Thrombocytopathy vs Platelet hyper-reactivity in COVID-19: diverse pathologies, disease outcomes and therapeutic implications

Platelets. 2022 Jan 2;33(1):48-53. doi: 10.1080/09537104.2021.1961718. Epub 2021 Nov 30.

Abstract

Coagulopathy is an evident complication of COVID-19 with predominance of a prothrombotic state. Platelet activation plays a key role. The terms "hyper-reactivity" and "hyperactivity" used in recent literature may not be clear or sufficient to explain the pathological events involved in COVID-related thrombosis (CRT). Inflammation may play a bigger role compared to thrombosis in COVID-related mortality because a smaller percentage of patients with COVID-19 die due to direct effects of thrombosis. Not all COVID-19 patients have thrombocytopenia and a few show thrombocytosis. We believe the platelet pathology is more complex than just activation or hyper-activation, particularly due to the platelets' role in inflammation. Understanding the pathology and consequences of platelets' role may help optimize management strategies and diminish CRT-associated morbidity and mortality. In this viewpoint report, we examine the published evidence of platelet hyper-reactivity in COVID-19 with a focused analysis of the key pathologies, diverse alterations, disease outcomes, and therapeutic targets. We believe that COVID-19 is a disease of inflammation and pathologic platelets, and based on the complexity and diverse pathologies, we propose the term "thrombocytopathy" as a more reflective term of the platelets' involvement in COVID-19. In our opinion, thrombocytopathy is the unpredictable pathologic alterations of platelets in function, morphology and number, caused by different factors with a variety of presentations.

Publication types

  • Review

MeSH terms

  • Abciximab / therapeutic use
  • Acute Disease
  • Anticoagulants / therapeutic use
  • Aspirin / therapeutic use
  • Blood Platelets / drug effects
  • Blood Platelets / pathology*
  • Blood Platelets / virology
  • COVID-19 / complications*
  • COVID-19 / diagnosis
  • COVID-19 / virology
  • COVID-19 Drug Treatment
  • Clopidogrel / therapeutic use
  • Cytokine Release Syndrome / complications*
  • Cytokine Release Syndrome / diagnosis
  • Cytokine Release Syndrome / drug therapy
  • Cytokine Release Syndrome / virology
  • Disseminated Intravascular Coagulation / complications*
  • Disseminated Intravascular Coagulation / diagnosis
  • Disseminated Intravascular Coagulation / drug therapy
  • Disseminated Intravascular Coagulation / virology
  • Fibrinolytic Agents / therapeutic use
  • Humans
  • Lung / blood supply
  • Lung / drug effects
  • Lung / pathology
  • Lung / virology
  • Platelet Activation / drug effects
  • Pulmonary Embolism / complications*
  • Pulmonary Embolism / diagnosis
  • Pulmonary Embolism / drug therapy
  • Pulmonary Embolism / virology
  • SARS-CoV-2 / pathogenicity*
  • Treatment Outcome

Substances

  • Anticoagulants
  • Fibrinolytic Agents
  • Clopidogrel
  • Aspirin
  • Abciximab