Daratumumab may be the most effective treatment for post-engraftment pure red cell aplasia due to persistent anti-donor isohemagglutinins after major ABO-mismatched allogeneic transplantation

Refractory Pure Red Blood Cell Aplasia Secondary to Major ABO-Incompatible Allogeneic Stem Cell Transplantation Successfully Treated With Daratumumab

Pure red cell aplasia (PRCA) is a rare hematologic phenomenon that is usually associated with inherited genetic mutations such as in Diamond-Blackfan anemia. However, due to the emergence of allogenic stem cell transplantation in the treatment of various malignant and non-malignant disorders, the incidence of PRCA has increased. PRCA following hematopoietic stem cell transplant (HSCT) is more commonly seen in the setting of a major ABO-incompatible transplant. Treatment of allo-HSCT induced PRCA can be initially supportive as it takes time for the bone marrow to fully recover. However, prolonged and/or failure of the bone marrow to recover, significantly increases patient's risk of iron overload in the setting of frequent transfusions. Iron deposition can potentially lead to severe life-threatening multiorgan involvement which can be fatal. Therefore, earlier recognition and intervention with immunomodulators in patients who undergo frequent transfusions can be beneficial to mitigate this risk. Here, we present a case with severe transfusion-dependent PRCA following major ABO-incompatible allo-HSCT successfully treated with daratumumab.

Pure red cell aplasia: The second hundred years

Pure red cell aplasia (PRCA) is a rare hematologic syndrome, characterized by an isolated normocytic anemia with severe reticulocytopenia, and defined by absence or near absence of erythroid precursors in the bone marrow. First described in 1922, PRCA may be a primary autoimmune or clonal myeloid or lymphoid disorder, but may also be secondary to other disorders of immune dysregulation/autoimmunity, to infections, to neoplasms, or to drugs. Insights from the study of PRCA have helped illuminate the understanding of the regulation of erythropoiesis. This review summarizes the classification, diagnostic, and therapeutic approach to PRCA as it begins its second century, with a particular focus on opportunities and challenges provided by new developments in the role of T-cells and T-cell regulatory mutations; the role of clonal hematopoiesis; and new developments in therapy for refractory PRCA and PRCA associated with ABO incompatible stem cell transplantation.

Case report: Successful treatment with daratumumab for pure red cell aplasia in a patient with mixed lymphoid chimerism after ABO-mismatched stem cell transplant for sickle cell disease

Pure red cell aplasia (PRCA) is a serious complication after ABO-mismatched allogeneic hematopoietic stem cell transplantation (HSCT). Following HSCT, persistent anti-donor isohemagglutinins against donor ABO antigens are considered the immunological cause of PRCA. Patients with post-transplant PRCA are at risk for graft rejection and prolonged red blood cell transfusion dependency. No standard treatment exists. Recently however, the anti-CD38 monoclonal antibody daratumumab has been reported to be an effective treatment for post-transplant PRCA in patients with complete donor chimerism. Here, we describe the first case of PRCA in a patient with mixed lymphoid patient/donor chimerism that was successfully treated with daratumumab. This is also the first report of a transplant recipient with sickle cell disease who was treated with this relatively new approach. Fourteen months post-transplantation and twelve months after treatment with daratumumab, our patient has a normal complete blood count and the anti-donor isohemagglutinins remain undetectable despite mixed lymphoid chimerism. Mixed chimerism is a common manifestation in adult patients with sickle cell disease transplanted with non-myeloablative conditioning and a matched sibling donor. The application of non-myeloablative HSCT for patients with sickle cell disease is steadily increasing. Therefore, the incidence of PRCA in this setting might also increase. As the risk of graft rejection due to PRCA can be especially high in patients with mixed chimerism, clinicians should be aware that daratumumab can be an effective treatment in the setting of mixed chimerism.

Pure red cell aplasia after hematopoietic stem cell transplantation - experimental therapeutic approaches

Not relevant.