SUNY Downstate Medical Center Brooklyn, New York, United States
Background: Acquired Amegakaryocytic Thrombocytopenia (AAMT) is a rare disorder with severely reduced megakaryocytes in the bone marrow, which is often initially misdiagnosed as immune thrombocytopenia (ITP). AAMT is often associated with systemic lupus erythematosus (SLE) via an autoantibody against the thrombopoietin receptor. AAMT can progress to aplastic anemia (AA). Overall mortality was 15% in SLE-induced AA.
Aims: Herein presents the first case report of SLE-induced AAMT and subsequent AA.
Methods: Case report
Results: A 27-year-old male presents with petechiae and bruises in his extremities. Family history of pernicious anemia of mother and sister with pityriasis lichenoides. Initial labs: WBC 3410, Hb 10.9, platelet < 2,000. No evidence of hemolysis, Hepatitis, HIV, or CMV/EBV infection. Peripheral smear was normal except for decreased platelets. For presumptive ITP, IVIG, steroids, and platelet transfusion were initiated. The patient was diagnosed with lupus (positive ANA and dsDNA, low C4). Bone marrow biopsy showed hypocellular marrow 30-40%, no evidence of leukemia/lymphoma, and severely decreased megakaryocytes, suggesting SLE-induced AAMT via autoimmune-mediated destruction of megakaryocytes.
Immunosuppression was initiated with mycophenolate mofetil, plasmapheresis, hydroxychloroquine, rituximab, and eltrombopag. Repeat marrow revealed reduced cellularity to 10-20%. NGS from BM biopsy for MDS did not detect any mutations, and karyotypes were normal. Patient was discharged with mycophenolate, methotrexate, steroids, and eltrombopag.
In 2 months, initial amegakaryocytic marrow has progressed to very severe aplastic anemia secondary to lupus, with all cell lines severely suppressed. Patient is still requiring platelet and pRBC transfusions weekly. Patient is currently awaiting bone marrow allotransplantation.
Conclusion(s): AAMT and AA are rare complications of SLE, and the treatment is not established. There are currently 23 SLE-associated AA case reports in English literature in PubMed. No histological or clinical features distinguish primary AA from SLE-induced AA. Therefore, clinicians should consider screening for lupus antibodies in unexplained pancytopenia.
