From the Guidelines
No, platelets are not produced in the liver. Platelets are 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 bone marrow, found within certain bones like the hip and sternum, is the primary site for blood cell production, including red blood cells, white blood cells, and platelets. The liver has many important functions, including:
- protein synthesis
- detoxification
- bile production but platelet production is not one of them. However, the liver does produce thrombopoietin, a hormone that stimulates platelet production in the bone marrow, as noted in the American College of Chest Physicians evidence-based clinical practice guidelines 1. When platelet counts are low, the liver increases thrombopoietin production, signaling the bone marrow to make more platelets. This relationship between the liver and platelet production might be the source of confusion about where platelets are actually made. Key points to consider when evaluating platelet production include:
- the role of megakaryocytes in the bone marrow
- the function of thrombopoietin produced by the liver
- the importance of the bone marrow as the primary site of blood cell production, including platelets 1.
From the Research
Platelet Production
- Platelets are not produced in the liver, but their production and clearance are mediated by the liver 2.
- The bone marrow is the primary site of platelet production, where megakaryocytes produce platelets 3.
Relationship Between Platelets and the Liver
- Platelets play a role in various liver diseases, including non-alcoholic fatty liver diseases, viral hepatitis, liver fibrosis, and hepatocellular carcinoma 2.
- Platelets can improve liver fibrosis by inactivating hepatic stellate cells and accelerating liver regeneration through various mechanisms 4.
Platelet Functions and Therapies
- Platelets have versatile functions, including regulation of hemostasis, fine-tuning of immune responses, and release of growth factors and cellular mediators 2.
- Novel therapies targeting specific platelet responses, populations, interactions, or priming conditions are being developed to treat platelet-related diseases 3.
- Romiplostim and eltrombopag are two medications used to treat immune thrombocytopenia, with romiplostim appearing to have slightly fewer adverse effects and higher costs 5, 6.