How COVID-19 causes blood clots and tiny microclots

Mechanisms of Thrombosis in SARS CoV-2 Infection

['FUNDING_R01'] · UNIVERSITY OF KENTUCKY · NIH-11258033

This work looks at why people with COVID-19 develop blood clots and tiny microclots that may lead to lasting tissue damage.

Quick facts

Phase['FUNDING_R01']
Study typeNih_funding
SexAll
SponsorUNIVERSITY OF KENTUCKY (nih funded)
Locations1 site (LEXINGTON, UNITED STATES)
Trial IDNIH-11258033 on ClinicalTrials.gov

What this research studies

Researchers will collect blood and other samples from people during acute COVID-19 illness and from people with lingering (long COVID) symptoms, and they will study those samples in the laboratory alongside cell and animal models. From early work they identified two ways clots may form: blood vessel cells release von Willebrand Factor (VWF) that traps a protective protein called protein S, and high levels of lipids and an inhibitor called PAI-1 block the clot-dissolving protein tPA. The team will measure these proteins, image microclots, and test how changing these pathways affects clot formation and breakdown. Their goal is to learn whether these combined problems create stable microclots that could explain localized tissue damage and persistent symptoms.

Who could benefit from this research

Good fit: Ideal candidates would include people with recent COVID-19 infection, hospitalized patients with clotting signs, and people experiencing long COVID symptoms who can provide blood samples.

Not a fit: People without a history of COVID-19 or whose health issues are unrelated to clotting are unlikely to benefit directly from this work.

Why it matters

Potential benefit: If successful, this could point to new treatments to prevent or dissolve microclots and lower the risk of long-term complications after COVID-19.

How similar studies have performed: Prior studies have shown COVID-19 raises clotting risk and that thrombotic events matter for outcomes, but the specific VWF–protein S interaction and the dyslipidemia/PAI-1 effect on tPA are relatively new mechanisms being explored.

Where this research is happening

LEXINGTON, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.

View on NIH RePORTER →

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.