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Lenalidomide is known to be effective in myelodysplastic syndromes (MDS) with del(5q) in improving anemia and suppressing del(5q) cells. MDS with del(5q) shows increase of nonlobulated megakaryocytes. However, histopathology of MDS with del(5q) treated with lenalidomide has not been fully studied. We investigated the morphologic changes in lenalidomide treated low- or intermediate-1-risk MDS with del(5q). All of evaluable patients showed high proportion of nonlobulated megakaryocytes. The nonlobulated megakaryocytes were markedly decreased in 6 patients during therapy in parallel with suppression of del(5q) cells. Our analysis suggests that single allele deletion of common deleted region inhibits nuclear lobulation of megakaryocytes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

We conducted a multicenter, open-label study to investigate the safety, efficacy, and pharmacokinetics of lenalidomide in Japanese patients with relapsed or refractory multiple myeloma The study was composed of the "monotherapy phase", a dose-escalation phase, to determine the tolerability to single agent lenalidomide and the "combination phase" to determine the safety and obtain preliminary data on the efficacy of lenalidomide plus dexamethasone. The primary end points were the tolerability to 25 mg lenalidomide and safety. Nine and six patients were enrolled in the monotherapy phase and the combination phase, respectively. Since 25 mg of monotherapy treatment did not satisfy the DLT criteria, this dose was employed in the combination phase. The major adverse event was myelosuppression. At the planned interim analysis (median study duration, 26.3 weeks), grade 3 or grade 4 neutropenia was observed with high frequency (66.7%). However, all adverse events observed were clinically manageable. In the combination cohort, the overall response rate (> or =PR) was 100%. The pharmacokinetics of lenalidomide showed rapid absorption and elimination after both single and multiple doses. In conclusion, 25 mg of lenalidomide was given safely as a single agent or in combination with dexamethasone in Japanese patients. The good efficacy of the combination therapy was also demonstrated in this study.

Lenalidomide is an immunomodulatory agent recently reported to be effective in the treatment of transfusion-dependent anemia due to low- or intermediate-1 risk myelodysplastic syndromes (MDS) associated with a deletion 5q (del 5q) cytogenetic abnormality. We conducted a multicenter, single-arm clinical trial to evaluate the safety and efficacy of lenalidomide in Japanese patients with anemia in low- or intermediate-1 risk MDS associated with the del 5q cytogenetic abnormality. Eleven patients (5 with transfusion-dependent anemia; 6 with transfusion-independent symptomatic anemia) received once daily oral administrations of 10 mg of lenalidomide for 21 consecutive days in a 28-day treatment cycle. The efficacy was assessed by the IWG criteria. At an interim analysis after > or =24 weeks of therapy, hemoglobin increase was noted in all 11 patients, with a median increase of 6.0 g/dL (range, 0.9-10.9) from the baseline. All transfusion-dependent patients achieved transfusion independence. Histopathologic and cytogenetic improvement was also noted. Neutropenia and thrombocytopenia were the most common adverse events related to lenalidomide. The adverse events were manageable, and no patients experienced serious adverse events or adverse events requiring treatment discontinuation. The results indicate that lenalidomide can be a useful agent for treating Japanese patients with anemia associated with low- or intermediate-1 risk MDS with the del 5q cytogenetic abnormality.

Molecular target therapy is the most progressive and promising anticancer therapy in last decade. Multiple myeloma is also one of the major therapeutic targets for using molecular based technology. The recent availability of clinical data regarding thalidomide-, lenalidomide-, and bortezomib-based regimens has provided new, effective treatment options for patients with both newly diagnosed and relapsed/refractory multiple myeloma. We are expecting that future clinical trials can be designed to achieve a high likelihood of success based on molecular studies, cell-signaling, and correlative science studies. Studies with these agents also provide new insight into the cancer biology underlying multiple myeloma in humans.

Although immunosuppressive therapy using antithymocyte globulin or cyclosporine A (CSA) is effective in selected patients with low-risk myelodysplastic syndrome, the response rates reported so far are inconsistent, and the indication of immunosuppressive therapy for myelodysplastic syndrome has not been clearly defined. We treated 20 myelodysplastic syndrome patients (17 refractory anemia cases [RA], 2 RA with excess blasts, and one RA with ringed sideroblasts) with 4 mg/kg per day of CSA for 24 weeks. Among the 19 patients evaluated, 10 showed hematologic improvement; 8 patients showed an erythroid response, 6 showed a platelet response, and one showed a neutrophil response. Most patients with hematologic improvement continued CSA thereafter, and the progressive response was observed until the latest follow-up (median, 30 months). Most toxicities associated with CSA usage were manageable, and no patient had developed acute leukemia up to this point. Short duration of illness, refractory anemia with minimal dysplasia determined by bone marrow morphology, and the presence of paroxysmal nocturnal hemoglobinuria-type cells were significantly associated with the platelet response. A minority of RA patients who did not possess such predictive variables achieved an isolated erythroid response. In conclusion, CSA may be a therapeutic option for patients with RA who do not have adverse prognostic factors.

We retrospectively evaluated the efficacy of mycophenolate mofetil (MMF) in the treatment of steroid-resistant acute and chronic graft-versus-host disease (GVHD) after hematopoietic stem cell transplantation. Thirteen patients, ten men and three women, consisted of 5 cases of acute myelogenous leukemia, 2 of acute lymphoblastic leukemia, 2 of chronic myelogenous leukemia, 2 of lymphoblastic lymphoma, and 1 case each of adult T-cell leukemia and peripheral T-cell lymphoma. The transfusions consisted of 5 peripheral blood, 7 bone marrow and 1 cord blood from 3 mothers, 4 siblings and 6 unrelated donors with conditioning treatments, including 8 total-body irradiation-based regimens, and 2 busulfan plus cyclophosphamide and 2 reduced-intensity regimens. GVHD prophylaxis included FK506 plus methotrexate (MTX) and/or antithymocyte globulin for 9 patients, and cyclosporine and MTX for 4 patients. All patients were treated with second-line MMF for steroid-refractory acute and/or chronic GVHD, and 11 patients improved. The adverse events were tolerable except for one patient in whom grade 3 neutropenia forced discontinuation of treatment. No case of non-relapse mortality occurred. We consider that MMF is beneficial and well tolerated for treatment of steroid-refractory GVHD.

Objective: Myelodysplastic syndromes (MDS) and aplastic anemia (AA) are the most common anemias that require transfusion therapy in Japan. This retrospective survey investigated relationships between iron overload, chelation practices, and morbidity/mortality in patients with these diseases., Method: Medical histories of transfusion-dependent patients were assessed at transfusion onset, chelation onset, and study end., Results: Data were collected from 292 patients with MDS, AA, pure red cell aplasia, myelofibrosis, and other conditions. Patients received a mean of 61.5 red blood cell units during the previous year. Fewer than half (43%) of patients had previously received deferoxamine (DFO) therapy. Only 8.6% received daily/continuous DFO. In all, 75 deaths were reported, with cardiac and liver failure noted in 24.0 and 6.7% of cases. Of these, 97% had ferritin levels >1000 ng/mL. Abnormal cardiac and liver function was observed in 21.9% (14/64) and 84.6% (11/13) of all patients assessed. Effective chelation with DFO resulted in improved serum ferritin, liver enzymes, and fasting blood sugar., Conclusions: Mortality is higher in heavily iron-overloaded patients, with liver and cardiac dysfunction being the primary cause. Daily/continuous chelation therapy was effective at reducing iron burden and improving organ function. Chelation therapy should be initiated once serum ferritin levels exceed 1000 ng/mL.

A 30-year-old man with acute myeloid leukemia who was pancytopenic after undergoing intensive chemotherapy developed pyrexia and severe pain of both lower legs. We immediately started empiric therapy with cefepime, vancomycin, and fluconazole for febrile neutropenia. However, symptoms progressed. After 4 days, Trichosporon was isolated from venous blood cultures. MRI showed hyperintense lesions within both gastrocnemius muscles and demonstrated reactive vasodilatation and interstitial tissue edema, thought to be induced by hyperpermeability of vessel membranes due to the local fungal infection. Amphotericin B was very effective against this organism. Trichosporosis is a rare infectious disease generally occurring in immunocompromized hosts. To the best of our knowledge, this is first reported case of bilateral Trichosporon infection of lower leg muscles. Severe leg pain was one of the most important signs of fungal infection in this patient with hematologic malignancy.

Frequency and clinical significance of cerebrospinal fluid (CSF) pleocytosis in hemopoietic stem cell (HSC) transplantation were surveyed. Cyclosporine (CSA)- or tacrolimus (FK506)-based regimens were used as graft-vs-host disease (GVHD) prophylaxis in allogeneic HSC transplantation. CSF pleocytosis with or without neurologic symptoms was detected in 12 of 25 patients receiving allogeneic HSC transplants but in none of 11 patients receiving autologous HSC transplants. Of the 12 patients with CSF pleocytosis, only one patient developed leukoencephalopathy later. There was a correlation between CSF cell numbers and trough levels of CSA but not with those of FK506. In patients receiving allogeneic HSC transplants, CSF pleocytosis may be relatively common and may reflect neurologic damage associated with calcineurin inhibitors.

Bortezomib is a novel proteasome inhibitor with significant antimyeloma activity. Its frequent adverse effects are manageable, including gastrointestinal symptoms, peripheral neuropathy, and thrombocytopenia. Severe lung toxicity has not previously been reported. Between June 2004 and September 2005, 13 Japanese patients with multiple myeloma were treated with bortezomib in Toranomon Hospital, Juntendo University School of Medicine, and Jichi Medical School. Four of them developed severe pulmonary complications, and 2 died of respiratory failure without progression of underlying disease. To our knowledge, this is the first report on life-threatening pulmonary adverse effects after bortezomib therapy. Previous clinical studies on bortezomib, mostly in the United States and Europe, have shown low incidences of pulmonary adverse effects. Our study suggests that bortezomib can cause serious lung injury, and that its incidence might vary among different ethnicities. Clinicians need to be alert to the possibility.

Background: Infertility after hemopoietic stem cell transplantation (HST) is a serious problem for young patients. Autologous gamete collection before HST may be a promising strategy to overcome infertility., Material/methods: From October 1988 to December 2003, six male and nine female patients with hematological malignancies had autologous gametes collected before HST. The data on autologous gamete collection were analyzed., Results: Sperm could be collected from three patients. However, in two of the three, the numbers and motility of the sperm were severely depleted because they received chemotherapy for one and 11 cycles, respectively. Normal sperm was only collected from one patient with myelodysplastic syndrome who had no history of receiving chemotherapy. One or more oocytes could be collected in five of nine female patients, although the five received multiple cycles of chemotherapy. The successful oocyte collection was associated with an ovulation stimulant., Conclusions: Autologous oocye collection before HST may be possible, even if patients receive multiple cycles of chemotherapy. In contrast, autologous sperm collection before HST may be difficult after patients receive chemotherapy. Successful pregnancy using autologous gametes after HST remains extremely difficult, especially in female patients; however, it is important to give information on infertility and autologous gamete collection to patients scheduled for HST.

Due to high frequency of side effects caused by high-dose total body irradiation (TBI) the nonmyeloablative regimen together with cytotoxic agents is currently used especially for elderly patients. However, immediate and long-term effects of low-dose irradiation used in allogeneic transplantation on stem cells is less well known. We have studied the effect of low-dose 3 Gy TBI on the number of hematopoietic stem cell (HSC) clones contributing simultaneously to granulocyte production in rhesus macaque. The number of clones after 3 Gy TBI decreased markedly by 2 to 3 weeks after 3 Gy TBI, followed by a period of clonal instability, and recovery to almost pre-3 Gy TBI clonal diversity. The clones accounting for this recovery contributed before 3 Gy TBI, suggesting the profound initial impact of TBI was on a pool of progenitor cells, whereas most of the more primitive HSCs remained unaffected and were able to again contribute to hematopoiesis after recovery. Clonal fluctuation may indirectly suggest the presence of short-term/long-term HSC populations in rhesus macaque bone marrow as reported in a mouse model. The results indicate that even low-dose irradiation affects hematopoietic clonal dynamics and have implications for design of conditioning regimens for transplantation purposes.

Background: Although directed differentiation of human embryonic stem (ES) cells would enable a ready supply of cells and tissues required for transplantation therapy, the methodology is limited. We have developed a novel method for hematopoietic development from primate ES cells. We first cultured cynomolgus monkey ES cells in vitro and transplanted the cells in vivo into fetal sheep liver, generating sheep with cynomolgus hematopoiesis., Methods: Cynomolgus ES cells were induced to mesodermal cells on murine stromal OP9 cells with multiple cytokines for 6 days. The cells (average 4.8 x 10 cells) were transplanted into fetal sheep in the liver (n=4) after the first trimester (day 55-73, full term 147 days). The animals were delivered at full term, and two of them were intraperitoneally administered with human stem-cell factor (SCF)., Results: Cynomolgus hematopoietic progenitor cells were detected in bone marrow at a level of 1% to 2% in all four sheep up to 17 months posttransplant. No teratoma was found in the lambs. After SCF administration, the fractions of cynomolgus hematopoiesis increased by several-fold (up to 13%). Cynomolgus cells were also detected in the circulation, albeit at low levels (<0.1%)., Conclusions: Long-term hematopoietic microchimerism from primate ES cells was observed after in vitro differentiation to mesodermal cells, followed by in vivo introduction into the fetal liver microenvironment. The mechanism of such directed differentiation of ES cells remains to be elucidated, but this procedure should allow further investigation.

A 40-year-old female with chronic myelogeneous leukemia (CML) in the chronic phase was treated with imatinib mesylate (STI571) because of interferon resistance. She achieved complete cytogenetic response but not complete molecular response 3 months after STI571 administration. Six months later, she developed severe liver damage without evidence of actively infectious hepatitis A, B, C, G, E, TT virus, Epstein-Barr virus or cytomegalovirus. A significant serum level of STI571 (107 ng/ml) was detected, although she had not taken the drug for 6 days. Liver biopsy demonstrated massive hepatic necrosis, consistent with drug-induced hepatitis. She achieved complete molecular response, although she did not take STI571 for 47 days after the development of hepatitis. These results suggest that both hepatitis and molecular response were associated with the serum STI571 concentration.

The successful engraftment of genetically modified hematopoietic stem cells (HSCs) without toxic conditioning is a desired goal for HSC gene therapy. To this end, we have examined the combination of intrabone marrow transplantation (iBMT) and in vivo expansion by a selective amplifier gene (SAG) in a nonhuman primate model. The SAG is a chimeric gene consisting of the erythropoietin (EPO) receptor gene (as a molecular switch) and c-Mpl gene (as a signal generator). Cynomolgus CD34+ cells were retrovirally transduced with or without SAG and returned into the femur and humerus following irrigation with saline without prior conditioning. After iBMT without SAG, 2-30% of colony-forming cells were gene marked over 1 year. The marking levels in the peripheral blood, however, remained low (<0.1%). These results indicate that transplanted cells can engraft without conditioning after iBMT, but in vivo expansion is limited. On the other hand, after iBMT with SAG, the peripheral marking levels increased more than 20-fold (up to 8-9%) in response to EPO even at 1 year posttransplant. The increase was EPO-dependent, multilineage, polyclonal, and repeatable. Our results suggest that the combination of iBMT and SAG allows efficient in vivo gene transduction without marrow conditioning.

A 46-year-old man with myeloproliferative disorder received a stem cell transplant from an HLA-identical unrelated donor. Eight months status post transplantation, during the course of tacrolimus therapy, the patient developed severe epigastric pain and fever. FGS findings showed eruptions with blisters in the esophagus and ulcers in the stomach. Biopsy specimens revealed acidophilic inclusion bodies in the nuclei. Varicella zoster virus (VZV) DNA copies were detected in the serum. No skin lesions were observed prior to hospital admission. The diagnosis of visceral VZV infection was made and the gastric and esophageal lesions were successfully healed with acyclovir (ACV). Severe abdominal pain is one of the most important signs of VZV infection for recipients of stem cell transplantation.

A proteasome inhibitor with a new molecular target (PS-341: bortezomib) was recently developed, and its efficacy in the treatment of refractory multiple myeloma has been reported in the United States. Here, we present a 54-year-old Japanese male patient with refractory multiple myeloma resistant to thalidomide. In 1998, the patient was diagnosed as having multiple myeloma (IgG-kappa) and underwent chemotherapy, autologous hematopoietic cell transplantation and interferon therapy, but the disease recurred. In December 2002, thalidomide and high-dose dexamethasone therapy was initiated, and while this combination therapy was effective at first, the multiple myeloma became unresponsive. On 23 June 2003, bortezomib therapy with the following regime was therefore started: 2.2 mg (1.3 mg/m2) of bortezomib was injected intravenously on days 1, 4, 8 and 11, and after a one-week break, another cycle was performed. Starting on day 8 of the administration, the serum total protein, IgG, serum calcium and LDH levels decreased rapidly, and after day 45 of the administration, blood transfusion was no longer needed. Since this is the first report of the use of bortezomib in the treatment of refractory multiple myeloma in Japan, further monitoring of this patient will provide extremely valuable information for developing a therapy against this disease.

Background: Although adenoviral vectors primarily derived from the adenovirus serotype 5 (Ad5) are widely used for many gene transfer applications, they cannot efficiently infect hematopoietic cells, since these cells do not express the coxsackie-adenoviral receptor (CAR)., Methods: We have developed a soluble fusion protein that bridges adenoviral fibers and the c-Kit receptor to alter Ad5 tropism to immature hematopoietic cells. The CAR-SCF fusion protein consists of the extracellular domains of CAR and stem cell factor (SCF). The human megakaryoblastic leukemia cell lines UT-7 and M07e, human chronic myelogenous leukemia cell line K-562, and erythroleukemia cell line TF-1 were used to assess CAR-SCF-assisted Ad5-mediated gene transfer. Hematopoietic cell lines were infected with an Ad5 vector (Ad5-eGFP) or a fiber-mutant Ad5/F35 (Ad5/F35-eGFP) expressing the enhanced green fluorescent protein gene in the presence or absence of CAR-SCF., Results: Twenty-four hours after infection, more than 80% of M07e cells infected in the presence of CAR-SCF were eGFP-positive, compared with very few eGFP-positive cells following Ad5-eGFP infection in the absence of CAR-SCF. The enhancement of Ad5-eGFP infection by CAR-SCF was greater than that caused by Ad5/F35-eGFP (50%). The ability of CAR-SCF to enhance Ad5-eGFP infectivity was highly dependent on cellular c-Kit expression levels. Furthermore, CAR-SCF also enhanced Ad5-mediated gene transfer into human primary CD34(+) cells., Conclusions: The CAR-SCF fusion protein assists Ad5-mediated transduction to c-Kit(+) CAR(-) hematopoietic cells. The use of this fusion protein would enhance a utility of Ad5-mediated hematopoietic cell transduction strategies., (Copyright 2003 John Wiley & Sons, Ltd.)

The ability to efficiently transfer a gene into repopulating hematopoietic stem cells would create many therapeutic opportunities. We have evaluated the ability of particles bearing an alternative envelope protein, that of the feline endogenous virus (RD114), to transduce stem cells in a nonhuman primate autologous transplantation model using rhesus macaques. We have previously shown this pseudotyped vector to be superior to the amphotropic vector at transducing cells in umbilical cord blood capable of establishing hematopoiesis in immunodeficient mice. Gene transfer efficiency as reflected by the number of genetically modified cells in hematopoietic tissues varied among the five monkeys studied from low levels (<1%) in three animals to much higher levels in two (20-60%). An animal that exhibited extremely high levels for several weeks was found by vector genome insertion site analysis to have reconstitution predominantly with a single clone of cells. This variability among animals is in keeping with computer simulations of reconstitution with limiting numbers of stem cells genetically modified at about 10% efficiency. Our studies provide insights into the biology of hematopoietic reconstitution and suggest approaches for increasing stem cell targeted gene transfer efficiency.

The hairy cell leukemia prolymphocytic variant, a subtype of hairy cell leukemia, is an extremely rare disease, especially in Japan. We report a case in which treatment with 2'-deoxycoformycin (DCF) improved the clinical features of the disease. The patient, a 70-year-old female, was first treated with 2-chlorodeoxyadenosine, but showed only transient improvement in the hematological findings. DCF was then administered every week. Following the start of this treatment, the leukemia cell count rapidly decreased and the platelet count simultaneously increased. This effect of DCF has so far been long term. More clinical studies are needed to confirm the therapeutic value of DCF.

Recent reports suggest that cells in active cell cycle have an engraftment defect compared with quiescent cells. We used nonhuman primates to investigate this finding, which has direct implications for clinical transplantation and gene therapy applications. Transfer of rhesus CD34(+) cells to culture in stem cell factor (SCF) on the CH-296 fibronectin fragment (FN) after 4 days of culture in stimulatory cytokines maintained cell viability but decreased cycling. Using retroviral marking with two different gene transfer vectors, we compared the engraftment potential of cytokine-stimulated cells versus those transferred to nonstimulatory conditions (SCF on FN alone) before reinfusion. In vivo competitive repopulation studies showed that the level of marking originating from the cells continued in culture for 2 days with SCF on FN following a 4-day stimulatory transduction was significantly higher than the level of marking coming from cells transduced for 4 days and reinfused without the 2-day culture under nonstimulatory conditions. We observed stable in vivo overall gene marking levels of up to 29%. This approach may allow more efficient engraftment of transduced or ex vivo expanded cells by avoiding active cell cycling at the time of reinfusion.

A 67-year-old woman was treated for acute myelogenous leukemia with trilineage dysplasia (AML-TLD) by combination chemotherapy with cytarabine, aclarubicin plus macrophage colony-stimulating factor (M-CSF) (referred to as CAM therapy). Complete remission was achieved after two courses of CAM therapy. After coculture of her bone marrow mononuclear cells with M-CSF in vitro, differentiation of leukemic cells into macrophages with apoptotis was observed. This case confirms an earlier report that an effect of M-CSF inducible by differentiation with apoptotic phenomena, against human leukemic cells was shown both in vitro and in vivo when achieving complete remission.

The impairment of engraftment ability after ex vivo or in vivo stimulation of hematopoietic stem cells, potentially related to induction of active cell cycling, has recently been a topic of intense interest. Our group has used the non-human primate autologous transplantation model and genetic marking to investigate a number of questions in hematopoiesis with direct relevance to human clinical applications. The issue of a potential reversible engraftment defect would have many implications for gene therapy and allogeneic or autologous transplantation. Initial in vitro studies with rhesus CD34+ cells indicated that after 4 days of stimulatory culture in stem cell factor (SCF), megakaryocyte growth and development factor (MDGF), and flt3 ligand (FLT), transfer of the cells to SCF alone on retronectin (FN) support resulted in decreased active cycling and a halt to proliferation, without a loss of viability or induction of apoptosis. We then directly compared the engraftment potential of cytokine-stimulated cells versus those transferred to SCF on FN alone before reinfusion, SCF/G-CSF mobilized CD34+ cells from three animals were split into two parts and transduced with either of two retroviral marking vectors for 4 days in the presence of SCF/FLT/MGDF on FN. One aliquot was cryopreserved, and the other was continued in culture without transduction for 2 days in the presence of SCF alone on FN. After total body irradiation, both aliquots were thawed and reinfused into each animal. In all animals, the level of marking from the fraction continued in culture for 2 days with SCF on FN was significantly higher than the level of marking from the aliquot transduced for 4 days without the 2-day period in SCF alone. This approach may allow more efficient engraftment of successfully transduced or ex vivo expanded cells by avoiding active cell cycling at the time of reinfusion.

We report a case in which treatment with all-trans-retinoic acid (ATRA) improved the clinical features of a 47-year-old female patient with acute adult T-cell leukemia (ATL). The patient was first treated several times with combination chemotherapy. but the number of ATL cells increased and other clinical manifestations progressed. ATRA 60 mg was then administered daily. ATRA treatment dramatically improved the patient's clinical features. In vitro examination revealed that ATRA inhibited the growth of ATL cells from the patient. These findings suggest that ATRA may be a useful treatment for patients with chemotherapy-resistant acute ATL.

A patient with a Philadelphia chromosome (Ph)-positive acute mixed-lineage leukemia (AMLL) expressing both major and minor BCR/ABL mRNA transcripts is described. Phenotypic analysis of the leukemic blasts revealed positivity for both myeloid and B-cell lineages. Southern blot analysis showed a rearrangement of the immunoglobulin heavy chain (IgH) gene. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed the expression of both major and minor BCR/ABL mRNA transcripts. To our knowledge, this is the first report of AMLL expressing both major and minor BCR/ABL mRNA transcripts and rearrangement of the IgH gene., (Copyright 2000 Wiley-Liss, Inc.)

Retroviral insertion site analysis was used to track the contribution of retrovirally transduced primitive progenitors to hematopoiesis after autologous transplantation in the rhesus macaque model. CD34-enriched mobilized peripheral blood cells were transduced with retroviral marking vectors containing the neo gene and were reinfused after total body irradiation. High-level gene transfer efficiency allowed insertion site analysis of individual myeloid and erythroid colony-forming units (CFU) and of highly purified B- and T-lymphoid populations in 2 animals. At multiple time points up to 1 year after transplantation, retroviral insertion sites were identified by performing inverse polymerase chain reaction and sequencing vector-containing CFU or more than 99% pure T- and B-cell populations. Forty-eight unique insertion sequences were detected in the first animal and also in the second animal, and multiple clones contributed to hematopoiesis at 2 or more time points. Multipotential clones contributing to myeloid and lymphoid lineages were identified. These results support the concept that hematopoiesis in large animals is polyclonal and that individual multipotential stem or progenitor cells can contribute to hematopoiesis for prolonged periods. Gene transfer to long-lived, multipotent clones is shown and is encouraging for human gene therapy applications.

Bilateral heel skin ulcers developed in a 50-year-old male in the chronic phase of chronic myelogenous leukemia who had been receiving hydroxyurea (HU) therapy for 3 years. Histological examination showed perivascular lymphocytic inflammation without vasculitis. After interruption of HU administration, the heel ulcers were completely resolved within 2 months. The clinical course strongly suggested that the heel ulcers were induced by long-term HU therapy.

A 20-year-old woman visited a nearby hospital because of sudden, severe, and unusual genital bleeding. She also exhibited severe anemia and thrombocytopenia. In transit to our hospital, the patient suddenly suffered cardiac arrest and died soon thereafter despite immediate blood transfusion and therapeutic intubation. Thrombotic thrombocytopenic purpura (TTP) was initially diagnosed at autopsy due to the observation of numerous fragmented erythrocytes in peripheral blood, evidence of hemolysis, and thrombotic microangiopathy in multiple organs. In addition, histopathologic and serologic findings disclosed an association with systemic lupus erythematosus (SLE). Test for anticardiolipin antibody was positive, and hemophagocytic findings were detected in lymph node specimens. Reports of TTP in association with SLE have been increasing in recent years. However, the mechanisms correlating these two illnesses have not been identified. We speculated that the rapid clinical course in this case was attributable to TTP that had been provoked by endothelial microangiopathy due to SLE, and moreover, the fact that the patient's general condition had been seriously complicated by excessive menstrual bleeding.

We recently determined that erythropoietin (EPO) activates 3 members of the signal transducer and activator of transcription (STAT) family, Stat1alpha, Stat3, and Stat5, in the human EPO-dependent cell lines, UT-7 and UT-7/EPO (Kirito et al, J Biol Chem 272:16507, 1997). In addition, we have shown that Stat1alpha, but not Stat3, is involved in EPO-induced cellular proliferation. In this study, we examined the roles of Stat1alpha and Stat3 in EPO-induced erythroid differentiation. UT-7/GM was used as a model system, because this cell line can differentiate into erythroid-lineage cells with EPO treatment (Komatsu et al, Blood 89:4021, 1997). We found that EPO did not activate Stat1alpha or Stat3 in UT-7/GM cells. Transfection experiments showed that both Stat1alpha and Stat3 inhibited the induction by EPO of gamma-globin and erythroid-specific 5-aminolevulinate synthetase transcripts, resulting in a reduction of the percentage of hemoglobin-positive cells. Dominant negative forms of Stat1alpha or Stat3 promoted the EPO-induced erythroid differentiation of UT-7/GM cells, even in the presence of granulocyte-macrophage colony-stimulating factor, although this cytokine never induced erythroid differentiation of the parent UT-7/GM cells with or without EPO. A cell cycle analysis showed that the constitutive activation of Stat1alpha, but not Stat3, shortened the period of G0/G1 prolongation caused by EPO stimulation. Taken together, our data suggest that Stat1alpha and Stat3 act as negative regulators in EPO-induced erythroid differentiation. Specifically, Stat1alpha may activate a cell cycle-associated gene(s), leading to the entry of cells into the cell cycle.

A 53-year-old male was diagnosed as having acute myelogenous leukemia (M2, FAB). He complained of double vision and right blepharoptosis after receiving remission induction chemotherapy. Magnetic resonance imaging (MRI) showed enlargement of the bilateral oculomotor nerves. Intrathecal injections of methotrexate and cytosine arabinoside were partially effective and repeated MRI showed shrinkage of the enlarged oculomotor nerves, after therapy. This case shows the importance of MRI in the early diagnosis of CNS leukemia.

A retrospective analysis was performed on 76 consecutive elderly patients with acute leukemia aged 60 years or more (48 men, 28 women). Forty patients were 60-69 years old, 28 were 70-79 years old and 8 were > or = 80 years old. There were 55 patients with acute myelogenous leukemia (AML), 13 acute lymphoblastic leukemia (ALL) and 8 AML from myelodysplastic syndrome (MDS/AML). Patients were treated with the JALSG protocol, CAG regimen, or low-dose Ara-C regimen for AML, and DVP/M-CHOP protocol for ALL. The complete remission (CR) rates were 52.7% (29 of 55) in AML, 61.5% (8 of 13) in ALL, and 0% in MDS/AML. The median CR durations were 226, 85, 0 days, and the median survivals were 204, 177, 99 days, respectively. CR rates were 65.3% for the JALSG protocol, 62.5% for the CAG regimen and 25.0% for low-dose Ara-C regimen. According to age, CR was obtained 62.5% in patients aged 60-69 years and 33.3% in patients over 70 years old. Our results indicated that patients aged 60-69 years should be treated with intensive chemotherapy.

The p210bcr/abl chimeric protein is implicated in the pathogenesis of Philadelphia chromosome-positive human leukemias. Previously, we generated transgenic mice expressing p210bcr/abl by the metallothionein enhancer/promoter (MT/p210bcr/abl) and observed that these mice reproducibly developed T cell leukemia. In this report, we describe the establishment, characterization, and chromosomal analysis of two novel leukemic cell lines derived from MT/p210bcr/abl leukemic mice. Both cell lines carried the transgene and showed the same gene rearrangement patterns as observed in the parental leukemic cells. Expression, tyrosine-phosphorylation, and enhanced kinase activity of the p210bcr/abl were also detected. RT-PCR/SSCP for p53 transcript revealed that one of the cell lines carried a mutation, in contrast to the normal pattern shown by the parental leukemic cells. In addition, the other cell line showed a karyotype of trisomy 15. These results suggest that the p53 mutation and chromosomal abnormality may confer a proliferative ability on leukemic cells in vitro. These new cell lines are considered to be a valuable model not only for examining the biologic properties of p210bcr/abl but also for investigating the malignant process that promotes the proliferation of the leukemic cells expressing p210bcr/abl. Furthermore, these cell lines could be used in therapeutic studies, including adoptive immunotherapy.

UT-7 is a human megakaryoblastic leukemia cell line with absolute dependence on interleukin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), or erythropoietin (EPO) for growth and survival. We isolated a novel subline, UT-7/GM after long-term culture of UT-7 with GM-CSF. The hemoglobin concentration and gamma-globin and EPO-receptor mRNA levels were significantly higher in EPO-treated UT-7/GM cells than in untreated cells. In contrast, the platelet factor 4 and glycoprotein IIb mRNA levels were much higher in thrombopoietin (TPO)-treated UT-7/GM cells than in untreated cells. Some TPO-treated cells had morphologically mature megakaryocytic characteristics such as a developed demarcation membrane in the cytoplasm and multilobular nuclei. These findings indicate that UT-7/GM is a bipotential cell line that can be induced to differentiate into erythroid and megakaryocytic lineages by EPO and TPO, respectively. Moreover, a minority of UT-7/GM cells acquired a high hemoglobin concentration by treatment with TPO, suggesting that TPO in part induced the erythroid differentiation of the UT-7/GM cells. Interestingly, GM-CSF inhibited the EPO- or TPO-induced erythroid differentiation and the TPO-induced megakaryocytic differentiation of UT-7/GM cells. These results support the hypothesis that cytokines influence the programming of gene expression required for lineage commitment or differentiation.