Kazuko Kudo

Human herpesvirus 6 viremia in bone marrow transplant recipients: clinical features and risk factors.

Human herpesvirus 6 (HHV-6) infection was studied in 82 bone marrow transplant (BMT) recipients (72 allogeneic, 10 autologous). All recipients and 30 donors were seropositive for HHV-6 antibody at the time of bone marrow transplantation. Thirty-one recipients (37.8%) had HHV-6 viremia 2-4 weeks after transplantation. The incidence of HHV-6 viremia was significantly higher among allogeneic BMT recipients than in autologous BMT recipients (P=.011). Therefore, the following analyses of allogeneic BMT recipients were carried out (n=72). Geometric mean antibody titers (log(10)) were significantly higher in recipients without viremia than in those with viremia (1.84+/-0.39 vs. 1.61+/-0.42; P=.022). Logistic regression analysis demonstrated that leukemia or lymphoma is an independent risk factor (P=.031) for HHV-6 viremia. Rash occurring within 1 month after transplantation was observed in 17 (54.8%) of 31 recipients with HHV-6 viremia but in only 8 (19.5%) of 41 recipients without HHV-6 viremia (P=.001).

Detection of neuroblastoma cells in bone marrow and peripheral blood at diagnosis by the reverse transcriptase‐polymerase chain reaction for tyrosine hydroxylase mRNA

Background. Bone marrow metastasis often occurs in patients with neuroblastoma; therefore, a sensitive assay to detect occult neuroblastoma cells in bone marrow (BM) and peripheral blood (PB) is needed. The feasibility and clinical value of using the reverse transcriptase‐ (RT) polymerase chain reaction (PCR) to amplify mRNA for tyrosine hydroxylase (TH), the first enzyme of catecholamine synthesis, was evaluated to detect neuroblastoma cells in patient samples.

Unrelated donor marrow transplantation in children with severe aplastic anaemia using cyclophosphamide, anti‐thymocyte globulin and total body irradiation

We report a favourable outcome in 15 patients with severe aplastic anaemia (SAA) who were <u200a20u2003years of age and who underwent bone marrow transplantation (BMT) from a human leucocyte antigen (HLA)‐matched unrelated donor. All patients were non‐responders to intensive immunosuppressive therapy (IST) and were multiply transfused. The conditioning regimen consisted of cyclophosphamide (60u2003mg/kg/d, on du2003−4 and −3), anti‐thymocyte globulin (2·5u2003mg/kg/d, on du2003−5 to −2) and total body irradiation (2·5u2003Gyu2003×u20032/d, on du2003−2 and −1). Patients received cyclosporine and methotrexate for prophylaxis of graft‐versus‐host disease (GVHD), except for the last four who received tacrolimus instead of cyclosporine. Donor/recipient pairs were identical for HLA class I and II antigens by serological typing, but four pairs were found to have a mismatch at the HLA‐A, ‐B or ‐DRB1 locus by high‐resolution typing. All patients achieved rapid engraftment and are alive at 2–86u2003months after transplantation (median follow‐up, 51u2003months). Moderate to severe acute GVHD occurred in 5 out of 15 patients (33%); only one patient developed extensive chronic GVHD. Considering our encouraging results, unrelated donor transplantation for SAA is recommended as a salvage therapy in non‐responders to IST.

Real-time quantitative reverse transcription-polymerase chain reaction for the detection of AML1-MTG8 fusion transcripts in t(8;21)-positive acute myelogenous leukemia.

Quantification of AML1-MTG8 fusion transcripts was performed by using real-time reverse transcription-polymerase chain reaction (RT-PCR) and the clinical value of this method was evaluated in t(8;21)-positive acute myelogenous leukemia (AML). A t(8;21)-positive cell line, Kasumi-1, was used for constructing standard curves and the corrected AML1-MTG8 mRNA expression level relative to the expression of the GAPDH housekeeping gene was calculated. Bone marrow samples from 14 patients with t(8;21)-positive AML were sequentially examined. The corrected AML1-MTG8 expression level at diagnosis varied in the range from 0.4 to 2.7 (median, 1.5) among the patients. When samples at 1, 3 and 6 months were examined after diagnosis, the corrected AML1-MTG8 expression level was found to decrease sequentially in all but one. AML1-MTG8 fusion transcripts were also detected in four of eight samples from patients in remission for more than 1 year. In conclusion, real-time RT-PCR can provide a rapid and accurate quantification of AML1-MTG8 fusion transcripts. This system could be useful to reveal the prognostic relevance of minimal residual disease in t(8;21)-positive AML.

High serum values of soluble CD154, IL‐2 receptor, RANKL and osteoprotegerin in Langerhans cell histiocytosis

To determine useful biochemical markers in Langerhans cell histiocytosis (LCH), we analyzed the serum levels of soluble CD154 (sCD154), IL2 receptor (sIL2‐R), receptor activator of NF‐κB ligand (sRANKL), and osteoprotegerin (OPG).

Engraftment of NOD/SCID/γcnull mice with multilineage neoplastic cells from patients with juvenile myelomonocytic leukaemia

Several lines of evidence indicate the clonal nature of juvenile myelomonocytic leukaemia (JMML), involving myeloid, erythroid, megakaryocyte and B‐lymphoid lineages. However, it is unclear whether the T‐lymphocyte lineage is involved. We demonstrated that cells from six patients with JMML repopulated in non‐obese diabetic/severe combined immunodeficient/γcnull mice and differentiated into granulocytes, monocytes, erythrocytes, B lymphocytes, T lymphocytes and natural killer cells. The percentage of human CD45 antigen‐positive cells ranged from 41% to 73% in the murine bone marrow 12u2003weeks after transplantation. To examine the involvement of lymphocyte subpopulations, we purified human CD3+, CD19+ and CD56+ cells from murine bone marrow cells transplanted from a patient with monosomy 7. Fluorescence in situ hybridization (FISH) showed the clonal marker in 96–100% of purified CD3+, CD19+ and CD56+ subpopulations. These findings support the concept that JMML originates in transplantable multilineage haematopoietic stem cells. This novel murine xenotransplant model should be useful for investigating the nature of stem cells and testing new therapies for patients with JMML.

Comprehensive analysis of gene alterations in acute megakaryoblastic leukemia of Down's syndrome.

Comprehensive analysis of gene alterations in acute megakaryoblastic leukemia of Downs syndrome

A novel mutation of the erythroid‐specific δ‐aminolevulinate synthase gene in a patient with non‐inherited pyridoxine‐responsive sideroblastic anemia

A novel missense mutation, G663A, in exon 5 of the erythroid‐specific δ‐aminolevulinate synthase gene (ALAS2) was identified in a Japanese male with pyridoxine‐responsive sideroblastic anemia. Activity of the mutant δ‐aminolevulinate synthase protein expressed in vitro was 15.1% compared with the normal control, but was increased up to 34.5% by the addition of pyridoxal 5′‐phosphate, consistent with the clinical response of the patient to pyridoxine treatment. The same mutation was also detected in genomic DNA from the oral mucosal membrane of the patient; however, it was not detected in other family members. These findings suggest that this G663A mutation is responsible for sideroblastic anemia in the proband, and may be an index mutation in this pedigree. Am. J. Hematol. 62:112–114, 1999.

Engraftment syndrome following allogeneic hematopoietic stem cell transplantation in children

Abstract:u2002 ES is a complication that occurs immediately before or at the timing of neutrophil engraftment following autologous or allogeneic SCT. It is characterized by fever, skin rash, and non‐cardiac pulmonary infiltrates. We evaluated the incidence, risk factors, and outcomes of ES following allogeneic SCT in children. Of 100 pediatric patients, 20 (20%) developed ES occurring at a median of 14u2003days (range 8–27u2003days) post‐transplant. Patients presented with fever (100%), skin rash (100%), diffuse pulmonary infiltration (25%), and body weight gain (85%). On multivariate analysis, significant risk factors for ES included younger age (<8u2003yr old) and human leukocyte antigen disparity between donors and recipients. Univariate analysis showed that patients with ES had a higher incidence of developing chronic graft‐versus‐host disease and ES was not associated with other complications. Event‐free survival did not significantly differ between patients with and without ES regardless of the presence of malignant or non‐malignant diseases.

Feasibility and results of bone marrow transplantation from an HLA-mismatched unrelated donor for children and young adults with acquired severe aplastic anemia.

Treating patients with severe aplastic anemia (SAA) who fail to respond to immunosuppressive therapy (IST) and do not have an HLA-matched donor is challenging. We report favorable outcomes in 11 patients who underwent bone marrow transplantation (BMT) from an HLA-mismatched unrelated donor. The median age was 11 years (range, 3–20 years). The conditioning regimen consisted of cyclophosphamide (200 mg/kg), antithymocyte globulin (10 mg/kg), and total body irradiation (5 Gy). Patients received tacrolimus and methotrexate for prophylaxis against graft-versus-host disease (GVHD). Donor-recipient pairs were mismatched for the HLA-DR antigen in 8 patients by serologic typing. HLA-A and HLA-B antigens were mismatched in 1 and 2 patients, respectively. Ten patients achieved engraftment. One patient who failed to engraft was rescued by a second transplantation from her mother, who was mismatched at 2 HLA antigens. Acute GVHD of grades II to IV occurred in 2 patients. Three patients developed limited chronic GVHD, and 1 patient developed extensive chronic GVHD of the lung. All patients are alive at 9 to 56 months after transplantation (median, 33 months). Considering our encouraging results, HLA-mismatched unrelated-donor BMT for SAA is feasible as a salvage therapy for nonresponders to IST.