Are platelets produced in the liver?

From the Guidelines

No, platelets are not produced in the liver. Platelets are primarily produced in the bone marrow by large cells called megakaryocytes, which fragment into thousands of platelets that are then released into the bloodstream 1. The process of platelet production, called thrombopoiesis, is regulated by the hormone thrombopoietin, which is produced primarily in the liver, as well as in the bone marrow and the kidney 1. While the liver plays a role in regulating platelet production through thrombopoietin production, the actual formation of platelets occurs in the bone marrow.

Key points to consider:

• Platelets are anucleated blood cells with a maximum circulating lifespan of 10 days 1
• Platelet production can increase up to 10-fold at times of increased need 1
• The liver has many important functions, including protein synthesis, detoxification, and metabolism, but platelet production is not one of them
• Platelets are crucial for blood clotting and preventing excessive bleeding when blood vessels are damaged, and they typically survive in the bloodstream for about 8-10 days before being removed by the spleen and liver.

In terms of morbidity, mortality, and quality of life, understanding the correct site of platelet production is essential for managing conditions related to platelet disorders, such as thrombocytopenia or thromboembolic events 1.

From the Research

Platelet Production

• Platelets are not produced in the liver, but rather in the bone marrow from megakaryocytes 2, 3.
• The liver plays a role in the clearance of platelets, and platelets are connected to the liver through various physiological and pathological processes 4.
• The bone marrow is the primary site of platelet production, with approximately 10^11 platelets being released daily from megakaryocytes 3.

Role of the Liver in Platelet Clearance

• The liver is involved in the regulation of platelet count and clearance, but it is not the primary site of platelet production 4.
• Platelets interact with the liver in various ways, including in the regulation of hemostasis, immune responses, and the release of growth factors and cellular mediators 4.

Platelet Production Mechanisms

• Platelet production involves complex cytoskeletal mechanisms, including microtubule and actin-based systems 3.
• Novel mechanisms of platelet production, such as centrosome clustering, have been proposed as triggers for proplatelet production 3.