Management of MHA
Although most patients with MHA do not experience significant bleeding problems, the recommended precautions for other bleeding disorders apply to MHA. Thus, patients should:
- Avoid any medications that impair platelet function, such as aspirin and other nonsteroidal anti-inflammatory drugs;
- Have regular dental care to avoid chronic blood loss from bleeding gums;
- Have renal function tested annually; and
- Have a hearing test every 5 years.7
There is no treatment to prevent the nonhematopoietic manifestations of MYH9-related disorders. It is possible that avoiding very loud noises at a young age may delay the process of hearing loss, and cochlear implants could be an option to improve severe hearing deficits.7
Intravenous immunoglobulin G, corticosteroids, and splenectomy (often used in treatment of immune thrombocytopenia purpura) are relatively ineffective for MHA.7 This further supports the need for an accurate diagnosis when platelet counts are low.
Given the autosomal dominance of MHA, it is important to assess all first-degree relatives for macrothrombocytopenia. A normal platelet count excludes MHA, and in these cases, the disease cannot be passed to offspring.7
Upon receipt of the CBC results, the provider immediately contacted the patient, who reported no evidence of bleeding, bruising, or petechiae. An appointment was made for the following morning, and if the patient were to experience any bleeding such as blood in stool or urine, gingival bleeding, hemoptysis, epistaxis, or petechiae, he agreed to go to the emergency department right away. The following day, results of a blood smear review received in the office revealed Döhle body-like cytoplasmic inclusions in nearly every neutrophil. In addition, the pathologist also observed platelet clumps and giant platelets on the blood smear. Given the patient’s history of “low platelets” and the results of the CBC, the patient was referred to a hematologist, who confirmed the diagnosis of MHA.
The patient was followed for 5 years before moving to another state. During that time, his platelet count remained between 20,000/μL and 50,000/μL, and he experienced no untoward bleeding. However, his hearing worsened and his glomerular filtration rate decreased from 62 to 42 mL/min. He was counseled about his diagnosis and instructed to wear a Medic-Alert bracelet to avoid misdiagnosis and inappropriate treatment. In addition, he was referred to a nephrologist for management of stage III chronic kidney disease. Given the inheritance pattern of MHA, both of the patient’s children were tested and had normal platelet counts.
An awareness of MYH9-related disorders is important to include as a consideration in the differential diagnosis of thrombocytopenia. Knowledge of MHA is essential to allow health care practitioners to provide specific patient education, observe for possible comorbid conditions, and prevent inappropriate treatment if MHA is confused with acquired thrombocytopenia.
Mary Jane Hanson, PhD, CRNP, FNP-BC, FAANP, is a professor and the director of graduate nursing and DNP programs at the University of Scranton and a family nurse practitioner at LVPG Family Medicine, in Albrightsville, Pennsylvania.
1. Saito H, Kunishima S. Historical hematology: May-Hegglin anomaly. Am J Hematol. 2008;83(4):304-306.
2. Kunishima S, Saito H. Advances in the understanding of MYH9 disorders. Curr Opin Hematol. 2010;17(5):405-410.
3. Althaus K, Greinacher A. MYH9-related platelet disorders. Semin Thromb Hemost. 2009;35(2):189-203.
4. Rao AK, Songdej N. Inherited thrombocytopenias: the beat goes on. Blood. 2015;125(5):748-750.
5. Ruhoy SM, Yates A. Macrothrombocytopenia with Döhle body-like granulocyte inclusions: a case report of May-Hegglin anomaly in a 33-year-old white woman with an update on the molecular findings of MYH9-related disease. Lab Med. 2016;47(3):246-250.
6. Balduini CL, Pecci A, Savoia A. Recent advances in the understanding and management of MYH9-related inherited thrombocytopenias. Brit J Haematol. 2011;154(2):161-174.
7. Althaus K, Greinacher, A. MYH-9 related platelet disorders: strategies for management and diagnosis. Transfus Med Hemother. 2010;37(5):260-267.
8. Althaus K, Najm J, Greinacher A. MYH9 related platelet disorders – often unknown and misdiagnosed. Klin Padiatr. 2011;223(3):120-125.