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Changes in functional activities of plasma fibrinogen after treatment with methylene blue and red light
Anna-Maija Suontaka1, Margareta Blombäck, John Chapman
1Department of Surgical Sciences/Blood Coagulation Research, Clinical Chemistry Building, Karolinska Hospital, SE-171 76 Stockholm, Sweden. Anna-Maija.Suontaka@ks.se
Background:
Methylene blue (MB) plus light treatment used for virus inactivation of human plasma units may lead to changes in the functional activities of fibrinogen.
Study Design And Methods:
Single-donor units of fresh plasma were treated with 1.0 microM MB and a red light dose of 48 J per cm2. The effects of MB plus red light treatment on fibrinogen clottability, fibrin polymerization and gelation, clot stabilization, and fibrinolysis were studied.
Results:
The concentration of clottable fibrinogen was unchanged during MB plus red light treatment, but a light-dose-dependent decrease of the concentration of functional fibrinogen was found. The initial release rate of fibrinopeptide A was slightly increased after MB plus red light treatment. Turbidity measurements of fibrin gel showed prolonged clotting time, lower fibrin fiber mass-to-length ratio, and slightly smaller fiber diameter. At a given clotting time, a gel with lower fibrin fiber mass-to-length ratio was produced. Clot stability and fibrinolysis remained normal. l-Histidine added to plasma before MB plus red light treatment normalized the thrombin-induced coagulation time in a dose-dependent way.
Conclusion:
MB plus red light treatment affected the polymerization and gelation phase of fibrin. A tighter fibrin gel structure was formed. No effect on stabilization of fibrin clot or fibrinolysis was found.
Insights
Methylene blue (MB) plus light treatment alters fibrinogen function, impacting fibrin polymerization and gel structure. This virus inactivation method affects fibrin clot formation but not stability or fibrinolysis.
Area of Science:
- Biochemistry
- Hematology
- Biotechnology
Background:
- Virus inactivation of human plasma using Methylene blue (MB) plus light may alter fibrinogen function.
- Fibrinogen is crucial for blood clotting.
Purpose of the Study:
- To investigate the effects of MB plus red light treatment on human plasma fibrinogen's functional activities.
- To assess impacts on fibrinogen clottability, polymerization, gelation, clot stabilization, and fibrinolysis.
Main Methods:
- Fresh plasma units were treated with 1.0 microM MB and 48 J/cm2 red light.
- Assessed fibrinogen clottability, fibrin polymerization, gelation, clot stabilization, and fibrinolysis.
- Evaluated effects using turbidity measurements and thrombin-induced coagulation with l-Histidine.
Main Results:
- Functional fibrinogen concentration decreased in a light-dose-dependent manner.
- MB plus light treatment prolonged clotting time and altered fibrin gel structure (lower mass-to-length ratio, smaller diameter).
- Clot stability and fibrinolysis remained unaffected; l-Histidine partially normalized coagulation.
Conclusions:
- MB plus red light treatment impacts fibrin polymerization and gelation, forming a tighter fibrin gel.
- No significant effects were observed on fibrin clot stabilization or fibrinolysis.
- The findings suggest potential implications for plasma product safety and efficacy.