Long-term outcome of patients with acquired chronic pure red cell aplasia (PRCA) following immunosuppressive therapy: a final report of the nationwide cohort study in 2004/2006 by the Japan PRCA collaborative study group.

Immunosuppressive therapy has been employed as the initial treatment for acquired chronic pure red cell aplasia (PRCA), such as idiopathic, thymoma-associated, or large granular lymphocyte (LGL) leukaemia-associated PRCA, which is thought to be immune-mediated. To explore the overall long-term outcome following immunosuppression and to identify the risk factors for death in these disorders, we conducted nationwide surveys in Japan 2004 and 2006, and identified a total of 185 patients with acquired chronic PRCA, including 72 idiopathic, 41 thymoma-associated and 14 LGL leukaemia-associated cases of PRCA for whom data was available. The present study evaluated 127 patients with these three subsets of PRCA. The median overall survival has not yet been reached in idiopathic PRCA. The estimated median overall survival times in patients with thymoma-associated and LGL leukaemia-associated PRCA were 142·1 and 147·8 months, respectively. Twenty-two deaths were reported, and the response to induction therapy and relapse of anaemia were found to be associated with death. The major causes of death were infection in seven patients and organ failure in another seven patients. The results suggest that maintenance therapy and the management of infectious complications are crucial for improving the prognosis of chronic PRCA.

[Life-Threatening Hyponatremia by Chemotherapy in a Patient with Non-Hodgkin's Lymphoma].

Cyclophosphamide and vincristine are known to be the chemotherapeutic agents most frequently associated with hyponatremia. Here, we report the case of a 69-year-old man with non-Hodgkin's lymphoma who developed severe hyponatremia during chemotherapy. The Japanese man was diagnosed with diffuse large B-cell lymphoma, and underwent chemotherapy treatment with THP-COP (cyclophosphamide, pirarubicin, vincristine, and prednisolone). In the first course of chemotherapy, he developed hyponatremia (nadir 109 mEq/L) and his urinary N-acetyl-ß-D-glucosaminidase (NAG) level had increased. After the second courses of chemotherapy with rituximab, pirarubicin, and prednisolone, without cyclophosphamide and vincristine, he had developed light hyponatremia (nadir 130 mEq/L). However, after the third and fourth courses of chemotherapy with rituximab, pirarubicin, prednisolone, and cyclophosphamide, he had developed a medium level of hyponatremia (nadir 124-125 mEq/L) and his NAG level had increased further. The possible mechanism of this phenomenon is due to renal tubular damage by cyclophosphamide. We conclude that extra caution is necessary if a patient develops severe hyponatremia following chemotherapeutic treatment with cyclophosphamide and vincristine.

AAV8 vector expressing IL24 efficiently suppresses tumor growth mediated by specific mechanisms in MLL/AF4-positive ALL model mice.

Mixed-lineage leukemia (MLL)/AF4-positive acute lymphoblastic leukemia (ALL) is a common type of leukemia in infants, which is associated with a high relapse rate and poor prognosis. IL24 selectively induces apoptosis in cancer cells and exerts immunomodulatory and antiangiogenic effects. We examined the effects of adeno-associated virus type 8 (AAV8) vector-mediated muscle-directed systemic gene therapy in MLL/AF4-positive ALL using IL24. In a series of in vitro studies, we examined the effects of AAV8-IL24-transduced C2C12 cell-conditioned medium. We also examined the effects of AAV8-IL24 in MLL/AF4 transgenic mice. The results revealed the effects of AAV8-IL24 in MLL/AF4-positive ALL both in vitro and in vivo. With regard to the mechanism of therapy using AAV8-IL24 in MLL/AF4-positive ALL, we demonstrated the antiangiogenicity and effects on the ER stress pathway and unreported pathways through inhibition of S100A6 and HOXA9, which is specific to MLL/AF4-positive ALL. Inhibition of S100A6 by IL24 was dependent on TNF-α and induced acetylation of p53 followed by activation of the caspase 8-caspase 3 apoptotic pathway. Inhibition of HOXA9 by IL24, which was independent of TNF-α, induced MEIS1 activation followed by activation of the caspase 8-caspase 3 apoptotic pathway. Thus, gene therapy using AAV8-IL24 is a promising treatment for MLL/AF4-positive ALL.

First report of infectious pericarditis due to Bordetella holmesii in an adult patient with malignant lymphoma.

Bordetella holmesii is a fastidious Gram-negative rod first identified in 1995. Though rare, it is isolated mainly in immunocompromised and asplenic hosts and is associated with bacteremia, pertussis-like respiratory tract infection, and endocarditis. Herein, we describe a unique B. holmesii infectious pericarditis patient with malignant lymphoma.

Interferon-gamma and tumor necrosis factor-alpha induce an immunoinhibitory molecule, B7-H1, via nuclear factor-kappaB activation in blasts in myelodysplastic syndromes.

During disease progression in myelodysplastic syndromes (MDS), clonal blasts gain a more aggressive nature, whereas nonclonal immune cells become less efficient via an unknown mechanism. Using MDS cell lines and patient samples, we showed that the expression of an immunoinhibitory molecule, B7-H1 (CD274), was induced by interferon-gamma (IFNgamma) and tumor necrosis factor-alpha (TNFalpha) on MDS blasts. This induction was associated with the activation of nuclear factor-kappaB (NF-kappaB) and nearly completely blocked by an NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC). B7-H1(+) MDS blasts had greater intrinsic proliferative capacity than B7-H1(-) MDS blasts when examined in various assays. Furthermore, B7-H1(+) blasts suppressed T-cell proliferation and induced T-cell apoptosis in allogeneic cocultures. When fresh bone marrow samples from patients were examined, blasts from high-risk MDS patients expressed B7-H1 molecules more often compared with those from low-risk MDS patients. Moreover, MDS T cells often overexpressed programmed cell death 1 (PD-1) molecules that transmit an inhibitory signal from B7-H1 molecules. Taken together, these findings provide new insight into MDS pathophysiology. IFNgamma and TNFalpha activate NF-kappaB that in turn induces B7-H1 expression on MDS blasts. B7-H1(+) MDS blasts have an intrinsic proliferative advantage and induce T-cell suppression, which may be associated with disease progression in MDS.

Clinical efficacy and safety of biapenem for febrile neutropenia in patients with underlying hematopoietic diseases: a multi-institutional study.

A multi-institutional study was conducted to assess efficacy and safety of biapenem (BIPM), a carbapenem antibiotic, as an initial-stage therapeutic agent for febrile neutropenia (FN) in patients with hematopoietic diseases. A total of 216 patients from 25 medical institutions were enrolled in this study; of these, 204 were included in the safety analysis and 178 in the efficacy analysis. The combined (excellent and good) response rate was 67.9%, and antipyretic effect (subsidence + tendency to subsidence) was achieved within 3 and 5 days of treatment in 67.3 and 75.9% of patients, respectively. Thus, the clinical responses were gratifying. A response rate of 61.7% (37/60) was observed even in high-risk FN patients in whom neutrophil counts prior to and at 72 h after the start of BIPM were ≤100/µl. BIPM is considered to be a highly promising drug, with prompt onset of clinical benefit, as an initial-stage therapeutic agent for the treatment of FN in patients with hematopoietic diseases.

[Loss of Philadelphia chromosome after graft failure following cord blood transplantation for Philadelphia chromosome-positive acute myeloid leukemia].

A 58-year-old male was diagnosed as having Philadelphia chromosome-positive acute myeloid leukemia and treated with imatinib combined chemotherapy followed by reduced-intensity cord blood transplantation. After transplantation, the graft was rejected but the Philadelphia-positive leukemia clone was eliminated. Following graft rejection, hematopoietic recovery with del (20q) gradually occurred. These findings suggest that this patient had transformed to acute myeloid leukemia from myelodysplastic syndrome with del (20q) after acquisition of the Philadelphia chromosome.

Induction of tumor-specific acquired immunity against already established tumors by selective stimulation of innate DEC-205(+) dendritic cells.

Two major distinct subsets of dendritic cells (DCs) are arranged to regulate our immune responses in vivo; 33D1(+) and DEC-205(+) DCs. Using anti-33D1-specific monoclonal antibody, 33D1(+) DCs were successfully depleted from C57BL/6 mice. When 33D1(+) DC-depleted mice were stimulated with LPS, serum IL-12, but not IL-10 secretion that may be mediated by the remaining DEC-205(+) DCs was markedly enhanced, which may induce Th1 dominancy upon TLR signaling. The 33D1(+) DC-depleted mice, implanted with syngeneic Hepa1-6 hepatoma or B16-F10 melanoma cells into the dermis, showed apparent inhibition of already established tumor growth in vivo when they were subcutaneously (sc) injected once or twice with LPS after tumor implantation. Moreover, the development of lung metastasis of B16-F10 melanoma cells injected intravenously was also suppressed when 33D1(+) DC-deleted mice were stimulated twice with LPS in a similar manner, in which the actual cell number of NK1.1(+)CD3(-) NK cells in lung tissues was markedly increased. Furthermore, intraperitoneal (ip) administration of a very small amount of melphalan (L: -phenylalanine mustard; L: -PAM) (0.25 mg/kg) in LPS-stimulated 33D1(+) DC-deleted mice helped to induce H-2K(b)-restricted epitope-specific CD8(+) cytotoxic T lymphocytes (CTLs) among tumor-infiltrating lymphocytes against already established syngeneic E.G7-OVA lymphoma. These findings indicate the importance and effectiveness of selective targeting of a specific subset of DCs, such as DEC-205(+) DCs alone or with a very small amount of anticancer drugs to activate both CD8(+) CTLs and NK effectors without externally added tumor antigen stimulation in vivo and provide a new direction for tumor immunotherapy.

Importance of maintaining the relative dose intensity of CHOP-like regimens combined with rituximab in patients with diffuse large B-cell lymphoma.

CHOP-like regimen combined with rituximab is a standard chemotherapy for diffuse large B-cell lymphoma (DLBCL). The relative dose intensity (RDI) was proposed as an index of the dose and administration interval of agents. Previous studies reported that the maintenance of the RDI during CHOP therapy improved the treatment results. However, few studies regarding RDI have reviewed patients receiving combination therapy with CHOP and rituximab. We investigated the influence of RDI maintenance, involving combination therapy with rituximab, on therapeutic effects in patients with DLBCL. We retrospectively examined 152 DLBCL patients who were treated with CHOP-like regimen combined with rituximab in whom the RDI could be followed up. Multivariate analysis revealed that international prognosis index (IPI) high intermediate-high (HI-H) (p = 0.005) and RDI of less than 70% (p = 0.007) were independent prognostic factors for low progression free survival. Concerning overall survival, IPI HI-H (p = 0.027) and an RDI of less than 70% (p = 0.002) were involved in an unfavorable prognosis. In addition, age over 60 years (p = 0.003), R-THPCOP (p = 0.034), or the presence of febrile neutropenia (p = 0.004) made RDI maintenance difficult, and prophylactic G-CSF therapy (p = 0.026) was useful for maintaining the RDI. Maintaining the RDI is important even in the era of rituximab-combined chemotherapy for DLBCL.

Functional B7.2 and B7-H2 molecules on myeloma cells are associated with a growth advantage.

PURPOSE: B7 family molecules expressed on antigen-presenting cells stimulate or inhibit normal immune responses. The aim of this study was to investigate whether functional B7.2 and B7-H2 molecules are expressed on myeloma cells and, if so, whether they are associated with pathophysiology in myeloma. EXPERIMENTAL DESIGN: The expression of B7.2 and B7-H2 molecules on normal plasma and neoplastic (myeloma) plasma cells was analyzed. The cell proliferation and immunomodulatory function of myeloma cells related to B7.2 and B7-H2 expression were examined. RESULTS: Human myeloma cell lines commonly expressed B7.2 and B7-H2 molecules. B7.2 expression on plasma cells was more common in myeloma patients (n = 35) compared with that in patients with monoclonal gammopathy of unknown significance (n = 12) or hematologically normal individuals (n = 10). Plasma cells expressing B7-H2 were observed in myeloma patients alone, although rarely. Patients whose myeloma cells showed high B7.2 expression were more anemic and thrombocytopenic than other myeloma patients. The expression of these molecules was induced or augmented by cultivating myeloma cells with autologous stroma cells or tumor necrosis factor-alpha, a key cytokine in myeloma biology. Cell proliferation was more rapid in the B7.2+ and B7-H2+ populations compared with the B7.2(-) and B7-H2(-) populations, respectively, in the human myeloma cell lines examined. B7.2 and B7-H2 molecules on myeloma cells induced normal CD4+ T cells to proliferate and produce soluble factors, including interleukin-10 that stimulate myeloma cell proliferation. CONCLUSIONS: Functional B7.2 and B7-H2 molecules detected on myeloma cells may be involved in the pathophysiology of myeloma.

Stem cell transplantation using non-myeloablative conditioning regimen with fludarabine for hematological malignancies.

Stem cell transplantation (SCT) is a useful treatment for hematological malignancies, but it is limited to younger patients because of its high treatment-related mortality. Fludarabine (Flu), a novel anticancer agent with potent immunosuppressive activity, used as a conditioning regimen (reduced intensity transplantation; RIST), can decrease treatment-related mortality, as recently reported. However, the best drug combination and the best timing for RIST remain unknown. We herein report the SCT outcomes of 36 patients undergoing Flu treatment at our institution since December 2002 and retrospectively analyze the results. RIST conditioning with Flu was well-tolerated. No severe toxicity related conditioning regimens was observed in our patients, even though there were 10 patients with a history of autologous (n = 5) or allogeneic stem cell transplantation (n = 5). Hematological engraftment was found in 33 patients. The median times for reconstitution of WBCs, RBCs, and platelets were 16 days, 27.5 days and 34 days, respectively. Stable complete donor chimerism after SCT was present in all patients with WBC engraftment, and no patients experienced late rejection. Thirty-two patients were evaluated for acute graft versus host disease (aGVHD). Nine patients had no aGVHD. The incidence of grade I/II and III/IV aGVHD was 78% and 22%, respectively. Skin lesions were the major sites of involvement. Gut involvement was present in 9 patients. All 4 patients with grade IV GVHD had stage four hepatic GVHD. Twenty-two patients were analyzed for chronic GVHD (cGVHD). Twelve patients had no cGVHD, 6 had limited type and 4 had extended type. The overall survival (OS), relapse rate (RR), and non-relapse mortality (NRM) in all patients over 7 years were found to be 41.7%, 20.1%, and 34.6%, respectively. Induction failures were present in 5 cases of AML and 1 case of NHL. Disease progression was the primary cause of death, which occurred in 12 of 21 patients. Six patients died of grade IV GVHD (n = 2) or complicated fungal infection contracted during the GVHD treatment (n = 4). One patient died of secondary MSD, which originated from donor hematopoietic cells. Two patients died of cerebral bleeding and cardiac rapture, respectively. We found that the patients' state on SCT was the most important factor in long-term survival. The OS of standard risk and high risk patients with hematological malignancies were 75% and 30.3%. We concluded that stem cell transplantation using a non-myeloablative conditioning regimen with Flu was a useful therapeutic approach for patients with hematological malignancies.

[Epstein-Barr virus-related B-cell lymphoma of the skin which developed early after cord blood transplantation for angioimmunoblastic T-cell lymphoma].

We report here a rare case of EBV-related post-transplantation lymphoproliferative disorder (PTLD) localized to the skin. The patient was a 64-year-old man diagnosed with angioimmunoblastic T cell lymphoma (AITL). He underwent cord blood transplantation with a reduced intensity conditioning regimen during partial remission after chemotherapy. On day 70 after transplantation, subcutaneous tumors developed near the left scapula and in the left upper arm. Pathological examination of the skin tumor revealed that this tumor was composed of diffuse large centroblast-like cells, the majority of which were CD20 positive, CD 79a positive, CD30 positive and Epstein-Barr virus (EBV) latency-associated RNA (EBER) positive, and EBV-DNA was also detected in tumor cells. At that time, real-time polymerase chain reaction documented no evidence of the EBV genome in his blood. Chimerism analysis revealed that the tumor cells were derived from donor cells, which led to the diagnosis of EBV-related PTLD. For treatment, in addition to decreasing the dose of tacrolimus, we administered rituximab and local irradiation to skin lesions, which led to disappearance of the tumors followed by continued complete remission.

Diagnostic utility of flow cytometry in low-grade myelodysplastic syndromes: a prospective validation study.

BACKGROUND: The diagnosis of myelodysplastic syndromes is not always straightforward when patients lack specific diagnostic markers, such as blast excess, karyotype abnormality, and ringed sideroblasts. DESIGN AND METHODS: We designed a flow cytometry protocol applicable in many laboratories and verified its diagnostic utility in patients without those diagnostic markers. The cardinal parameters, analyzable from one cell aliquot, were myeloblasts (%), B-cell progenitors (%), myeloblast CD45 expression, and channel number of side scatter where the maximum number of granulocytes occurs. The adjunctive parameters were CD11b, CD15, and CD56 expression (%) on myeloblasts. Marrow samples from 106 control patients with cytopenia and 134 low-grade myelodysplastic syndromes patients, including 81 lacking both ringed sideroblasts and cytogenetic aberrations, were prospectively analyzed in Japan and Italy. RESULTS: Data outside the predetermined reference range in 2 or more parameters (multiple abnormalities) were common in myelodysplastic syndromes patients. In those lacking ringed sideroblasts and cytogenetic aberrations, multiple abnormalities were observed in 8/26 Japanese (30.8%) and 37/55 Italians (67.3%) when the cardinal parameters alone were considered, and in 17/26 Japanese (65.4%) and 42/47 Italians (89.4%) when all parameters were taken into account. Multiple abnormalities were rare in controls. When data from all parameters were used, the diagnostic sensitivities were 65% and 89%, specificities were 98% and 90%, and likelihood ratios were 28.1 and 8.5 for the Japanese and Italian cohorts, respectively. CONCLUSIONS: This protocol can be used in the diagnostic work-up of low-grade myelodysplastic syndromes patients who lack specific diagnostic markers, although further improvement in diagnostic power is desirable.

Leukemogenesis of b2a2-type p210 BCR/ABL in a bone marrow transplantation mouse model using a lentiviral vector.

The BCR/ABL fusion oncogene found in Philadelphia-positive leukemia exists in three principle forms: p190, p210 and p230. P210 BCR/ABL is commonly found in patients with chronic myelogenous leukemia (CML) and is further categorized into b3a2 or b2a2 subtypes on the basis of the BCR breakpoint. Although these 2 subtypes may be clinically heterogeneous, only the b3a2 BCR/ABL gene has been extensively studied at the molecular and cellular levels. In the present study, we compared the in vivo leukemogenic activity of the b3a2 and b2a2 BCR/ABL genes by using lentiviral transduction/transplantation mouse models. Lineage-depleted bone marrow cells of BALB/c mice were transduced with a lentiviral vector including either b2a2 or b3a2 BCR/ABL cDNA and then transplanted into lethally irradiated mice. In this model, p210 BCR/ABL subtype developed only B220(+), CD3e(-), Gr1(-), and Mac1(-) B-cell acute lymphoblastic leukemia but not myeloid leukemia. There were no differences in the incidence of leukemogenesis, the white blood cell count, the percentage of blast cells, or the survival rates between the b2a2 and b3a2 groups. We have demonstrated that b2a2-type BCR/ABL has leukemogenic activity similar to that of b3a2-type BCR/ABL.

[Development of new mixing method of Busulfex injection for the purpose of improvement of medical safety method: the prefilled syringe method].

Busulfex is a new type of busulfan which can be administered intravenously. Usually it is administered over 2 hours every 6 hours. Its injection should be finished within 8 hours after mixture with a saline, which may bring some troublesome in clinical practice. We, here, introduce the prefilled-syringe method; Busulfex is filled into an injection syringe made of polypropylene beforehand under a sterile condition, and mixed with a saline just before the administration at the bed side. To evaluate the safety of this method we studied the stability of busulfan solution in the syringe physically and chemically. The drug solution was made with the same ingredients as Busulfex, filled into a syringe, and stored at 4 degrees C until use. Then, the transparency of this solution was studied with spectroscopy and the concentration of busulfan was analyzed directly by HPLC. Busulfan solution stored in non-colored injection syringe at 4 degrees C was stable for up to 96 hours both physically and chemically. We concluded that prefilled-syringe method is ease and safe way to administer Busulfex on scheduled time.

Flow cytometric parameters with little interexaminer variability for diagnosing low-grade myelodysplastic syndromes.

Recent studies have suggested that flow cytometry (FCM) helps diagnose myelodysplastic syndromes (MDS). However, appropriate FCM diagnostic parameters that are easily reproducible by different examiners remain unclarified. We found that "the Ly/Mbl CD45 ratio (mean fluorescence intensity [MFI] of CD45 on lymphocytes/MFI of CD45 on CD34+ myeloblasts)," "the percentage of CD34+ myeloblasts among all nucleated cells," and "the percentage of CD34+ B-cell precursors among all CD34+ cells" had little interexaminer variability. These parameters can be analyzed from one test tube for three-color FCM, and their analysis in combination can diagnose a certain percentage of low-grade MDS patients.

Long-term response and outcome following immunosuppressive therapy in thymoma-associated pure red cell aplasia: a nationwide cohort study in Japan by the PRCA collaborative study group.

BACKGROUND: Thymoma-associated pure red cell aplasia (PRCA) accounts for a significant proportion of cases of secondary PRCA and immunosuppressive therapy has been reported to be useful in this condition. However, because of its rarity, the long-term response and relapse rates after immunosuppressive therapy are largely unknown, and optimal management of this disorder remains unclear. The aim of this study was to collect more information on the outcome of patients with thymoma-associated PRCA. DESIGN AND METHODS: We conducted a nationwide survey in Japan. From a total of 185 patients, comprising 73 with idiopathic and 112 with secondary PRCA, 41 patients with thymoma were evaluated for this report. End-points of this study were the response rate, duration of the response after immunosuppressive therapy and overall survival. RESULTS: Surgical removal of thymoma was reported in 36 patients, 16 of whom developed PRCA at a median of 80 months post-thymectomy. First remission induction therapy was effective in 19 of 20 patients treated with cyclosporine, 6 of 13 patients treated with corticosteroids and 1 of 1 treated with cyclophosphamide. No cyclosporine-responders relapsed within a median observation period of 18 months (range; 1 to 118 months). Relapse of anemia was observed in three corticosteroid-responders who did not receive additional cyclosporine. Only two patients were in remission after stopping therapy for 19 and 67 months. The estimated median overall survival time of all patients was 142 months. CONCLUSIONS: Thymoma-associated PRCA showed an excellent response to cyclosporine and cyclosporine-containing regimens were effective in preventing relapse of anemia. It does, however, remain uncertain whether cyclosporine can induce a maintenance-free hematologic response.

Clinical features of adult acute leukemia with 11q23 abnormalities in Japan: a co-operative multicenter study.

To clarify the clinical features of adult patients with acute leukemia (AL) with 11q23 abnormalities, we performed a retrospective analysis of data from 58 adult Japanese patients: 51 with acute myeloid leukemia (AML), and 7 with acute lymphoblastic leukemia (ALL). The incidences according to fusion partners in AML were: t(9;11), 31.3%; t(11;19), 27.4%; t(6;11), 21.5%. The incidence of patients with t(11;19) was higher than those in the US and Europe, and the incidence of t(4;11) was lower than that in childhood. The results indicated the poor prognosis of AML with 11q23 abnormalities regardless of the fusion partners. AML patients with 11q23 aged <60 years in the first CR who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed a more favorable outcome than those treated without allo-HSCT, although the differences were not statistically significant (P = 0.322 for DFS, P = 0.138 for OS). This result suggests that treatment strategies including allo-HSCT may be considered in the first CR in cases of AML with 11q23 abnormalities. However, further studies involving a large number of cases are required to assess the effect of allo-HSCT on adult AL with 11q23 abnormalities.

Multicenter prospective trial evaluating the tolerability of imatinib for Japanese patients with chronic myelogenous leukemia in the chronic phase: does body weight matter?

Imatinib at a daily dose of 400 mg is the standard treatment for chronic myelogenous leukemia in the chronic phase. However, the feasibility of this dose for small Japanese adults has not been clarified. We prospectively investigated the toxicity and efficacy of this dose in adult Japanese patients. Among the 89 evaluable patients with a median body weight of 62.8 kg, imatinib therapy was held in 40 subjects (45%), due to Grade 3-4 toxicities in 30 patients (75%) and Grade 2 toxicities at the discretion of the attending physician in 10 patients (25%). However, treatment was resumed and the dose was gradually increased until 62 of the 89 patients tolerated a maintenance dose of 400 mg. Older age and lower body weight were significant independent risk factors for discontinuation of imatinib. After a median follow-up period of 31 months, 84 patients were alive without progression. The complete cytogenetic response rate was 60 and 90% at 6 months and 1 year after starting imatinib, respectively. Older patients and those with a lower body weight were less likely to achieve a complete cytogenetic response. These findings suggest that the body weight has a significant influence on the toxicity and efficacy of imatinib in patients with a small body size, although dose reduction in proportion to weight may result in an inadequate response to imatinib.

[Drug-induced anemia].

Drug-induced anemia includes many kind of anemias with different mechanisms. Mechanisms of drug-induced anemia are divided into two groups, namely erythrocyte injury in peripheral blood and damage of erythroid progenitor cells or erythroblasts. Hemolytic anemias are included in the former and megaloblastic anemia, ringed sideroblastic anemia and pure red cell aplasia are included in the latter. When the drug induced anemia is suspected, complete blood cell count including reticulocyte count and examination of the blood smear and blood chemistry tests should be done. Also, history of the medication should be precisely taken. As for the treatment of drug-induced anemia, the responsible drug should be stopped immediately and individual therapy will be done if necessary.