Microclots (amyloid fibrin)
Abnormal fibrin-amyloid microclots proposed to impair oxygen delivery — biologically intriguing, clinically contested.
The fibrinaloid-microclot hypothesis proposes that abnormal, clot-resistant microclots impair tissue oxygen delivery. The mechanism is biologically intriguing and supported by growing imaging and proteomic data, but the treatment evidence is weak and contested, and carries serious harm potential. The best randomized evidence — a trial of therapeutic plasma exchange — was negative; 'triple therapy' anticoagulation rests on a small uncontrolled preprint and risks major bleeding; nattokinase is in-vitro only. The rigorous test (the STIMULATE-ICP anticoagulation arm) has not yet reported. Any anticoagulation/apheresis decision belongs with a physician, never self-directed.
How it's tested
Microclot imaging (fluorescence / flow cytometry)
Thioflavin-T staining of a blood smear to quantify fibrin-amyloid microclots. Promising but not yet standardized or validated against healthy-control thresholds.
D-dimer
A cheap, GP-orderable blood marker of clot breakdown. A weak, indirect signal for the microclot hypothesis but inexpensive.
Treatment options & their evidence
Graded honestly — including treatments that failed in good trials, which is worth knowing.
Aspirin / nattokinase (antiplatelet, fibrinolytic supplement)
Anecdotal onlySerious harm riskNo randomized evidence for Long COVID; nattokinase is in-vitro only, and the 'triple therapy' anticoagulation data is a small uncontrolled preprint.
Caution: Bleeding risk, additive with other antithrombotics. Never combine anticoagulants/antiplatelets ('triple therapy') outside specialist supervision.
Anticoagulation (in a trial) / plasmapheresis
Failed in trialsSerious harm riskpromise 0 · 1 RCTThe best randomized test — therapeutic plasma exchange — was negative; the rigorous anticoagulation test (STIMULATE-ICP) has not reported. HELP apheresis evidence is uncontrolled and costly.
Caution: Major/fatal bleeding risk; invasive apheresis carries line, citrate, and infection risks plus financial harm. Decisions belong with a physician, never self-directed.