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Updated: Jul 1, 2025
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Assessment of Factor VIII Activity and D-Dimer Levels in the Post-COVID Period
Mirjana Kovac1,2, Milena Todorovic Balint1,3, Marija Milenkovic1,4
1Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Insights
Post-COVID-19 infection, elevated Factor VIII (FVIII) and D-dimer levels indicate a persistent hypercoagulable state. This is more pronounced in older patients and those with severe COVID-19 clinical presentation.
Area of Science:
- Hematology
- Infectious Diseases
- Cardiovascular Medicine
Background:
- COVID-19 infection is known to cause hypercoagulability due to hemostatic system alterations.
- While acute and hospitalized phases have been studied, the post-discharge hemostatic status remains under-evaluated.
- Factor VIII (FVIII) and D-dimer are key markers for assessing thrombotic risk.
Purpose of the Study:
- To investigate changes in FVIII and D-dimer levels in the post-COVID-19 phase.
- To assess the influence of patient age and COVID-19 clinical severity on these hemostatic markers.
- To determine if a hypercoagulable state persists after hospital discharge.
Main Methods:
- Prospective study of 115 COVID-19 patients from July 2020 to December 2022.
- Categorized patients into asymptomatic/mild (68) and moderate/severe (47) clinical presentations.
- Monitored FVIII and D-dimer levels at 1, 3, and 6 months post-infection.
Main Results:
- Elevated FVIII levels were observed 3 and 6 months post-infection, particularly in older individuals (p<0.05).
- Patients with moderate/severe COVID-19 showed a statistically significant increase in FVIII activity at 6 months (p=0.041).
- Increased FVIII activity correlated with elevated D-dimer levels, suggesting ongoing hypercoagulability.
Conclusions:
- COVID-19 infection can lead to a sustained hypercoagulable state in the post-infection period.
- Elevated FVIII activity post-COVID-19 is more prominent in older patients and those with moderate to severe disease.
- Monitoring FVIII and D-dimer is crucial for assessing long-term thrombotic risk in COVID-19 survivors.
Abstract:
Changes in the hemostatic system during COVID infection lead to hypercoagulability. Numerous studies have evaluated hemostatic abnormalities in COVID patients during acute infection, in the period of hospitalization. However, the hemostatic status following hospital discharge has not been sufficiently assessed. Considering the importance of FVIII and D-dimer levels as markers for the assessment of thrombosis, our study aimed to evaluate changes in these markers, as well as the influence of patient's age and clinical presentation of COVID infection on those hemostatic markers in the post-COVID phase. This prospective study (July 2020 to December 2022) included 115 COVID patients, 68 (59%) with asymptomatic/mild and 47 (41%) with moderate/severe clinical presentation. Patient follow-up included laboratory evaluation of FVIII and D-dimer levels at 1, 3, and 6 months following the COVID infection. Three months after the COVID infection, elevated FVIII was recorded in 44% of younger versus 65% of older individuals, p = 0.05, respectively, and 30 versus 57% (p = 0.008) 6 months post-COVID infection. With a focus on clinical presentation, a higher number of patients with moderate/severe COVID had elevated FVIII activity, but a statistically significant difference was observed only for the 6 months (32% mild vs. 53% moderate/severe, p = 0.041) post-infection time point. Following a COVID infection, an increase in FVIII activity suggests a continued hypercoagulable state in the post-COVID period and correlates with elevated D-dimer levels. This increase in FVIII is more pronounced in patients with moderate/severe clinical picture and those patients older than 50 years.
