Mitochondrial DNA levels in plasma products: A comparative study of apheresis plasma from COVID-19 convalescent donors and apheresis and fresh frozen plasma from non-infected donors.

BACKGROUND

Cellular and mitochondrial stress can trigger the extracellular release of mitochondrial DNA (mtDNA) as damage-associated molecular patterns (DAMPs), which may amplify inflammatory responses and contribute to transfusion-related adverse events. This study aimed to quantify mtDNA levels in plasma products, assess the effects of storage duration and preparation method (apheresis vs. FFP).

STUDY DESIGN AND

METHODS

A cross-sectional analysis was conducted from March 2022 to March 2023. Plasma samples included 16 units of fresh frozen plasma (FFP) obtained via whole blood centrifugation and 32 units of apheresis plasma collected using the Haemonetics MCS+ system. Apheresis donors were stratified into COVID-19-convalescent (n = 16) and non-infected (n = 16) groups. Convalescent donors had resolved mild-to-moderate infection for at least 30 days, confirmed by RT-PCR. mtDNA quantification was performed using real-time qPCR. Data were analyzed with GraphPad Prism 8 using appropriate parametric and non-parametric tests.

RESULTS

Apheresis plasma from non-infected donors had the highest mean mtDNA concentration (2.3 × 10⁶ copies/mL), followed by convalescent plasma (8.2 × 10⁵ copies/mL) and FFP (6.0 × 10⁵ copies/mL). FFP mtDNA levels remained stable during storage, while apheresis plasma demonstrated a significant increase over 30 days. A moderate positive correlation was observed between mtDNA concentration and antibody titers in convalescent plasma.

CONCLUSION

mtDNA concentrations vary by plasma preparation method. These findings highlight the relevance of processing variables in transfusion safety and suggest mtDNA may serve as a molecular marker for product quality.