Amegakaryocytic Thrombocytopenia

Excerpt

Amegakaryocytic thrombocytopenia in both congenital and acquired forms represents a severe subtype of thrombocytopenia characterized by diminished or absent megakaryocytes without additional bone marrow abnormalities. Congenital amegakaryocytic thrombocytopenia manifests with severe thrombocytopenia and various bleeding manifestations at birth, often progressing to bone marrow failure. In contrast, acquired amegakaryocytic thrombocytopenia typically emerges later in life, possibly due to immune-mediated mechanisms. Acquired amegakaryocytic thrombocytopenia is typically a diagnosis of exclusion, becoming apparent as bleeding complications following treatment failure of immune thrombocytopenia.

Diagnosis involves bone marrow biopsy and genetic testing. Clinicians diagnose congenital amegakaryocytic thrombocytopenia by demonstrating homozygous or compound heterozygous mutations in the c-myeloproliferative leukemia virus, thrombopoietin receptor (c-MPL) proto-oncogene. In contrast, clinicians base the diagnosis of acquired amegakaryocytic thrombocytopenia on clinical suspicion and reduced or absent megakaryocytes in the bone marrow. Allogeneic hematopoietic stem cell transplant is the only curative option for patients with congenital amegakaryocytic thrombocytopenia and a c-MPL mutation, whereas treating the underlying condition combined with immunosuppressive medications targets acquired amegakaryocytic thrombocytopenia.