The Importance of Blood Platelets

By SWA

Introduction

Blood platelets, also known as thrombocytes, are small, anucleated cell fragments that play a vital role in hemostasis—the process that prevents excessive bleeding when blood vessels are injured. Produced by megakaryocytes in the bone marrow through a process called thrombopoiesis, platelets act quickly to seal damaged blood vessels and promote wound healing. Their production and function depend on hormonal regulation, proper nutrition, and a healthy immune system.

However, platelets can be significantly affected by various infections, including those caused by viruses, bacteria, and fungi. These infections can decrease platelet production, increase platelet destruction, or cause abnormal platelet activation, all of which pose serious health risks.

How Platelets Are Formed

Platelets are formed through a well-orchestrated biological process:

  • Megakaryocytes: Large bone marrow cells that give rise to platelets by cytoplasmic fragmentation.

  • Thrombopoiesis: The process of platelet production, regulated mainly by the hormone thrombopoietin (TPO).

  • Nutritional Requirements: Essential vitamins and minerals—like B12, folate, iron, and vitamin C—support megakaryocyte development and platelet function.

Platelet Function in the Body

Platelets are the first responders to vascular injury. They adhere to damaged endothelium, become activated, and clump together to form a plug that prevents further bleeding. Von Willebrand factor (VWF) facilitates this process by helping platelets adhere to the site of injury.

Infections That Damage Blood Platelets

Several viruses, bacteria, and fungi can impair platelet production or function. These pathogens may:

  • Destroy platelets directly

  • Suppress bone marrow activity

  • Trigger an autoimmune response against platelets

  • Cause abnormal platelet activation and consumption

Viruses

  1. Dengue Virus

    • A major cause of thrombocytopenia (low platelet count), especially in tropical regions.

    • Damages bone marrow and increases platelet destruction.

    • Can cause hemorrhagic fever and internal bleeding.

  2. HIV (Human Immunodeficiency Virus)

    • Directly infects megakaryocytes, reducing platelet production.

    • Can cause immune thrombocytopenic purpura (ITP), where the immune system attacks platelets.

  3. Hepatitis C Virus (HCV)

    • Linked to chronic liver disease and platelet destruction.

    • May lead to hypersplenism (enlarged spleen), which sequesters and destroys platelets.

  4. Epstein-Barr Virus (EBV) and Cytomegalovirus (CMV)

    • Common causes of viral-induced thrombocytopenia, especially in children and immunocompromised patients.

  5. Zika and Chikungunya Viruses

    • Emerging viruses that can affect platelet count and function similarly to dengue.

Bacteria

  1. Sepsis (Bloodstream Infection)

    • Caused by various bacteria like E. coli, Staphylococcus aureus, or Streptococcus pneumoniae.

    • Leads to disseminated intravascular coagulation (DIC), where widespread clotting uses up platelets and clotting factors.

  2. Helicobacter pylori

    • Associated with immune thrombocytopenic purpura (ITP).

    • Eradication of this bacterium can sometimes improve platelet counts in affected individuals.

  3. Rickettsial Infections (e.g., Rocky Mountain spotted fever)

    • Can damage blood vessels and reduce platelet count through increased consumption and destruction.

Fungi

  1. https://pmc.ncbi.nlm.nih.gov/articles/PMC4719210/#:~:text=Patients%20undergoing%20bone%20marrow%20or%20solid%20organ,be%20immunocompetent%20also%20acquire%20invasive%20fungal%20infections. (Candida species)

    • Invasive fungal infections can impair bone marrow function and cause thrombocytopenia in critically ill or immunocompromised individuals.

  2. Histoplasmosis and Aspergillosis

    • Fungal infections that may infiltrate the bone marrow and suppress platelet production, particularly in patients with weakened immune systems (e.g., chemotherapy, AIDS).

Research and Innovations: Platelet Bioreactors

Given the complexity and vulnerability of platelet production, researchers are developing platelet bioreactors—lab-based systems that use stem cells and biomaterials to generate functional platelets. This technology aims to supplement or replace donor platelets, especially for patients with chronic low counts or infections that damage platelets.

Summary

Blood platelets are essential components of the circulatory system, crucial for clotting and wound repair. While their production and function are tightly regulated under normal conditions, infections caused by viruses (like dengue and HIV), bacteria (like those involved in sepsis or H. pylori infection), and fungi (such as Candida or Aspergillus) can severely compromise platelet health. Recognizing and managing these infections is key to preserving platelet function and preventing life-threatening complications such as bleeding, thrombosis, or immune-mediated destruction. As medical research advances, new technologies like platelet bioreactors offer hope for better treatment and management of thrombocytopenia and platelet disorders.

References:

Von Willebrand factor, platelets and endothelial cell interactions
https://www.sciencedirect.com/science/article/pii/S1538783622150816

Platelet interaction with von Willebrand factor is enhanced by shear-induced clustering of glycoprotein Ibα
https://haematologica.org/article/view/6846

von Willebrand Factor and Platelet Glycoprotein Ib: A Thromboinflammatory Axis in Stroke https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.02884/full

T cells from patients with Candida sepsis display a suppressive immunophenotype https://pmc.ncbi.nlm.nih.gov/articles/PMC4719210/#:~:text=Patients%20undergoing%20bone%20marrow%20or%20solid%20organ,be%20immunocompetent%20also%20acquire%20invasive%20fungal%20infections.

A rare presentation of progressive disseminated histoplasmosis in an immunocompetent patient from a non-endemic region
https://www.sciencedirect.com/science/article/pii/S2211753913000213#:~:text=Thrombocytopenia%20is%20reported%20in%20histoplasmosis%20along%20with,the%20present%20case%20are%20rare%20%5B18%5D%2C%20%5B19%5D.

 

© 2000-2025 Sieglinde W. Alexander. All writings by Sieglinde W. Alexander have a fife year copy right. Library of Congress Card Number: LCN 00-192742

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