Acquired Amegakaryocytic Thrombocytopenic Purpura Progressing into Aplastic Anemia

Abstract

Acquired amegakaryocytic thrombocytopenic purpura (AATP) is a rare hematological disorder characterized by severe thrombocytopenia and a complete or near-to complete absence of megakaryocytes in the bone marrow, while granulopoiesis, as well as erythropoiesis are usually preserved. Although autoimmune mechanisms are believed to be causative, the exact underlying pathogenesis is not known. To date, only few cases have been reported and management of this disease remains controversial with immunosuppression being the treatment modality of choice in the majority of patients. In this article, we report a case of newly acquired AATP without an associated autoimmune disease, refractory to corticoids, intravenous immunoglobulin (IVIG) and second-generation TPO (thrombopoietin) agonists, which have recently been approved for the treatment of thrombocytopenia. Finally, in accordance with other reports, disease progression into aplastic anemia has occurred.

Acquired Amegakaryocytic Thrombocytopenic Purpura that Presented as Cyclic Thrombocytopenia Associated with Anti-Phospholipid Antibody Syndrome

“…It has been reported to occur in patients of all ages. Males account for over half of both patients younger than 30-years-old and those older than 60-years-old, where as females are affected most in the 40-60 years age group [9]. The diagnostic criteria for AATP are as follows: (1) Usually only thrombocytopenia is seen (but slight leukocytopenia and anemia may be present), (2) A reduction in the number of megakaryocytes to < 1/ mm 2 , and (3) The absence of dysplasia from all cell types.…”

“…As for possible immunological therapies, immunosuppressive drugs, such as cyclosporine, rituximab, and anti-thymocyte globulin (ATG), and allogeneic hematopoietic stem cell transplantation are optional treatments for selected cases [1,12,19]. The response rate of cyclosporine was reported to be about 50%, while that of ATG was 80% [9], but ATG therapy carries a risk of infection and long-term hospitalization. Recently, eltrombopag and romiplostim have been reported to be effective in certain cases [10,20].…”

Aplastic Anemia and Good Syndrome in a Heavily Treated Stage IV Thymoma Patient: A Case Report and Review of the Literature

“…In the literature, there have been 30 cases of AATP without significant comorbidities and autoimmune disease that have also shown a rapid progression to AA [26]. The rapid progression of AATP to AA in these cases suggests that thymoma-associated AATP may have a more aggressive disease course than thymoma-associated PRCA.…”

Acquired amegakaryocytic thrombocytopenia as a rare cause of thrombocytopenia during pregnancy

“…The underlying mechanism for AATP is not fully elucidated but is thought to be related to an anti-TPO autoantibody, directed against the TPO receptor, possibly a defect in the early progenitor cells of the megakaryocyte lineage or a cell-mediated suppression of megakaryocytopoiesis 6 7. AATP may be associated with dysplastic changes and be an early precursor of myelodysplastic syndrome or aplastic anaemia 8–11…”