Tokiko Nagamura-Inoue

Disease-specific analyses of unrelated cord blood transplantation compared with unrelated bone marrow transplantation in adult patients with acute leukemia

We made a disease-specific comparison of unrelated cord blood (CB) recipients and human leukocyte antigen allele-matched unrelated bone marrow (BM) recipients among 484 patients with acute myeloid leukemia (AML; 173 CB and 311 BM) and 336 patients with acute lymphoblastic leukemia (ALL; 114 CB and 222 BM) who received myeloablative transplantations. In multivariate analyses, among AML cases, lower overall survival (hazard ratio [HR]=1.5; 95% confidence interval [CI], 1.0-2.0, P= .028) and leukemia-free survival (HR=1.5; 95% CI, 1.1-2.0, P= .012) were observed in CB recipients. The relapse rate did not differ between the 2 groups of AML (HR=1.2; 95% CI, 0.8-1.9, P= .38); however, the treatment-related mortality rate showed higher trend in CB recipients (HR=1.5; 95% CI, 1.0-2.3, P= .085). In ALL, there was no significant difference between the groups for relapse (HR=1.4, 95% CI, 0.8-2.4, P= .19) and treatment-related mortality (HR=1.0; 95% CI, 0.6-1.7, P= .98), which contributed to similar overall survival (HR=1.1; 95% CI, 0.7-1.6, P= .78) and leukemia-free survival (HR=1.2; 95% CI, 0.9-1.8, P= .28). Matched or mismatched single-unit CB is a favorable alternative stem cell source for patients without a human leukocyte antigen-matched related or unrelated donor. For patients with AML, decreasing mortality, especially in the early phase of transplantation, is required to improve the outcome for CB recipients.

Transplantation of allogeneic hematopoietic stem cells for adult T-cell leukemia: A nationwide retrospective study

Allogeneic hematopoietic stem cell transplantation (HSCT) is increasingly used as a curative option for adult T-cell leukemia (ATL), an intractable mature T-cell neoplasm causally linked with human T-cell leukemia virus type I (HTLV-I). We compared outcomes of 386 patients with ATL who underwent allogeneic HSCT using different graft sources: 154 received human leukocyte antigen (HLA)-matched related marrow or peripheral blood; 43 received HLA-mismatched related marrow or peripheral blood; 99 received unrelated marrow; 90 received single unit unrelated cord blood. After a median follow-up of 41 months (range, 1.5-102), 3-year overall survival for entire cohort was 33% (95% confidence interval, 28%-38%). Multivariable analysis revealed 4 recipient factors significantly associated with lower survival rates: older age (> 50 years), male sex, status other than complete remission, and use of unrelated cord blood compared with use of HLA-matched related grafts. Treatment-related mortality rate was higher among patients given cord blood transplants; disease-associated mortality was higher among male recipients or those given transplants not in remission. Among patients who received related transplants, donor HTLV-I seropositivity adversely affected disease-associated mortality. In conclusion, allogeneic HSCT using currently available graft source is an effective treatment in selected patients with ATL, although greater effort is warranted to reduce treatment-related mortality.

Identification and characterization of nucleophosmin/B23/numatrin which binds the anti-oncogenic transcription factor IRF-1 and manifests oncogenic activity.

Interferon regulatory factor-1 (IRF-1) acts as a transcriptional activator in the interferon system and as a tumor suppressor. The loss of functional IRF-1 has been observed in a significant number of patients with myelodysplastic syndrome (MDS) and leukemia, suggesting a potentially critical role of IRF-1 in human oncostasis. Here we report an alternative mechanism by which IRF-1 may be inactivated. We purified an IRF-1 association molecule which was revealed to be identical to a nuclear factor nucleophosmin (NPM)/B23/numatrin. Functional analysis showed that NPM inhibited the DNA-binding and transcriptional activity of IRF-1. Moreover, NPM was overexpressed in several clinical leukemia samples and human-derived leukemia cell lines. Finally, overexpression of NPM in NIH3T3 cells resulted in malignant transformation. These results suggest the possible involvement of NPM in inactivating IRF-1-dependent anti-oncogenic surveillance in human cancer development.

Comparison of mesenchymal stem cells derived from arterial, venous, and Wharton's jelly explants of human umbilical cord.

We isolated mesenchymal stem cells (MSC) from arteries (UCA), veins (UCV), and Wharton’s jelly (UCWJ) of human umbilical cords (UC) and determined their relative capacities for sustained proliferation and multilineage differentiation. Individual UC components were dissected, diced into 1–2 mm³ fragments, and aligned in explant cultures from which migrating cells were isolated using trypsinization. Preparations from 13 UCs produced 13 UCWJ, 11 UCV, and 10 UCA cultures of fibroblast-like, spindle-shaped cells negative for CD31, CD34, CD45, CD271, and HLA-class II, but positive for CD13, CD29, CD44, CD73, CD90, CD105, and HLA-class I. UCV cells exhibited a significantly higher frequency of colony-forming units fibroblasts than did UCWJ and UCA cells. Individual MSCs could be selectively differentiated into osteoblasts, chondrocytes, and adipocytes. When compared for osteogenic potential, UCWJ cells were the least effective precursors, whereas UCA-derived cells developed alkaline phosphatase activity with or without an osteogenic stimulus. UC components, especially blood vessels, could provide a promising source of MSCs with important clinical applications.

Umbilical cord-derived mesenchymal stem cells: Their advantages and potential clinical utility

Human umbilical cord (UC) is a promising source of mesenchymal stem cells (MSCs). Apart from their prominent advantages, such as a painless collection procedure and faster self-renewal, UC-MSCs have shown the ability to differentiate into three germ layers, to accumulate in damaged tissue or inflamed regions, to promote tissue repair, and to modulate immune response. There are diverse protocols and culture methods for the isolation of MSCs from the various compartments of UC, such as Whartons jelly, vein, arteries, UC lining and subamnion and perivascular regions. In this review, we give a brief introduction to various compartments of UC as a source of MSCs and emphasize the potential clinical utility of UC-MSCs for regenerative medicine and immunotherapy.

Unrelated Cord Blood Transplantation for Severe Aplastic Anemia

In the present study we evaluated the feasibility of unrelated cord blood transplantation (UCBT) in patients with severe aplastic anemia (SAA). The outcome of 31 SAA patients (median age 28; range: 0.9-72.3 years old) who received UCBT was analyzed. The cumulative incidences of the neutrophil and platelet recovery after UCBT were 54.8 and 72.2%, respectively (95% confidence interval [CI] = 36.0%-70.3% and 51.3%-85.3%, respectively). The cumulative incidences of grade > or =II acute and chronic graft-versus-host disease (aGVHD, cGVHD) were 17.1% (95% CI = 6.2%-32.8%) and 19.7% (95% CI = 6.2%-38.8%), respectively. Currently, 13 patients are alive, having survived for 33.7 months (median; range: 6-77 months) after UCBT. The probability of overall survival (OS) at 2 years was 41.1% (95% CI = 23.8%-57.7%). A conditioning regimen that included low-dose total body irradiation (TBI) (2-5 Gy), fludarabine, and cyclophosphamide resulted in a favorable OS (80%; 95% CI = 20.4%-96.9%). This result suggests that UCBT using the optimal conditioning regimen can be a salvage treatment for patients without a suitable bone marrow donor and warrants evaluation in further prospective studies.

Impact of graft-versus-host disease on outcomes after allogeneic hematopoietic cell transplantation for adult T-cell leukemia: a retrospective cohort study

Allogeneic hematopoietic cell transplantation (HCT) is an effective treatment for adult T-cell leukemia (ATL), raising the question about the role of graft-versus-leukemia effect against ATL. In this study, we retrospectively analyzed the effects of acute and chronic graft-versus-host disease (GVHD) on overall survival, disease-associated mortality, and treatment-related mortality among 294 ATL patients who received allogeneic HCT and survived at least 30 days posttransplant with sustained engraftment. Multivariate analyses treating the occurrence of GVHD as a time-varying covariate demonstrated that the development of grade 1-2 acute GVHD was significantly associated with higher overall survival (hazard ratio [HR] for death, 0.65; P = .018) compared with the absence of acute GVHD. Occurrence of either grade 1-2 or grade 3-4 acute GVHD was associated with lower disease-associated mortality compared with the absence of acute GVHD, whereas grade 3-4 acute GVHD was associated with a higher risk for treatment-related mortality (HR, 3.50; P < .001). The development of extensive chronic GVHD was associated with higher treatment-related mortality (HR, 2.75; P = .006) compared with the absence of chronic GVHD. Collectively, these results indicate that the development of mild-to-moderate acute GVHD confers a lower risk of disease progression and a beneficial influence on survival of allografted patients with ATL.

Comparison of Unrelated Cord Blood Transplantation and HLA-Mismatched Unrelated Bone Marrow Transplantation for Adults with Leukemia

Recent advances in unrelated cord blood transplantation (UCBT) and high-resolution typing of human leukocyte antigen (HLA) from an unrelated donor have increased choices in alternative donor/stem cell source selection. We assessed HLA-mismatched locus-specific comparison of the outcomes of 351 single-unit UCB and 1,028 unrelated bone marrow (UBM) adult recipients 16 years old or older at the time of transplantation who received first stem cell transplantation with myeloablative conditioning for acute leukemia or myelodysplastic syndromes. With adjusted analyses, HLA 0 to 2 mismatched UCBT showed similar overall mortality (relative risk [RR] = 0.85, 95% confidence interval [CI], 0.68-1.06; P = .149) compared with that of single-HLA-DRB1-mismatched UBMT. UCBT showed inferior neutrophil recovery (RR = 0.50, 95% CI, 0.42-0.60; P < .001), lower risk of acute graft-versus-host disease (RR = 0.55, 95% CI, 0.42-0.72; P < .001), and lower risk of transplantation-related mortality (RR = 0.68, 95% CI, 0.50-0.92; P = .011) compared with single-HLA-DRB1-mismatched UBMT. No significant difference was observed for risk of relapse (RR = 1.28, 95% CI, 0.93-1.76; P = .125). HLA 0 to 2 antigen-mismatched UCBT is a reasonable second alternative donor/stem cell source with a survival outcome similar to that of single-HLA-DRB1-mismatched or other 7 of 8 UBMT.

Cytokine production by primary human macrophages infected with highly pathogenic H5N1 or pandemic H1N1 2009 influenza viruses

Highly pathogenic H5N1 avian influenza viruses have caused infection in humans, with a high mortality rate, since 1997. While the pathogenesis of this infection is not completely understood, hypercytokinaemia and alveolar macrophages are thought to play a role. To gain further insight into the cytokine-mediated pathogenesis of this infection in humans, we measured various cytokines produced by primary human macrophages infected with H5N1, pandemic H1N1 or seasonal influenza viruses. We found that many cytokines were produced at higher levels on infection with the H5N1 strains tested compared with seasonal influenza viruses. Interestingly, the extent of cytokine induction varied among the H5N1 strains and did not correlate with replicative ability in macrophages. Further, a pandemic H1N1 virus induced higher levels of several cytokines compared with seasonal viruses and some H5N1 strains. Our results demonstrate that high cytokine induction is not a universal feature of all H5N1 viruses.

Identification of a melanoma antigen, PRAME, as a BCR/ABL-inducible gene

In order to elucidate molecular events in BCR/ABL‐induced transformation, we adopted a polymerase chain reaction (PCR)‐based technique of differential display and compared mRNA expression in human factor‐dependent cells, TF‐1, with that in factor‐independent cells, ID‐1, which were established from TF‐1 cells by transfection of BCR/ABL. Cloning and sequencing of a gene which was upregulated in ID‐1 cells revealed that the gene was identical to a melanoma antigen, PRAME. Our present study demonstrated that PRAME was markedly expressed in primary leukemic cells with chronic myeloid leukemia (CML) in blastic crisis and Philadelphia (Ph)+‐acute lymphoblastic leukemia (ALL), in which BCR/ABL played an important role as a pathogenic gene. Moreover, comparison of PRAME expression among CD34+ cells with CML in blastic, accelerated, and chronic phases revealed a higher expression in CML in advanced phases. Thus PRAME was considered to be a good candidate for a marker of Ph+‐leukemic blast cells as well as a new target antigen of leukemic blast cells that cytotoxic T cells can recognize.