Motohiro Shindo

Severe Hepatic Injury Caused by Imatinib Mesylate Administered for the Treatment of Chronic Myeloid Leukemia and the Efficacy of Prednisolone for its Management

Imatinib mesylate is a specific inhibitor of BCR-ABL tyrosine kinase, which is now widely used for the treatment of chronic myeloid leukemia (CML) with a high efficacy. Although severe hepatic injury caused by imatinib mesylate is rare, such a side effect may force patients to discontinue taking imatinib mesylate. In the present paper, we report on the case of a 51-year-old woman with CML who experienced hepatic injury with severe hyperbilirubinemia caused by imatinib mesylate. The findings from a liver biopsy specimen and her clinical course suggested the hepatic injury to presumably have been caused by an allergic mechanism. The co-administration of prednisolone was thus tried, and she has been able to continue imatinib mesylate administration without any liver dysfunction and finally was able to obtain a complete cytogenetic response. We therefore recommend that prednisolone should be tried when severe hepatic injury caused by imatinib mesylate is observed, since it might enable such patients to continue imatinib mesylate treatment and thereby improve the prognosis in such cases.

High Level of Serum Soluble Interleukin-2 Receptor at Transplantation Predicts Poor Outcome of Allogeneic Stem Cell Transplantation for Adult T Cell Leukemia

The prognosis for adult T cell leukemia/lymphoma (ATL) is very poor, and only allogeneic hematopoietic stem cell transplantation (allo-SCT) has been considered to be a curative treatment for ATL. In this study, we retrospectively analyzed data for patients who had received allo-SCT for ATL in Hokkaido, the northernmost island of Japan, to determine prognostic factors. Fifty-six patients with a median age of 57 years received allo-SCT. Twenty-eight (50.0%) patients had acute type and 22 (46.4%) had lymphoma type. Twenty-three (41.1%) patients received allo-SCT in complete remission (CR), whereas the others were in non-CR. Seventeen (30.4%) patients received myeloablative conditioning and the others received reduced-intensity conditioning. With a median follow-up period of 48 months (range, 17 to 134 months), 1-year overall survival (OS) and 5-year OS rates were 55.4% and 46.1%, respectively. The survival curve reached a plateau at 22 months after stem cell transplantation (SCT). Male sex, high level of serum soluble interleukin-2 receptor (sIL-2R) at SCT, and non-CR at SCT were determined to be significant risk factors for OS. A high level of sIL-2R at SCT was a risk factor for poor OS in patients with non-CR at SCT by univariate analysis (P = .02), and it remained significant after adjustment by sex (hazard ratio, 2.73 [95% confidence interval, 1.07 to 7.90]). A high level of sIL-2R at SCT was also determined to be a risk factor for disease progression (P = .02). This region-wide study showed encouraging results for survival after allo-SCT for ATL and demonstrated for the first time that a high level of sIL-2R at SCT predicts worse SCT outcome.

Current therapeutic strategies for multiple myeloma.

The introduction of novel molecular targeting agents against multiple myeloma has dramatically and rapidly changed the therapeutic strategies for this incurable hematologic disease. Novel agents such as thalidomide, bortezomib and lenalidomide have significantly improved the response rate, progression-free survival, and overall survival compared with conventional chemotherapies, and made it easy to control the disease for longer periods of time. Initial therapies for newly diagnosed myeloma patients depend on the individual’s clinical condition. Induction therapy with novel agents and high-dose chemotherapy followed by autologous stem cell transplantation is a standard therapy for newly diagnosed younger myeloma patients. On the other hand, several combinations of novel agents and other drugs (melphalan, prednisone, dexamethasone, etc.) are widely used as initial therapy for transplantation-ineligible myeloma patients. Although the clinical advantage of maintenance therapy after induction therapy has been reported, it is not recommend in routine practice. Maintenance therapy would be an option for some patients. Despite the significant improvements with the use of novel agents, the majority of patients eventually relapse. A number of treatment options including novel agents, which demonstrated marked clinical effects, are reported in the setting of salvage therapy. The choice of appropriate therapy for relapsed or refractory patients must take the disease status or patient status in consideration. Furthermore, a new generation of novel agents such as pomalidomide, carfilzomib or panobinostat has recently become available for relapsed or refractory myeloma. It is necessary to determine the optimal combination of drugs, administration timing and patients to be treated in future clinical trials.

Loss of ABCB7 gene: pathogenesis of mitochondrial iron accumulation in erythroblasts in refractory anemia with ringed sideroblast with isodicentric (X)(q13)

An isodicentric (X)(q13) (idicXq13) is a rare, acquired chromosomal abnormality originated by deletion of the long arm from Xq13 (Xq13-qter), and is found in female patients with hematological disorders involving increased ringed sideroblasts (RSs), which are characterized by mitochondrial iron accumulation around the erythroblast nucleus. The cause of increased RSs in idicXq13 patients is not fully understood. Here, we report the case of a 66-year-old female presenting with refractory anemia with ringed sideroblasts (RARS), and idicXq13 on G-banded analysis. We identify the loss of the ABCB7 (ATP-binding cassette subfamily B member-7) gene, which is located on Xq13 and is involved in mitochondrial iron transport to the cytosol, by fluorescent in situ hybridization (FISH) analysis and the decreased expression level of ABCB7 mRNA in the patient’s bone marrow cells. Further FISH analyses showed that the ABCB7 gene is lost only on the active X-chromosome, not on the inactive one. We suggest that loss of ABCB7 due to deletion of Xq13-qter at idicXq13 formation may have contributed to the increased RSs in this patient. These findings suggest that loss of the ABCB7 gene may be a pathogenetic factor underlying mitochondrial iron accumulation in RARS patients with idicXq13.

Induction of leukemia-specific antibodies by immunotherapy with leukemia-cell-derived heat shock protein 70

Cancer immunotherapy using heat shock protein (HSP) derived from autologous tumor requires cluster of differentiation (CD)4+ as well as CD8+ T‐cells for the prolongation of patient survival, suggesting that a humoral immune response through CD4+ T‐cells is important in addition to cellular immunity. However, the role of humoral responses in HSP‐based autologous tumor immunotherapy remains unclear. In the present study, we investigated whether leukemia‐specific antibodies and antibody‐mediated cytotoxicity against autologous leukemia cells have a crucial role in a mouse A20 leukemia model by immunizing A20‐derived HSP70. Immunization with A20‐derived HSP70 induced the production of anti‐A20‐antibodies and the antibodies recognized HSP70‐binding peptides derived from A20. One of those was a major histocompatibility complex (MHC) class‐I binding peptide, which has been clarified as the target peptide of CD8+ cytotoxic T‐cells (CTL) against A20. The anti‐A20‐antibodies produced by immunization with A20‐derived HSP70 induced complement‐dependent cytotoxicity (CDC) against A20 in vitro. In addition, immunization with A20‐derived HSP70 increased intracellular interleukin‐4 (IL4)‐production of CD4+ T‐cells, confirming the activation of type‐2 helper T‐cells. Taken together, immunization with leukemia‐cell‐derived HSP70 induces antibodies against leukemia‐cell‐specific peptides and might play a crucial role in the eradication of leukemia cells by CDC in mice. These findings will enable future establishment of a novel therapeutic strategy using antileukemia antibodies in HSP‐based autologous tumor immunotherapy. (Cancer Sci 2008; 99: 1427–1434)

A Multicenter Retrospective Study of Mogamulizumab Efficacy in Adult T-Cell Leukemia/Lymphoma.

Micro‐Abstract Mogamulizumab recently became available for the treatment of adult T‐cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab for ATL treatment in patients in Japan and found that mogamulizumab is an effective therapeutic strategy in ATL. Some concern exists that the use of mogamulizumab in patients undergoing hematopoietic stem cell transplantation patients might cause severe graft‐versus‐host disease. Determining the optimum number of mogamulizumab administrations should be a priority for future studies. Background: Mogamulizumab, a defucosylated humanized monoclonal antibody targeting C‐C chemokine receptor 4, recently became available for the treatment of adult T‐cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab in ATL treatment in patients on Hokkaido Island, Japan. Materials and Methods: A total of 125 patients with ATL treated from January 2010 to December 2014 in 20 hospitals affiliated with the Hokkaido Hematology Study Group were enrolled in the present retrospective study. Results: Of the 125 ATL patients, 62 (46.6%) presented with the acute type, 51 (38.3%) with the lymphoma type, and 12 (9.0%) with the chronic type; the latter group included 7 unfavorable chronic cases. The median age at diagnosis was 68 years (range, 35‐86 years). The median survival for those with acute, lymphoma, and unfavorable chronic types was 302, 279, and 921 days, respectively. Advanced age, high lactate dehydrogenase level, poor performance status (3‐4), and the existence of B symptoms were unfavorable prognostic factors for overall survival (OS). Survival rate calculated from the day of diagnosis was significantly higher in patients treated with mogamulizumab. The OS of individuals receiving hematopoietic stem cell transplantation (HSCT) was superior to that of the non‐HSCT group. The median interval between the last mogamulizumab dose and allogeneic HSCT was 38 days (range, 21‐53 days). Of the 22 HSCT recipients who were not treated with mogamulizumab, overall acute graft‐versus‐host disease (aGVHD) and grade III‐IV aGVHD occurred in 12 (54.5%) and 3 (13.6%) patients, respectively. However, overall aGVHD and grade III‐IV aGVHD developed in 8 (88.9%) and 3 (33.3%) of the 9 HSCT recipients treated with mogamulizumab, respectively. Conclusion: Mogamulizumab improves OS in patients with ATL, although its use in HSCT patients might trigger severe GVHD. Determining the optimal pre‐HSCT mogamulizumab treatment regimen is thus a priority.

The three isoforms of hepcidin in human serum and their processing determined by liquid chromatography-tandem mass spectrometry (LC-tandem MS)

Hepcidin, the iron regulatory hormone, has three isoforms; -20, -22 and -25. While hepcidin-25 has been studied extensively, the physiological significance of other isoforms remains poorly understood. Using a quantitative method based on liquid chromatography-tandem mass spectrometry (LC-tandem MS) developed by our group, we quantified hepcidin isoforms in human serum to elucidate their characteristics, and investigated the role of hepatocytes in isoform processing. Hepcidin isoforms in serum obtained from 40 healthy volunteers were quantified. Synthetic hepcidin peptides were added to healthy serum, and to HepG2 culture media, and hepcidin isoform concentrations determined. All three hepcidin isoforms were detected in human serum; however, hepcidin-25 concentrations were highest. The three hepcidin isoforms showed a strong positive correlation with each other and with serum ferritin. Additionally, while hepcidin-20 was strongly correlated with serum creatinine, the other isoforms were not. Hepcidin-20 and -25 levels were also increased in chronic kidney disease (CKD) serum. Hepcidin-22 rapidly degraded into hepcidin-20, whereas hepcidin-25 remained relatively stable. Finally, hepcidin-22 degradation into hepcidin-20 was accelerated in the presence of HepG2. This method has enabled us to reveal fundamental characteristics of the three hepcidin isoforms in serum and may be a powerful tool for quantifying hepcidin isoform expression and processing.

A novel five-way chromosomal translocation observed in chronic myelogenous leukemia

Most patients with chronic myelogenous leukemia (CML) show a Philadelphia (Ph) chromosome with a characteristic translocation between chromosomes 9 and 22. However, there are variant complex translocations involving other chromosomes in addition to the standard translocation. We describe a case of CML showing a complex and novel chromosomal translocation involving five chromosomes, t(4;12;7;9;22).

Two cases of mycosis fungoides treated by reduced‐intensity cord blood transplantation

Mycosis fungoides is a cutaneous T‐cell lymphoma, which is clinically divided into three stages: patch, plaque and tumor. Despite a variety of treatments the prognosis is poor in advanced mycosis fungoides. Recently, allogeneic hematopoietic stem cell transplantation has been successfully applied for such cases. We performed reduced‐intensity umbilical cord blood transplantation for two advanced mycosis fungoides patients. Case 1 was a 56‐year‐old man and case 2 was a 30‐year‐old woman. Tumors of each case were refractory to conventional chemotherapy. Although radiation therapy was considerably effective, tumors relapsed after several months. Reduced‐intensity umbilical cord blood transplantation was performed because case 1 had no human leukocyte antigen‐identical siblings and the sibling of case 2 did not agree to be the donor. The male patient died of pulmonary failure 23 days after reduced‐intensity umbilical cord blood transplantation. The case 2 patient succeeded in reduced‐intensity umbilical cord blood transplantation and remained in complete/partial remission for 13 months. However, chemotherapy‐resistant tumors relapsed, and allogeneic hematopoietic stem cell transplantation was performed at 17 months. She died of cerebral hemorrhage 23 days after the procedure. Reduced‐intensity umbilical cord blood transplantation may be included in the treatments for advanced mycosis fungoides, where graft‐versus‐lymphoma effect seems to be a significant factor for the success of the treatment.

Non-transferrin-bound iron assay system utilizing a conventional automated analyzer

BACKGROUND Iron is an essential metal in the body, but its excessive accumulation causes damage in various organs through free radical production. Iron homeostasis is therefore tightly regulated. However, when iron balance collapses, such as in prolonged transfusion, transferrin (Tf) is fully saturated and non-Tf-bound iron (NTBI) appears in the serum. Monitoring serum NTBI levels is therefore crucial in the assessment of the clinical status of patients with iron overload, since NTBI is associated with cellular and organ damage. Several methods for NTBI determination have been reported, but these are extremely complicated and very few laboratories can quantify NTBI at present. METHODS We established a novel assay system utilizing automated analyzers that are widely used in clinical laboratories for diagnostic testing. In this assay, NTBI is chelated by nitrilotriacetic acid (NTA), after which the iron is reduced and transferred to nitroso-PSAP, a chromogen. RESULTS The assay shows excellent linearity, reproducibility, and compatibility with HPLC, one of the most reliable conventional methods for NTBI quantification. CONCLUSIONS Our novel method for NTBI measurement is high-throughput and may be a useful and powerful tool in the study of the physiological and clinical importance of NTBI.