National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Acquired amegakaryocytic thrombocytopenia


Other Names:
Severe thrombocytopenia and selective, marked decrease or absence of megakaryocytes; AAT; Acquired pure megakaryocytic aplasia
Acquired amegakaryocytic thrombocytopenia is a rare blood disorder that causes severe thrombocytopenia with no other blood abnormalities. It is so named because the level of large bone marrow cells that produce platelets, called megakaryocytes, are significantly lower or absent.[1][2] Signs and symptoms of the condition include prolonged bleeding; easy bruising; rash (pinpoint red spots called petechia); bleeding in the mouth and gums; and/or frequent nosebleeds.[3][4] There are many potential causes of the condition. Although standard treatment guidelines have not been established, various immunosuppressive treatment approaches have been utilized with success in affected people.[1][2] 
Last updated: 10/26/2015
The signs and symptoms of acquired amegakaryocytic thrombocytopenia vary but may include:[3][4]
  • Prolonged bleeding, even from minor cuts
  • Easy bruising
  • Rash (pinpoint red spots called petechia)
  • Bleeding in the mouth and gums
  • Frequent nosebleeds

Last updated: 10/26/2015
There are many potential causes of acquired amegakaryocytic thrombocytopenia. For example, the condition can be associated with:[1][2]
In some people, the condition is an early sign of a more severe progressive disease, such as aplastic anemia, myelodysplasia, or leukemia.[1]
Last updated: 10/26/2015
A diagnosis of acquired amegakaryocytic thrombocytopenia is often suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis. This may include:[3][4]
Once the diagnosis is confirmed, a healthcare provider will likely recommend other tests in an attempt to determine the underlying cause of the condition.
Last updated: 10/26/2015
Standard treatment guidelines have not been established for acquired amegakaryocytic thrombocytopenia. However, various immunosuppressive treatment approaches have been utilized in affected people. In several case reports, affected people were successfully treated with cyclosporine either alone or in combination with other immunosuppressive medications (i.e. antithymocyte globulin). Other therapies for acquired amegakaryocytic thrombocytopenia have included rituximab, danazol, azathioprine, and bone marrow transplant with variable success.[1]

To determine the best treatment for you or a family member, please speak with a healthcare provider.
Last updated: 10/26/2015
The long-term outlook (prognosis) for people with acquired amegakaryocytic thrombocytopenia varies based on the underlying cause. Some people respond well to treatment and long-term remissions have been documented in several case reports.[1] In others, the condition progresses rapidly to aplastic anemia or myelodysplasia.[5] There are currently no good predictors to aid in assessing the likelihood of response to therapy or overall prognosis.[6]
Last updated: 10/26/2015

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Acquired amegakaryocytic thrombocytopenia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • The National Heart Lung and Blood Institute (NHLBI) provides information on thrombocytopenia in general. The NHLBI was created to conduct research and distribute health information on diseases of the heart, blood vessels, lungs, and blood.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Acquired amegakaryocytic thrombocytopenia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have acquired amegakaryocytic thrombocytopenia. Can you help me find more information on this disease, its treatment, and its long-term prognosis? See answer


  1. Brown GE, Babiker HM, Cantu CL, Yeager AM, Krishnadasan R.. "Almost bleeding to death": the conundrum of acquired amegakaryocytic thrombocytopenia. Case Rep Hematol. 2014. 2014; Accessed 10/26/2015.
  2. Patel M, Kalra A, Surapaneni R, Schwarting R, Devereux L. Acquired amegakaryocytic thrombocytopenia in a patient with occupational chemical exposure. Am J Ther. January-February 2014; 21(1):e17-20.
  3. Thrombocytopenia. National Heart, Lung, and Blood Institute. September 2012; http://www.nhlbi.nih.gov/health/health-topics/topics/thcp.
  4. Thrombocytopenia. MedlinePlus. February 2014; https://www.nlm.nih.gov/medlineplus/ency/article/000586.htm.
  5. Bulcahndani D et al.,. Acquired pure megakaryocytic aplasia: Report of a single case treated with Mycophenolate Mofetil. American Journal of Hematology. 2007;
  6. Felderbauer P et al.,. Case Report: Acquired pure megakaryocytic aplasia: a seoarate haematological disease entity or a syndrome with multiple causes?. Eur J Haematol. 2004;