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Activating mutations of KIT play an important role in the pathophysiology of several human malignancies, including acute myeloid leukemia. Activated KIT kinase is therefore a promising molecular target for the treatment of many malignancies harboring KIT activation. Here we examined the potency of a novel KIT inhibitor KI-328 against different types of mutant KIT kinases recurrently identified in AML. KI-328 shows selective potency against KIT kinase for the in vitro kinase assay, and inhibits the growth of wild-type (Wt)- and mutant-KIT-expressing cells, while it has little potency against D816V-KIT. Comparable analysis of several potent KIT inhibitors regarding growth inhibitory effects on a variety of mutant-KIT-expressing cells revealed that multi-kinase inhibitors have the same potency against D816V-KIT as other mutant KITs; however, the predominant potency against D816V-KIT was observed in heat shock protein 90 (HSP90) inhibitors. Furthermore, HSP90 inhibitors suppress the growth of D816V-KIT-expressing cells at the concentration at which the growth of other mutant-KIT-expressing cells is not affected. These results collectively indicated that potent KIT inhibitors have different potency against the type of mutant KIT kinases. Therefore, KIT inhibitors are required to validate potency against several types of mutant KIT kinases for the clinical development.

Acute myeloid leukemia (AML) has been thought to be the consequence of two broad complementation classes of mutations: class I and class II. However, overlap-mutations between them or within the same class and the position of TP53 mutation are not fully analyzed. We comprehensively analyzed the FLT3, cKIT, N-RAS, C/EBPA, AML1, MLL, NPM1, and TP53 mutations in 144 newly diagnosed de novo AML. We found 103 of 165 identified mutations were overlapped with other mutations, and most overlap-mutations consisted of class I and class II mutations. Although overlap-mutations within the same class were found in seven patients, five of them additionally had the other class mutation. These results suggest that most overlap-mutations within the same class might be the consequence of acquiring an additional mutation after the completion both of class I and class II mutations. However, mutated genes overlapped with the same class were limited in N-RAS, TP53, MLL-PTD, and NPM1, suggesting the possibility that these irregular overlap-mutations might cooperatively participate in the development of AML. Notably, TP53 mutation was overlapped with both class I and class II mutations, and associated with morphologic multilineage dysplasia and complex karyotype. The genotype consisting of complex karyotype and TP53 mutation was an unfavorable prognostic factor in entire AML patients, indicating this genotype generates a disease entity in de novo AML. These results collectively suggest that TP53 mutation might be a functionally distinguishable class of mutation.

The interactions between chemokines and their receptors may have an important role in initiating GVHD after allogeneic hematopoietic SCT (allo-HSCT). CCL25 and CCR9 are unique because they are exclusively expressed in epithelial cells and in Peyer's patches of the small intestine. We focused on rs12721497 (G926A), one of the non-synonymous single nucleotide polymorphisms (SNPs) in the CCR9 gene, and analyzed the SNP of donors in 167 consecutive patients who received allo-HSCT from an HLA-identical sibling donor. Genotypes were tested for associations with acute and chronic GVHD in each organ and transplant outcome. Multivariate analyses showed that the genotype 926AG was significantly associated with the incidence of acute stageor =2 skin GVHD (hazard ratio: 3.2; 95% confidence interval (95% CI): 1.1-9.1; P=0.032) and chronic skin GVHD (hazard ratio: 4.1; 95% CI: 1.1-15; P=0.036), but not with GVHD in other organs or with relapse, non-relapse mortality or OS. To clarify the functional differences between genotypes, each SNP in retroviral vectors was transfected into Jurkat cells. In chemotaxis assays, the 926G transfectant showed greater response to CCL25 than the 926A transfectant. In conclusion, more active homing of CCR9-926AG T cells to Peyer's patches may produce changes in Ag presentation and result in increased incidence of skin GVHD.

Here we report the identification of a novel human leukocyte antigen (HLA)-B44–restricted minor histocompatibility antigen (mHA) with expression limited to hematopoietic cells. cDNA expression cloning studies demonstrated that the cytotoxic T lymphocyte (CTL) epitope of interest was encoded by a novel allelic splice variant of HMSD, hereafter designated as HMSD-v. The immunogenicity of the epitope was generated by differential protein expression due to alternative splicing, which was completely controlled by 1 intronic single-nucleotide polymorphism located in the consensus 5′ splice site adjacent to an exon. Both HMSD-v and HMSD transcripts were selectively expressed at higher levels in mature dendritic cells and primary leukemia cells, especially those of myeloid lineage. Engraftment of mHA+ myeloid leukemia stem cells in nonobese diabetic/severe combined immunodeficient (NOD/SCID)/γcnull mice was completely inhibited by in vitro preincubation with the mHA-specific CTL clone, suggesting that this mHA is expressed on leukemic stem cells. The patient from whom the CTL clone was isolated demonstrated a significant increase of the mHA-specific T cells in posttransplantation peripheral blood, whereas mHA-specific T cells were undetectable in pretransplantation peripheral blood and in peripheral blood from his donor. These findings suggest that the HMSD–v–encoded mHA (designated ACC-6) could serve as a target antigen for immunotherapy against hematologic malignancies.

Graft failure and nonrelapse mortality (NRM) are major obstacles after the first unrelated-donor bone marrow transplantation (UD-BMT) with reduced-intensity conditioning. We evaluated UD-BMT with fludarabine (5 x 25 mg/m2) and melphalan (2 x 90 mg/m2) treatment combined with short-term methotrexate and tacrolimus (n = 20) or cyclosporine (n = 2) therapy for 22 patients with hematologic malignancies who were ineligible for conventional conditioning. Only 9 patients were in remission at transplantation. Seventeen patients underwent HLA-matched or DRB1 allele-mismatched transplantation, and 5 patients underwent HLA-A allele-mismatched or serologically HLA-DR-mismatched transplantation. Regimen-related toxicities were tolerable, although transient oral mucositis, hepatobiliary enzyme elevation, and diarrhea were observed frequently. All evaluable patients achieved sustained neutrophil engraftment, and all patients tested showed complete donor chimerism on day 28. With a median follow-up of 16 months, NRM and overall survival rates at 1 year were 19% and 81%, respectively, among the patients who underwent HLA-matched or DRB1 allele-mismatched transplantation. Acute graft-versus-host disease (GVHD) of grades II to IV occurred in 26% of the patients. The cumulative incidence of chronic GVHD was 44%. Despite the small number of patients and the short follow-up period, this reduced-intensity regimen enabled satisfactory engraftment and achievement of rapid complete donor chimerism with tolerable toxicities in the patients, including those who underwent HLA-mismatched UD-BMT.

Empirical antifungal therapy is the current standard of care for patients with febrile neutropenia unresponsive to broad-spectrum antimicrobials. Although a number of antifungal agents are currently available, the need remains for effective but less toxic alternatives for this indication. We therefore conducted a phase 2 study of micafungin for 80 patients with hematologic diseases who were suffering from persistent or recurrent fever after at least 96 h of antibacterial therapy. The patients were treated with micafungin at a fixed dose of 150 mg/day. Of the 78 evaluable patients, 54 (69 %) achieved defervescence by the time of neutrophil recovery, and 56 (72 %) completed the treatment in accordance with the provision of the protocol. Four patients developed invasive fungal infection, nine changed antifungal therapy because of lack of efficacy, and three discontinued micafungin because of drug-related adverse events. Based on the composite end point taking account of these, the overall treatment success rate was 60 %, with the lower limit of a 90 % confidence interval (50.3 %) exceeding the predefined threshold success rate (50 %). These findings show the efficacy and safety of micafungin for empirical antifungal therapy in patients with persistent or recurrent febrile neutropenia, warranting further investigation of this drug in a phase 3 study.

We report here on a case of a 27-year-old woman in her first pregnancy. She was diagnosed with idiopathic thrombocytopenic purpura (ITP) at the age of 14 years. At 36 weeks of gestation, she was admitted to our hospital due to thrombocytopenia. We initially suspected ITP exacerbated by pregnancy. Laboratory results revealed mild anemia, thrombocytopenia (5.0×10(9)/l), and slightly elevated liver enzymes and lactate dehydrogenase. The next day, hemoglobin fell to 6.6 g/dl. Thrombotic thrombocytopenic purpura (TTP) was suspected on the basis of hemolytic anemia with schistocytes and a negative Coombs' test. Plasma exchange and methylprednisolone were initiated immediately. ADAMTS13 analysis showed a severe deficiency in ADAMTS13 activity but no inhibitors. At Day 6, the platelet count rose to 223×10(9)/l and she delivered a live baby by cesarean section. Currently, the patient receives fresh frozen plasma infusions every 2 weeks due to suspected Upshaw-Schulman syndrome.

Purpose In this study, we sought to evaluate the efficacy and toxicity of high-dose therapy followed by autologous peripheral blood stem cell transplantation (autoPBSCT) after rituximab-containing induction chemotherapy with in vivo purging for relapsed or refractory chemosensitive advanced-stage follicular lymphoma (FL). Patients and Methods A rituximab-containing regimen was used as induction chemotherapy and as in vivo purging before PBSC collection. Patients achieving partial or complete response received a regimen consisting of high-dose melphalan and total-body irradiation (TBI). Results A total of 18 patients with a median age of 45 years were enrolled. The number of previous chemotherapy regimens was 2. The principal nonhematologic toxicities were grade 3 febrile neutropenia and diarrhea. One patient experienced pneumocystis pneumonia, 2 developed interstitial pneumonitis, and 1 experienced agammaglobulinemia, all of whom had complete improvement except for the patient having agammaglobulinemia. Grade 4 toxicities were not observed, and there have been neither treatment-related mortality nor secondary malignancy to date. At a median follow-up of 4.0 years, the 4-year estimated overall and failure-free survival rates were 100% and 88.9%, respectively. Conclusion Consolidation of high-dose melphalan and TBI followed by autoPBSCT with in vivo purging is feasible and effective for relapsed or refractory chemosensitive FL. Longer follow-up is needed to confirm the role and late toxicities.

The Asian variant of intravascular large B-cell lymphoma (AIVL) is a rare aggressive lymphoma characterized by various clinical symptoms, hemophagocytic syndrome and predominant growth within vessels. We present a 73-year-old man with relapsed AIVL who had been treated with six courses of CHOP regimen. A half year later, he presented with high fever, sweat, dementia and hepatosplenomegaly without lymphadenopathy. A bone marrow biopsy showed prominent hemophagocytosis and immunological staining disclosed an augmented intrasinusal pattern of atypical large lymphocytes characteristic of the CD20+ and CD5+ phenotypes. As salvage therapy, CND-R (rituximab, cladribine, mitoxantrone, dexamethasone) was performed, and the clinical symptoms immediately and dramatically improved. Subsequently, CND-R therapy was repeated every 4 weeks. No serious adverse events were observed with the exception of grade 4 neutropenia and grade 3 thrombocytopenia. After completion of the fifth course, a bone marrow biopsy pathologically confirmed complete remission, leading to termination of this therapy. The patient has remained in remission for more than 15 months. CND-R therapy, which is effective for indolent lymphoma, may be one of the candidates in salvage therapy for relapsed AIVL.

Summary Minor histocompatibility antigens (mHags) play crucial roles in the induction of graft versus host disease (GVHD) and/or graft versus leukaemia (GVL) effects following human leucocyte antigen (HLA)-identical haematopoietic stem cell transplantation (HSCT). Using HLA-A*3101- and -A*3303-restricted cytotoxic T lymphocyte (CTL) clones generated from different post-HSCT recipients, we identified two novel mHag epitopes encoded by the leader sequence of cathepsin H (CTSH) isoform a. The nonameric sequence ATLPLLCAR was defined as an HLA-A*3101-restricted epitope (CTSHR/A31), while a decameric peptide featuring a one N-terminal amino acid extension, WATLPLLCAR, was presented by HLA-A*3303 (CTSHR/A33). The immunogenicity of both epitopes was totally dependent on the polymorphic C-terminal arginine residue and substitution with glycine completely abolished binding to the corresponding HLA molecules. Thus, the immunogenicity of this mHag is exerted by differential HLA binding capacity. CTSH is relatively ubiquitously expressed at protein levels, thus it may be involved in GVHD and anti-leukaemic/tumour responses. Interestingly, however, CTL clones predominantly lysed targets of haematopoietic cell origin, which could not be explained in terms of the immunoproteasome system. Although the mechanisms involved in the differential susceptibility remain to be determined, these data suggest that CTSH-encoded mHags could be targets for GVL effects.

Since 1999, we started to modify the conditioning regimen in allogeneic stem cell transplantation for middle-aged to elderly patients (= 50), and experimented with 3 conditioning regimens. The clinical outcome was compared between fludarabine/melphalan (FLU/MEL) conditioning and two other conditioning regimens (reduced TBI (7.5 Gy) and BU/CY). From 1999 through 2005, a total of 33 patients aged 50 or more with a hematological malignancy received allogeneic transplantation in our institute. Seventeen received FLU/MEL conditioning and 16 received the other conditioning regimens. The FLU/MEL group included more patients receiving unrelated bone marrow transplantation. There were no differences in primary disease, risk, HLA disparity, GVHD prophylaxis and stem cell source. Sustained engraftment was achieved in all evaluable patients in both groups. Regimen-related toxicities were the same in both groups. Transplant-related-mortality (TRM), relapse rate and disease-free survival were 22% and 25%, 25% and 47%, 59% and 37% in the FLU/MEL group and in the other group, respectively. The incidence of grade II-IV acute GVHD was 25% and 13%, respectively, and that of chronic GVHD was 38% and 56%, respectively. FLU/MEL conditioning achieved satisfactory engraftment. Although the relapse rate showed a lower tendency with FLU/MEL conditioning, there were no differences as far as TRM was concerned. FLU/MEL conditioning could be a novel conditioning regimen for middle-aged to elderly patients.

Abstract 4146 Introduction KIT is a type III receptor tyrosine kinase together with FLT3, PDGFR and FMS. The interaction of KIT and its ligand stem cell factor (SCF) plays an important role in the cell survival, proliferation and differentiation. Activating mutations of KIT have been demonstrated in several kinds of human malignancies, such as mastocytoma, gastrointestinal stromal tumor, and acute myeloid leukemia (AML). Since KIT mutation seems a poor prognostic factor in CBF leukemia and the KIT expression is observed in most AML cells, KIT serves a molecular target for the treatment of AML. To date, several small molecules have been demonstrated to have a potency against KIT kinase, while KIT selective inhibitors are not yet developed for the clinical use. We recently developed a novel KIT selective inhibitor KI-328, and evaluated here its inhibitory effect on wild-type (Wt) and mutant KIT kinases. Methods We identified 5 types of KIT mutations (D816V, M541L, V540L, T417F/del418-419 and N822K) in AML cells, and established these mutant-KIT, as well as Wt-KIT, expressing IL-3-dependent mouse myeloid precursor 32D cells. Using these Wt- and mutant KIT expressing 32D cells, we examined the anti-leukemia activity of KI-328 in comparison with another potent KIT inhibitors. Results In Wt- and M541L-KIT expressing cells, KITs were phosphorylated by the SCF stimulation. In contrast, mutant KITs were constitutively phosphorylated in D816V-, V540L-, T417F-, and N822K-KIT expressing cells. However, the autonomous proliferation was observed only in D816V-KIT expressing cells, and the other mutant KIT expressing cells required SCF for their proliferations like Wt-KIT expressing cells. These results were confirmed by the colony formation ability in the semi-liquid media, where only D816V-KIT expressing cells could form the colony without any growth factors. The growth inhibitory effect of KI-328 was, therefore, examined in the existence of 50 ng/ml of SCF. KI-328 inhibited the growth of Wt-, M541L-, V540L-, T417F- and N822K-KIT expressing cells with the GI50 value 127 nM, 229 nM, 575 nM, 445 nM and 997 nM, respectively. The cell cycle analysis showed the KI-328 increased sub-G1 populations in these cells at each GI50 value. In consistent with the growth inhibitory effects, KI-328 potently inhibited the phosphorylations of Wt- and mutant KITs except D816V as well as their downstream molecules STAT3, AKT, MAPK at the concentration of over the GI50 value, indicating the proof of concept that KI-328 inhibits the growth of these cells by the KIT kinase inhibition. However, the significant growth inhibition was not observed in D816V-KIT expressing cells up to the 5 μM, and more than 2 μM of KI-328 were required for the de-phosphorylation of D816V-KIT. We further examined whether another potent KIT inhibitors showed the different sensitivities between D816V-KIT and Wt-KIT. Multi-kinase inhibitors such as dasatinib and sunitinib showed the same growth inhibitory effects on D816V- and Wt-KIT expressing cells: each GI50 value against D816V- and Wt-KIT was 43 nM and 72 nM, and 116 nM and 206 nM, respectively. In contrast, imatinib, which is relatively selective against KIT kinase, did not inhibit the growth of the D816V-KIT expressing cells like KI-328. Conclusions We demonstrated that KI-328 is a potent and selective KIT inhibitor. Although KI-328 did not show the significant growth inhibitory effect on the D816V-KIT expressing 32D cells up to the 5 μM, G-CSF mediating neutrophil maturation was observed when those were treated with less than 1 μM of KI-328, indicating that KI-328 has a weak potency against the D816V-KIT kinase. Therefore, the combination therapy with another potent KIT inhibitors, such as HSP90 inhibitor, might conquer the resistance against the D816V-KIT kinase. Since the kinase inhibitory profile seemed to be associated with the resistance against the D816V-KIT kinase, the structural analysis of the D816V-KIT is required for developing more potent inhibitors against all mutant KIT kinases. Disclosures: Shiotsu: Kyowa Hakko Kirin Co., Ltd.: Employment. Kiyoi:Kyowa Hakko Kirin Co. Ltd.: Consultancy; Novartis Pharma Co. Ltd.: Research Funding. Ishida:Kyowa Hakko Kirin Co., Ltd.: Employment. Naoe:Kyowa Hakko Kirin Co., Ltd. : Research Funding; Chugai Pharmaceutical Co.,Ltd.: Research Funding; Wyeth K.K.: Research Funding.

Chemokines are a group of small molecules that regulate trafficking of leukocytes through interactions with a subset of seven-transmembrane, G protein-coupled chemokine receptors. Their interactions may play an important role in initiating acute graft-versushost disease (GVHD) after allogeneic hematopoietic stem cell transplanation. CCR9 is a very unique receptor because, outside of the thymus, it is almost exclusively expressed by epithelial cells and Pyer’s patches in the small intestine. We focused on rs12721497 (G926A), one of the single nucleotide polymorphisms (SNPs) in the CCR9 gene, and analyzed the impact of its genotype on the onset of organ-specific acute GVHD and transplant outcome. Included in the study were consecutive patients who had received allogeneic bone marrow or peripheral blood stem cell transplantation from an HLA-identical sibling donor at the Nagoya University Hospital and the Japanese Red Cross Nagoya First Hospital between 1987 and 2006. Of these, a total of 167 patients who received T cell replete transplantation with short-term methotrexate and cyclosporine as a GVHD prophylaxis were analyzed. Informed consent was obtained from all patients and donors, and the study was approved by the ethics committees at Nagoya University Hospital and Japanese Red Cross Nagoya First Hospital. The CCR9 G926A genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism method using genomic DNA obtained from donor cells. The impact of CCR9 genotype on the incidence of acute GVHD in each organ, overall survival rates, relapse rates and nonrelapse mortality rates were analyzed using the Cox proportional hazard regression model. Age, intensity of conditioning, total body irradiation, disease risk, remission state and graft source were used as covariates for adjustment. Median age was 38 years old (range 15–62). Diseases were malignancies (n=148) and non-malignancies (n=19). The incidences of acute GVHD were 22% (grade I), 12% (grade II) and 6.6% (grade III-IV). The frequencies of the AA, AG and GG genotype were 94%, 6% and 0%, respectively. CCR9 926AG genotype was significantly associated with the incidence of stage³2 skin GVHD (hazard ratio 3.2; 95% CI, 1.1–9.1), but not associated with the incidence of liver GVHD, intestinal GVHD, grade II-IV GVHD, overall survival rates, relapse rates and nonrelapse mortality rates. In conclusion, the frequencies of each genotype were compatible with the reports in HapMap database. It was notable that donor CCR9 SNPs affected the incidence of skin GVHD, but did not affect that of intestinal GVHD. Beilhack et al. (Blood. 2008;111:2919–2928) recently reported redundancy of secondary lymphoid organs at different anatomical sites in GVHD initiation. They suggested that primed T cells could initiate GVHD at different sites from their original priming sites. Since Pyer’s patches are important as sites of antigen presenting, T cell homing to Pyer’s patches may be different between each CCR9 926AG genotype, resulting in different incidences of skin GVHD. We are now investigating the functional differences between each genotype.

Acute myeloid leukemia (AML) is a heterogeneous disorder of hematopoietic progenitor cells. The World Health Organization (WHO) classification of the myeloid neoplasm incorporates genetic, immunophenotypic, biologic and clinical features. Although the WHO classification recognizes several chromosomal translocations they are frequently seen in AML patients, for categorizing the AML with recurrent genetic abnormalities, a number of other genetic alterations such as point mutations and gene rearrangements have not been included. To date, several genetic alterations, which are involved in the pathogenesis of AML and associated with prognosis of patients, have been documented. Therefore, it is required to establish the detailed classification of AML according to the genetic status. In this study, we comprehensively analyzed the genetic alterations and in de nove AML patients and investigated the association with mutational status, cytogenetic status and clinical features in comparison with the WHO classification. The study population included 144 newly diagnosed de nove AML patients consisting of 38 recurrent genetic abnormalities (RGA), 34 multilineage dysplasia (MLD) and 72 not otherwise categorized (NOC) according to WHO subcategories. Bone marrow samples were obtained from the patients after obtaining informed consent for banking and molecular analyses. Mutations in FLT3, cKIT, NPM1, N-RAS, TP53, C/EBPA, AML1, WT1 and MLL/PTD were analyzed as previously described. In consistent with previous reports, FLT3 (24%), cKIT (5%), NPM1 (20%), N-RAS (8%), C/EBPA (12%), AML1 (2%), MLL-PTD (9%), WT1 (3%) and TP53 (8%) mutations were frequently observed. No significantly different distribution was found in the prevalence of FLT3, N-RAS, C/EBPA, AML1 and MLL-PTD mutations among the WHO categories. However, the skewed prevalence was found in cKIT, NPM1 and TP53 mutations: cKIT mutation was frequently found in AML-RGA, NPM1 mutation was not found in AML-RGA, and TP53 mutation was preferentially found in AML-MLD. N-RAS, C/EBPA, AML1 and WT1 mutations were not identified in AML-RGA, though their distributions were not statistically significant among the WHO categories. It is notable that 9 of 12 (75%) patients who have TP53 mutation are categorized in AML with MLD and 8 of the 9 have complex-karyotype. Importantly, 8 of 9 (88.9%) showed complex karyotype, and 5 of them deleted chromosome 17. In this study, we found 2 additional patients harboring TP53 mutation in the other categories, while they did not show the complex karyotype and chromosome 17 abnormality. Furthermore, complex karyotype was found in 14 of the 144 entire AML patients, while 10 of them were categorized in AML-MLD. The remaining 4 patients were categorized in AML-NOC. Three of them showed del(17) or del(17p), though TP53 mutation was not identified. The genotype consisting of complex karyotype and TP53 mutation was, therefore, specifically found in AML-MLD. Thus TP53 mutation and complex-karyotype AML are significantly correlated and associated with the presence of multi-lineage dysplasia (P= .000 and P= .000, respectively). Moreover, these patients have significantly inferior induction rate and overall survival in AML with MLD. These results suggest that TP53 mutation and complex-karyotype AML distinguish a disease entity in AML with MLD.

Acute myeloid leukemia (AML) is a heterogeneous clonal disorder of hematopoietic progenitor cells, and is thought to be the consequence of two broad complementation classes of mutations: those that confer a proliferative and/or survival advantage to hematopoietic progenitors, and those that impair hematopoietic differentiation and confer properties of self-renewal. To date, several genetic alterations, which are involved in the pathophysiology of the AML development, have been apparent, and some of them have been disclosed to have an impact on the clinical management. Therefore, it is required to establish the detailed classification of AML according to the genetic status. In this study, we comprehensively analyzed the genetic alterations in AML patients in comparison with the WHO classification. The study population included 115 newly diagnosed AML patients consisting of 25 recurrent genetic abnormalities, 25 multilineage dysplasia, 7 therapy-related and 56 not otherwise categorized WHO subcategories. Bone marrow samples were obtained from the patients after obtaining informed consent for banking and molecular analyses. Mutations in FLT3, cKIT, NPM1, N-RAS, p53, C/EBPa, AML1 and AKT1 genes were analyzed as previously described. In consistent with previous reports, FLT3 (20.9%), NPM1 (14.8%) and C/EBPa (13.0%) mutations were frequently observed, while no AKT1 mutation was found. Furthermore, NPM1 mutation was not found in AML with recurrent genetic abnormalities and C/EBPa mutation was not found in AML with recurrent genetic abnormalities or therapy related. Nine cases have double mutations of FLT3 and NPM1 genes, and 3 have FLT3 and C/EBPa mutations. Of note is that 15 of 25 (60%) AML with multilineage dysplasia cases have at least one mutation in p53, NPM1, C/EBPa, FLT3, N-RAS and AML1 genes and that p53 mutation was selectively found in the cases with complex karyotype. However, 4 AML with multilineage dysplasia cases with normal karyotype did not have any mutations in the analyzed genes. Comprehensive genetic analysis clarifies the detailed molecular base of AML and could make the subdivision of the WHO classification by combining the analysis for clinical impacts. Especially, mutation status in p53, NPM1 and C/EBPa genes seems to be useful for the subdivision of the AML with multilineage dysplasia, which is the most heterogeneous subcategory in the WHO classification.

The management of relapsed or refractory B-cell non-Hodgkin's lymphoma (B-NHL) remains challenging. We investigated the efficacy and safety of salvage chemoimmunotherapy (CHASER) in patients with relapsed or refractory B-NHL who had radiographically measurable disease and adequate major organ function. The CHASER treatment consisted of: rituximab 375 mg/m(2), day 1; cyclophosphamide 1200 mg/m(2), day 3; cytarabine 2 g/m(2), days 4 and 5; etoposide 100 mg/m(2), days 3-5; and dexamethasone 40 mg, days 3-5. The treatment was repeated every 3 weeks up to a total of four courses in the absence of disease progression. Thirty-two patients were enrolled and received a median of four courses of treatment (range 1-4 courses) per patient. Twenty patients (63%) were previously treated with rituximab-containing regimens. The median age was 54 years (range 28-67 years). The treatment was generally well tolerated, with major toxicities being grade 4 neutropenia (n = 32), thrombocytopenia requiring transfusion (n = 28), and grade 3 transaminase elevation (n = 2). Overall response rates in the entire group, and in patients with indolent (n = 17) and aggressive (n = 15) diseases were 84%, 100% and 67%, respectively. Responses were observed similarly in patients with (n = 20) and without (n = 12) previous rituximab exposure (85% and 83%, respectively). Stem cell harvest was successful in 19 of 22 patients. The median time to treatment failure for the entire group was 24.5 months. This promising result of high activity and favorable toxicity profile warrants further investigation in large-scale multicenter trials.

Background: High-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) is one of the treatment options for relapsed or refractory follicular lymphoma (FL). However, whether ASCT is able to bring cure for relapsed FL, or what optimal high-dose regimen is remaining to be established. Patients and Methods: Chemotherapy to obtain response and in vivo purging effect was CHASER regimen reported previously: rituximab 375 mg/m2 on day 1; cyclophosphamide 1200mg/m2 on day 3; cytarabine 2g/m2 on days 4–5; etoposide 100mg/m2 on days 3–5. Patients who achieved partial or complete response by CHASER were treated with L-PAM/TBI regimen comprised four fractionated TBI (8–12Gy) on days -6 to -5 or -5 to -4 and high-dose L-PAM 60 mg/m2 on days -3 to -1 followed by autologous peripheral blood stem cell transplantation (auto-PBSCT) on day 0. Results: Seventeen patients (median age 45 yrs; range, 26–59 yrs) were treated by this regimen. A median value of infused CD34 positive cells was 3.1×106/kg (range, 1.7–10.1). All patients experienced grade 4 hematological toxicities and febrile neutropenia (FN) were observed in most of patients. Protracted thrombocytopenia was observed in some patients. No grade 4 non-hematologic toxicity was observed. Major grade 3 non-hematologic toxicities were FN and gastrointestinal. Two patients experienced grade 3 vomiting (11.8%), and nine patients experienced grade 3 diarrhea (52.9%), and two patients experienced grade 3 mucositis (11.8%). Two patients developed interstitial pneumonitis on days 130 and 229. They improved by steroid treatment immediately. The median times to reach a white blood cell count greater than 1.0×109/L and platelet count 50×109/L were 11days and 17days, respectively. Engraftment was obtained in all patients. There was no treatment related mortality within days 28 after auto-PBSCT. At a median follow-up of 2.6 years (range, 0.3–4.5 years), all patients were alive without relapse. No second malignancies was observed until now. Conclusions: L-PAM/TBI regimen followed by in vivo-purged auto-PBSCT collected by CHASER might bring high %CR and have curable potential for patients with relapsed or refractory advanced FL, although large-scaled study is needed.

Steroid is the key drug for acute GVHD, however, steroid therapy often increases the incidence of virus infections. But the direct evidence of steroid therapy and various virus infections after transplantation has not been reported yet. Here we evaluated the relationship between the amount of steroid therapy and incidence of virus infections during the first 100 days post transplantation. Two hundred eight patients transplanted between 1997 and 2003 were retrospectively analyzed. Methylpredonisone (mPSL) (1–2mg/kg) was used for the treatment of acute GVHD. Between 1997 and 1999, we used mPSL pulse therapy (500mg–1g/day) for the secondary treatment of GVHD. Most of these patients died of progressive gut GVHD. However, autopsy revealed that cause of death was transplantation related microangiopathy. (Nishida et. al. BMT33, 1143) Thus, since 2001, mPSL pulse therapy has not been used for steroid resistant GVHD. In addition, for the initial treatment of GVHD, we prefer to use 1mg/kg of mPSL for the same reason. Thus, in our institute, amount of steroid was decreased after 2001. Patients were divided into 2 groups according to the initial dose of methylpredonisone (mPSL) used before day 100; Group A (0.5–1.0 mg/kg), Group B (≥2 mg/kg). Interestingly, the incidence of adenovirus infection was well correlated with the percentage of patients in Group B. (Table and Figure) In 1997, 1998 and 1999, percentage of patients in Group B (≥2mg/kg of mPSL) was 32.1, 22.2 and 18.6%, respectively, and incidence of adenovirus infection was 21.4, 14.8 and 17.9%, respectively. Whereas in 2001, 2002 and 2003, percentage of patients in Group B was 12.5%, 3.4% and 11.8%, respectively and incidence of adenovirus infection was 3.1, 3.4 and 5.9%, respectively. On the contrary, incidence of CMV, HSV and HZV infections was not correlated with the steroid therapy, suggesting that each virus has its own threshold of immunosuppression for reactivation. Reactivation of CMV (antigenemia) generally occurred after transplantation independent on the amount of steroid used. However, reactivation of adenovirus may require additional immunosuppression such as middle to high dose of mPSL. In our previous study, steroid therapy was a risk factor of adenovirus infection. (Miyamura et. al. BMT4, 535, BMT25, 545) There is no relationship was observed steroid therapy and HSV and HZV infections. They are commonly observed in a host whose immunological status is normal, suggesting that immuno-suppression is not crucial for these herpes virus infection. Three patients who received ATG developed EBV infection in this population. Reactivation of EBV may need greater immunosuppression than reactivation of adenovirus needs. These differences may reflect the precursor frequencies of CTL against each virus. percentage of patients who received >2mg mPSL and Incidence of virus infection 1997 1998 1999 2000 2001 2002 2003 mPSL ≥2mg/kg 32.1 22.2 18.6 17.2 12.5 3.4 11.8 ADV 21.4 14.8 17.9 6.9 3.1 3.4 5.9 CMV 42.9 55.6 60.7 34.5 56.3 51.7 55.9 VZV 3.6 14.8 7.1 17.2 9.4 17.2 5.9 HSV 25.0 3.7 7.1 0.0 3.1 3.4 5.9 Figure Figure

We retrospectively studied 49 patients in a single institute to evaluate the long-term outcome of total lymphoid irradiation (TLI) conditioning for allogeneic stem cell transplantation (allo-SCT) to treat aplastic anemia (AA). Most of the patients had received transfusions and had undergone previous treatment, with 33 receiving related transplants and 16 receiving unrelated transplants. Conditioning consisted of cyclophosphamide (Cy; 200 mg/kg) plus TLI (750 cGy) for related transplantation and Cy plus total body irradiation (TBI; 500 cGy) and TLI (500 cGy) for unrelated transplantation. Antithymocyte globulin (ATG) was added for 6 of the unrelated transplantations. Graft-versus-host-disease (GVHD) prophylaxis consisted mainly of cyclosporine (CSA) and methotrexate (MTX). Graft failure developed in 2 patients (4.1%). With a median follow-up of 7 years, overall survival (OS) was 81% and was not statistically significantly different between the patients receiving related transplants and those receiving unrelated transplants. In multivariate analyses, a history of previous treatment with ATG was the sole factor associated with a worse survival rate, and the interval from diagnosis to treatment was not prognostic. The incidence of acute (grade II to IV) GVHD (aGVHD) was 23%, and that of chronic GVHD (cGVHD) was 29%. Female-to-male transplantation was the sole factor associated with chronic GVHD. B cell lymphoproliferative disorder developed only after the ATG-containing conditioning. No other secondary malignancies developed after long-term follow-up. Our findings suggest that TLI conditioning is feasible and effective for patients with AA.

To clarify the clinical significance of a serologic HLA-DR mismatch after unrelated-donor transplantation, we evaluated for hematologic malignancies 123 cases of unrelated bone marrow transplantation carried out in a single institution between 1995 and 2004. Of the patients in these cases, 12 were serologically mismatched at the single HLA-DR locus. Eighty-two patients who received HLA-matched transplantations were used as controls. Conditioning consisted of a conventional total body irradiation —based regimen or a fludarabine-based reduced-intensity regimen. Prophylaxis for graft-versus-host disease (GVHD) consisted of tacrolimus plus short-term methotrexate. Graft failure did not develop. With a median follow-up of 42 months (range, 11-99 months), rates of overall survival, nonrelapse mortality, and relapse at 4 years were 63%, 38%, and 0%, respectively, all of which were comparable with those after HLA-matched transplantation. The frequency of acute GVHD of grades II to IV was 75%, significantly higher than after HLA-matched transplantation (42%, P = .046), and there was a trend toward an increased incidence of acute GVHD of grades III to IV after serologically HLA-DR —mismatched unrelated transplantation (27% versus 10%, P = .093). Chronic GVHD developed in 4 of 11 evaluable patients, an incidence comparable with that after HLA-matched transplantation. In summary, serologically HLA-DR —mismatched unrelated transplantation is feasible and might be an acceptable alternative for the Japanese population, although the higher incidence of acute GVHD is notable.