[Successful unrelated cord blood transplantation for extensive meningeal juvenile xanthogranuloma developing after treatment of Langerhans cell histiocytosis in a child].

A 2-year and 4-month-old boy developed Langerhans cell histiocytosis (LCH) at the left parietal region of the skull. After treatment with chemotherapy, the patient achieved remission but experienced three relapses. After 3 years, he complained of headache, blurred vision, and lethargy. Brain magnetic resonance imaging revealed multiple dura-based meningeal masses. Biopsy was performed, and the patient was then diagnosed with juvenile xanthogranuloma (JXG). The analysis of both LCH/JXG tissues revealed BRAF V600E mutation. The JXG masses were not responsive to prednisolone, which was injected locally, radiotherapy (24 Gy), and chemotherapy (2-chlorodeoxy-adenosine). In addition, since the patient developed macrophage activation syndrome associated with systemic JXG progression, he received unrelated cord blood transplantation (u-CBT) at the age of 10 years and 11 months. Engraftment was performed at day 42, and significant GVHD was not observed. Four months after CBT, the patient was treated with infliximab (Remicade®) and dexamethasone palmitate (Limethasone®). The size of the intracranial JXG masses gradually decreased after u-CBT and disappeared after 4 years. Currently, the patient is doing well at the age of 25 years and is receiving androgen replacement therapy.

Childhood pheochromocytoma in a survivor of central primitive neuroectodermal tumor.

Pheochromocytoma and central nervous system primitive neuroectodermal tumor are both neural crest-derived tumors. The former is usually benign and develops mainly in adulthood and the latter brain tumor mainly occurs in childhood and has a poor prognosis. We report a case of a 15-year-old boy who developed pheochromocytoma after more than 10 years of complete remission of central primitive neuroectodermal tumor. Thus far, there have been no reports of childhood cancer survivors who developed pheochromocytoma. This quite rare occurrence of two tumors in a single patient may imply some unidentified linkage or common genetic background.

A case of pulmonary pleomorphic carcinoma with preexisting interstitial pneumonia successfully treated with pembrolizumab.

Pulmonary pleomorphic carcinoma is often refractory to chemotherapy and follows an aggressive clinical course. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced lung cancer, and a few cases with pleomorphic carcinoma have been reported to show tumor shrinkage after therapy with ICIs. When treating patients with ICIs, patient selection is essential, and monitoring and management of immune-related adverse events, including pneumonitis, are needed. We herein report a case of pulmonary pleomorphic carcinoma with preexisting interstitial pneumonia treated with pembrolizumab, antiprogrammed cell death 1 antibody. Our report highlights important considerations necessary when treating advanced pleomorphic carcinoma patients complicated with interstitial pneumonia. We also review the literature regarding the use of ICIs in such patients.

A nationwide survey of newly diagnosed childhood idiopathic thrombocytopenic purpura in Japan.

BACKGROUND: We evaluated the clinical pictures, outcome for childhood idiopathic thrombocytopenic purpura (ITP) and the trends of the choice of management for childhood ITP in Japan. METHOD: Every year, questionnaires were sent to all institutions that employ the active members of the Japanese Society of Pediatric Hematology. The questionnaires included age, sex, date of diagnosis, platelet count at diagnosis, the presence or absence of antecedent infection, hemorrhagic symptoms, initial management, and the outcome of all patients newly diagnosed with ITP. RESULTS: A total of 986 newly diagnosed as ITP patients were reported between January 2000 and December 2005. The occurrence of ITP peaked in boys less than 1 year of age, and at 1 year of age in girls. The male-to-female ratio was 1.24:1. Wet purpura was observed in more than half of the patients with platelet counts of <10,000/microL. The initial treatment varied among the patients with different platelet counts at diagnosis; most of the patients with platelet counts <20,000/microL received intravenous immunoglobulin or oral corticosteroids. Conversely, cases without any aggressive treatment increased to a larger degree in patients with > or =20,000/microL of platelet. CONCLUSIONS: These findings indicate that overall compliance to the Japanese guideline is considered to be relatively good in Japan.

A conditioning regimen of busulfan, fludarabine, and melphalan for allogeneic stem cell transplantation in children with juvenile myelomonocytic leukemia.

A pilot study was undertaken using a myeloablative conditioning with fludarabine, busulfan, and melphalan to improve the outcome of HSCT in 10 children, aged six months to six yr, with JMML. All patients were conditioned with oral busulfan (560 mg/m(2)), fludarabine (120 mg/m(2)), and melphalan (180-210 mg/m(2)) prior to HSCT, and received stem cells from bone marrow in seven cases, and from cord blood in three cases. Engraftment was documented in eight patients, whereas graft failure occurred in two, one of whom had received HLA-mismatched cord blood and other had received bone marrow from HLA-mismatched mother. Three patients, including two in who graft failure had occurred, relapsed. Five patients developed acute GVHD and two developed chronic GVHD. Seven patients are alive and in remission 27-69 months after transplantation. Thus, our study showed that HSCT following conditioning with fludarabine, busulfan, and melphalan was well tolerated and appeared to be effective for JMML.

Antithymocyte globulin and cyclosporine for treatment of 44 children with hepatitis associated aplastic anemia.

We analyzed the outcomes of 44 children with hepatitis associated aplastic anemia (HAA) who received immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CsA). Fourteen (31.8%) patients achieved complete response and 17 (38.6%) achieved partial response, for an overall response rate of 70.4% after 6 months. Seven non-responders received bone marrow transplantation from an HLA-matched unrelated donor and 6 out of 7 are alive. The probability of overall survival at 10 years was 88.3+/-4.9%, which supports the role of IST with ATG and CsA as treatment of choice for children with HAA without an HLA identical sibling donor.

Treatment with candesartan combined with angiotensin-converting enzyme inhibitor for immunosuppressive treatment-resistant nephrotic syndrome after allogeneic stem cell transplantation.

Most cases of nephrotic syndrome following stem cell transplantation (SCT) occur 6 months after SCT. The patients are treated with immunosuppressive therapies; however, in some cases treatment is not effective. We used enalapril, an angiotensin-converting enzyme inhibitor (ACEI) and candesartan, an angiotensin II receptor blocker (ARB), for the control of proteinuria in a case of immunosuppressive treatment (IST)-resistant nephrotic syndrome. A 15-year-old boy with acute lymphoblastic leukemia underwent allogeneic peripheral blood SCT from a completely HLA-matched sibling after completion of a conditioning regimen composed of 12-Gy doses of total-body irradiation, 600 mg/m2 thiotepa, and 140 mg/m2 melphalan. Twenty-eight months after SCT, minimal-change nephrotic syndrome was diagnosed on the basis of biopsy findings. Although neither cyclosporine (trough level, 100-150 ng/mL) nor corticosteroid was effective, proteinuria disappeared 2 months after the beginning of treatment with tacrolimus (trough level, 13-20 ng/mL), and remission was maintained for 23 months. Nephrotic syndrome recurred, however, and was resistant to tacrolimus. Findings at the second renal biopsy revealed membranous nephropathy. An ARB (candesartan, 4 mg/ day) in combination with an ACEI (enalapril, 5 mg/day) was started. Proteinuria improved within 2 weeks. We suggest that ARB combined with ACEI can be used to control proteinuria in patients with IST-resistant nephrotic syndrome after SCT.

Consensus guideline for diagnosis and treatment of childhood idiopathic thrombocytopenic purpura.

A practice guideline aimed at standardizing the treatment for childhood idiopathic thrombocytopenic purpura (ITP) is presented. This consensus guideline is based on a survey carried out via a questionnaire prepared by the ITP Committee of the Japanese Society of Pediatric Hematology and sent to society members. The survey questionnaire included questions on the diagnosis of ITP submitted for the purpose of revising the ITP diagnostic guideline prepared in 1990 by the Research Group for Intractable Hematopoietic Disorders; a revised diagnostic guideline also is presented.

Establishment of a monosomy 7 leukemia cell line, MONO-7, with a ras gene mutation.

A monosomy 7 leukemia cell line, designated MONO-7, was established from the peripheral blood of a patient with monosomy 7 acute myelocytic leukemia (French-American-British classification M0). The cells were cultured continuously for more than 24 months in RPMI-1640 medium supplemented with 10% heat-inactivated fetal calf serum. The cell line exhibits an unclassified appearance. Cytochemically, alpha-naphthol-acetate esterase and myeloperoxidase are negative. Immunophenotypically, the cell line expresses CD33, CD13, CD56, CD34, CD38, HLA-DR, and CD45, but lacks T and B cell-associated antigens. Karyotypic analysis of the cell line showed only 45,XY,-7. Analysis of the N-ras gene mutation demonstrated identical mutations in fresh leukemic cells and the MONO-7 cell line. Clonal rearrangements of the immunoglobulin heavy-chain gene, T-cell receptor beta-chain gene, or T-cell receptor gamma-chain gene were not found in DNA extracted from MONO-7 cells. The growth of MONO-7 cells in vitro was stimulated by recombinant human granulocyte-macrophage colony-stimulating factor or interleukin 3. To our knowledge, this is the first report of the establishment of a cell line with the karyotype 45,XY,-7 without any other abnormality and with a ras gene mutation.

Clinical significance of minimal residual disease in childhood acute myeloid leukemia.

Many studies have assessed the clinical significance of the detection of minimal residual disease (MRD) in acute leukemia. Thus far, many studies have suggested that MRD detection to evaluate the response to chemotherapy is useful for predicting the prognosis of childhood acute lymphoblastic leukemia (ALL). However, few studies have reported on the significance of MRD in childhood acute myeloid leukemia (AML), because of small numbers of patients and limited availability of MRD markers. Therefore, we monitored MRD using currently available markers at several points during the treatment for childhood AML and tried to intensify the treatment based on the results of MRD. Thirty-one patients (26 de novo cases and 5 other cases) were examined for MRD between February 1999 and May 2002. After the first consolidation therapy (consolidation 1), the expression of Wilms tumor gene (WT1) and/or leukemia-specific fusion genes such as AML1/MTG8, PML/RAR alpha, and MYH11/CBF beta were analyzed. Patients with positive MRD but in hematological remission at that point were recommended to undergo stem cell transplantation (SCT). Positive WT1 expression (more than 10(3) copies/microgram RNA) was detected in 18 of 31 patients (58.1%) at onset. After consolidation 1 therapy, the WT1 expression became negative in 14 of 18 patients. The AML1/MTG8 fusion gene was expressed in 8 patients, PML/RAR alpha was expressed in 3 patients, and MYH11/CBF beta was expressed in 1 patient. Four of the 8 patients with AML1/MTG8 expression and all 3 with PML/RAR alpha expression also demonstrated positive WT1 expression at onset. Eight (5 de novo cases and 3 other cases) of the 31 patients had no available MRD markers. Four patients who showed pesistently high expression of WT1 after consolidation 1 therapy underwent SCT, and only 1 patient remained in complete remission (CR). Among 14 patients who became negative for WT1 expression, 6 patients received SCT for various reasons. Among 8 patients with the AML1/MTG8 fusion gene, 2 became MRD negative and 6 continued to be positive. Four of these 6 patients underwent SCT, and all but one who underwent syngeneic SCT became MRD negative. On the other hand, 1 of the 2 patients who continued on chemotherapy continued to be MRD positive, suggesting a graft-versus-leukemia effect in allogeneic SCT. All patients with the PML/RAR alpha and MYH11/CBF beta fusion gene continued to be in CR. The 3-year event-free survival in de novo AML was 69.4% +/- 9.8% (n = 26), a result that is encouraging and superior to other reported outcomes. Thus, an MRD-based treatment strategy together with conventional risk factors appears to be required for further improving the outcomes of AML.

The kinetics of immune reconstitution after cord blood transplantation and selected CD34+ stem cell transplantation in children: comparison with bone marrow transplantation.

The present study compares immune reconstitution after allogeneic cord blood transplantation (CBT) and CD34+ stem cell transplantation (CD34-SCT) with that after bone marrow transplantation (BMT). Eighty-eight children who underwent CBT (20 patients), BMT (58), and CD34-SCT (10) were enrolled, and lymphocytes and T-, B-, and natural killer-lymphocyte subsets were monitored for more than 5 years after transplantation. CBT recipients showed significant ircreases in (1) total lymphocyte counts (P < .001), (2) CD4+/CD8+ cell ratios (P < .01), (3) CD4+ and CD4+CD45RA+ cells (P < .001), (4) CD8+CD11b+ cells (P < .001), and (5) CD19+ and CD19+CD5+ cells (P < .0001) and marked decreases in the frequencies of CD8+ and CD8+CD11b- cells (P < .0001). CD34-SCT recipients showed lower lymphocyte counts in the first 6 months and an emergence of lymphocyte and CD4+CD45RA+ cells at approximately 9 months and 1 year. Both CBT and CD34-SCT recipients showed increased frequencies of CD56+ cells at 1 month (CD34-SCT versus BMT, P < .001) but decreased frequencies after 6 months (CBT versus BMT, P < .001). Lymphoproliferative responses to exogenous interleukin 2 were constantly lower in CBT and CD34-SCT recipients than in BMT recipients. These results suggest that the delay in immune reconstitution after CBT in the early phase was mainly qualitative and related to the immaturity of cells, whereas the delay in CD34-SCT was mainly quantitative in the first several months.

Unmanipulated HLA-haploidentical bone marrow transplantation for the treatment of fatal, nonmalignant diseases in children and adolescents.

Fetomaternal microchimerism has been demonstrated, and immunologic tolerance to unshared HLA antigens between mother and offspring may be suggested. We used T-cell-repleted bone marrow transplantation (BMT) from their HLA-haploidentical mothers to treat 6 patients with fatal nonmalignant diseases. The number of mismatched HLA loci in the graft-versus-host disease (GVHD) direction was 3 in 4 patients and 2 in 2 patients. The number in the host-versus-graft direction was 3 in 4 patients, 2 in 1 patient, and 1 in 1 patient. Microchimerism of inherited paternal antigens was demonstrated in 5 donors, and microchimerism of noninherited maternal antigens was detected in 3 recipients. GVHD prophylaxis consisted of short-course methotrexate, tacrolimus, and mycophenolate mofetil (3 patients) or short-course methotrexate, tacrolimus, and methylprednisolone (1 patient). Engraftment was achieved in 5 patients who had received preconditioning, and T-cell engraftment was confirmed in 1 patient with severe combined immunodeficiency. Acute GVHD developed in 3 patients: grade 1 in 2 patients and grade 2 in 1 patient. Chronic GVHD was observed in 5 patients: localized type in 3 patients and extended type in 2 patients. Five patients were alive 11 to 30 months after BMT and 1 patient died of chronic GVHD. Unmanipulated haploidentical BMT from a maternal donor may be the treatment of choice of poor-prognosis nonmalignant diseases.

MNX1-ETV6 fusion gene in an acute megakaryoblastic leukemia and expression of the MNX1 gene in leukemia and normal B cell lines.

Patients with infant acute myeloid leukemia (AML) who carry a t(7;12)(q36;p13) translocation have been reported to have a poor clinical outcome. MNX1-ETV6 fusion transcripts (previously HLXB9-ETV6) were rarely detected in AML patients having t(7;12)(q36;p13). A 23-month-old girl with acute megakaryoblastic leukemia (AMKL) exhibited chromosome abnormalities, including add(7)(q22), and del(12)(p12p13). Southern blot analysis of bone marrow cells showed an ETV6 gene rearrangement. Reverse transcriptase-polymerase chain reaction (RT-PCR) followed by sequence analysis revealed the presence of an MNX1-ETV6 fusion gene. The patient responded well to chemotherapy, achieved complete remission, and at writing had been in complete remission for 60 months. The MNX1 expression by RT-PCR was significantly more frequent in Epstein-Barr virus-transformed B-cell lines derived from normal adult lymphocytes than in leukemic cell lines. This represents a novel case of an AMKL patient with MNX1-ETV6 fusion transcripts who had a good prognosis.

Toll-like receptor signaling is impaired in dendritic cells from patients with X-linked agammaglobulinemia.

Bruton's tyrosine kinase (BTK), which is defective in patients with X-linked agammaglobulinemia (XLA), is expressed not only in B cells but also in monocytes and dendritic cells (DCs). DCs play a crucial role in the innate immune response against infections by sensing pathogens through Toll-like receptors (TLRs). However, it is not known whether BTK deficiency in XLA might impair TLR-mediated signaling in DCs, which are susceptible to various infections. The phenotypic maturation and cytokine production mediated by TLRs were examined in monocyte-derived DC from XLA patients and normal controls. The TLR expression in DCs was analyzed by flow cytometry. TLR-mediated signaling in DCs was evaluated for the phenotypic maturation based on CD83 expression and production of cytokines, such as TNF-alpha, IL-6 and IL-12p70. TLR levels in DCs were similar between XLA and controls. TLR2, TLR4 and TLR7/8 ligands elicited less phenotypic maturation of DCs from XLA patients than normal controls based on CD83 expression. Stimulation with TLR2, TLR4 and TLR7/8 ligands, as well as TLR3 ligand, resulted in significantly lower production of TNF-alpha, but neither IL-6 nor IL-12p70, by DCs from XLA patients in comparison to normal controls. These findings suggest that BTK may thus be required for TLR signaling in DCs. The impaired TLR signaling in DCs may therefore be partly responsible for the occurrence of severe infections with bacteria and some viruses in XLA patients.

Molecular genetic analysis of a variant Bernard-Soulier syndrome due to compound heterozygosity for two novel glycoprotein Ibbeta mutations.

Bernard-Soulier syndrome (BSS) is a rare bleeding disorder characterized by giant platelets, thrombocytopenia, and prolonged bleeding time. It is caused by abnormalities in the glycoprotein (GP) Ib/IX/V complex, the receptor for von Willebrand factor (vWF). Most cases of BSS described so far involve quantitative rather than qualitative defects in the complex. In this study, we investigated the effects of two naturally occurring mutations in the GPIbbeta gene, C122S and 443delG, on the expression of the GPIb/IX complex identified in a variant type of BSS in which the platelets had severely reduced GPIbalpha ( approximately 10%) and less markedly reduced GPIbbeta and GPIX ( approximately 20%) expression. Immunoblot analysis showed the absence of non-reduced GPIb (GPIbalpha/GPIbbeta) in the patient's platelets. Transient transfection experiments in 293T cells revealed the expression of GPIbbeta Ser122 polypeptide and absence of GPIbbeta 443delG polypeptide. Although no disulfide-linked association was observed between GPIbbeta Ser122 and GPIbalpha, GPIbbeta Ser122 was non-covalently associated with both GPIbalpha and GPIX subunits on the cell surface when cotransfected with wild-type GPIbalpha and GPIX. Chinese hamster ovary cells stably expressing GPIbalpha/Ibbeta Ser122/IX had the ability to bind soluble vWF and to aggregate in the presence of ristocetin. These results suggest that despite disruption of the disulfide linkage between GPIbalpha and GPIbbeta, GPIb/IX is formed, but its stability may be impaired, resulting in low levels of the complex on the platelet membranes.

Correlation between phenotypic heterogeneity and gene mutational characteristics in familial hemophagocytic lymphohistiocytosis (FHL).

BACKGROUND: Classification of familial hemophagocytic lymphohistiocytosis (FHL) into FHL2, FHL3, and other subtypes based on genetic abnormalities has recently become possible. We studied the phenotypic differences among these subtypes in Japan. METHODS: Forty patients clinically diagnosed with FHL were analyzed. Perforin abnormality was screened by flow cytometric analysis and/or DNA sequencing in these patients, and those without perforin abnormalities were further examined for the presence of mutations in the Munc13-4 gene by DNA sequencing. The correlation between clinical features and genetic subtypes was investigated. RESULTS: Of the 40 HLH patients, 11 showed perforin gene mutations (classified as FHL2) and ten had Munc13-4 gene mutations (FHL3), but neither mutation was noted in 19 patients (non-FHL2/3). Although the majority of the patients developed the disease before the age of 1 year, the onset in three FHL2 patients with missense mutations was late (7, 11, and 12 years). Incidence of deficient natural killer cell activity was higher in FHL2 patients (9/9 FHL2, 4/9 FHL3, and 6/17 non-FHL2/3; P = 0.005). The serum levels of ferritin and soluble interleukin-2 receptor were significantly higher in FHL2 patients with nonsense perforin mutations compared to other subgroups (P < or = 0.05). Epstein-Barr virus infection was involved in 8 of the 40 HLH patients: one FHL2, one FHL3, and six non-FHL2/3. CONCLUSIONS: Although clinical features of FHL3 appear to be homogeneous, the heterogeneous clinical features of FHL2 depend upon the nature of perforin gene mutations. Characterization of the non-FHL2/3 group with regard to FHL1 or other novel gene mutations remains to be conducted.

Improved outcome in the treatment of pediatric multifocal Langerhans cell histiocytosis: Results from the Japan Langerhans Cell Histiocytosis Study Group-96 protocol study.

BACKGROUND: The treatment outcome of multifocal childhood Langerhans cell histiocytosis (LCH) has not been satisfactory and has resulted in poor therapeutic responses with high mortality and a high incidence of reactivation with late sequelae. To overcome these issues, the Japan LCH Study Group-96 (JLSG-96) protocol was conducted prospectively from 1996 to 2001 in Japan. METHODS: Newly diagnosed children with multifocal LCH were classified into 2 groups: a single-system multisite (SS-m) group and a multisystem (MS) group. All patients initially were treated on Protocol A, which consisted of 6 weeks of induction therapy with combined cytosine arabinoside, vincristine (VCR), and prednisolone (PSL) followed by 6 months of maintenance therapy. Patients who had a poor response to the induction of Protocol A were switched to a salvage regimen (Protocol B), which consisted of an intensive combination of doxorubicin, cyclophosphamide, VCR, and PSL. RESULTS: In total, 91 patients were treated, including 32 patients in the SS-m group and 59 patients in the MS group. At the median 5-year follow-up, 96.9% of patients in the SS-m group and 78.0% of patients in the MS group had good response status. Diabetes insipidus developed in 3.1% of patients in the SS-m group and in 8.9% of patients in the MS group. The overall survival rate at 5 years for the SS-m and MS groups was 100% and 94.4% +/- 3.2%, respectively. CONCLUSIONS: The JLSG-96 protocol attained very low mortality for pediatric patients with multifocal LCH.

Allogeneic haematopoietic cell transplantation from alternative donors with a conditioning regimen of low-dose irradiation, fludarabine and cyclophosphamide in Fanconi anaemia.

A pilot study was undertaken using a fludarabine-based conditioning regimen to improve haematopoietic cell transplantation (HCT) from alternative donors in 27 Fanconi anaemia (FA) patients. Patients were conditioned with 150-180 mg/m2 of fludarabine, 40 mg/kg of cyclophosphamide, 5-10 mg/kg of antithymocyte globulin, and 300-450 cGy of thoracoabdominal/total body irradiation. One patient who received unrelated cord blood transplantation failed to engraft, another patient died of sepsis. The 1-year overall survival was 96.3% (95% CI, 89-100). This conditioning regimen exerted an immunosuppressive effect that enabled durable engraftment in alternative donor HCT without severe toxicity.