Shuro Yoshida

Chemotherapy-resistant human AML stem cells home to and engraft within the bone-marrow endosteal region

Acute myelogenous leukemia (AML) is the most common adult leukemia, characterized by the clonal expansion of immature myeloblasts initiating from rare leukemic stem (LS) cells. To understand the functional properties of human LS cells, we developed a primary human AML xenotransplantation model using newborn nonobese diabetic/severe combined immunodeficient/interleukin (NOD/SCID/IL)2rγnull mice carrying a complete null mutation of the cytokine γc upon the SCID background. Using this model, we demonstrated that LS cells exclusively recapitulate AML and retain self-renewal capacity in vivo. They home to and engraft within the osteoblast-rich area of the bone marrow, where AML cells are protected from chemotherapy-induced apoptosis. Quiescence of human LS cells may be a mechanism underlying resistance to cell cycle–dependent cytotoxic therapy. Global transcriptional profiling identified LS cell–specific transcripts that are stable through serial transplantation. These results indicate the potential utility of this AML xenograft model in the development of novel therapeutic strategies targeted at LS cells.

CD34 + CD38 + CD19 + as well as CD34+CD38-CD19+ cells are leukemia-initiating cells with self-renewal capacity in human B-precursor ALL

The presence of rare malignant stem cells supplying a hierarchy of malignant cells has recently been reported. In human acute myelogenous leukemia (AML), the leukemia stem cells (LSCs) have been phenotypically restricted within the CD34+CD38− fraction. To understand the origin of malignant cells in primary human B-precursor acute lymphocytic leukemia (B-ALL), we established a novel in vivo xenotransplantation model. Purified CD34+CD38+CD19+, CD34+CD38−CD19+ and CD34+CD38−CD19− bone marrow (BM) or peripheral blood (PB) cells from three pediatric B-ALL patients were intravenously injected into sublethally irradiated newborn NOD/SCID/IL2rγnull mice. We found that both CD34+CD38+CD19+ and CD34+CD38−CD19+ cells initiate B-ALL in primary recipients, whereas the recipients of CD34+CD38−CD10−CD19− cells showed normal human hematopoietic repopulation. The extent of leukemic infiltration into the spleen, liver and kidney was similar between the recipients transplanted with CD34+CD38+CD19+ cells and those transplanted with CD34+CD38−CD19+ cells. In each of the three cases studied, transplantation of CD34+CD38+CD19+ cells resulted in the development of B-ALL in secondary recipients, demonstrating self-renewal capacity. The identification of CD34+CD38+CD19+ self-renewing B-ALL cells proposes a hierarchy of leukemia-initiating cells (LICs) distinct from that of AML. Recapitulation of patient B-ALL in NOD/SCID/IL2rγnull recipients provides a powerful tool for directly studying leukemogenesis and for developing therapeutic strategies.

Human cord blood--derived cells generate insulin-producing cells in vivo.

Here we report the capacity of human cord blood (CB)–derived cells to generate insulin‐producing cells. To investigate in vivo capacity of human CB–derived cells, T cell–depleted mononuclear cells were intravenously transplanted into nonobese diabetic/severe combined immunodeficient/β2‐microglobulinnull mice within 48 hours of birth. At 1–2 months post‐transplantation, immunofluorescence staining for insulin and fluorescence in situ hybridization (FISH) analysis using a human chromosome probe indicated that human CB–derived cells generated insulin‐producing cells at a frequency of 0.65% ± 0.64% in xenogeneic hosts. Reverse transcription–polymerase chain reaction analysis confirmed the transcription of human insulin in the pancreatic tissue of the recipient mice. To clarify the mechanism underlying CB‐derived insulin‐producing cells, double FISH analysis using species‐specific probes was performed. Almost equal proportions of human chromosome+ murine chromosome− insulin+ cells and human chromosome+ murine chromosome+ insulin+ cells were present in recipient pancreatic islets. Taken together, human CB contains progenitor cells, which can generate insulin‐producing cells in recipient pancreatic tissues across a xenogeneic histocompatibility barrier by fusion‐dependent and ‐independent mechanisms.

Adult T-cell leukemia development from a human T-cell leukemia virus type I carrier after a living-donor liver transplantation.

Adult T-cell leukemia (ATL) develops in a human T-cell leukemia virus type I (HTLV-I) carrier. The development of malignancy during immunosuppressive treatment following organ transplantation is one of the late fatal complications. We describe the development of three cases of ATL in eight HTLV-I carriers within 164 living-donor liver transplant recipients undergoing immunosuppressive treatment. All three cases were immunosuppressed with tacrolimus. Acute-type ATL was diagnosed at 6, 9, and 25 months after living-donor liver transplantation, based on increased numbers of CD4+25+ lymphocytes exhibiting “flower-like” nuclei, and the elevation of lactate dehydrogenase. Southern blot analysis demonstrated the clonal proliferation of ATL cells in peripheral blood. The ATL cells originated from the recipient, as demonstrated by fluorescence in situ hybridization analysis using sex chromosomal markers. Our observations suggest that immunosuppressive treatment for the prevention of graft rejection after living-donor liver transplantation may induce the development of ATL in an HTLV-I carrier.

Human cord blood- and bone marrow-derived CD34+ cells regenerate gastrointestinal epithelial cells

In the present study, we aimed to clarify the capacity of human cord blood‐ and bone marrow‐ derived progenitor cells to generate gastrointestinal epithelial cells in clinical and experimental transplantation settings. First, in a clinical transplantation setting, gastrointestinal tissues derived from female pediatric or juvenile recipients of allogeneic sex‐mismatched bone marrow and cord blood transplantation were examined for the presence of donor‐derived epithelial cells. Gastrointestinal specimens of allogeneic recipients included Y chromosome+ cytokeratin+ epithelial cells at a frequency of 0.4–1.9%. To further determine the capacity of purified human progenitor cells, human cord blood‐ or bone marrow‐derived CD34+ cells were transplanted into newborn NOD/SCID/β2‐microglobulinnull mice as an experimental transplantation assay. When gastrointestinal tissues derived from recipient mice were subjected to FISH and immunofluorescence analyses, human epithelial cells were identified at a frequency of 0.24– 0.58% at 3 months posttransplantation. Finally, double FISH analyses using species‐specific probes revealed that human chromosome+ epithelial cells did not possess any murine chromosomes, indicating that donor‐derived epithelial cells were not generated only by cell fusion. On the basis of these findings, it is concluded that purified human cord blood and bone marrow CD34+ progenitor cells can generate gastrointestinal epithelial cells across allogeneic and xenogeneic histocompatibility barriers.

Disseminated tuberculosis following second unrelated cord blood transplantation for acute myelogenous leukemia.

Abstract: Here we report the case of a 43‐year‐old Japanese woman with acute myelogenous leukemia who underwent 2 unrelated cord blood transplantations (UCBT), terminating in fatal disseminated tuberculosis (TB). The patient did not achieve remission despite intensive chemotherapy, and subsequently underwent UCBT with a standard conditioning regimen. However, engraftment was not achieved. Fifty days after the first UCBT, the patient underwent a second UCBT with a reduced‐intensity conditioning regimen. She developed a pre‐engraftment immune reaction, which responded well to prednisolone, and engraftment was documented. However, 50 days after the second UCBT, the patient presented with high fever and developed pneumonia despite antibiotic and antifungal treatments. Thereafter, Mycobacterium tuberculosis was detected in blood cultures and specimens of bronchoalveolar lavage, thus indicating disseminated TB. Despite anti‐tuberculous treatment, she died on day 85. TB should always be considered as a possible diagnosis when treating febrile immunocompromised patients.

Clinical Features and Treatment Outcomes of 81 Patients with Aggressive Type Adult T-cell Leukemia-lymphoma at a Single Institution over a 7-year Period (2006-2012)

OBJECTIVE Despite the remarkable advances in chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT), adult T-cell leukemia-lymphoma (ATL) is still associated with a high mortality rate. It is therefore essential to elucidate the current features of ATL. METHODS We retrospectively analyzed 81 patients with aggressive type ATL at our institution over a 7-year period based on Shimoyamas diagnostic criteria. RESULTS Eighty-one patients with a median age of 67.5 years were classified as having acute (n=47), lymphoma (n=32), or chronic type (n=2) ATL. They were initially treated by either palliative therapy (n=25) or systemic chemotherapy [n=56; cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) therapy (n=25)/vincristine, cyclophosphamide, doxorubicin, and prednisone (VCAP)-doxorubicin, ranimustine, and prednisone (AMP)-vindesine, etoposide, carboplatin, and prednisone (VECP) therapy (VCAP-AMP-VECP) or CHOP-VMMV therapy (n=31)], and showed median survival durations of 16 and 277 days, respectively. Subsequent to the initial treatment, HSCT (n=6) was performed for certain patients, thus revealing that two-thirds (n=4) relapsed, and one-third (n=2) survived for 131 days and 203 days, respectively. The relapsed ATL patients were treated with conventional salvage therapy (n=29) or anti-CC chemokine receptor 4 antibody (mogamulizumab) (n=3). The patients treated with mogamulizumab demonstrated complete response (2) and partical response (1) with short duration periods of 82 days, 83 days, and 192 days, respectively. Among the five long-term survivors (>5 years) who received chemotherapy, most showed a low and intermediate risk according to the ATL prognostic index. CONCLUSION In our study, the overall survival of ATL remains poor due to the advanced age of the patients at diagnosis, a high proportion of patients receiving palliative therapy, and a small proportion of long-term survivors receiving chemotherapy and undergoing HSCT. This study illustrates the current clinical features, treatment strategies, and outcomes in clinical practice.

Successful treatment of non-Hodgkin’s lymphoma with rituximab and dose-adjusted CHOP therapy in a patient with concomitant end-stage renal disease requiring haemodialysis

Although malignancy is a fatal complication of end-stage renal disease (ESRD) requiring haemodialysis, successful treatment of haematological malignancies has been rarely reported. We describe the case of a 64-year-old man who presented with non-Hodgkin’s lymphoma (NHL; clinical stage, IVB) concomitant with ESRD. Before chemotherapy, haemodialysis was initiated, and one course of dose-adjusted CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) therapy followed by eight courses of rituximab therapy were administered according to the performance status and degree of organ dysfunction. Consequently, the patient was disease free for 27 months. Thus, rituximab plus CHOP combination therapy was effective for NHL concomitant with ESRD.

The Impact of a Humanized CCR4 Antibody (Mogamulizumab) on Patients with Aggressive-Type Adult T-Cell Leukemia-Lymphoma Treated with Allogeneic Hematopoietic Stem Cell Transplantation

Although a humanized CCR4 antibody (mogamulizumab) was reported to be effective for refractory adult T-cell leukemia-lymphoma (ATL), several reports regarding the use of mogamulizumab before allo-hematopoietic stem cell transplantation (HSCT) strongly indicated a high incidence of severe acute graft-versus-host-disease (GVHD) and treatment-related mortality (TRM). We retrospectively analyzed nine aggressive-type ATL patients who underwent allo-HSCT at a single institution in Miyazaki from 2006.1.1 to 2015.7.31. Among nine ATL patients, three had used mogamulizumab before treatment with allo-HSCT because of the poor control of refractory ATL. All three patients were treated with four to eight cycles of mogamulizumab. The interval from last administration of mogamulizumab to allo-HSCT was two to five months. All three patients with prior mogamulizumab treatment developed mild-moderate acute GVHD (grade 2) 28, 34, or 40 days after allo-HSCT. Acute GVHD was controlled by prednisolone treatment. Two patients in complete remission before allo-HSCT exhibited relatively prolonged survival (survival rate, 66%). Moreover, one patient developed human T-cell leukemia virus type 1-associated myelopathy-mimicking myelitis at five months after allo-HSCT. In contrast, two of six ATL patients without a history of mogamulizumab use survived (survival rate 33%). Thus, in cases of mogamulizumab use before treatment with allo-HSCT for refractory ATL, an appropriately long interval from the last administration of mogamulizumab to allo-HSCT may be one of factors to reduce TRM by acute GVHD, and to subsequently enhance graft-versus-tumor effects in ATL cases. Furthermore, caution is needed when administering mogamulizumab before allo-HSCT for severe GVHD and TRM.

The impact of hepatitis B core antibody levels on HBV reactivation after allogeneic hematopoietic SCT: an 11-year experience at a single center

The impact of hepatitis B core antibody levels on HBV reactivation after allogeneic hematopoietic SCT: an 11-year experience at a single center