Clinical implications of NUP98::NSD1 fusion at diagnosis in adult FLT3-ITD positive AML

OBJECTIVES

The cryptic fusion oncogene NUP98::NSD1 is known to be associated with FLT3-ITD mutation in acute myeloid leukemia (AML), and an independent poor prognostic factor in pediatric AML. However, there are little data regarding the clinical significance of NUP98::NSD1 in adult cohort.

METHODS

We conducted a multicenter retrospective study to investigate the prevalence, clinical characteristics, and prognostic impact of NUP98::NSD1 in adult FLT3-ITD-positive AML patients.

RESULTS

In a total of 97 FLT3-ITD-positive AML patients, six cases (6.2%) were found to harbor the NUP98::NSD1 fusion transcript. NUP98::NSD1 positive cases had significantly higher platelet counts and a higher frequency of FAB-M4 morphology than NUP98::NSD1 negative cases. NUP98::NSD1 was found to be mutually exclusive with NPM1 mutation, and was accompanied by the WT1 mutation in three of the six cases. The presence of NUP98::NSD1 fusion at the time of diagnosis predicted poor response to cytarabine-anthracycline-based intensive induction chemotherapy (induction failure rate: 83% vs. 36%, p = .038). Five of the six cases with NUP98::NSD1 underwent allogeneic hematopoietic stem cell transplantation (HSCT). Two of the five cases have successfully maintained remission, with one of them being rescued through a second HSCT.

CONCLUSIONS

Detecting NUP98::NSD1 in adult FLT3-ITD-positive AML is crucial to recognizing chemotherapy-resistant group.

Use of Mixed Lymphocyte Reaction Assay to Evaluate Immune Tolerance before Kidney Transplantation with an Immunosuppression-Free Protocol following Hematopoietic Stem Cell Transplantation from the Same Donor

Several cases of kidney transplantation after hematopoietic stem cell transplantation (HSCT) from the same donor for end-stage renal disease have been reported. In those cases, immunosuppressive drugs were discontinued since immune tolerance was supposed to be induced. Theoretically, the recipient's immune system recognizes the kidney allograft as its own tissue with the same human leukocyte antigen (HLA) profile, and the kidney allograft will not be rejected, even without the use of immunosuppressive agents. However, almost all recipients receive immunosuppressants in the early stages after kidney transplantation owing to concerns of acute rejection. Here, we report a successful case of post-HSCT kidney transplantation without the use of immunosuppressive drugs, in which a mixed lymphocyte reaction (MLR) assay was used to evaluate immune tolerance before kidney transplantation. The patient was a 25-year-old woman. Five years prior, she developed acute myeloid leukemia and underwent HLA-half-matched peripheral blood stem cell transplantation. Thereafter, she was in remission of the acute myeloid leukemia, but 1 year later, she developed renal graft-versus-host disease. Subsequently, the patient's renal function gradually deteriorated to end-stage renal failure, and she underwent kidney transplantation with the previous stem cell donor: her mother. HLA typing of donor and recipient showed a complete chimerism in the peripheral blood. The pretransplantation complement-dependent cytotoxic crossmatch and flow cytometric T-cell crossmatch results were both negative, and HLA antibody measurements were all negative. The MLR assay revealed no T-lymphocyte reaction to the donor; therefore, immunosuppressants were not used. Two years after transplantation, the patient's serum creatinine concentration was around 0.8 mg/dL (down from 4 mg/dL before transplantation). No abnormalities were observed in a renal biopsy performed after 3 months. Our study, along with others, indicates that immune tolerance to a donor develops in post-HSCT kidney transplantation from the same donor.

Subclinical minute FLT3-ITD clone can be detected in clinically FLT3-ITD-negative acute myeloid leukaemia at diagnosis

Recent advances in next-generation sequencing (NGS) have enabled the detection of subclinical minute FLT3-ITD. We selected 74 newly diagnosed, cytogenetically normal acute myeloid leukaemia (AML) samples in which FLT3-ITD was not detected by gel electrophoresis. We sequenced them using NGS and found minute FLT3-ITDs in 19 cases. We compared cases with clinically relevant FLT3-ITD (n = 37), cases with minute FLT3-ITD (n = 19) and cases without detectable FLT3-ITD (n = 55). Molecular characteristics (location and length) of minute FLT3-ITD were similar to those of clinically relevant FLT3-ITD. Survival of cases with minute FLT3-ITD was similar to that of cases without detectable FLT3-ITD, whereas the relapse rate within 1 year after onset was significantly higher in cases with minute FLT3-ITD. We followed 18 relapsed samples of cases with clinically FLT3-ITD-negative at diagnosis. Two of 3 cases with minute FLT3-ITD relapsed with progression to clinically relevant FLT3-ITD. Two of 15 cases in which FLT3-ITD was not detected by NGS relapsed with the emergence of minute FLT3-ITD, and one of them showed progression to clinically relevant FLT3-ITD at the second relapse. We revealed the clonal dynamics of subclinical minute FLT3-ITD in clinically FLT3-ITD-negative AML. Minute FLT3-ITD at the initial AML can expand to become a dominant clone at relapse.

Shorter duration of venetoclax administration to 14 days has same efficacy and better safety profile in treatment of acute myeloid leukemia

Venetoclax (VEN) is now widely used in the treatment of acute myelogenous leukemia (AML) in elderly patients who are not eligible for intensive remission induction therapy. Prolonged myelosuppression, increased incidence of infection, and long duration of hospital stay were major concerns for VEN treatment cases, and we thought that shortening the duration of VEN administration during induction therapy might solve these problems. Thirteen newly diagnosed AML patients who underwent VEN+azacitidine (AZA) induction therapy from March 2021 to June 2022 at Kushiro Rosai Hospital were analyzed retrospectively. The median age was 79 (range, 68-86) years, and 8 of the patients (61.5%) were classified as high risk according to the ELN 2017 risk stratification. Eight patients received VEN for 14 days (VEN14 group), and 5 patients received VEN for 28 days (VEN28 group). The composite complete remission (CRc) rate was 76.9% in total, and the CRc rates in the VEN14 and VEN28 groups were almost the same (75.0% and 80.0%, respectively). The median overall survival (OS) was not reached in the VEN14 group and was 254 days in the VEN28 group. The median event-free survival (EFS) was not reached in the VEN14 group and was 178 days in the VEN28 group. The VEN14 group might have a possibility to reduce febrile neutropenia (37.5% vs. 80%) and reduce the duration of hospital stay (median, 21.5 vs. 31 days) compared with the VEN28 group. VEN14 produced the same CRc rate and survival rate, safer profile, and shorter duration of hospital stay than VEN28.

Clinical features of complex karyotype in newly diagnosed acute myeloid leukemia

Complex karyotype acute myeloid leukemia (CK-AML) has been classified as an adverse-risk subtype. Although a few reports have further classified CK-AML as typical (including monosomy of chromosomes 5, 7 and 17 or deletion of 5q, 7q and/or 17p) or atypical, the clinical features of these subtypes in Japanese patients remain unclear. We retrospectively analyzed a total of 115 patients with CK-AML, including 77 with typical CK-AML and 38 with atypical CK-AML. Median overall survival (OS) was significantly shorter in patients with typical CK-AML than atypical CK-AML (143 days vs. 369 days, P = 0.009). Among patients with typical CK-AML, those with monosomy 17 or deletion of 17p had significantly shorter OS than patients without such abnormalities (105 days vs. 165 days, P = 0.033). TP53 mutations were more predominant in patients with typical CK-AML than in patients with atypical CK-AML (69.7% vs. 32.4%, P < 0.001). Patients with typical CK-AML had a poor prognosis regardless of TP53 mutation status. Among patients with atypical CK-AML, however, prognosis was worse for those with the TP53 mutation than those without the mutation. In conclusion, prognosis is extremely poor for both typical CK-AML and atypical CK-AML with TP53 mutation.

Improved prognosis with additional medium-dose VP16 to CY/TBI in allogeneic transplantation for high risk ALL in adults

Allogeneic hematopoietic stem cell transplantation (HSCT) with the conventional cyclophosphamide and total body irradiation (CY/TBI) regimen is an essential therapeutic strategy for acute lymphoblastic leukemia (ALL) in adults. Medium-dose etoposide (VP16, 30-40 mg/kg) can be added to intensify this CY/TBI regimen and reduce relapse; however, differences in prognosis between the VP16/CY/TBI and CY/TBI regimens have not yet been fully analyzed. We conducted a retrospective cohort study using a Japanese transplant registry database to compare the prognosis between the VP16/CY/TBI (VP16, total 30-40 mg/kg) (N = 376) and CY/TBI (N = 1178) regimens in adult patients with ALL transplanted at complete remission (CR) between January 1, 2000 and December 31, 2014. Our analyses indicated that VP16/CY/TBI significantly reduced relapse compared with CY/TBI (risk ratio, 0.75; 95% confidence interval [CI], 0.56-1.00; P = .05) with a corresponding improvement in leukemia-free survival (hazard ratio [HR], 0.76; 95%CI, 0.62-0.93; P = .01), particularly in patients transplanted at CR1 with advanced-risk (positive minimal residual disease, presence of poor-risk cytogenetics, or an initial elevated leukocyte count) (HR, 0.75; 95%CI, 0.56-1.00; P = .05) or those transplanted beyond CR2 (HR, 0.58; 95%CI, 0.39-0.88; P = .01). The addition of VP16 did not increase post-transplant complications or nonrelapse mortality (HR, 0.88; 95%CI, 0.65-1.18; P = .38). This study is the first to reveal the efficacy of the addition of medium-dose VP16 to CY/TBI in high-risk ALL. To establish new myeloablative conditioning regimens including VP16, a large-scale prospective study is necessary.

Increased non-relapse mortality due to high-dose cytarabine plus CY/TBI in BMT/PBSCT for acute lymphoblastic leukaemia in adults

The efficacy of high-dose cytarabine (HDCA) plus cyclophosphamide/total-body irradiation (CY/TBI) has been proved in cord blood transplantation (CBT) for acute lymphoblastic leukaemia (ALL), but not in bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT). In this cohort study, we compared the prognosis of CY/TBI (N = 1244) and HDCA/CY/TBI (N = 316) regimens in BMT/PBSCT for ALL. The addition of HDCA decreased post-transplant relapse, while significantly increasing non-relapse mortality (risk ratio, 1·33), and overall survival was not improved. The positive effects of HDCA reported in CBT cannot be extrapolated to BMT/PBSCT, and HDCA may not be recommended in these procedures.

Allogeneic stem cell transplantation for adult patients with acute lymphoblastic leukemia who had central nervous system involvement: a study from the Adult ALL Working Group of the Japan Society for Hematopoietic Cell Transplantation

The prognosis for adult acute lymphoblastic leukemia (ALL) patients with central nervous system (CNS) involvement (CNS+) who received allogeneic hematopoietic stem cell transplantation (allo-SCT) remains unclear. We retrospectively compared the outcomes of allo-SCT for patients with CNS involvement and for patients without CNS involvement (CNS-) using a database in Japan. The eligibility criteria for this study were as follows: diagnosis of ALL, aged more than 16 years, allo-SCT between 2005 and 2012, and first SCT. Data for 2582 patients including 136 CNS+ patients and 2446 CNS- patients were used for analyses. As compared with CNS- patients, CNS+ patients were younger, had worse disease status at SCT and had poorer performance status (PS) at SCT (P < 0.01). Incidence of relapse was higher in CNS+ patients (P = 0.02), and incidence of CNS relapse was also higher (P < 0.01). The probability of 3-year overall survival (OS) was better in CNS- patients (P < 0.01) by univariate analysis. However, in patients who received SCT in CR, there was no difference in the probability of OS between CNS+ and CNS- patients (P = 0.38) and CNS involvement did not have an unfavorable effect on OS by multivariate analysis. CNS+ patients who achieved CR showed OS comparable to that of CNS- patients.

Pharmacokinetics and dose adjustment of etoposide administered in a medium-dose etoposide, cyclophosphamide and total body irradiation regimen before allogeneic hematopoietic stem cell transplantation

BACKGROUND

We investigated the pharmacokinetics of etoposide (ETP) to reduce the inter-individual variations of ETP concentrations in patients with acute leukemia who underwent allogeneic hematopoietic stem cell transplantation. We also carried out an in vivo study using rats to verify the dose adjustment.

METHODS

This study included 20 adult patients. ETP was administered intravenously at a dose of 15 mg/kg once daily for 2 days (total dose: 30 mg/kg) combined with standard conditioning of cyclophosphamide and total body irradiation. In an in vivo study using rats, ETP was administered intravenously at a dose of 15 mg/kg or an adjusted dose. The ETP plasma concentration was determined by using HPLC. The pharmacokinetic parameters were estimated by using a 1-compartment model.

RESULTS

The peak concentration (Cmax) of ETP and the area under the plasma concentration-time curve (AUC) of ETP differed greatly among patients (range of Cmax, 51.8 - 116.5 μg/mL; range of AUC, 870 - 2015 μg · h/mL). A significant relationship was found between Cmax and AUC (R = 0.85, P < 0.05). Distribution volume (Vd) was suggested to be one of the factors of inter-individual variation in plasma concentration of ETP in patients (range of Vd, 0.13 - 0.27 L/kg), and correlated with Alb and body weight (R = 0.56, P < 0.05; R = 0.40, P < 0.05 respectively). We predicted Vd of rats by body weight of rats (with normal albumin levels and renal function), and the dose of ETP was adjusted using predicted Vd. In the dose adjustment group, the target plasma ETP concentration was achieved and the variation of plasma ETP concentration was decreased.

CONCLUSION

The results suggested that inter-individual variation of plasma concentration of ETP could be reduced by predicting Vd. Prediction of Vd is effective for reducing individual variation of ETP concentration and might enable a good therapeutic effect to be achieved.

Occurrence of adverse events caused by valganciclovir as pre-emptive therapy for cytomegalovirus infection after allogeneic stem cell transplantation is reduced by low-dose administration

BACKGROUND

Pre-emptive therapy with valganciclovir (VGCV) has become the standard therapy for preventing cytomegalovirus (CMV) infection after allogeneic hematopoietic stem cell transplantation (HSCT). The effectiveness of low-dose VGCV (900 mg per day) has been shown to be equal to that of standard-dose VGCV (900 mg twice daily); however, individualized optimal dosing and toxicity of VGCV have not been reported.

METHODS

We conducted a retrospective study to evaluate the optimal dose of VGCV as pre-emptive therapy for preventing CMV infection by comparing the frequency of adverse events (AEs) and clinical efficacy in a low-dose VGCV group with those in a standard-dose VGCV group. Thirty-eight patients who were administered VGCV because of CMV antigenemia after HSCT were analyzed.

RESULTS

Neutropenia (standard-dose group: 33%, low-dose group: 15%, P = 0.26) and thrombocytopenia (standard-dose group: 39%, low-dose group: 15%, P = 0.14) were frequent AEs of VGCV, and a significantly higher frequency of overall AEs was detected in the standard-dose group than in the low-dose group (P < 0.01). In comparison of dosage based on weight, dosage of VGCV >27 mg/kg was closely related to onset of AEs (P = 0.04).

CONCLUSIONS

Low-dose VGCV was not inferior in clinical efficacy, including clearance rate of CMV antigenemia and incidence of consequent CMV disease, to standard-dose VGCV as was previously reported. Initial low-dose VGCV for pre-emptive CMV therapy markedly reduces hematologic toxicity and has clinical efficacy equivalent to that of standard-dose VGCV. It is therefore reasonable for patients, except for noticeably overweight patients, to be given initial low-dose VGCV.

Allogeneic hematopoietic stem cell transplantation in adult acute lymphoblastic leukemia: potential benefit of medium-dose etoposide conditioning

The outcomes of adult acute lymphoblastic leukemia (ALL) patients with chemotherapy or autologous hematopoietic stem cell transplantation (HSCT) are unsatisfactory. Therefore, allogeneic (allo) HSCT has been applied to those patients in first complete remission (CR1), and has shown a long-term survival rate of approximately 50 %. In terms of myeloablative conditioning (MAC) regimen, higher dose of cyclophosphamide (CY) and total body irradiation (TBI) (the standard CY + TBI) has been generally applied to allo HSCT. Other MAC regimens such as busulfan-based or etoposide-based regimens have also been used. Among those, medium-dose etoposide (ETP) in addition to the standard CY + TBI conditioning regimen appears to be promising for allo HSCT in adult ALL when transplanted in ALL patients aged under 50 years in CR1 and also in CR2, showing an excellent outcome without increasing relapse or transplant-related mortality (TRM) rates. By contrast, reduced-intensity conditioning (RIC) regimens have also been applied to adult ALL patients and favorable outcomes have been obtained; however, relapse and TRM rates remain high. Therefore, an allo HSCT conditioning regimen which deserves further study for adult ALL patients aged under 50 years in CR1 and CR2 appears to be medium-dose ETP + CY + TBI and RIC is suitable for patients aged over 50 years or for younger patients with comorbid conditions. On the contrary, new therapeutic strategies for adult ALL patients are increasingly utilized with better outcomes; namely, various tyrosine kinase inhibitors for Philadelphia chromosome (Ph)-positive ALL, human leukocyte antigen-haploidentical HSCT, and pediatric-inspired regimens for Ph-negative ALL. Therefore, the optimal treatment modality should be selected considering patient’s age, Ph-positivity, donor availability, risk classification, efficacy, and safety.

Ultrasonographic evaluation of gastrointestinal graft-versus-host disease after hematopoietic stem cell transplantation

Gastrointestinal graft‐versus‐host disease (GI‐GVHD) is a major and life‐threatening complication of hematopoietic stem cell transplantation (HSCT). This study evaluated the efficacy of ultrasonography (US) for assessing and monitoring GI‐GVHD. GI tract was evaluated by US in 81 patients. US findings were positive in 43 patients, including 11 false positive, and negative in 38 patients. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of US for the diagnosis of GI‐GVHD were 100%, 78%, 74%, 100%, and 86%, respectively. Diffuse wall thickening of the ileum was the most frequent finding in patients with GI‐GVHD. Severity of GI‐GVHD was correlated with the thickness of internal low echoic layer of the wall, the echogenicity of mesenteric fat tissue, and the intensity of Doppler signaling. We classified US findings of GI‐GVHD into four US grades. There was a significant correlation between clinical stage of GI‐GVHD and the US grade. These ultrasonographic abnormalities were improved with clinical improvement of GI‐GVHD upon treatment. Thus, US is an effective and efficient non‐invasive means of identifying the extent and severity of GI‐GVHD and monitoring response to treatment.

Ultra-high level of serum soluble interleukin-2 receptor at diagnosis predicts poor outcome for angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of non-Hodgkin lymphoma and displays an aggressive clinical course with poor outcome. To identify prognostic factors for AITL, we retrospectively analyzed 36 patients with AITL. The median age was 74 years with 83% of the patients having advanced stage. Eighty-three percent received CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone)-like chemotherapies, resulting in an overall response rate of 63%. With a median follow-up of 9 years, the estimated overall survival at 5 years was 33.3%. Median serum level of soluble interleukin-2 receptor (sIL-2R) was 5615 U/mL at diagnosis, and over 10 000 U/mL of sIL-2R was identified as a significant poor prognostic factor, independent of the International Prognostic Index, Prognostic Index for peripheral T-cell lymphoma and Prognostic index for AITL (hazard ratio [HR], 4.42; 95% confidence interval [CI], 1.49-13.11; log-rank, p < 0.01). Our study shows that an ultra-high level of serum sIL-2R at diagnosis is a significant poor prognostic biomarker for AITL.

Hepatitis B virus (HBV) reverse seroconversion (RS) can be prevented even in non-responders to hepatitis B vaccine after allogeneic stem cell transplantation: long-term analysis of intervention in RS with vaccine for patients with previous HBV infection

BACKGROUND

Reactivation of hepatitis B virus (HBV) infection, reverse seroconversion (RS), is a serious complication after allogeneic stem cell transplantation (alloHSCT). We previously conducted a post-transplant hepatitis B vaccine intervention trial and demonstrated the vaccine efficacy in preventing HBV-RS. This report is an update of the hepatitis B vaccine study.

METHODS

In this trial, 21 patients were enrolled and received a standard 3-dose regimen of hepatitis B vaccine after discontinuation of immunosuppressants, whereas 25 transplant recipients with previous HBV infection did not receive the vaccine and served as controls.

RESULTS

None of the 21 patients in the vaccine group developed HBV-RS and 12 controls developed HBV-RS in median follow-up periods of 60 months (range 13-245). HBV vaccine resulted in a positive value of hepatitis B surface antibody (HBsAb) titer in 9 patients, while HBsAb remained negative in 12 patients. Presence of a high titer of HBsAb before vaccination was associated with conversion into HBsAb positivity after vaccination.

CONCLUSION

These results demonstrated the long-term effects of HBV vaccine for preventing HBV-RS after alloHSCT. Of note, no HBV-RS occurred, even in patients who did not achieve conversion into HBsAb positivity after vaccination.

Stenotrophomonas maltophilia infection during allogeneic hematopoietic stem cell transplantation: a single-center experience

To examine risk factors for Stenotrophomonas maltophilia (S. maltophilia) infection during allogeneic hematopoietic stem cell transplantation (allo-HSCT), we retrospectively analyzed 259 patients who underwent allo-HSCT. Not only S. maltophilia infection but also S. maltophilia colonization was associated with mortality during allo-HSCT. Among 52 episodes in 39 patients in whom S. maltophilia was detected, documented infection developed in 33 episodes (25 patients). The onset of S. maltophilia infection in the period from the conditioning regimen to engraftment was associated with a high mortality rate. Breakthrough S. maltophilia infection developed in 24% of the patients during prophylactic administration of fluoroquinolones, to which S. maltophilia is sensitive. Reinsertion of a central venous catheter (CVC) immediately after removal was suggested to be a risk for persistent S. maltophilia infection in the period of neutropenia. Our results indicated that (i) onset of S. maltophilia infection in the period from the conditioning therapy to engraftment and (ii) removal and immediate reinsertion of a CVC as treatment after the onset of S. maltophilia infection are possible risk factors for S. maltophilia-related mortality during allo-HSCT.

Bone marrow graft-versus-host disease: evaluation of its clinical impact on disrupted hematopoiesis after allogeneic hematopoietic stem cell transplantation

Idiopathic cytopenias are frequently observed in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We have previously reported the effect of graft-versus-host disease (GVHD) on bone marrow (BM) in murine models, indicating that the osteoblast injury mediated by donor T cells was associated with bone marrow suppression and delayed immune reconstitution. In this study, we prospectively evaluated the relevance of these findings in 51 patients. Patients with chronic GVHD manifested the loss of osteoblasts, contributing to cytopenic symptoms (P = .0427 compared with patients without cytopenic symptoms). The loss of osteoblasts was significantly associated with the extensive type of chronic GVHD (P = .012), and flow cytometric analyses revealed lower numbers of CD19(+) B cells and a significantly increased CD4 to CD8 ratio (P = .0002) in these patients. Our data, for the first time to our knowledge, summarize the detailed analyses of the effect of GVHD on BM in the clinical allo-HSCT patients.

A comparison of oral mucositis in allogeneic hematopoietic stem cell transplantation between conventional and reduced-intensity regimens

Severe oral mucositis developed in allogeneic hematopoietic stem cell transplantation (HSCT) accompanies intolerable pain and risk for systemic bacteremia infection. Conventional stem cell transplantation (CST) and reduced-intensity regimens for allogeneic HSCT (RIST) may differently affect the occurrence and severity of oral mucositis. Here, we comparatively examined oral mucositis in patients undergoing CST and that in RIST patients to search for measures to alleviate oral mucositis. We retrospectively analyzed the data of 130 consecutive patients undergoing HSCT (conventional, 60; RIST, 70). Oral mucositis was evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. We also investigated the risk factors for severe oral mucositis in each regimen. The incidence of oral mucositis was not significantly different between RIST and CST patients. The use of opioid analgesics to control pain due to oral mucositis was significantly less in patients undergoing RIST compared with those receiving CST. The risk factors for severe oral mucositis, determined by univariate and multivariate analyses, were "younger age (<40)" in CST and "longer duration of neutropenia (≥ 14 days)" in RIST. Although the incidences of oral mucositis were almost the same, the need for opioid analgesics and the risk factors for severe oral mucositis differed between CST and RIST patients.

[Successful treatment with reduced-intensity cord blood transplantation for acute myeloid leukemia with complete tetraploidy (92, XXXX)]

A 56-year-old female was diagnosed with acute myeloid leukemia (FAB: AML-M1). G-banding karyotype of her bone marrow showed complete tetraploidy (92, XXXX [24/24]). Although she achieved complete remission (CR) after induction therapy and maintained CR during consolidation therapy, relapse occurred only 2 months after discharge. When the relapse occurred, bone marrow karyotypic analysis showed complete tetraploidy again. The patient received reduced-intensity cord blood transplantation (RI-CBT), which induced CR for the second time. The patient is currently alive 24 months after transplantation and there have not been any signs of recurrence to date. There have been a few reports of AML with near-tetraploidy, but cases of AML with complete tetraploidy are extremely rare. Tetraploid AML has been reported to have a poor prognosis and there have been very few cases maintaining CR over the long term after chemotherapy alone. This is the first case of complete tetraploid AML successfully treated by RI-CBT. The clinical course of this case suggests that hematopoietic stem cell transplantation during the first CR phase should be considered a treatment option for tetraploid AML.

[Successful combination therapy by meropenem and colistin for multi-drug-resistant Pseudomonas aeruginosa infection after allogeneic bone marrow transplantation]

A 66-year-old male with acute type adult T-cell leukemia that was refractory to chemotherapy underwent unrelated allogeneic bone marrow transplantation after non-myeloablative conditioning with fludarabine, busulfan and total body irradiation. During an episode of neutropenia on day 12 after transplantation, pneumonia and sepsis due to multi-drug resistant Pseudomonas aeruginosa developed. Drug susceptibility tests demonstrated resistance to all kinds of intravenous antibiotics available for P. aeruginosa in Japan. Multi-drug susceptibility tests by the breakpoint-checkerboard plate method were then performed and combination therapy with meropenem hydrate and colistin was started based on the test results. After starting treatment, clinical symptoms and laboratory data immediately improved and engraftment of neutrophils was achieved on day 18. Infections with multi-drug-resistant P. aeruginosa are often critical for patients after hematopoietic stem cell transplantation and are difficult to control. In this paper, we report a case of severe multi-drug-resistant P. aeruginosa infection that was successfully treated by combination therapy selected using the breakpoint-checkerboard plate method.

Expansion of CD4(+)CD25 (+) regulatory T cells from cord blood CD4(+) cells using the common γ-chain cytokines (IL-2 and IL-15) and rapamycin

Rapamycin has important roles in the modulation of regulatory T cells. We tried to expand CD4(+)CD25(+) regulatory T cells (Treg cells) from umbilical cord blood (CB) CD4-positive cells using interleukin (IL)-15 or IL-2 with transforming growth factor (TGF)-β and rapamycin. We were able to obtain more than 500-fold expansion of CD4(+)CD25(+) cells from CB CD4(+) cells using IL-15 and TGF-β with rapamycin. These expanded CD4(+)CD25(+) cells expressed forkhead box P3 (FoxP3) mRNA at a level about 100-fold higher and could suppress allogeneic mixed lymphocyte culture (MLC) by more than 50%. Early after rapamycin stimulation, CB CD4(+) cells showed increased expression of FoxP3 and a serine/threonine kinase Pim2 and sustained expression of negative phosphoinositide 3-kinase regulator phosphatase and tensin homolog deleted on chromosome 10 (PTEN). On the other hand, CD4(+)CD25(+) cells expanded with rapamycin for 8 days showed much higher levels of FoxP3 mRNA expression and decreased expression of PTEN. A comparison of IL-15 stimulation and IL-2 stimulation showed slightly higher efficiency of IL-15 for expansion of CD4(+)CD25(+) cells, and for FoxP3 expression, IL-15 also showed significantly higher efficacy for inhibition of MLC. The combination of the common γ-chain cytokine IL-15, TGF-β, and rapamycin may be a useful means for expanding Treg cells. Pim2 expression early after stimulation with rapamycin may be important for conferring rapamycin resistance for growth of Treg cells. IL-15 is not less useful than IL-2 for expansion of Treg cells.

Signaling from fibroblast growth factor receptor 2 in immature hematopoietic cells facilitates donor hematopoiesis after intra-bone marrow-bone marrow transplantation

Fibroblast growth factor (FGF) and FGF receptor (FGFR) are expressed in various cells including endothelial progenitor cells and hematopoietic cells. The interaction between FGF and FGFR is associated with the proliferation, migration, and survival of these cells. In this report, we examined the effects of FGFR2 signaling on hematopoiesis in immature hematopoietic cells, using mutant mice in which a constitutively active form of FGFR2 mutant was caused to be overexpressed by the Tie2 promoter (FGFR2 Tg mice). Under normal conditions, hematopoiesis of FGFR2 Tg mice and wild type (Wt) mice do not differ significantly, except for the weight and cell numbers of the thymus. However, the c-kit(+)Sca-1(+)lineage⁻ bone marrow cells (BMCs) of FGFR2 Tg mice facilitate the formation of colony-forming units of culture. When these BMCs were transplanted into the recipient bone marrow (intra-bone marrow-bone marrow transplantation), there was better reconstitution of donor hematopoietic cells. In the in vitro experiment, the c-kit(+)Sca-1(+)lineage⁻ BMCs from FGFR2 Tg mice showed fewer apoptotic cells than those from Wt mice. These results suggest that the antiapoptotic effect of FGFR2 signaling facilitates the hematopoiesis of FGFR2 Tg mice.

Increased risk of bacterial infection after engraftment in patients treated with allogeneic bone marrow transplantation following reduced-intensity conditioning regimen

Although bacterial infection is a major cause of death even after reduced-intensity conditioning (RIC) for allogeneic stem cell transplantation (SCT), little is known about the epidemiology and risk factors. The incidence of bacterial infection in 43 patients who received allogeneic bone marrow transplantation (BMT) using a RIC regimen was compared with that in 68 patients who received BMT using a myeloablative conditioning regimen, and risk factors for bacterial infection were identified. Before engraftment, incidences of febrile neutropenia (FN) and documented infections (DI) were significantly decreased in RIC patients (FN: 59.5% vs. 89.6%, P<0.01, DI: 4.8% vs. 17.9%, P<0.01). However, incidence of bacterial infection was significantly increased in RIC patients in the post-engraftment phase (53.8% vs. 11.1%, log-rank, P<0.01). Blood stream was the most frequent focus of infection in both groups. In multivariate analysis, RIC and acute graft-versus-host disease were revealed to be significant risk factors for bacterial infection in this phase. In summary, risk of bacterial infection after engraftment was significantly higher in RIC patients, although infection was decreased before engraftment, and we need to develop a RIC-specific strategy against bacterial infection after RIC SCT.

Reduced intensity conditioning regimen with fludarabine, busulfan, and low-dose TBI (Flu-BU2-TBI): clinical efficacy in high-risk patients

Reduced intensity conditioning (RIC) regimens are widely used in allogeneic stem cell transplantation (SCT). In this study, we retrospectively investigated the clinical outcomes of RIC with fludarabine (Flu; 180 mg/m(2)), intravenous busulfan (BU; 6.4 mg/kg) or oral BU (8 mg/kg), and low-dose total body irradiation (TBI; 4 Gy) (Flu-BU2-TBI) in 66 patients (median age: 54.5 years) with various hematological malignancies. Thirty-eight patients (58%) were high-risk patients (median age: 56 years). The overall survival rate at 2 years of the high-risk patients was 64.5%, which was comparable to the survival rate of 70.9% in standard-risk patients (P = 0.68). The relapse rates at 2 years in the standard-risk and high-risk patients were 16 and 28%, respectively, and day 100 treatment-related mortality rates were 0 and 6%, respectively. The Flu-BU2-TBI regimen for high-risk patients showed therapeutic effects equivalent to those for standard-risk patients and favorable outcomes compared with those of other previous RIC regimens.

Successful treatment of acute myelogenous leukemia with favorable cytogenetics by reduced-intensity stem cell transplantation

Acute myelogenous leukemia (AML) with favorable cytogenetics responds well to chemotherapy. If the leukemia relapses, allogenic hematopoietic stem transplantation (allo-HSCT) is considered as a treatment option. Since the efficacy of reduced-intensity stem cell transplantation (RIST) for AML with favorable cytogenetics has not been established, we retrospectively analyzed the outcomes of allo-HSCT in AML patients according to cytogenetic risks. The outcome of allo-HSCT for AML patients with favorable cytogenetics seemed to be superior to that for AML patients with intermediate cytogenetics. In AML patients with favorable cytogenetics, the 3-year overall survival (OS) and relapse-free survival (RFS) rates were 88 and 76%, respectively, in the RIST group. Both the 3-year OS and RFS rates were 81% in the conventional stem cell transplantation (CST) group. The outcome of RIST for AML patients with favorable cytogenetics was comparable to that for patients who received CST despite the more advanced age and greater organ dysfunction in RIST group than in CST group. None of the patients died within 90 days after RIST. Moreover, there was no relapse in patients with favorable cytogenetics who were in hematological remission prior to RIST. Thus, RIST for AML patients with favorable cytogenetics in remission is safe and effective.

Regimen-related mucosal injury of the gut increased the incidence of CMV disease after allogeneic bone marrow transplantation

Cytomegalovirus (CMV) infection is 1 of the major causes of morbidity in patients undergoing allogeneic stem cell transplantation (allo-SCT). The incidences of CMV antigenemia and CMV disease in 43 patients who received allogeneic bone marrow transplantation (BMT) using a reduced-intensity conditioning (RIC) regimen, which mainly consisted of fludarabine (Flu), busulfan (Bu), and total body irradiation (TBI), were compared with those in 68 patients who received a myeloablative conditioning (MAC) regimen, and risk factors for CMV antigenemia and CMV disease were identified. Before engraftment, grade 3-4 mucosal injury because of the conditioning regimen was significantly decreased in RIC patients (stomatitis: P = .02; diarrhea: P < .01). Rate of engraftment, incidences of acute graft-versus-host disease (aGVHD), and rate of corticosteroid administration were not different in RIC patients and MAC patients. Although the incidences of CMV antigenemia were not significantly different in RIC patients and MAC patients (64.1% versus 57.8%, log rank, P = .59), the incidence of CMV disease was significantly decreased in RIC patients (5.4% versus 20.3%, log rank, P = .04). CMV seropositivity in the patients (P < .01) and corticosteroid administration (P < .01) were revealed by multivariate analysis to be significant risk factors for CMV antigenemia. Grade II-IV aGVHD (P = .02) and grade 3-4 diarrhea before engraftment (P = .04) were revealed to be risk factors for CMV disease. The present study is the first study to show that severe diarrhea before engraftment is a significant risk factor for CMV disease. In summary, risk of CMV disease was significantly decreased in patients without severe mucosal injury of the gut because of the conditioning regimen before engraftment.

HB vaccination in the prevention of viral reactivation in allogeneic hematopoietic stem cell transplantation recipients with previous HBV infection

Hepatitis B virus (HBV)-reverse seroconversion (RS) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a frequent late-onset complication in recipients with previous HBV infection. We followed 38 allo-HSCT recipients with previous HBV infection, and conducted posttransplant HB vaccine intervention in 13 recipients. First, we followed the recipients without any intervention (historic control) until 2003; hence, we commenced HB vaccination. Out of the patients who underwent transplantation after 2003, 13 recipients were immunized by a standard three-dose regimen after immunosuppressant cessation (vaccine group), whereas 12 recipients were observed without any intervention (nonvaccine group). Eight of the 13 historic control group recipients and 3 of the 12 nonvaccine group recipients, but none of the 13 vaccine group recipients, suffered HBV-RS. Cumulative risks of HBV-RS at 3 years post-HSCT in the historic control, nonvaccine and vaccine groups were 41%, 39%, and 0% respectively (P=.022). We therefore conclude that intervention with HB vaccines is significantly effective in preventing post-HSCT HBV-RS.

High mortality rate of (NZW x BXSB)F1 mice induced by administration of lipopolysaccharide attributes to high production of tumour necrosis factor-alpha by increased numbers of dendritic cells

(NZW x BXSB)F1 mice (W/BF1 mice) have been reported to be a type of autoimmune-prone mice, showing symptoms of proteinuria, anti-DNA antibodies and anti-platelet antibodies. In this paper, we report that W/BF1 mice show hyperproduction of tumour necrosis factor (TNF)-alpha, responding to lipopolysaccharide (LPS) in comparison with normal mice, resulting in induction of death. In normal mice, monocytes/macrophages (Mo/MØ) are the main producer of TNF-alpha, while both Mo/MØ and dendritic cells (DCs) produce TNF-alpha in W/BF1 mice. Because the number of DCs is higher in W/BF1 mice, the main producers of TNF-alpha in W/BF1 mice are thought to be DCs. Moreover, administration of anti-TNF-alpha antibodies rescued the W/BF1 mice from death induced by LPS, suggesting that TNF-alpha is crucial for the effect of LPS. Although there is no significant difference in the expression of Toll-like receptor-4 (TLR-4) on DCs between B6 and W/BF1 mice, nuclear factor kappa b activity of DCs from W/BF1 mice is augmented under stimulation of LPS in comparison with that of normal mice. These results suggest that the signal transduction from TLR-4 is augmented in W/BF1 mice in comparison with normal mice, resulting in the hyperproduction of TNF-alpha and reduced survival rate. The results also suggest that not only the quantity of endotoxin, but also the host conditions, the facility to translate signal from TLR, and so on, could reflect the degree of bacterial infections and prognosis.

Analyses of expression of cytoglobin by immunohistochemical studies in human tissues

Cytoglobin (Cygb) is a recently discovered member of the vertebrate globin family, which includes probably most extensively studied proteins, hemoglobin (Hb), myoglobin (Mb) and neuroglobin (Ngb). It has been reported that Cygb is expressed ubiquitously at the mRNA or protein level. However, details of the distribution of Cygb in the various tissues have hitherto been unclear. In this experiment, we clarified the distribution of Cygb in various human tissues by immunohistochemical staining. First, we prepared a rabbit anti human Cygb polyclonal antibody. Using the antibody, we stained a tissue array slide containing 60 normal tissues from 40 human organs. We confirmed the staining patterns of the antibodies in these various tissues using autopsy samples from our university. In general, Cygb is positive in the epithelial cells, hepatocytes, pancreatic acinar cells, cardiomyocytes and skeletal muscle but rarely so in cells in the interstitial tissues. Cytoglobin is usually positive in the cytoplasm, but is also positive in the nucleus in some hepatocytes. In contrast, Cygb is negative in the smooth muscle. The distribution of Cygb could suggest its roles.

Intra-bone marrow injection of donor bone marrow cells suspended in collagen gel retains injected cells in bone marrow, resulting in rapid hemopoietic recovery in mice

We have recently developed an innovative bone marrow transplantation (BMT) method, intra-bone marrow (IBM)-BMT, in which donor bone marrow cells (BMCs) are injected directly into the recipient bone marrow (BM), resulting in the rapid recovery of donor hemopoiesis and permitting a reduction in radiation doses as a pretreatment for BMT. However, even with this IBM injection, some of the injected BMCs were found to enter into circulation. Therefore, we attempted to modify the method to allow the efficient retention of injected BMCs in the donor BM. The BMCs of enhanced green fluorescent protein transgenic mice (C57BL/6 background) were suspended in collagen gel (CG) or phosphate-buffered saline (PBS), and these cells were then injected into the BM of irradiated C57BL/6 mice. The numbers of retained donor cells in the injected BM, the day 12 colony-forming units of spleen (CFU-S) counts, and the reconstitution of donor cells after IBM-BMT were compared between the CG and PBS groups. The number of transplanted cells detected in the injected BM in the CG group was significantly higher than that in the PBS group. We next carried out CFU-S assays. The spleens of mice in the CG group showed heavier spleen weight and considerably higher CFU-S counts than in the PBS group. Excellent reconstitution of donor hemopoietic cells in the CG group was observed in the long term (>100 days). These results suggest that the IBM injection of BMCs suspended in CG is superior to the injection of BMCs suspended in PBS.

FKBP51 expressed by both normal epithelial cells and adenocarcinoma of colon suppresses proliferation of colorectal adenocarcinoma

It has been reported, as a result of Western blot analyses, that FKBP51 is expressed in various tissues, but that it is not expressed in the pancreas, lung, colon, stomach, or spleen. In this paper, we show, using Western blot analyses, reverse transcriptase polymerase chain reaction, and immunohistochemical analyses of samples from colon cancer patients, that both normal epithelial cells and adenocarcinoma in the human colon express FKBP51, and that there are no significant differences in the expressions of FKBP51 between them. We also show that FKBP51 suppresses the proliferation of colorectal adenocarcinoma, possibly due to the suppression of functions of the glucocorticoid receptors.