findings.