T-Cell-Replete Haploidentical Hematopoietic Stem Cell Transplantation for a Patient With Tcf3-Hlf-Positive Acute Lymphoblastic Leukemia Extramedullary Relapse After Unrelated Bone Marrow Transplantation.

TCF3-HLF-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has an extremely poor prognosis. A 2-year-old boy with TCF3-HLF-positive BCP-ALL had an isolated extramedullary relapse in multiple bones after allogeneic hematopoietic stem cells transplantation (HSCT) from a human leukocyte antigen-matched unrelated donor. In this study, he received a T-cell-replete haploidentical HSCT (TCR-haplo-HSCT) from his father when in nonremission state, which resulted in a sustained complete remission for over 3 years. Immune therapies for patients with an extramedullary relapse of TCF3-HLF-positive BCP-ALL have been attempted; however, long-term efficacies of these therapies remain unknown. Our TCR-haplo-HSCT may be an effective therapeutic option for such patients.

T-cell replete haploidentical stem cell transplantation with low dose anti-thymocyte globulin for relapsed/refractory Ewing sarcoma family tumors.

BACKGROUND: Despite intensive multimodal therapies, the prognosis of relapsed/ refractory Ewing sarcoma family tumors (RR-ESFTs) is dismal. Some case reports using allogeneic stem cell transplantation (allo SCT) for RR-ESFTs have been reported, however, the efficacy of allo SCT is yet to be established. AIM: The purpose of this study was to evaluate the response and toxicity of T-cell replete haploidentical SCT (TCR-haplo-SCT) in RR-ESFTs. METHODS AND RESULTS: In this study, we retrospectively analyzed six patients with RR-ESFTs who received TCR-haplo-SCT. Four patients had relapsed and two patients had refractory Ewing sarcoma. Before the TCR-haplo-SCT, all patients received a reduced intensity-conditioning regimen containing fludarabine, melphalan, and low-dose rabbit anti-thymocyte globulin (2.5 mg/kg), as well as graft-versus-host disease (GVHD) prophylaxis, which consisted of tacrolimus, methotrexate, and prednisolone. Primary neutrophil engraftment was achieved in all the patients. Four patients developed acute GVHD (aGVHD) (grade I, 1; grade II, 1; grade III, 2), and two patients developed chronic GVHD (cGVHD). Among the four that developed aGVHD, three survived for 14, 116, and 129 months without relapse, while one died due to a transplant-related complication. In contrast, the two patients who did not develop aGVHD experienced relapse early after TCR-haplo-SCT. CONCLUSIONS: In this study, three of the six patients with RR-ESFTs survived for more than one year without relapse, and the treatment toxicity was considered acceptable even for patients who underwent high-intensity pretreatment. TCR-haplo-SCT could be a potential therapeutic option for patients with RR-ESFTs.

Effects of second transplantation with T-cell-replete haploidentical graft using low-dose anti-thymocyte globulin on long-term overall survival in pediatric patients with relapse of leukemia after first allogeneic transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the preferred treatment for children with high-risk hematologic malignancies, but post-allo-HSCT relapse has a poor prognosis and limited treatment options. We evaluated the feasibility, outcome, and risk factors influencing survival after T-cell-replete haploidentical HSCT with low-dose anti-thymocyte globulin (ATG) in 30 patients with post-allo-HSCT relapse of acute lymphoblastic leukemia and acute myeloid leukemia. Overall, 50% of the patients had complete remission (CR) before the second transplant and the overall survival (OS) rate was 52%. In surviving patients (median follow-up 614 days), Kaplan-Meier analysis revealed estimated 2-year leukemia-free survival and OS rates of 48.1% and 61.1%, respectively. Cumulative incidences of 2-year non-relapse mortality and relapse were 24.7% and 36.3%, respectively. Achieving CR before the second allo-HSCT was a predominant independent prognostic factor identified in the multivariate analysis, with a significantly improved 2-year OS rate of 86.7%. T-cell-replete haplo-HSCT with low-dose ATG for second allo-HSCT may benefit a selected patient population.

Effectiveness of T-Cell Replete Haploidentical Hematopoietic Stem Cell Transplantation for Refractory/Relapsed B Cell Acute Lymphoblastic Leukemia in Children and Adolescents.

Background: The prognosis of refractory/relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) remains dismal owing to acquired resistance to chemotherapeutic agents. This study aimed to evaluate the efficacy of T-cell replete HLA haploidentical hematopoietic stem cell transplantation (TCR-haplo-HSCT) for pediatric refractory/relapsed BCP-ALL (RR-BCP-ALL). Methods: Nineteen pediatric patients with RR-BCP-ALL underwent TCR-haplo-HSCT between 2010 and 2019 at the Fukushima Medical University Hospital. The disease status at TCR-haplo-HSCT included complete remission (CR) in eight patients and non-CR with active disease in 11 patients. Total body irradiation-based, busulfan-based, and reduced-intensity conditioning regimens were employed in 11, 6, and 2 patients, respectively. Low-dose anti-thymocyte globulin (thymoglobulin, 2.5 mg/kg) was used in all patients. Graft-vs.-host disease (GVHD) prophylaxis was administered with tacrolimus, methotrexate, and prednisolone. Results: All patients received peripheral blood stem cells as the stem cell source. The HLA disparities in graft vs. host directions were 2/8 in one, 3/8 in five, and 4/8 in 13 patients. Among 18 patients who achieved primary engraftment, acute GVHD occurred in all 18 evaluable patients (grade II, 9; grade III, 8; grade IV, 1), and chronic GVHD was observed in 10 out of 15 evaluable patients. Three patients died because of transplant-related mortality. The 3-year overall survival (OS) and leukemia-free survival rates were 57.4 and 42.1%, respectively. Compared to patients older than 10 years in age (N = 10), those younger than 10 years in age (N = 9) showed an excellent OS rate (3-year OS rate: patients < 10 years old, 100%; patients > 10 years old, 20% [95% confidence interval, 3.1-47.5]; p = 0.002). Conclusions: We suggest that TCR haplo-HSCT with low-dose ATG conditioning has the potential to improve the transplantation outcomes in patients with RR-BCP.

Alloantigen-activated (AAA) CD4+ T cells reinvigorate host endogenous T cell immunity to eliminate pre-established tumors in mice.

BACKGROUND: Cancer vaccines that induce endogenous antitumor immunity represent an ideal strategy to overcome intractable cancers. However, doing this against a pre-established cancer using autologous immune cells has proven to be challenging. "Allogeneic effects" refers to the induction of an endogenous immune response upon adoptive transfer of allogeneic lymphocytes without utilizing hematopoietic stem cell transplantation. While allogeneic lymphocytes have a potent ability to activate host immunity as a cell adjuvant, novel strategies that can activate endogenous antitumor activity in cancer patients remain an unmet need. In this study, we established a new method to destroy pre-developed tumors and confer potent antitumor immunity in mice using alloantigen-activated CD4+ (named AAA-CD4+) T cells. METHODS: AAA-CD4+ T cells were generated from CD4+ T cells isolated from BALB/c mice in cultures with dendritic cells (DCs) induced from C57BL/6 (B6) mice. In this culture, allogeneic CD4+ T cells that recognize and react to B6 mouse-derived alloantigens are preferentially activated. These AAA-CD4+ T cells were directly injected into the pre-established melanoma in B6 mice to assess their ability to elicit antitumor immunity in vivo. RESULTS: Upon intratumoral injection, these AAA-CD4+ T cells underwent a dramatic expansion in the tumor and secreted high levels of IFN-γ and IL-2. This was accompanied by markedly increased infiltration of host-derived CD8+ T cells, CD4+ T cells, natural killer (NK) cells, DCs, and type-1 like macrophages. Selective depletion of host CD8+ T cells, rather than NK cells, abrogated this therapeutic effect. Thus, intratumoral administration of AAA-CD4+ T cells results in a robust endogenous CD8+ T cell response that destroys pre-established melanoma. This locally induced antitumor immunity elicited systemic protection to eliminate tumors at distal sites, persisted over 6 months in vivo, and protected the animals from tumor re-challenge. Notably, the injected AAA-CD4+ T cells disappeared within 7 days and caused no adverse reactions. CONCLUSIONS: Our findings indicate that AAA-CD4+ T cells reinvigorate endogenous cytotoxic T cells to eradicate pre-established melanoma and induce long-term protective antitumor immunity. This approach can be immediately applied to patients with advanced melanoma and may have broad implications in the treatment of other types of solid tumors.

Intracranial Hemorrhage in a Pediatric Patient with Chronic Myeloid Leukemia in Chronic Phase: A Case Report.

Chronic myeloid leukemia (CML) is an uncommon entity in pediatric patients. CML in chronic phase (CML-CP) has a relatively favorable outcome. Leukostasis occurs in 9.7% of patients with CML. One of the most serious leukostasis-related complications is intracranial hemorrhage (ICH). However, this is very rare in patients with CML-CP, and few early mortalities have been reported in CML patients with leukostasis. We report the case of a 14-year-old female patient with CML-CP who developed ICH 8 days after admission. A 14-year-old girl developed symptoms of fatigue and slight fever and was diagnosed with CML-CP. She was treated with imatinib and received low-molecular-weight heparin owing to coagulation abnormalities. However, 6 days later, she developed sensorineural hearing loss, which is a symptom of leukostasis. She received hydroxyurea to reduce her white blood cell (WBC) count, and her treatment was changed from imatinib to nilotinib. The WBC and platelet counts remained unchanged, blast counts did not increase, and mild coagulation abnormality persisted. Eight days after admission, she suddenly lost consciousness and experienced respiratory arrest. Cranial computed tomography revealed multiple ICH lesions and brain hernia. She received intensive care but was diagnosed with brain death by electroencephalography and died 14 days after hospitalization. ICH is very rare in patients with CML-CP; however, patients with leukostasis and coagulation abnormalities can develop severe hemorrhage, even in the chronic phase. Thus, it is necessary to accurately estimate the cause and provide appropriate treatment for these patients.

Decline of serum albumin precedes severe acute GVHD after haploidentical HSCT.

BACKGROUND: Haploidentical hematopoietic stem cell transplantation (HSCT) is a useful therapy for relapsed/refractory acute leukemia or lymphoma because of the strong graft-vs-leukemia (GVL) effect. However, it is often accompanied by severe acute graft-versus-host disease (aGVHD), which is the most serious complication after haploidentical HSCT. Thus, it is important to control the severity of aGVHD while maintaining the GVL effect. In our experience of pediatric haploidentical HSCT, it takes several days for aGVHD to become severe after the appearance of initial symptoms, mostly skin rashes. In this study, we aimed to identify useful biomarkers at the onset of aGVHD that predict subsequent development of severe aGVHD. METHODS: Forty-five consecutive children with relapsed/refractory acute leukemia or lymphoma who developed aGVHD after haploidentical HSCT were enrolled. We analyzed possible biomarkers from samples collected at the onset of acute GVHD. RESULTS: Nineteen patients developed grade 1-2 aGVHD, and 26 patients developed grade 3-4 aGVHD. There was no significant difference in patient characteristics between the two groups. Transplant-related mortality occurred only in the grade 3-4 aGVHD group (34.5%). Multivariate analysis revealed that serum albumin was an independent biomarker for predicting the severity of aGVHD (P = 0.009). The area under the receiver operating characteristic curve of serum albumin was 0.864. CONCLUSIONS: The serum albumin level at the onset of aGvHD could be a useful biomarker for the development of subsequent severe aGVHD in pediatric patients after haploidentical HSCT.

Optimal timing of apheresis for the efficient mobilization of peripheral blood progenitor cells recruited by high-dose granulocyte colony-stimulating factor in healthy donors.

Predictors of peripheral blood stem cell (PBSC) yield can potentially improve the comfort, safety, and efficacy of CD34+ cell collection from donors treated with recombinant human granulocyte colony-stimulating factor (G-CSF). We investigated 181 apheresis procedures on 109 healthy allogeneic donors to identify factors correlating with efficient PBSC collection. Apheresis started on Day 4 or 5 and continued up to Day 6 of G-CSF administration. CD34+ cell　yields on Days 4 and 5 were comparable, and significantly higher than on Day 6. This suggests that starting apheresis on Day 4 rather than Day 5 may be preferable, to reduce G-CSF exposure and optimize yield, even if multi-day collection is required. More CD34+ cells were collected from male and cytomegalovirus (CMV)-seronegative donors than from female and CMV-seropositive donors, respectively. The yields of CD34+ cells were similarly high in both male and female donors aged 20-29 years; yields decreased in female donors in their thirties, and were comparably low in both male and female donors in their forties and thereafter. These findings should guide decision-making about when to begin apheresis, and encourage careful consideration of donor factors such as gender, age, and CMV serostatus when collecting PBSCs.

Pneumorrhachis in children: A report of two cases and review of the literature.

Pneumorrhachis refers to the clinical presentation of air within the spinal canal, and it is rarely associated with pneumomediastinum, particularly in young children. Pneumorrhachis associated with pneumomediastinum is generally asymptomatic. Here we report 2 unusual cases involving very young children with pneumorrhachis secondary to pneumomediastinum and present a review of the relevant literature. Case 1 involved a 4-year-old girl who presented with wheezing, violent coughing, and dyspnea associated with bronchiolitis. Case 2 involved a 3-year-old boy who presented with wheezing, violent coughing, and dyspnea associated with interstitial pneumonia possibly caused by graft-versus-host disease with human herpesvirus 6 infection after allogeneic hematopoietic stem cell transplantation. In both cases, pneumorrhachis improved with oxygen inhalation therapy and treatment of the underlying disease. Pneumorrhachis is rarely associated with neurological problems; however, decompressive laminectomy may be indicated to relieve the air block. Because pneumorrhachis is rare in children and neurological sequelae may be difficult to identify, close clinical, and radiographic observations are necessary. Plain radiography is not sufficient, and computed tomography should be performed to rule out intraspinal air.

Various checkpoint molecules, and tumor-infiltrating lymphocytes in common pediatric solid tumors: Possibilities for novel immunotherapy.

Long-term survival rates for pediatric patients with cancer have significantly improved, but novel approaches are desired for those with refractory/relapsed solid tumors. Recently, programed cell death-1/programed cell death-ligand-1 blockade has emerged as an effective option for many intractable cancers. However, not all patients show objective response to such therapy. On the other hand, several other checkpoint pathways, including Herpes virus entry mediator (HVEM)/B- and T-lymphocyte attenuator (BTLA), galectin-9 (GAL9)/T-cell immunoglobulin and mucin domain-3 (TIM3), and major histocompatibility complex class II (MHC-II)/lymphocyte activation gene-3 (LAG3), also regulate immune responses in the tumor microenvironment and may be alternative targets for novel immune therapies. In this study, we examined 65 common pediatric solid tumors and characterized the expression of Herpes virus entry mediator, GAL9, and MHC-II on tumor cells and their corresponding receptors B- and T-lymphocyte attenuator, TIM3, and LAG3, respectively, on tumor-infiltrating lymphocytes (TILs) with immunohistochemistry. Whereas the expression of GAL9 and MHC-II was limited, 73% of rhabdomyosarcomas and 100% of osteosarcomas expressed moderate to high levels of Herpes virus entry mediator on the tumor. TILs were detected in all tumor samples except one osteosarcoma. Interestingly, 45% of rhabdomyosarcomas, and 45% of osteosarcomas expressed moderate to high levels of both Herpes virus entry mediator on the tumor cells and B- and T-lymphocyte attenuator on the TILs. Results showed that a subset of pediatric solid tumors expressed tumor-associated checkpoint molecules, and TILs expressed corresponding receptors for these checkpoint molecules. Thus, immunogenic environments may be created, and checkpoint blockade may induce favorable immune responses.

Usefulness of fluorodeoxyglucose positron emission tomography/computed tomography for detection of a neuroblastic nodule in a ganglioneuroblastoma: a case report.

BACKGROUND: Ganglioneuroblastoma, nodular is defined as a composite tumor of biologically distinct clones. The peripheral neuroblastic tumors in this category are characterized by the presence of grossly visible neuroblastoma nodules coexisting with ganglioneuroblastoma, intermixed, or with ganglioneuroma. Making a correct diagnosis of ganglioneuroblastoma, nodular is often difficult by biopsy or partial tumor resection, because the neuroblastic nodule could be hidden and not sampled for pathological examination. CASE PRESENTATION: We report a case of a Japanese boy aged 3 years, 8 months, with an unresectable abdominal tumor and elevated vanillylmandelic acid and homovanillic acid levels. The initial biopsy was ganglioneuroma. However, after the second biopsy from a hidden neuroblastoma nodule that was clearly highlighted by fluorodeoxyglucose positron emission tomography/computed tomography, we reached the diagnosis of ganglioneuroblastoma, nodular. Because the nodule demonstrated neuroblastoma, differentiating subtype, with a low mitosis-karyorrhexis index (favorable histology) and nonamplified MYCN, the boy was treated according to the intermediate-risk protocol and is now alive and well 4 years after the diagnosis. CONCLUSIONS: This case illustrates the critical role of fluorodeoxyglucose positron emission tomography/computed tomography for detecting a neuroblastoma nodule in a ganglioneuroblastoma.

T-cell-replete haploidentical stem cell transplantation using low-dose antithymocyte globulin in children with relapsed or refractory acute leukemia.

We evaluated the efficacy and toxicity of T-cell-replete haploidentical stem cell transplantation (TCR-haploSCT) using low-dose antithymocyte globulin (ATG) in children with refractory/relapsed (R/R) acute leukemia. From October 2009 to April 2016, 39 consecutive patients with R/R acute leukemia who underwent TCR-haploSCT were included. At the time of TCR-haploSCT, 17 patients were in complete remission (CR), but 22 had active disease. Thirty-three patients received a myeloablative regimen and six received a reduced-intensity conditioning regimen. Graft-versus-host disease (GvHD) prophylaxis comprised tacrolimus, methotrexate, prednisolone, and low-dose ATG (thymoglobulin 2.5 mg/kg). Neutrophil engraftment (> 0.5 × 109/L) was 95% after a median of 13 days. The median follow-up period was 527 days, with mean 3-year overall and disease-free survival rates of 45.1% [standard deviation (SD), ± 8.5%) and 33.8% (SD, ± 7.9%), respectively. The cumulative incidence of acute GvHD was 73.0%, but that of grade III-IV acute GvHD was 34.1%. The 3-year cumulative incidences of relapse and transplant-related mortality were 50.3 and 15.9%, respectively. Age < 10 years at transplantation was associated with a better overall survival in the multivariate analysis. These data suggest that TCR-haploSCT using a low-dose ATG combined with the GvHD prophylaxis described here has a significant anti-leukemic activity, particularly in younger patients.

T cell replete-haploidentical second hematopoietic stem cell transplantation for primary graft failure in pediatric patients with hematologic malignancies.

GF is one of the fatal complications of allogeneic HSCT. To rescue patients with primary GF, a second HSCT should be conducted as soon as possible, but the optimal donor source and technique have yet to be established. In this study, we retrospectively analyzed six children with hematologic malignancies who received TCR-haploidentical second HSCT for primary GF. The median interval between the prior HSCT and the second HSCT was 37.5 days. All patients received fludarabine and ATG containing reduced-intensity re-conditioning before the second HSCT. All patients, except one who died early, achieved both neutrophil and Plt engraftment at a median time of 15 and 33 days, respectively. Chimerism analysis showed that all engrafted patients achieved complete donor chimerism within 3 weeks. Four patients developed acute GVHD, and three patients developed chronic GVHD. TRM occurred in two patients. Median follow-up of the four survivors was 6.8 years, and all remained in sustained remission until the last follow-up. These results suggested that a TCR-haploidentical second HSCT for pediatric patients is feasible, and this approach may provide a potent option for children with primary GF.

Pre-emptive rituximab for Epstein-Barr virus reactivation after haplo-hematopoietic stem cell transplantation.

BACKGROUND: Epstein-Barr virus-related post-transplantation lymphoproliferative disease (EBV-PTLD) is a serious complication in hematopoietic stem cell transplantation (HSCT) recipients. METHODS: We conducted a retrospective study to investigate the incidence and potential risk factors for EBV reactivation and to assess the efficacy of the management of EBV reactivation with pre-emptive rituximab in children who had T-cell-replete haploidentical HSCT (TCR-haplo-SCT) with low-dose anti-thymocyte globulin (ATG). EBV-DNA level in peripheral blood (PB) was measured when suspected EBV reactivation were observed. When the EBV-DNA level in PB increased to >1,000 copies/106 peripheral blood mononuclear cells (PBMC), patients were pre-emptively treated with rituximab (375 mg/m2 /dose). RESULTS: A total of 19 (50%) of 38 patients received rituximab infusion at a median time of 56 days after HSCT (range, 17-270 days). The median viral load at initiation of therapy was 2,900 copies/106 PBMC (range, 1,000-650 000). Pre-emptive therapy was started after a median of 2 days (range, 0-7 days). The median number of weekly treatment cycles was 2 (range, 1-3). None of the patients developed PTLD or other EBV-associated diseases. CONCLUSION: Pre-emptive rituximab therapy could be a useful strategy for EBV-PTLD in TCR-haplo-SCT recipients with low-dose ATG.

Comprehensive technical and patient-care optimization in the management of pediatric apheresis for peripheral blood stem cell harvesting.

BACKGROUND: Pediatric apheresis for peripheral blood stem cell transplantation should be carried out with due concern for low corporeal blood volume and vulnerability to hypocalcemia-related complications, hypovolemic shock, and hypervolemic cardiac overload. STUDY DESIGN AND METHODS: We retrospectively investigated a total of 267 apheresis procedures from 1990 to 2013 on 93 children between 0 and 10 years old, including 89 patients and 4 healthy donors, with body weights of 6.3 to 44.0 kg. RESULTS: The median CD34+ cell yield per apheresis procedure was 2.3 × 106 CD34+ cells/kg (0.2-77.9 × 106 CD34+ cells/kg). Adverse events occurred in 11.6% of procedures (n = 31), including mild perivascular pain (n = 12), emesis (n = 9), hypotension (n = 3), urticaria (n = 2), numbness (n = 2), chest pain (n = 1), facial flush (n = 1), and abdominal pain (n = 1). Among hypotensive events, shock in a 9.6 kg one-year-old boy required emergency treatment in 1996. Thereafter, we adopted continuous injection of calcium gluconate, ionized calcium monitoring, central venous catheter access and circuit priming with albumin in addition to concentrated red cells. Since then we have had fewer complications: 16.4% per apheresis during 1990-1997 versus 5.8% during 1998-2013. No healthy pediatric donors suffered from any late-onset complications related to apheresis or G-CSF administration. CONCLUSION: By employing appropriate measures, peripheral blood stem cell apheresis for small children can have an improved safety profile, even for children weighing <10 kg.

Idiopathic Hyperammonemia That Developed During Initial Treatment With Steroid in a Patient With Newly Diagnosed Leukemia.

Idiopathic hyperammonemia (IHA) has been described as a complication of intensive chemotherapy for the treatment of hematologic malignancy but has subsequently been found in patients undergoing bone marrow transplantation and in those with solid tumors treated with 5-fluorouracil. Although IHA is a rare complication, it is sometimes associated with high mortality in hematologic malignancies. Here we report the case of a 15-year-old boy in whom hyperammonemia developed during the initial treatment with prednisolone for newly diagnosed acute lymphoblastic leukemia and who survived after early detection and oral lactulose therapy. To the best of our knowledge, this is the first report of IHA that was not induced by intensive chemotherapy, stem cell transplantation, or asparaginase therapy in a patient with newly diagnosed leukemia, but developed during an initial treatment with a steroid. Early detection of IHA by measuring the plasma ammonia level in patients with neurological symptoms may improve the outcome.

Malignant peritoneal mesothelioma in a child: chemotherapy with gemcitabine and platinum was effective for the disease unresponsive to other treatments.

Malignant peritoneal mesothelioma in children is a very rare disease and has a poor prognosis. Unlike malignant mesothelioma in adults, there is no clear causal association between this very rare malignancy in children and asbestos exposure. We report a case of peritoneal mesothelioma in an 11-year-old boy who presented with ascites. He was diagnosed with malignant mesothelioma on the basis of histopathological findings. His disease showed resistance to pemetrexed, but was treated successfully with platinum-based therapy with gemcitabine. He has achieved long-term survival in partial remission with stable disease.

Loss of mismatched HLA in myeloid/NK cell precursor acute leukemia relapse after T cell-replete haploidentical hematopoietic stem cell transplantation.

Myeloid/natural killer cell precursor acute leukemia (MNKL) is an aggressive disease with a high relapse rate even after allogeneic hematopoietic stem cell transplantation (SCT). We report a patient with MNKL who had a donor lymphocyte infusion (DLI) for relapse after T cell-replete human leukocyte antigen (HLA)-haploidentical SCT, but relapsed again 20 months later with loss of mismatched HLA. This case suggests that a strong graft-versus-leukemia effect of haploidentical SCT can be expected in MNKL patients. In the haploidentical setting, DLI should be considered for patients with relapsed leukemia whose leukemic cells have not lost HLA cell surface expression.

Intrinsic temperature sensitivity of influenza C virus hemagglutinin-esterase-fusion protein.

Influenza C virus replicates more efficiently at 33°C than at 37°C. To determine whether hemagglutinin-esterase-fusion protein (HEF), a surface glycoprotein of influenza C virus, is a restricting factor for this temperature sensitivity, we analyzed the biological and biochemical properties of HEF at 33°C and 37°C. We found that HEF exhibits intrinsic temperature sensitivities for surface expression and fusion activity.

Prooxidant action of hinokitiol: hinokitiol-iron dependent generation of reactive oxygen species.

Hinokitiol (alpha-thujaplicin, 2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one), one of the tropolone compounds purified from the woods of Chamaecyparis and Thujopsis (hinoki and hiba), produced reactive oxygen species as a complex with transition metals. Hinokitiol/iron complex inactivated aconitase, the most sensitive enzyme to reactive oxygen, whereas it did not affect aldolase and glyceraldehyde 3-phosphate dehydrogenase. The inactivation of aconitase was iron-dependent, and prevented by TEMPOL, a scavenger of reactive oxygen species and superoxide dismutase, suggesting that the hinokitiol/iron-mediated generation of superoxide anion is responsible for the inactivation of aconitase. Addition of hinokitiol effectively enhanced the ascorbate/copper-mediated formation of 8-hydroxy-2'-deoxyguanosine in DNA. Cytotoxic effect of hinokitiol can be explained by its prooxidant properties: hinokitiol/transition metal complex generates reactive oxygen species causing inactivation of aconitase and production of hydroxyl radical resulting in the formation of DNA base adduct.