Essential thrombocytosis (ET) is an uncommon blood disease, which occurs due to the excess production of platelets. The condition increases the risk of having blood clots. This chronic disease has no known cure currently, and thus drugs are only taken to relieve symptoms.
Clinical Presentation
In most cases, ET does not have noticeable symptoms. However, due to the overproduction of platelets, whose main function is to help in blood clotting, one may experience the development of thrombus in different body parts. Clots can be formed anywhere in the body, but with this condition, they commonly occur in feet, hands, and brain. Depending on where the clot has formed, one may experience headaches, chest pain, dizziness, numbness, erythromelalgia, and fainting (Chuzi & Stein, 2017). In cases where the platelets count exceeds one million per microliter of blood, ET leads to bleeding through nose, mouth, and stool (Tefferi & Barbui, 2017). If a thrombus forms in an artery, one may experience a mild stroke (Chuzi & Stein, 2017).
Risk Factors
Age is one of the common risk factors for ET. As people grow old, the functionality of different body organs reduces. People over the age of 50 years are more likely to suffer from ET. Gender is also another predisposing factor with women being more vulnerable to the condition as compared to men. Over 90 percent of individuals with ET have an acquired gene mutation, which causes the disorder (Tefferi & Barbui, 2017).
Pathophysiology
The cause of the increased production of platelets by the megakaryocytes in the bone marrow is unclear. However, one of the possibilities is autonomous production whereby megakaryocytic precursors form colonies without the presence of exogenous thrombopoietin (Tpo) (Shimoda, Shide, & Kameda, 2017). Additionally, some individuals with ET have mutations in one of the following genes – myeloproliferative leukemia virus oncogene (MPL), calreticulin (CALR), or Janus kinase 2 (JAK2) (Shimoda et al., 2017). MPL and CALR account for about 3-5 and 25 percent of ET cases respectively, while JAK2 is responsible for over 50 percent of the occurrences of the condition (Shimoda et al., 2017). Other causes include increased sensitivity to interleukin-3, decreased functionality of platelet-inhibiting factors, and defects of the accessory cell microenvironment.
Diagnosis
Individuals with a platelet count above 450,000 per microliter of blood are eligible for ET diagnosis. The common procedures involve blood tests to determine the number, size, and activity of platelets (Tefferi & Barbui, 2017). Additionally, such tests seek to establish gene mutations, markers of inflation, and levels of iron in the blood. Bone marrow tests are also carried out to determine the presence of abnormal cells or high levels of megakaryocytes.
Treatment
As mentioned earlier, there is no known cure for ET. Therefore, the available treatment procedures only reduce the severity of symptoms. However, with proper medical care, a patient can have the normal human lifespan. The available medications include hydroxyurea, anagrelide, and iInterferon alfa (Tefferi & Barbui, 2017). The drugs are administered together with low dosage of aspirin to reduce the production of blood cells by the bone marrow. In emergency cases, platelet pheresis is carried out. In this procedure, blood is allowed to flow into a tube for platelet removal before being returned to the body (Tefferi & Barbui, 2017).
Conclusion
ET is rare blood disorder whereby the bone marrow overproduces platelets. Its etiology is unknown, but gene mutations have been pointed out as the probable causes. Age, gender, and hereditary elements are the main predisposing factors. Even though the condition does not have cure, different drugs are used to relieve symptoms.
References
Chuzi, S., & Stein, B. L. (2017). Essential thrombocythemia: A review of the clinical features, diagnostic challenges, and treatment modalities in the era of molecular discovery. Leukemia & Lymphoma, 58(12), 2786-2798.
Shimoda, K., Shide, K., & Kameda, T. (2017). Mutant calreticulin causes essential thrombocythemia. Oncotarget, 8(51), 88251-88252.
Tefferi, A., & Barbui, T. (2017). Polycythemia vera and essential thrombocythemia: 2017 update on diagnosis, risk-stratification, and management. American Journal of Hematology, 92(1), 94-108.