The COVILOT Study
Understanding Long COVID: how blood clotting, inflammation and the immune system may play a role:
The COVILOT study investigates how changes in blood clotting, inflammation, and lung perfusion may explain persistent symptoms experienced by individuals after a COVID-19 infection. This research aims to improve our understanding of Long COVID and inform better diagnosis and treatment strategies.
Why this study?
Long COVID is a condition that can cause symptoms like fatigue, chest pain, shortness of breath, and brain fog for months or even years after a SARS-CoV-2 infection. Research shows that this may be linked to problems with the blood and the immune system. Our study focuses on thromboinflammation, a process involving both inflammation and abnormal blood clotting, which may persist in some people and contribute to their symptoms.
In this study, we look at inflammation and blood clotting in people with Long COVID. We also use lung scans to see how well blood flows through the lungs. In addition, we collect a sample from the nose to find out whether certain viruses or bacteria in the airways are linked to ongoing symptoms or changes in the immune system.
What does participation involve?
We will conduct two types of studies:
Case–Control Study
We will compare people with severe Long COVID to individuals who recovered from COVID-19 without long-term symptoms. Participants will:
• Provide a blood sample
• Provide a nasopharyngeal swab for microbiological analyses
• Complete a questionnaire about symptoms and quality of life
• (For some participants) Undergo a CT lung scan to examine blood flow in the lungs
Prospective Cohort Study
We will follow individuals with and without Long COVID over time. Participants will:
• Provide a blood sample
• Fill in questionnaires at multiple time points
• Possibly provide additional blood samples at follow-up
If you're unable to visit the hospital, we can arrange a home visit for blood collection.
Who can take part?
We are looking for:
• Adults (18+) with a confirmed or suspected past SARS-CoV-2 infection
• People with Long COVID symptoms for 6 months or more
• People who have fully recovered from COVID-19 and do not experience ongoing symptoms to enroll as controls
You do not need to have been hospitalized. We aim to include individuals both with and without Long COVID to allow meaningful comparisons.
Where will the study take place?
Study visits will take place in the southern region of the Netherlands at hospital locations including Maastricht UMC+ (MUMC+) and Radboud UMC. Some procedures, such as blood collection, may also be conducted at home to reduce the burden on participants.
What do we hope to learn?
The COVILOT study will help us:
• Identify blood-based biomarkers linked to Long COVID
• Investigate how thromboinflammatory changes relate to ongoing symptoms
• Examine how these changes may lead to reduced lung perfusion
• Study the types of bacteria and viruses in the nose and throat to see if they play a role in Long COVID and if they are linked to different respiratory and general symptoms
• Improve future diagnosis and treatment options
Is it safe?
The study includes common procedures like blood draws, nasopharyngeal swabs and, for some participants, a CT scan. Risks are minimal and clearly explained before participation. The study is currently pending ethical approval, and no participant inclusion will start before approval is obtained.
Want to stay informed?
If you are interested in receiving updates or being contacted once the study starts recruiting, please get in touch with the research team [contact form].
Wat is de rol van de bloedstolling en het afweersysteem bij Long COVID?
Sommige mensen ontwikkelen blijvende klachten na een COVID-19 infectie. Dit wordt Long COVID genoemd. De COVILOT studie onderzoekt hoe veranderingen in de bloedstolling, het afweersysteem en de longen de Long COVID klachten kunnen verklaren. Het doel van de COVILOT studie is het verzamelen van meer kennis over Long COVID. Deze kennis kan dan gebruikt worden om beter te bepalen wie Long COVID heeft en hoe de behandeling van patiënten met Long COVID verbetert kan worden.