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Amegakaryocytic thrombocytopenia is a rare hematologic disorder characterized by a profound reduction in platelet production due to the near absence of megakaryocytes, leading to severe thrombocytopenia. This case report elucidates the diagnostic and therapeutic challenges encountered in managing such rare hematological conditions alongside significant cardiovascular disease. We detail the case of a patient who presented with chest pain and was diagnosed with non-ST elevation myocardial infarction (NSTEMI). Subsequent investigations revealed severe thrombocytopenia and underlying triple vessel disease, complicating immediate surgical intervention. Initial management strategies aimed at treating presumed immune thrombocytopenia proved ineffective. A definitive diagnosis of amegakaryocytic thrombocytopenia was established following a bone marrow biopsy. Despite treatment adjustments, including the administration of thrombopoietin agonists and immunosuppression, platelet counts improved but did not reach levels safe for coronary artery bypass grafting (CABG). This case underscores the critical importance of achieving adequate hematologic stability prior to surgical procedures in patients with complex cardio-hematologic profiles to minimize perioperative risks and optimize patient outcomes, illustrating the ongoing challenges in managing severe thrombocytopenia in cardiac patients.

Abstract Association between thymoma and pure red cell aplasia is already well‐documented in literature whereas acquired amegakaryocytic thrombocytopenia is rarely reported. In this case, even with the addition of eltrombopag to standard immunosuppression, the cytopenias did not improve, probably due to the lack of surgical resection of the tumor.

Good's syndrome is a form of acquired immunodeficiency characterized by the presence of thymoma with hypogammaglobulinemia, as well as the absence of B lymphocytes, CD 4+ lymphopenia, and inversion of the CD4 + / CD8 + ratio. This pathology facilitates the appearance of infectious and immune complications. [ABSTRACT FROM AUTHOR]

Background Acquired amegakaryocytic thrombocytopenia (AAMT) is a rare disorder characterized by thrombocytopenia, marked megakaryocytic hypoplasia, and preserved other-lineage hematopoiesis in the bone marrow. The etiology of AAMT remains poorly understood owing to its rarity. Case description We encountered a diagnostically challenging case involving a 66-year-old man who showed severe thrombocytopenic bleeding with isolated megakaryocytic hypoplasia, elevated serum thrombopoietin levels, glycoprotein IIb/IIIa antibody positivity, and prolonged platelet transfusion refractoriness following mantle cell lymphoma (MCL). Treatment with corticosteroids and intravenous immunoglobulin was ineffective, while a combination of multiagent chemotherapy, including rituximab, was beneficial for both thrombocytopenia and MCL. Ultimately, the patient was diagnosed with AMMT and immune thrombocytopenia (ITP)-like platelet destruction. Discussion This case suggests that AAMT and ITP are non-exclusive and sometimes overlap as components of a broad spectrum of platelet-related autoimmune diseases.

Association between thymoma and pure red cell aplasia is already well‐documented in literature whereas acquired amegakaryocytic thrombocytopenia is rarely reported. In this case, even with the addition of eltrombopag to standard immunosuppression, the cytopenias did not improve, probably due to the lack of surgical resection of the tumor. [ABSTRACT FROM AUTHOR]

Idiopathic acquired aplastic anemia can be successfully treated with Anti Thymocyte Globulin (ATG)-based immune suppressive therapy and is therefore considered a T cell-mediated auto immune disease. Based on this finding, several other forms of idiopathic acquired bone marrow failure are treated with ATG as well. For this review, we extensively searched the present literature for evidence that ATG can lead to enduring remissions in different forms of acquired multi- or single-lineage bone marrow failure. We conclude that ATG-based therapy can lead to an enduring hematopoietic response and increased overall survival (OS) in patients with acquired aplastic aplasia. In patients with hypocellular myelodysplastic syndrome, ATG can lead to a hematological improvement without changing the OS. ATG seems less effective in acquired single-lineage failure diseases like Pure Red Cell Aplasia, Amegakaryocytic Thrombocytopenia and Pure White Cell Aplasia, suggesting a different pathogenesis in these bone marrow failure states compared to aplastic anemia. T cell depletion is hypothesized to play an important role in the beneficial effect of ATG but, as ATG is a mixture of polyclonal antibodies binding to different antigens, other anti-inflammatory or immunomodulatory effects could play a role as well.

We here describe a case involving a 67-yearold female patient who was referred to our hospital due to severe anemia (hemoglobin, 5.0 g/dL), thrombocytopenia (platelet count, 0.6×104/μL), and a mediastinal shadow with calcification noted on X-ray. On admission, an anterior mediastinal tumor was detected, and bone marrow biopsy revealed few megakaryocytes and severely reduced numbers of erythroid cells. The diagnosis was thymoma with pure red cell aplasia (PRCA) and acquired amegakaryocytic thrombocytopenia (AAMT). On Day 8 of admission, the patient received immunosuppressive therapy together with cyclosporine for the 2 severe hematologic diseases, which were stabilized within 2 months. Subsequently, total thymectomy was performed. The diagnosis of the tumor invading the left lung was invasive thymoma, Masaoka- Koga stage III. The histological diagnosis was World Health Organization type AB. Thymoma accompanied with PRCA and AAMT is very rare, and, based on our case, immunotherapeutic therapy for the hematologic disorders should precede surgical intervention.

Pathogenic variants in MECOM , a gene critical to the self-renewal and proliferation of hematopoietic stem cells, are known to cause a rare bone marrow failure syndrome associated with amegakaryocytic thrombocytopenia and bilateral radioulnar synostosis known as RUSAT2. However, the spectrum of disease seen with causal variants in MECOM is broad, ranging from mildly affected adults to fetal loss. We report two cases of infants born preterm who presented at birth with symptoms of bone marrow failure including severe anemia, hydrops, and petechial hemorrhages; radioulnar synostosis was not observed in either patient, and, unfortunately, neither infant survived. In both cases, genomic sequencing revealed de novo variants in MECOM considered to be responsible for their severe presentations. These cases add to the growing body of literature that describe MECOM -associated disease, particularly MECOM as a cause of fetal hydrops due to bone marrow failure in utero. Furthermore, they support the use of a broad sequencing approach for perinatal diagnosis, as MECOM is absent from available targeted gene panels for hydrops, and highlight the importance of postmortem genomic investigation., (© 2023 Dash et al.; Published by Cold Spring Harbor Laboratory Press.)

Totally implantable venous access devices (TIVAD) or implantable catheter ports are devices which can be implanted subcutaneously. They enable prolonged and repeated access to the vascular system, into the peritoneal cavity or intravertebral space. This device is particularly useful for repeated medical injection, for blood sampling or transfusion of blood and blood derivatives and for total parenteral nutrition (TPN). Although many patients benefit from the insertion of TIVAD without any secondary effects, any surgical implantation can nevertheless lead to complications. ‎In this study, we investigated the advantages and disadvantages of TIVAD catheter in pediatric age group. A total of 94 cases, 2 to 14 years old, were included in our study. We implanted TIVAD in these patients for chemotherapy in 83 cases (88.29%), for prolonged TPN in 6 cases (6.38%), for corticosteroid and antibiotic therapy after ‎Kasai operation in 2 cases (2.12%), for intermittent IV therapy in 2 cases (2.12%) and for need to partial parenteral nutrition in 1 case (1.06%). Out of 94 cases, 14 cases (15%) had some kind of complications and 80 cases (85%) had no complication. There was no mortality. Most patients and their parents (82 cases, 87.23%) were satisfied from TIVAD. ‎It seems that TIVAD can be a useful device for many chronic patients who need an IV access for multiple injections.

Amegakaryocytic thrombocytopenia (AMT) is a rare cause of acquired thrombocytopenia. The pathogenesis and treatment of AMT is not clearly known. Here we demonstrate a 50-year-old man presented with the clinical manifestations of severe thrombocytopenia (7000 platelets/µl) with a marked decrease to absent of megakaryocytes in the bone marrow. The patient did not respond to intravenous immunoglobulin, cyclosporine or high dose prednisone. After the treatment with anti-CD20 antibody (Rituximab), the patient's clinical symptoms and platelet counts improved.

Amegakaryocytic thrombocytopenia (AMT) is a rare cause of acquired thrombocytopenia. The pathogenesis and treatment of AMT is not clearly known. Here we demonstrate a 50-year-old man presented with the clinical manifestations of severe thrombocytopenia (7000 platelets/μl) with a marked decrease to absent of megakaryocytes in the bone marrow. The patient did not respond to intravenous immunoglobulin, cyclosporine or high dose prednisone. After the treatment with anti-CD20 antibody (Rituximab), the patient's clinical symptoms and platelet counts improved. [ABSTRACT FROM AUTHOR]

Abstract: Acquired amegakaryocytic thrombocytopenia and pure red cell aplasia rarely occur concurrently. We report a case in which these disorders were associated with an occult large granular lymphocyte leukemia. The peripheral blood cytopenias improved after glucocorticoids and intravenous immunoglobulin were administered, and response was maintained with cyclosporine. Large granular lymphocyte leukemia should be suspected in the setting of unexplained bone marrow failure. [Copyright &y& Elsevier]

Amegakaryocytic thrombocytopenia is an extremely rare disorder in systemic lupus erythematosus, and its mechanism and treatment are still largely unknown. We describe a 42-year-old woman with systemic lupus erythematosus who presented various clinical manifestations of life-threatening amegakaryocytic thrombocytopenia (10,000 platelets/mm3 with a marked decrease of megakaryocytes in the bone marrow), proteinuria, psychosis, refractory chylothorax, ascites, and type II diabetes caused by the anti-insulin receptor autoantibody. She was initially treated with prednisolone (25-50 mg/day) and cyclosporine A (200 mg/day) without any improvement in severe thrombocytopenia. However, her clinical symptoms, including platelet counts, dramatically improved, with a concurrent decrease in the anti-c-Mpl antibody, an autoantibody against the thrombopoietin receptor, after a subsequent treatment with rituximab (375 mg/m2 intravenously, weekly, for two consecutive weeks). Our case suggested that amegakaryocytic thrombocytopenia in patients with systemic lupus erythematosus might be mediated by the anti-c-Mpl antibody and could be treated with rituximab through elimination of pathogenic B cells producing autoimmune antibodies. [ABSTRACT FROM AUTHOR]

Abstract: Acquired amegakaryocytic thrombocytopenic purpura (AATP) is a hematological disorder characterized by severe thrombocytopenia, probably due to an immunologically induced absence of megakaryocytes with a marked decrease or total absence of megakaryocytes in the bone marrow. AATP may be differentiated from other causes of peripheral destruction of platelets, such as immune thrombocytopenia (ITP). Currently, there are no standard treatments for AATP. However, immunosuppressive therapy including steroids, androgens, anti-thymocyte globulin (ATG), cyclophosphamide, cyclosporine A, immunoglobulins, splenectomy, and allogenic bone marrow transplantation (BMT) have all been utilized with varying degrees of success. However, a positive response in patients with AATP using steroids alone has rarely been reported in the literature. [Copyright &y& Elsevier]

The association of bone marrow failure and skeletal defects has been frequently noted, however, the genetic basis for most of these syndromes remains unclear. We describe a previously uncharacterized autosomal dominant syndrome of amegakaryocytic thrombocytopenia associated with radial-ulnar synostosis. The clinical features of this syndrome appear to be distinct from other similar conditions, including Fanconi's anaemia and thrombocytopenia-absent radii (TAR). The physical findings at diagnosis and clinical management of each case are detailed, as well as a discussion of this disorder in the context of other syndromes in which marrow failure and skeletal defects are prominent features. We also review recent developments in molecular genetics that may provide important clues to the underlying aetiology of this condition. [ABSTRACT FROM AUTHOR]

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare disorder of undefined aetiology. The disease presents with severe thrombocytopenia and absence of megakaryocytes in the bone marrow. Furthermore, CAMT patients may develop bone marrow aplasia. To obtain more insight into the mechanism underlying CAMT, five children were analysed. All patients had increased plasma thrombopoietin (Tpo) levels, indicating a platelet production defect. Bone marrow-derived CD34+ stem cells from three patients were cultured in an in vitro liquid culture system to study megakaryocytopoiesis. CD34+ cells from two of the three patients failed to differentiate into megakaryocytes. The lack of megakaryocyte formation could imply that a defect in the c-mpl gene, encoding the Tpo receptor, exists. Sequencing of c-mpl revealed mutations in four of five patients. Three patients had point mutations and/or a deletion in the coding regions of c-mpl. All point mutations led to an amino acid substitution or to a premature stop codon. In one patient, a homozygous mutation in the last base of intron 10 was found that resulted in loss of a splice site. This study showed that mutations in c-mpl could be the cause of thrombocytopenia in CAMT in the majority of patients. Furthermore, Tpo has been shown to have an anti‐apoptotic effect on stem cells. Therefore, mutations in c-mpl might not only affect megakaryocyte formation but may also impair stem cell survival, which could explain the occurrence of bone marrow failure as final outcome in patients with CAMT. [ABSTRACT FROM AUTHOR]

Acquired amegakaryocytic thrombocytopenia (AATP) is a thrombocytopenic disorder characterized by a decrease in megakaryocytes in the bone marrow. AATP is effectively treated with immunosuppressive therapy. We report a case of a 68-years-old male referred to us due to purpuric lesions on the extremities and was noted to be thrombocytopenic. Bone marrow biopsy showed AATP with autoimmune hemolytic anemia (AIHA). Only two cases of AATP associated with AIHA have been reported. AATP should be differentiated carefully from other causes of peripheral destruction of platelets, such as immune thrombocytopenia (ITP)., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Ikeda et al.)

Mononeuritis multiplex involves inflammation of two or more nerves, typically in unrelated parts of the body. It has been well described in bleeding disorders like idiopathic thrombocytopenic purpura (ITP) and Hemophilia. Acquired amegakaryocytic thrombocytopenia (AAT) is a bleeding diathesis characterized by thrombocytopenia but with reduced number of megakaryocytes in the bone marrow, as against ITP. Though AAT is a well described entity, peripheral nervous system manifestations have not been described so far. We report a young man who has presented with bleeding diathesis and mononeuritis multiplex due to AAT. The mechanism of development of mononeuritis multiplex and treatment options are discussed. [ABSTRACT FROM AUTHOR]

Idiopathic acquired aplastic anemia can be successfully treated with Anti Thymocyte Globulin (ATG)-based immune suppressive therapy and is therefore considered a T cell-mediated auto immune disease. Based on this finding, several other forms of idiopathic acquired bone marrow failure are treated with ATG as well. For this review, we extensively searched the present literature for evidence that ATG can lead to enduring remissions in different forms of acquired multi- or single-lineage bone marrow failure. We conclude that ATG-based therapy can lead to an enduring hematopoietic response and increased overall survival (OS) in patients with acquired aplastic aplasia. In patients with hypocellular myelodysplastic syndrome, ATG can lead to a hematological improvement without changing the OS. ATG seems less effective in acquired single-lineage failure diseases like Pure Red Cell Aplasia, Amegakaryocytic Thrombocytopenia and Pure White Cell Aplasia, suggesting a different pathogenesis in these bone marrow failure states compared to aplastic anemia. T cell depletion is hypothesized to play an important role in the beneficial effect of ATG but, as ATG is a mixture of polyclonal antibodies binding to different antigens, other anti-inflammatory or immunomodulatory effects could play a role as well. [ABSTRACT FROM AUTHOR]

Muraoka K, Ishii E, Ihara K, Imayoshi M, Miyazaki S, Hara T, Hamasaki Y. Successful bone marrow transplantation in a patient withc-mpl-mutated congenital amegakaryocytic thrombocytopenia from a carrier donor.Pediatr Transplantation 2005.© 2005 Blackwell MunksgaardCongenital amegakaryocytic thrombocytopenia (CAMT) is characterized by severe thrombocytopenia and the absence of megakaryocytes in bone marrow. Furthermore, mutation of thec-mplgene has been identified as a cause of this disorder. The only curative treatment is allogeneic stem cell transplantation (SCT). The current report describes a patient exhibitingc-mplmutation in both alleles who underwent transplantation of allogeneic bone marrow donated by her brother, ac-mplmutated carrier, employing a fludarabine-based conditioning regimen. Engraftment and reconstitution of hematopoietic cells was rapid and without complications. These findings suggest that the carrier donor displaying thec-mplmutation can serve as a donor source for SCT. [ABSTRACT FROM AUTHOR]

Thymic tumors are rare diseases with an incidence of 0.15 cases per 100,000 person-years. They can be associated with a variety of other syndromes, such as Myasthenia Gravis or autoimmune disorders. Among them, pure red cell aplasia is a hemato-pathological condition characterized by anemia, reticulocytopenia and erythroid cell hypoplasia of bone marrow. Here, we reported a case of a 62-year-old female with a long history of neurologic symptoms due to Myasthenia Gravis. She was diagnosed with thymoma, with mediastinal mass and pleural thickening. After chemoradiotherapy treatment, she was surgically resected successfully, but she developed anemia and severe thrombocytopenia, worsening in respiratory failure requiring intubation. A bone marrow biopsy was performed resulting in a red-cell aplasia with marked hypoplasia of megakaryocytopoiesis compatible with pure red cell aplasia with acquired thrombocytopenia. Considering that there are no standard treatments, clinical condition improvement was achieved only after some lines of medical treatment. Our data, together with the few already published, help to raise the attention towards acquired cytopenias and the need to optimize the treatment for a potentially life-threatening condition., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Abstract: We report the case of a 41-year-old man with malignant thymoma complicated by amegakaryocytic thrombocytopenia 10 years after diagnosis of myasthenia gravis. A bone marrow aspirate showed an absence of megakaryocytes with normal maturation and differentiation of myeloid precursors. Three months later, severe neutropenia occurred, and a bone marrow examination confirmed the diagnosis of severe aplastic anemia. Associations between thymoma and myasthenia gravis, between thymoma and pure red cell aplasia, and between thymoma and aplastic anemia are well documented. Amegakaryocytic thrombocytopenia is not a recognized paraneoplastic syndrome complicating thymoma. Amegakaryocytic thrombocytopenia complicating thymoma may be a very early presentation of impending aplastic anemia. [Copyright &y& Elsevier]

Presents a letter to the editor about human parvovirus published in the January 1, 2005 issue of the "British Journal of Haematology."

We report a rare case of myelodysplastic syndrome that presented early as amegakaryocytic thrombocytopenia in a collodion baby, which is a rare congenital disorder characterized by thick, taut membrane resembling oiled parchment or collodion, which is subsequently shed. To our knowledge, this is the first reported case of a collodion baby who presented with amegakaryocytic thrombocytopenia and who has a significant family history of the same condition. We document the rarity of this possible association and also the need for further study to establish whether a causal relationship exists.