工藤 寿子

Introduction: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by accumulation of bone marrow-derived immature dendritic cells harboring oncogenic mutations in mitogen-activated protein kinase (MAPK) pathway genes, such as BRAF V600E, and various reactive inflammatory cells. Infants with chemo-resistant multisystem disease with risk organ involvement [MS-RO(+)] have poor prognosis. Further, relapsed infants have a significant risk of developing disastrous neuro-degenerative central nervous system disease. Areas covered: This review covers published papers on hematopoietic stem cell transplantation (HSCT) for LCH selected through a literature search on PubMed between years 1985 and 2019. Expert opinion: Infants with refractory MS-RO(+) disease or with frequent treatment-resistant relapses can benefit from allogeneic HSCT (allo-HSCT). Selection of an HLA-matched sibling or unrelated cord blood (UCB) stem cell source and use of reduced intensity conditioning (RIC) preparative regimens, based on the combination fludarabine with melphalan, are preferable. Most deaths after HSCT occur within 3 months, due to transplantation-related complications. LCH disease activity usually regresses over 3 months after allo-HSCT in survivors. The disease activity at HSCT is the most important prognostic factor. Prior to HSCT, the disease activity should be reduced by treatment.

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Objective: Langerhans cell histiocytosis (LCH) is characterized by immature dendritic cell proliferation, infiltration of LCH lesions by various inflammatory cells, and a lesional cytokine storm. It is classified into three groups on the basis of disease extent, namely, multisystem with risk-organ involvement (MS +), multisystem without risk-organ involvement (MS -), and single-system (SS) disease. We comprehensively analyzed whether serum levels of cytokines/chemokines reflect the disease extent. Methods: Serum samples from 52 children with LCH (eight, 25, and 19 with MS +, MS -, and SS, respectively) and 34 control children were analyzed quantitatively for 48 humoral factors. DNA samples extracted from biopsied LCH lesions from 12 patients were tested for BRAF V600E status. Results: The LCH patients had significantly higher serum levels of IL-1Ra, IL-3, IL-6, IL-8, IL-9, IL-10, IL12, IL-13, IL-15, IL-17, IL-18, TNF-alpha, G-CSF, M-CSF, MIF, HGF, VEGF, CCL2, CCL3, CCL7, CXCL1, and CXCL9 than the controls by univariate analysis. Of these IL-9, IL-15 and MIF were significant by multivariate analysis; but not differed between MS and SS diseases. MS disease associated with significantly higher IL-2R, IL-3, IL-8, IL-18, M-CSF, HGF, CCL2, CXCL1, and CXCL9 levels than SS disease by univariate analysis. Of these, CCL2 and M-CSF were significant by multivariate analysis. IL-18 levels were significantly higher in MS + disease than MS disease. The LCH patients with BRAF V600E mutation had higher serum levels of CCL7. Conclusion: Numerous inflammatory cytokines and chemokines play a role in LCH. Of those, more specific ones reflect the disease extent (MS vs. SS and MS + vs. MS -) or the BRAF V600E mutation status. It is thought that the most responsible cytokines and chemokines involved in the poor outcome may become future candidate therapeutic targets in LCH.

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© 2016, The Japanese Society of Hematology. The JLSG-96 study reported very low mortality rates for children newly diagnosed with multifocal Langerhans cell histiocytosis (LCH). The JLSG-02 study was performed to further improve the prognosis from 2002 to 2009. The present study compared the therapeutic results of these two studies in terms of multisystem disease. All patients were treated with 6 weeks of the Induction A regimen, comprising cytarabine, vincristine and prednisolone, followed by maintenance therapy. Poor responders to Induction A were switched to Induction B. JLSG-02 has been revised from JLSG-96 in the following respects: prednisolone dosage during Induction A increased; duration of maintenance therapy extended from 24 to 48 weeks; cyclosporine introduced to Induction B for progressive disease. One hundred forty-seven children with multisystem LCH were evaluated. Of these, 84 were positive for risk of organ involvement (RO) and 63 were RO-negative. At the 6-week point, 76.2 % of RO+ and 93.7 % of RO− patients responded to Induction A. Five-year event-free survival (EFS) was 46.2 % [95 % confidence (CI), 35.5–56.9] for RO+ and 69.7 % (58.4–81.1) for RO−, which was significantly superior to that in JLSG-96 [26.8 % (13.3–40.4) and 38.9 % (16.4–61.4), respectively]. The intensified induction and prolonged maintenance regimens in JLSG-02 improved EFS in patients with multisystem LCH.

Osteopontin (OPN) acts as an osteoclast activator, a proinflammatory cytokine, and a chemokine attracting histiocytes/monocytes and is abundantly expressed in Langerhans cell histiocytosis (LCH). We investigated whether serum OPN levels are related to disease types in LCH. Fifty-eight newly diagnosed LCH patients were studied; eight with risk organ (liver, spleen and/or hematopoietic) involvements positive multisystem (MS+) disease, 27 with risk organ involvement negative multisystem (MS-) disease and 23 with single system (SS) disease. Pediatric patients with non-inflammatory disease (n = 27) were used as controls. All of patients with MS+ disease were younger than 3 years. Serum OPN levels and 44 kinds of humoral factors were measured by ELISA and Bio-Plex suspension array system, respectively. In the patients younger than 3 years, the median serum OPN level (interquartile range) was 240.3 ng/ml (137.6-456.0) in MS+ (n = 8); 92.7 ng/ml (62.0-213.8) in MS- (n = 14) and 72.5 ng/ml (55.6-94.0) in SS (n = 9) and 74.4 ng/ml (42.2-100.0) in control (n = 12). The OPN values were significantly higher in the MS+ group than the MS-, SS and control groups (p = 0.044, p = 0.001 and p = 0.002, respectively), but not different between the MS-, SS and control groups. In the patients older than 3 years, the median level of serum OPN (IQR) was 56.2 ng/ml (22.9-77.5) in MS- (n = 13), 58.9 ng/ml (31.0-78.7) in SS (n = 14) and 41.9 (28.9-54.1) in control (n = 15). These values did not differ significantly between each group. The serum OPN levels were positively correlated with the serum IL-6, CCL2, IL-18, IL-8 and IL-2 receptor concentration. OPN may be involved in risk organ dissemination and poor prognosis of LCH through the function as inflammatory cytokine/chemokine. (C) 2014 Elsevier Ltd. All rights reserved.

The purpose of this review is to provide an updated overview of the pathogenesis and treatment of Langerhans cell histiocytosis (LCH). The pathogenesis of LCH remains obscure and the optimal treatment for LCH has not been established, although incremental progress has been made. Proinflammatory cytokines and chemokines are known to play a role in LCH, which suggests that LCH is an immune disorder. However, the oncogenic BRAF mutation is also detected in more than half of LCH patients, which suggests that LCH is a neoplastic disorder. Remaining major issues in the treatment of LCH are how to rescue patients who have risk-organ involvement but do not respond to first-line therapy, the optimal treatment for the orphan disease of multifocal adult LCH, and how to reduce and treat central nervous system-related consequences, such as central diabetes insipidus and neurodegeneration. More research is needed to better understand the pathogenesis of this disease and to resolve the treatment issues.

Myeloid leukemia of Down syndrome has a better prognosis than sporadic pediatric acute myeloid leukemia. Most cases of myeloid leukemia of Down syndrome are characterized by additional cytogenetic changes besides the constitutional trisomy 21, but their potential prognostic impact is not known. We, therefore, conducted an international retrospective study of clinical characteristics, cytogenetics, treatment, and outcome of 451 children with myeloid leukemia of Down syndrome. All karyotypes were centrally reviewed before assigning patients to subgroups. The overall 7-year event-free survival for the entire cohort was 78% (+/- 2%), with the overall survival rate being 79% (+/- 2%), the cumulative incidence of relapse 12% (+/- 2%), and the cumulative incidence of toxic death 7% (+/- 1%). Outcome estimates showed large differences across the different cytogenetic subgroups. Based on the cumulative incidence of relapse, we could risk-stratify patients into two groups: cases with a normal karyotype (n=103) with a higher cumulative incidence of relapse (21%+/- 4%) than cases with an aberrant karyotype (n=255) with a cumulative incidence of relapse of 9% (+/- 2%) (P=0.004). Multivariate analyses revealed that white blood cell count >= 20x10(9)/L and age >3 years were independent predictors for poor event-free survival, while normal karyotype independently predicted inferior overall survival, event-free survival, and relapse-free survival. In conclusion, this study showed large differences in outcome within patients with myeloid leukemia of Down syndrome and identified novel prognostic groups that predicted clinical outcome and hence may be used for stratification in future treatment protocols.

Recent reports revealed that intravenous (iv) busulfan (BU) may not only reduce early nonrelapse mortality (NRM) but also improve overall survival (OS) probability in adults. Therefore, we retrospectively compared outcomes for 460 children with acute leukemia who underwent hematopoietic stem cell transplantation with either iv-BU (n=198) or oral busulfan (oral-BU) (n=262) myeloablative conditioning. OS at 3years was 53.4%±3.7% with iv-BU and 55.1%±3.1% with oral-BU the difference was not statistically significant (P= 77). OS at 3years in 241 acute lymphoblastic leukemia and 219 acute myeloid leukemia patients was 56.4%±5.5% with iv-BU and 54.6%±4.1 with oral-BU (P= 51) and 51.0%±5.0% with iv-BU and 55.8%±4.8% with oral-BU (P= 83), respectively. Cumulative incidence of relapse at 3years with iv-BU was similar to that with oral-BU (39.0%±3.6% and 36.4%±3.1%, respectively P= 67). Cumulative incidence of NRM at 3years was 16.6%±2.7% with iv-BU and 18.3%±2.5% with oral-BU (P= 51). Furthermore, multivariate analysis showed no significant survival advantage with iv-BU. In conclusion, iv-BU failed to show a significant survival advantage in children with acute leukemia. © 2013 American Society for Blood and Marrow Transplantation.

Infants (< 1 year old) with acute myeloid leukemia (AML) are particularly vulnerable to intensive cytotoxic therapy. Indeed, the mortality rate was high among infants enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 study, which prompted us to temporarily suspend patient enrollment and amend the protocol. Forty-five infants with AML were enrolled. For patients aged < 2 years, drug doses were adjusted for body weight. Following the protocol amendments, doses for infants were reduced by a further 33 % in the initial induction course. Six infants died during the induction phase (including five early deaths), mainly due to pulmonary complications. The 3-year probability of overall survival (pOS) in all 45 infants [55.9 %, 95 % confidence interval (CI) 37.9-70.6 %] was significantly lower than that of patients aged 1 to < 2 years (77.0 %, 95 % CI 62.7-86.3 %) and those aged a parts per thousand yen2 years (74.7 %, 95 % CI 69.2-79.4 %) (P = 0.037), mainly due to the higher non-relapse mortality rate in infants. No early deaths occurred after the protocol amendments, and the 3-year pOS of the 17 infants enrolled thereafter was 76.4 % (95 % CI 48.8-90.4 %). In conclusion, appropriate dose reduction is essential to avoid early deaths when treating infants with AML.

Background: Voriconazole is a triazole antifungal agent with potent activity against a broad spectrum of pathogens, including Aspergillus and Candida species. In human adults, allelic polymorphisms of CYP2C19 are known to correlate with significant variation in voriconazole plasma concentration. Here, we report an analysis of CYP2C19 phenotype and voriconazole plasma concentrations in children. Methods: This retrospective study included 37 children who had voriconazole plasma concentrations measured from May 2006 to June 2011. All had single-nucleotide polymorphisms that define the 3 major CYP2C19 alleles. Patients were classified as follows: normal metabolizers, intermediate metabolizers, poor metabolizers, or hypermetabolizers. Results: The frequencies of the 3 CYP2C19 genetic polymorphisms were similar to those previously reported for Japanese adults. Trough plasma concentrations of voriconazole were significantly higher in the poor metabolizer and intermediate metabolizer groups compared with the normal metabolizer and hypermetabolizer groups (P=0.004). Two patients with high plasma concentrations experienced voriconazole-related severe adverse events (syndrome of inappropriate antidiuretic hormone secretion and cardiac toxicities). Conclusions: The current study suggests that a significant association exists in children between the voriconazole plasma concentration and the CYP2C19 phenotype. Dose adjustment based on CYP2C19 phenotype may be useful during voriconazole therapy, especially for Japanese children, who as a group have a higher incidence of the poor metabolizer and intermediate metabolizer phenotypes.

Myeloid leukemia in Down syndrome (ML-DS) is associated with good response to chemotherapy and favorable prognosis. Because little research has been focused on refractory/relapsed (R/R) cases, we conducted a retrospective analysis for R/R ML-DS. Among ML-DS patients diagnosed between 2000 and 2010 in Japan, 26 relapsed (25 in the BM and 1 in the skin), and 3 refractory patients were enrolled. The male/female ratio was 18/11. The median age at initial diagnosis of ML-DS was 2 years, and the median time to relapse was 8.6 months. Each patient initially had been treated with ML-DS-specific protocols. Thirteen of the 26 patients achieved complete remission with various kinds of reinduction chemotherapies; 2 of 8 survived without further recurrence after receiving allogeneic hematopoietic stem cell transplantation, and 4 of 5 maintained complete remissions with chemotherapy alone. Treatment failures mostly were associated with disease progression rather than treatment-related toxicities. The 3-year OS rate was 25.9% +/- 8.5%. A longer duration from initial diagnosis to relapse was a significant favorable prognostic factor (P < .0001). We conclude that clinical outcome for patients with R/R ML-DS generally are unfavorable, even in those receiving hematopoietic stem cell transplantation. Novel methods to identify poor prognostic factors for ML-DS are necessary. (Blood. 2012;120(9):1810-1815)

Background Hemophagocytic lymphohistiocytosis (HLH) is associated with hypercytokinemia in children. Although HLH can be also observed after hematopoietic stem cell transplantation (HSCT), the incidence and clinical features of HLH after HSCT remain obscure. Procedure The clinical features of HLH after HSCT (post-HSCT HLH) were investigated in children with malignancies, immune deficiencies, or aplastic anemia. The HLH/Langerhans Cell Histiocytosis (LCH) Committee of the Japanese Society of Pediatric Hematology (JSPH) sent questionnaires to hospitals with JPSH members asking for details of cases in which HLH occurred after HSCT between 1998 and 2008. Results Among 42 children who were diagnosed with post-HSCT HLH between 1998 and 2008 in Japan, 37 fulfilled our inclusion criteria; of these, 26 were classified as early-onset (onset <30 days after HSCT) and 11 were classified as late-onset (onset >30 days after HSCT). In the early-onset group, the presence of respiratory symptoms, high levels of total bilirubin, and triglycerides at onset and the lack of control of GVHD with tacrolimus were significantly associated with non-resolution of HLH (P?<?0.05). The survival rate was significantly higher in patients with resolution of HLH than in those without resolution (59% vs. 14%, P?<?0.05). Conclusions These findings suggest that early-onset post-HSCT HLH is a specific entity of HLH, and appropriate diagnosis and prompt management need to be established. Pediatr Blood Cancer 2012; 59: 110114. (C) 2011 Wiley Periodicals, Inc.

Background Idiopathic pneumonia syndrome (IPS) is a severe complication that can occur after hematopoietic stem cell transplantation (HSCT) and is often associated with a fatal outcome despite intensive supportive care. Procedure. To assess the incidence and risk factors of IPS, we reviewed 251 consecutive patients (median age, 7.0 years) who received HSCT at the Department of Pediatrics, Nagoya University Hospital, between January 1990 and July 2009. Results. Twenty of 251 (cumulative incidence of IPS at 2 years after HSCT, 8.0%; 95% confidence interval (CI), 5.1-12.4%) patients developed IPS. The median duration from HSCT to diagnosis of IPS was 67 days (range, 12-486 days). Patients with IPS had significantly higher 5-year transplant-related mortality compared to patients without IPS (52% (95% CI, 19-77%) vs. 13% (95% CI, 5-25%), P < 0.001), and the probability of 5-year overall survival was significantly worse for patients with IPS (42% (95% CI, 25-64%) vs. 68% (95% CI, 59-76%), P = 0.01). By multivariate analysis, high risk in underlying disease (HR, 2.5; 95% CI, 1.0-6.7; P = 0.05) and a busulfan-containing regimen (HR, 3.5; 95% CI, 1.3-9.9; P < 0.01) were identified as the independent risk factors for developing IPS. Conclusion. The prophylactic strategies for IPS in patients with these risk factors were warranted. Pediatr Blood Cancer 2012;58:780-784. (C) 2011 Wiley Periodicals, Inc.

Fifty percent of Diamond-Blackfan anemia (DBA) patients possess mutations in genes coding for ribosomal proteins (RPs). To identify new mutations, we investigated large deletions in the RP genes RPL5, RPL11, RPL35A, RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26. We developed an easy method based on quantitative-PCR in which the threshold cycle correlates to gene copy number. Using this approach, we were able to diagnose 7 of 27 Japanese patients (25.9%) possessing mutations that were not detected by sequencing. Among these large deletions, similar results were obtained with 6 of 7 patients screened with a single nucleotide polymorphism array. We found an extensive intragenic deletion in RPS19, including exons 1-3. We also found 1 proband with an RPL5 deletion, 1 patient with an RPL35A deletion, 3 with RPS17 deletions, and 1 with an RPS19 deletion. In particular, the large deletions in the RPL5 and RPS17 alleles are novel. All patients with a large deletion had a growth retardation phenotype. Our data suggest that large deletions in RP genes comprise a sizable fraction of DBA patients in Japan. In addition, our novel approach may become a useful tool for screening gene copy numbers of known DBA genes. (Blood. 2012;119(10):2376-2384)

To determine the ability of recent systemic chemotherapy protocols to reduce the incidence of central diabetes insipidus (CDI) in Langerhans cell histiocytosis (LCH), 43 CDI cases that belonged to a cohort of 348 pediatric patients with multi-focal LCH who were treated with the JLSG-96/-02 protocols were analyzed. The overall incidence of CDI was 12.4%, but in 24 cases CDI was already present at the time LCH was diagnosed. Thus, CDI developed during or after systemic chemotherapy over a follow-up period of 5.0 (0.2-14.7) years in only 19 patients (5.9%), with 7.4% at 5-year cumulative risk by Kaplan-Meier analysis. In two cases, complete resolution of CDI was noted. Anterior pituitary hormone deficiency was detected in 13 cases, while CDI-associated neurodegenerative disease was observed in six cases. The JLSG-96/-02 protocol appears to effectively reduce the occurrence of CDI. However, novel therapeutic measures are required to reverse pre-existing CDI and to prevent CDI-associated neurological complications.

We report two patients with chronic granulomatous disease (CGD). The first patient presented with granulomatous colitis and pulmonary aspergillosis, and the second patient with liver abscess and restrictive pulmonary disorder. Both patients underwent allogeneic hematopoietic stem cell transplantation, the first from an HLA-matched sibling donor, and the second from an HLA-matched unrelated donor, after preconditioning with fludarabine, anti-thymocyte globulin, cyclophosphamide, and total-body irradiation of 3 Gy. The engraftment was prompt and the regimen-related toxicity was mild. The patients are able to return to their daily lives with full donor chimerism, although the second patient underwent a living-related-donor orthotopic liver transplantation from his mother for chronic liver graft-versus-host disease. The conditioning regimen we used was feasible and applicable to patients with CGD accompanied by inflammatory disease and severe infection.

Although some studies have reported that TBI and MEL offer an effective conditioning regimen for autologous SCT in acute leukemia, little has been reported regarding outcomes of allogeneic SCT. We retrospectively evaluated outcomes for 50 pediatric patients who underwent allo-SCT conditioned with intravenous MEL (180-210 mg/m(2)) and fractionated TBI (12-13.2 Gy) from HLA-identical related donors. Nineteen patients were in CR1, 18 were in CR2, and 13 showed advanced-stage disease (&gt;= CR3). Patients had received allo-SCT from HLA-identical siblings (n = 45) or phenotypically HLA-identical family donors (n = 5). Median duration of follow-up for all disease-free patients was 61 months (range, 8.8-177 months). At the time of analysis, 12 patients had died. Eleven of those died of relapse, and one died of TRM. DFS rates for all patients, patients with AML (n = 12), and patients with lymphoid malignancy (n = 38) were 61.4% and 82.1%, respectively. DFS rates for CR1, CR2, and &gt;= CR3 cases were 89.2%, 88.1%, and 23.1%, respectively (p &lt; 0.05). MEL/TBI for pediatric patients with hematological malignancies was associated with lower relapse rates and no increase in toxicity, resulting in better survival.