The effect of donor leukocyte infusion on refractory pure red blood cell aplasia after allogeneic stem cell transplantation in a patient with myelodysplastic syndrome developing from Kostmann syndrome.

We describe the clinical course of a patient who experienced refractory pure red cell aplasia (PRCA) after undergoing HLA-matched allogeneic peripheral blood stem cell transplantation (allo-PBSCT) for refractory anemia with an excess of blasts in transformation that had evolved from Kostmann syndrome. The treatment for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) developing from Kostmann syndrome has not been standardized. We treated this patient with allo-PBSCT using a regimen combining high-dose cytosine arabinoside with granulocyte colony-stimulating factor, in addition to total body irradiation and cyclophosphamide without preceding intensive chemotherapy. The donor was ABO incompatible. Myeloid and platelet recoveries were achieved rapidly. Erythroid engraftment was not evident, however, and the patient was given a diagnosis of PRCA. Regimen-related toxicity and graft-versus-host disease (GVHD) were limited. The PRCA did not respond to various therapies, including the discontinuation of immunosuppressants for the induction of chronic GVHD, human recombinant erythropoietin, immunosuppressive treatment with steroids, cyclosporin A, and human anti-CD20 antibody (rituximab). The patient received transfusions 48 times until the resolution of his anemia by donor leukocyte infusion (DLI) at 25 months after PBSCT. He is now clinically well (performance status, 100%) with normal blood cell counts at 5 years after SCT. An in vitro study demonstrated that serum from the recipient blocked the differentiation of erythroid cells in the bone marrow. The results indicate that the conditioning regimen we describe seems safe and effective for those who have MDS/AML and that DLI might be a valuable approach for refractory PRCA after ABO-incompatible SCT.

One allele deletion of the RB1 gene in a case of refractory anemia with del(13)(q12q14): a fluorescence in situ hybridization study of the RB1 gene.

The tumor suppressor gene RB1 is known to be located on chromosome band 13q14. We investigated the involvement of the RB1 gene in a case of refractory anemia with del(13)(q12q14) by florescence in situ hybridization (FISH) analysis using the RB1 locus (13q14) DNA probe. Bone marrow cells derived from this patient exhibited a single signal of the RB1 gene in 58 of 100 bone marrow cells, as determined by interphase FISH analysis. Hematopoietic colony-forming assays showed that the absolute number of erythroid, myeloid, and mixed colonies was comparable to that of normal subjects. FISH analysis of selected colonies revealed that only a single signal for the RB1 gene was detected in five of five granulocyte macrophage-colony-forming units (CFUs), four of five erythroid burst-forming units, and two of four mixed CFUs (total 11/14: 78.6%). Thus, the majority of hematopoietic progenitor cells lacked one allele of the RB1 gene, suggesting that in this particular case the RB1 gene played an important role in abnormal hematopoiesis.