強力化学療法と同種骨髄移植療法が施行し得たｌｇＡ欠損症を伴う急性骨髄性白血病の１症例

Abstract

Deficiency of IgA with circulating class-specific anti-IgA antibodies is one of the major causes of anaphylactic reaction in transfusion medicine. This problem is more serious in the management of patients with hematological malignancies or other types of bone marrow failure. Here we report a case of acute myeloid leukemia with IgA deficiency who underwent intensive chemotherapy and allogeneic bone marrow transplantation. To avoid the production of anti-IgA antibody, platelet concentrates were collected from donors who were IgA-deficient. Additional support with platelets and RBC components from donors who had circulating IgA was provided using products washed and replaced with 0.9% normal saline. Complete remission was achieved after a single course of remission induction therapy. After one course of consolidation chemotherapy, allogeneic bone marrow transplantation from an HLA-matched sibling was performed. No anaphylactic reaction was observed after any transfusion. No circulating anti-IgA antibodies were detectable after the full recovery of hematopoiesis in this patient. These findings indicate that allogeneic blood component products collected from donors with IgA deficiency are useful in myeloablative therapy in patients with hematological disorders. By washing with normal saline, products from donors with normal IgA levels are also acceptable. Further studies to elucidate the clinical usefulness of precise genomic and expressional analysis of IgA gene are required to ensure the safety of transfusion medicine in patients with IgA deficiency. Furthermore, the establishment of blood bank registry systems for IgA-deficient blood donors is important to the maintenance of a stable supply of blood components for IgA-deficient patients who require transfusion therapy.