Correlation between dysplastic lineage and type of cytopenia in myelodysplastic syndromes patients with refractory anemia according to the FAB classification

OBJECTIVES

To analyze the correlation between dysplastic lineage and type of cytopenia in myelodysplastic syndromes.

METHODS

We analyzed the correlation between dysplasia and cell count using the data set of our previous morphologic study.

RESULTS

There were no correlations between dysgranulopoiesis of 10% or more and absolute neutrophil count (ANC). Similarly, hyposegmented mature neutrophils (Pelger) of 10% or more were not related to ANC. Interestingly, the platelet count of patients with dysmegakaryopoiesis (dys Mgk) was higher than that of patients without dys Mgk (dys Mgk ≥10% vs <10%, P = .08; dys Mgk ≥40% vs <40%, P = .02; micromegakaryocytes ≥10% vs <10%, P = .004).

CONCLUSIONS

Since low cell counts did not correlate with the presence of dysplastic features, we suggest that dysplastic features do not directly relate to apoptosis.

[Aplastic anemia complicated with ulcerative colitis]

A 37-year-old female who presented with pancytopenia in April 2008 was diagnosed with aplastic anemia stage 2 with a normal karyotype. She had a PNH phenotype in her red blood cells (RBC) and granulocytes, and HLA DR15. Her aplastic anemia was deteriorated from stage 2 to stage 3, and she required periodic RBC transfusions. Four months after cyclosporine therapy, the pancytopenia improved and she did not need RBC transfusion. However, three months thereafter, she again required RBC transfusions after developing severe ulcerative colitis. Although mesalazine and steroid pulse therapy improved her ulcerative colitis, her transfusion dependency persisted. Eleven months after the diagnosis of aplastic anemia, equine anti-thymocyte globulin (ATG) and cyclosporine were administered, but no hematological improvement was obtained. Six months after the administration of ATG and cyclosporine, transformation to refractory cytopenia with multilineage dysplasia (RCMD) with 7-monosomy was observed. An allogeneic bone marrow transplant (BMT) from a HLA-identical sibling was performed 23 months after the diagnosis of aplastic anemia. Complete remission of both the aplastic anemia and ulcerative colitis was obtained without medication. Although the relationship between aplastic anemia and ulcerative colitis remains unclear, immunological abnormalities might be involved in the pathogenesis of both disorders because she had PNH phenotype in RBC and HLA DR15 and because allogeneic BMT improved both disorders.

Intensified consolidation therapy with dose-escalated doxorubicin did not improve the prognosis of adults with acute lymphoblastic leukemia: the JALSG-ALL97 study

We designed a treatment protocol for newly diagnosed adult acute lymphoblastic leukemia (ALL) in the pre-imatinib era, employing intensified consolidation therapy with a total of 330 mg/m² doxorubicin and adopting slightly modified induction and maintenance regimen of the CALGB 8811 study. Of 404 eligible patients (median age 38 years, range 15-64 years), 298 (74%) achieved complete remission (CR). The 5-year overall survival (OS) rate was 32%, and the 5-year disease-free survival (DFS) rate was 33%. Of 256 Philadelphia chromosome (Ph)-negative patients, 208 (81%) achieved CR and the 5-year OS rate was 39%, and 60 of them underwent allogeneic-hematopoietic stem cell transplantation (allo-HSCT) from related or unrelated donors during the first CR, resulting in 63% 5-year OS. Of 116 Ph-positive patients, 65 (56%) achieved CR and the 5-year OS rate was 15%, and 22 of them underwent allo-HSCT from related or unrelated donors during the first CR, resulting in 47% 5-year OS. In Ph-negative patients, multivariate analysis showed that older age, advanced performance status and unfavorable karyotypes were significant poor prognostic factors for OS and higher WBC counts for DFS. The present treatment regimen could not show a better outcome than that of our previous JALSG-ALL93 study for adult ALL.

A Phase I/II study of nilotinib in Japanese patients with imatinib-resistant or -intolerant Ph+ CML or relapsed/refractory Ph+ ALL

Nilotinib is a second-generation BCR-ABL kinase inhibitor with improved potency and selectivity compared to imatinib. A Phase I/II dose-escalation study was designed to evaluate the efficacy, safety, and pharmacokinetics of nilotinib in Japanese patients with imatinib-resistant or -intolerant Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) or relapsed/refractory Ph+ acute lymphoblastic leukemia (ALL). A total of 34 patients were evaluated in this analysis and had a median duration of drug exposure of 293 (range 13-615) days. All 6 CML-CP patients without complete hematologic response (CHR) at baseline rapidly achieved CHR. A major cytogenetic response was achieved in 94% of patients with CML-CP, including a complete cytogenetic response in 69%. A major molecular response was achieved by 56%. These responses were also observed in patients with CML in advanced stages and Ph+ ALL. Non-hematologic adverse events were mostly mild to moderate. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 50 and 28% of patients, respectively. Overall, the results of this study suggest that nilotinib induced significant responses in imatinib-resistant or -intolerant patients with CML-CP and CML in advanced stages and Ph+ ALL. The results of this study confirmed the efficacy and safety of nilotinib in Japanese patients.

Phase 1/2 clinical study of dasatinib in Japanese patients with chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia

A phase 1/2 study was conducted to assess the safety and efficacy of dasatinib in Japanese patients with chronic myelogenous leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) resistant or intolerant to imatinib. In phase 1, 18 patients with chronic phase (CP) CML were treated with dasatinib 50, 70, or 90 mg twice daily to evaluate safety. Dasatinib <or= 90 mg twice daily was well tolerated. In phase 2, dasatinib 70 mg was given twice daily to CP-CML patients for 24 weeks and to CML patients in accelerated phase (AP)/blast crisis (BC) or Ph(+) ALL for 12 weeks. In the CP-CML group (n = 30) complete hematologic response was 90% and major cytogenetic response (MCyR) 53%. In the AP/BC-CML group (n = 11) major hematologic response (MaHR) was 64% and MCyR 27%, whereas in the Ph(+) ALL group (n = 13) MaHR was 38% and MCyR 54%. Dasatinib was well tolerated and most of the nonhematologic toxicities were mild or moderate. Dasatinib therapy resulted in high rates of hematologic and cytogenetic response, suggesting that dasatinib is promising as a new treatment for Japanese CML and Ph(+) ALL patients resistant or intolerant to imatinib.

Prospective monitoring of BCR-ABL1 transcript levels in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia undergoing imatinib-combined chemotherapy

The clinical significance of minimal residual disease (MRD) is uncertain in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL) treated with imatinib-combined chemotherapy. Here we report the results of prospective MRD monitoring in 100 adult patients. Three hundred and sixty-seven follow-up bone marrow samples, collected at predefined time points during a uniform treatment protocol, were analysed for BCR-ABL1 transcripts by quantitative reverse transcription polymerase chain reaction. Ninety-seven patients (97%) achieved complete remission (CR), and the relapse-free survival (RFS) rate was 46% at 3 years. Negative MRD at the end of induction therapy was not associated with longer RFS or a lower relapse rate (P = 0.800 and P = 0.964 respectively). Twenty-nine patients showed MRD elevation during haematological CR. Of these, 10 of the 16 who had undergone allogeneic haematopoietic stem cell transplantation (HSCT) in first CR were alive without relapse at a median of 2.9 years after transplantation, whereas 12 of the 13 who had not undergone allogeneic HSCT experienced a relapse. These results demonstrate that, in Ph+ ALL patients treated with imatinib-combined chemotherapy, rapid molecular response is not associated with a favourable prognosis, and that a single observation of elevated MRD is predictive of subsequent relapse, but allogeneic HSCT can override its adverse effect.

Karyotype at diagnosis is the major prognostic factor predicting relapse-free survival for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with imatinib-combined chemotherapy

To identify factors associated with relapse-free survival (RFS), 80 patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia, enrolled in a phase II study of imatinib-combined chemotherapy, were analyzed. The median follow-up of surviving patients was 26.7 months (maximum, 52.5 months). Twenty-eight out of 77 patients who had achieved CR relapsed. The probability of RFS was 50.5% at 2 years. Multivariate analysis revealed that the presence of secondary chromosome aberrations in addition to t(9;22) at diagnosis constitute an independent predictive value for RFS (p=0.027), and increase the risk of treatment failure by 2.8-fold.

A novel gene, ANKRD28 on 3p25, is fused with NUP98 on 11p15 in a cryptic 3-way translocation of t(3;5;11)(p25;q35;p15) in an adult patient with myelodysplastic syndrome/acute myelogenous leukemia

We identified a novel gene fusion of ANKRD28 (ankyrin repeat domain 28) on 3p25 to NUP98 on 11p15 in a patient with adult myelodysplastic syndrome/acute myelogenous leukemia. A partially cryptic 3-way translocation, t(3;5;11)(p25;q35;p15), that had initially been supposed to be t(3;5)(p25;q35) was revealed by precise breakpoint mapping via fluorescence in situ hybridization analysis with bacterial artificial chromosome clones. This translocation produces the expression of 2 in-frame fusion transcripts, the novel ANKRD28-NUP98 and NUP98-NSD1, and 1 out-of-frame NSD1-ANKRD28 transcript. Transient overexpression of ANKRD28-NUP98 in NIH/3T3 cells, but not the C-terminal deletion mutant of ANKRD28 (DeltaC-ANKRD28), caused significantly increased focus formation compared with mock-transfectant controls. ANKRD28-NUP98 was localized in the nucleolus and cytoplasm, whereas ANKRD28 and DeltaC-ANKRD28 were found exclusively in the cytoplasm. Alteration of the subcellular localization of ANKRD28 might have contributed to the leukemogenesis in this case. This report is the first of ANKRD28 as an NUP98 fusion partner, and this case implies that this fusion may be responsible for hematologic malignancies.

[POEMS syndrome presenting with transient immunoglobulin isotype switching after successful treatment with autologous peripheral blood stem cell transplantation]

A 60-year-old man was admitted with muscle weakness and numbness in the extremities. Based on the existence of monoclonal gammopathy of the IgG-lamda type, a slight increase of plasma cells in the bone marrow, and an elevated level of serum vascular endothelial growth factor (VEGF), the diagnosis of POEMS syndrome was made. After peripheral blood stem cell collection by etoposide and G-CSF, the patient received high dose melphalan (200 mg/m2) therapy supported by autologous peripheral blood stem cell transplantation (autoPBSCT). After high-dose chemotherapy with autoPBSCT, the serum VEGF level normalized and the monoclonal IgG-lamda, disappeared. The patient gradually recovered from a bedridden state and at the time of writing has no impairment in his activities of daily life. After the autoPBSCT, monoclonal IgG-kappa, protein was detected transiently in serum. The new monoclonal immunoglobulin was considered to be due to normal immune reconstitution after myeloablation rather than alteration of the abnormal plasma cell clone, similarly as oligoclonal immunoglobulins occur in multiple myeloma after autoPBSCT. AutoPBSCT with high-dose chemotherapy should be considered among the treatments of choice for POEMS syndrome.

Clinical features and outcome of T-lineage acute lymphoblastic leukemia in adults: A low initial white blood cell count, as well as a high count predict decreased survival rates

Although biological and clinical features differ between B-lineage acute lymphoblastic leukemia (ALL) and T-lineage ALL (T-ALL), there have been few reports that focused on the prognosis for T-ALL in adults, primarily due to its rarity. Here, we studied the long-term outcomes and prognostic factors specific for adult T-ALL by combining patient data from the three prospective trials conducted by the Japan Adult Leukemia Study Group (JALSG). Among 559 patients whose immunophenotypes could be evaluated, 87 (15.6%) were identified as T-ALL. Of them, 66 patients (75.8%) achieved complete remission, and relapse occurred in 41 patients. With a median follow-up for surviving patients of 7.5 years, the probability of overall survival was 35.0% at 5 years. Risk factor analysis revealed that serum albumin levels, initial white blood cell (WBC) counts, and age had independent values for predicting survival. For WBC, not only the high-count group (50 x 10(9)l(-1) or higher), but also the low-count group (less than 3 x 10(9)l(-1)) showed a significantly lower survival rates than the intermediate-count group (p=0.0055 and 0.0037, respectively). Although our findings need confirmation, these results will be helpful in the identification of prognostically distinct subgroups within adult T-ALL.

Imatinib provides durable molecular and cytogenetic responses in a practical setting for both newly diagnosed and previously treated chronic myelogenous leukemia: a study in nagasaki prefecture, Japan

To evaluate the efficacy of imatinib in a practical setting, we registered 43 patients with newly diagnosed chronic myelogenous leukemia (CML) (group I) and 56 patients with previously diagnosed CML (group II) at 11 hematology centers in Nagasaki prefecture, Japan, from December 2001 to July 2005 and analyzed the molecular responses. Cytopenia, fluid retention, and skin rash were major adverse events, along with elevation in creatine phosphokinase levels. With a follow-up of approximately 3.5 years, imatinib treatment led to 88.7% overall survival (OS) and 85.2% progression-free survival (PFS) rates for group I, and 79.8% OS and 76.6% PFS rates for group II; the rates were not significantly different despite a lower average imatinib dose in group II. The rates of complete cytogenetic response at 30 months and major molecular response at 24 months were 86.1% and 62.5%, respectively, in group I, and 77.9% and 58.3% in group II; the rates were not significantly different. As has been reported by other groups, these results demonstrate that imatinib treatment can provide excellent clinical and molecular effects for not only newly diagnosed but also previously treated CML patients in practical settings that cover a wider variety of patients than clinical trials.

Improvement of criteria for refractory cytopenia with multilineage dysplasia according to the WHO classification based on prognostic significance of morphological features in patients with refractory anemia according to the FAB classification

In the criteria of refractory cytopenia with multilineage dysplasia (RCMD) according to the WHO (World Health Organization) classification, the frequency threshold concerning dysplasia of each lineage was defined as 10%. To predict overall survival (OS) and leukemia-free survival (LFS) for patients with refractory anemia (RA) according to the French-American-British (FAB) classification, we investigated prognostic factors based on the morphological features of 100 Japanese and 87 German FAB-RA patients, excluding 5q-syndrome. In the univariate analysis of all patients, pseudo-Pelger-Huet anomalies >or=10% (Pelger+), micromegakaryocytes >or=10% (mMgk+), dysgranulopoiesis (dys G) >or=10% and dysmegakaryopoiesis (dys Mgk) >or=40% were unfavorable prognostic factors for OS and LFS (OS; P<0.001, LFS; P<0.001). The prognostic effects of the morphological features were similar in both Japanese and German patients. However, dys Mgk >or=10% was not correlated with OS and LFS. In the multivariate analysis, mMgk+ and dys Mgk>or=40% were adverse prognostic factors for OS for all patients, and dys G >or=10% and dys Mgk>or=40% were adverse prognostic factors for LFS for all patients. On the basis of the present analysis, we propose the following modified morphological criteria for RCMD. Modified RCMD should be defined as FAB-RA, excluding 5q-syndrome with dys G >or=10%, dys Mgk>or=40% or mMgk+.

Expression of the myeloperoxidase gene in AC133 positive leukemia cells relates to the prognosis of acute myeloid leukemia

We previously reported that the percentage of myeloperoxidase (MPO) positive blasts had a prognostic impact on survival of patients with acute myeloid leukemia (AML). To extend this observation, we quantitatively measured the level of the MPO gene in AC133 positive leukemia cells that would contain a putative AML stem/progenitor compartment. AML cases were divided into the MPO gene high (MPOg-H) and MPO gene low (MPOg-L) groups. Only patients belonging to the MPOg-H group had a favorable chromosomal translocation, t(8;21), and having no morphological dysplasia that was associated with MPOg-L. The difference in the survival of MPOg-H and MPOg-L was statistically meaningful, demonstrating the possible prognostic impact of the expression of MPO gene in AC133 positive leukemia cells.

Serum Levels of Thl/Th2 Cytokines, Angiogenic Growth Factors, and Other Prognostic Factors in Young Adult Patients with Hemophagocytic Syndrome

Serum levels of T helper 1 (Th1)/T helper 2 (Th2) cytokines, angiogenic growth factors, and other prognostic factors were measured in 5 young adult patients with virus-associated hemophagocytic syndrome (HPS). Levels of 2 Th1 cytokines (interleukin [IL]-18 and tumor necrosis factor-alpha), 2 Th2 cytokines (IL-10 and IL-6), and 2 angiogenic growth factors (soluble intercellular adhesion molecule-1 and hepatocyte growth factor) were high in all of the patients examined, whereas those of Th1 cytokines such as IL-12 and macrophage inflammatory protein-1a were normal or low. Levels of IL-18 and IL-10 were highest in case 2, with a fatal outcome, and were lowest in case 4, with rapid recovery within 1 month. Although IFN-gamma levels were not elevated in 2 patients (cases 3 and 5), IL-18 levels were markedly high in both of these cases and the IL-6 level was highest in case 3. In contrast with the marked increase in the level of IL-10, the levels of IL-6, sIL-2R, and ferritin decreased rapidly and returned to normal within 2 months after therapy in case 3. The IL-18 level decreased somewhat, but remained elevated for 6 months, and the patient achieved a complete response within 11 months. Taken together, our findings suggest that both IL-18 and IL-10, but not IL-12, may play important roles in young adult patients with HPS via enhancing and suppressing Th1 immune responses, respectively.

High complete remission rate and promising outcome by combination of imatinib and chemotherapy for newly diagnosed BCR-ABL-positive acute lymphoblastic leukemia: a phase II study by the Japan Adult Leukemia Study Group

PURPOSE

A novel therapeutic approach is urgently needed for BCR-ABL-positive acute lymphoblastic leukemia (ALL). In this study, we assessed the efficacy and feasibility of chemotherapy combined with imatinib.

PATIENTS AND METHODS

A phase II study of imatinib-combined chemotherapy was conducted for newly diagnosed BCR-ABL-positive ALL in adults. Eighty patients were entered into the trial between September 2002 and January 2005.

RESULTS

Remission induction therapy resulted in complete remission (CR) in 77 patients (96.2%), resistant disease in one patient, and early death in two patients, as well as polymerase chain reaction negativity of bone marrow in 71.3%. The profile and incidence of severe toxicity were not different from those associated with our historic chemotherapy-alone regimen. Relapse occurred in 20 patients after median CR duration of 5.2 months. Allogeneic hematopoietic stem-cell transplantation (HSCT) was performed for 49 patients, 39 of whom underwent transplantation during their first CR. The 1-year event-free and overall survival (OS) rates were estimated to be 60.0%, and 76.1%, respectively, which were significantly better than those for our historic controls treated with chemotherapy alone (P < .0001 for both). Among the current trial patients, the probability for OS at 1 year was 73.3% for those who underwent allogeneic HSCT, and 84.8% for those who did not.

CONCLUSION

Our results demonstrated that imatinib-combined regimen is effective and feasible for newly diagnosed BCR-ABL-positive ALL. Despite a relatively short period of observation, a major potential of this treatment is recognized. Longer follow-up is required to determine its overall effect on survival.

Difference in clinical features between Japanese and German patients with refractory anemia in myelodysplastic syndromes

Several reports indicate that there might be differences in clinical features between Asian and Western myelodysplastic syndrome (MDS) cases. We analyzed refractory anemia (RA) in French-American-British (FAB) classification cases diagnosed in Japan and Germany to perform a more exact comparison between Asian and Western MDS types. In the first step, we analyzed agreement of morphologic diagnosis between Japanese and German hematologists. Blood and bone marrow slides of 129 patients diagnosed with FAB-RA, FAB-RA with ringed sideroblasts (RARS), or aplastic anemia were selected randomly and evaluated separately by each group. The agreements of diagnoses according to FAB and World Health Organization (WHO) classifications were 98.4% and 83.8%, respectively. Second, we compared clinical features between 131 Japanese and 597 German patients with FAB-RA. Japanese patients were significantly younger than German patients. Japanese patients had more severe cytopenias. However, prognosis of Japanese patients was significantly more favorable than that of German patients. Japanese patients had a significantly lower cumulative risk of acute leukemia evolution than did German patients. Frequency of WHO-RA in Japanese patients with FAB-RA was significantly higher than that in German patients. In conclusion, our results indicate that the clinical features of Japanese patients with FAB-RA differ from those of German patients.

[Successful treatment with CHOP therapy for progressive of primary macroglobulinemia without further increase of serum IgM]

A 61-year-old man with primary macroglobulinemia (PMG) had been followed without any treatment as he had no apparent manifestations. After 1 year and 3 months, he was admitted to our hospital with a fever. No signs or symptoms of infection and no progressive increase of serum IgM levels was observed. Non-Hodgkin's lymphoma was not additionally found. Fever without infection, elevated serum LDH level and further enlargement of the spleen compelled us to diagnose his condition as deterioration of the PMG. An immediate fall in his temperature and serum IgM levels was observed after CHOP therapy. Effective therapy must be discussed in the deterioration of this type of disease.

[Diffuse large B-cell lymphoma with strongly positive MIB-1 stain and clinical features resembling Burkitt lymphoma]

A 62-year-old woman was admitted to our hospital because of gastric mucosal bleeding. Gastroendoscopy revealed a gastric tumor which was diagnosed from the biopsied specimen as diffuse large B-cell lymphoma (DLBCL). Lymphoma cells had infiltrated the bone marrow showed morphological features resembling Burkitt lymphoma (BL). Nearly 100% of the cells in the bone marrow were positive for MIB-1 immunostaining. The chromosomal study was normal. Surface marker analysis disclosed that the cells were positive for CD10, CD19, CD20 and CD25. As lymphoma cells had infiltrated the central nervous system, combined chemotherapy was performed accompanied with intrathecal administration of anticancer drugs. Although transient improvement was observed, the patient died of the advanced disease three months after admission. As we have shown here, there are some cases of DLBCL with immunohistochemical features resembling BL. Further consideration about the appropriate chemotherapy program for this type of disease might be necessary.

Successful Treatment with Imatinib Mesylate in a Case of Minor BCR-ABL-Positive Acute Myelogenous Leukemia

Philadelphia (Ph) chromosome-positive acute myelogenous leukemia (AML) is a rare disease that is resistant to conventional antitumor chemotherapy and has a poor prognosis. We describe a case of Ph chromosome-positive AML in which imatinib mesylate was used and a favorable outcome was obtained.A 64-year-old man was found to have Ph chromosome-positive, minor BCR-ABL-positive AML. Remission could not be induced by remission induction therapy with antitumor agents. Because the patient had a serious concomitant infectious disease, administration of 600 mg/day of imatinib mesylate, a specific inhibitor of BCR-ABL tyrosine kinase, was started after written informed consent was obtained. Complete cytogenetic response (CCR) was achieved without serious adverse events and persisted for more than 1 year. Our results suggested that imatinib mesylate was very useful for treating Ph chromosome-positive AML.

Efficacy and safety of imatinib mesylate for patients in the first chronic phase of chronic myeloid leukemia: results of a Japanese phase II clinical study

Imatinib mesylate is a relatively new drug that targets the BCR-ABL chimeric protein, the molecular basis of chronic myeloid leukemia (CML). A phase II clinical trial in 39 Japanese patients in the first chronic phase of CML was conducted with imatinib mesylate at a dose of 400 mg/day. Hematologic complete response was obtained in 92.3% of the patients, complete cytogenetic response (CR) was obtained in 43.6%, and major partial CR was obtained in 20.5% of the patients. Although 29 of 39 patients required an adjustment of dosing because of grade 3 or 4 adverse events, most of the events were reversible, and 25 of the 29 patients were able to resume therapy. Between day 15 and day 35, grade 3 or 4 neutropenia and/or leukocytopenia occurred in 13 patients, and grade 3 thrombocytopenia occurred in 5 patients. Overall, nonhematologic grade 3 adverse events occurred in 28.2% of the patients. These data support the use of imatinib mesylate as the treatment of choice for chronic-phase CML patients.

Combination of intensive chemotherapy and imatinib can rapidly induce high-quality complete remission for a majority of patients with newly diagnosed BCR-ABL-positive acute lymphoblastic leukemia

The outcome for adult patients with BCR-ABL-positive acute lymphoblastic leukemia (ALL) remains dismal and long-term survival can hardly be achieved except by allogeneic hematopoietic stem cell transplantation (HSCT). The Japan Adult Leukemia Study Group (JALSG) has recently started a phase 2 trial with intensive chemotherapy and imatinib for newly diagnosed BCR-AB-positive ALL patients, and we present here the interim results for the first 24 patients. All patients except one case of early death (96%) attained complete remission (CR) after a single course of remission induction therapy. Polymerase chain reaction (PCR) negativity was achieved in 28% of the patients on day 28, in 50% on day 63, and in up to 78% during the follow-up period. The toxicity profile was almost similar to that with chemotherapy alone. As a result, 15 patients (63%) could receive an allogeneic HSC transplant during their first CR. Although the number of patients is small and the observation period is too short, the combination therapy is very promising and produces high-quality CR for most newly diagnosed patients with BCR-ABL-positive ALL. This is especially useful because it provides the patients with a better chance to receive an allogeneic HSC transplant.

Membranous Nephropathy after Allogeneic Stem Cell Transplantation: Report of 2 Cases

Nephrotic syndrome (NS) is a rare complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The cases of 2 patients who developed NS after receiving allo-HSCT for chronic myelogenous leukemia and acute lymphoblastic leukemia are described. In both cases, renal biopsy revealed membranous nephropathy (MN), and the patients achieved remission after treatment with prednisolone. Previously reported cases and our experience suggest that most NS patients show MN in histologic tests after allo-HSCT and that its development is related to graft-versus-host disease. Early treatment with steroids seems effective for resolving symptoms of NS and improving renal function.

[Intensive multi-drug chemotherapy for acute myeloid leukemia in a renal allograft recipient]

A Fifty-two year old male, who had received a renal transplantation from his sibling 14 years previously, was referred to our hospital because of leukocytosis, anemia and thrombocytopenia. A bone marrow examination revealed an increase of leukemic blasts with morphological dysplasia of mature hematopoietic cells. The diagnosis of acute myeloid leukemia (AML) with multilineage dysplasia without antecedent myelodysplastic syndrome was made. Since the patient's general condition and the function of the transplanted kidney were well maintained, intensive therapy for his AML was chosen. The dosage of the immune suppressive reagents that were administered to prevent the rejection of the transplanted kidney were reduced during chemotherapy to minimize the adverse effect of immune suppression, and G-CSF was administrated to shorten the neutropenic period. Along with these supportive strategies, cytosine arabinoside and idarubicin-based induction therapy followed by four courses of intensive consolidation therapy were successfully performed without disturbing his renal function. It is suggested that intensive chemotherapy is feasible for post-transplant AML patients when their general condition and transplanted renal functions are well maintained.

HTLV-1 proviruses encoding non-functional TAX in adult T-cell leukemia

Adult T-cell leukemia (ATL) is associated with prior infection with human T-cell leukemia virus type 1 (HTLV-1). TAX, the major transactivator of HTLV-1, has been implicated in the immortalization of infected T-cells, but molecular mechanisms of in vivo malignant cell transformation induced by HTLV-1 remain unclear. To investigate the role of TAX in the monoclonal proliferation of ATL cells, we determined the nucleotide sequence of tax DNA clones obtained from 6 ATL patients and analysed the biological function of their products. We found that ATL cells from 2 of these patients possessed tax with a nonsense or frame-shift mutation resulting in the premature termination of its protein product, which was no longer functional. This strongly argued against an indispensable role of TAX for the maintenance of ATL cells in vivo. On the other hand, the frequency of nucleotide substitutions found in non-functional tax DNA clones from these patients was significantly lower than those in functional tax DNA clones from the others, suggesting a role for TAX in the genome instability of infected cells. Although mismatch repair defects in the microsatellite markers, including those in hMSH3, hMSH6, BAX, TGF-beta RII, and E2F4 genes, were infrequent, we found an increase in the number of CAG repeats of the E2F4 microsatellite marker in 1 patient. These findings indicate that while TAX may be a necessary prerequisite for malignant transformation of infected cells, it is not essential for the maintenance of ATL cells in vivo.

Differential response to stem cell factor and Flt3 ligand by the FAB subtype in acute myeloid leukemia clonogenic cells

Proliferative response of blast clonogenic cells to various hematopoietic growth factors (HGF), including stem cell factor (SCF) and flt3 ligand (FL) was investigated in 100 patients with acute myeloid leukemia (AML) and chronic myelogenous leukemia (CML) in myeloid crisis (MC). The frequency of spontaneous colony formation was significantly high in CML in MC (55%) and AML French-American-British (FAB) subtype M4 (48%) compared with M2 (16%). No spontaneous colony was formed in any of the patients with M1 and M3. The frequency of proliferative response to various HGF alone and in combination according to FAB subtype and CML in MC was as follows: that to granulocyte colony-stimulating factor (G-CSF) was lowest in M1 and CML in MC (50%) compared with other FAB subtypes (>or=86%), that to granulocyte-macrophage CSF (GM-CSF) was lowest in CML in MC (44%) compared with FAB subtypes (>or=74%), and that to interleukin-3 (IL-3) was lowest in CML in MC (30%) compared with FAB subtypes (>or=78%). SCF and FL stimulated blast colony formation in 11% and 17% of patients with M3, respectively, but there was no response to both, and in 60% and 57% of patients with CML in MC, respectively, with 14% showing a response to both. The frequency of proliferative response to both SCF and FL increased in the order of M1 (33%), M2 (63%), M4-5 (95%), and M6 (100%). The results are summarized as follows: absence of spontaneous colony formation and response to HGF other than SCF and FL, designated as HGF-dependent growth (M3); spontaneous colony formation and lowest response to HGF, designated as autonomous growth (CML in MC); and spontaneous colony formation and highest response to HGF including SCF and FL, designated as autocrine growth (M4-6). M1 and M2 were intermediate between CML in MC and M4-6. The relation between in vitro growth pattern of blast clonogenic cells and prognosis in AML FAB subtype and CML in MC is discussed.

[Antileukemic drug--a selective inhibitor of BCR-ABL tyrosine kynase, imatinib(STI571)]

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder characterized by Philadelphia chromosome and resultant production of the constitutively activated BCR-ABL tyrosine kinase. Imatinib (STI571), selective inhibitor of the ABL-tyrosine kinase, inhibits the activity of BCR-ABL tyrosine kinase. A phase I and II study of STI571 showed remarkable cytogenetic effect in patients with interferon-refractory CML, offering new hope for therapy for CML. It will, however, require long-term follow-up data from phase II and III clinical studies to validate the effect of STI571 on survival. As therapy for CML improves, monitoring minimal residual disease will be important.

[Clinical manifestations and staging system]

Patients with chronic myeloid leukemia(CML) are often diagnosed after a routine blood examination when a raised leukocyte count is found. The disease is biphasic or triphasic. The initial chronic phase lasts on 2-6 years without severe symptoms. But ultimately it either changes abruptly to an acute crisis phase or an accelerated phase which later progresses to the acute crisis phase. The acute phase is refractory to treatment and has a median duration of 3 months. Clinical features of the accelerated phase and the acute crisis phase are very diverse. The classification for the phases of CML proposed by the International Bone Marrow Transplantation Registry is reasonable.