Azacitidine treatment for myeloid leukemia associated with Down syndrome: A nationwide retrospective study in Japan.

Hypomethylating agent treatment for myeloid leukemia associated with Down syndrome (ML-DS) has been scarcely reported. Herein, we collected information on azacitidine treatment for ML-DS in Japan. Forty-eight cycles of azacitidine treatment were performed for 12 patients, including 11 relapsed or refractory (R/R) patients. In 40 cycles, azacitidine was used as monotherapy. No azacitidine-related death was observed. One cycle concurrently administered with methotrexate-based intrathecal therapy was discontinued due to toxicities. Only 4 of the 19 cycles given in non-remission achieved complete or partial remission. In conclusion, although most toxicities were acceptable, azacitidine monotherapy might be insufficient for R/R ML-DS cases.

Blinatumomab Maintenance Therapy Following Bone Marrow Transplantation for Early Relapsed Pediatric B-cell Precursor Acute Lymphoblastic Leukemia and Analysis of Lymphocyte Subset Changes.

Blinatumomab, a CD19/CD3 bispecific T-cell engager, is recognized as an effective immunotherapy for relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, the efficacy and safety of blinatumomab in post-hematopoietic stem cell transplantation (HSCT) maintenance therapy has not been established. A 5-year-old male patient with BCP-ALL suffered a relapse in his bone marrow during maintenance therapy. After re-induction therapy with UK-R3 regimen, 2.3% of the blasts remained. Then the blinatumomab was administered, and he achieved minimal residual disease (MRD)-negative complete remission (CR). After two cycles of blinatumomab, he underwent allogeneic bone marrow transplantation (BMT) from his human leukocyte antigen (HLA)-matched sibling, following conditioning with total body irradiation, etoposide, and cyclophosphamide. Two cycles of blinatumomab maintenance therapy were initiated to prevent relapse. There was no exacerbation of graft-versus-host disease (GVHD) or other severe adverse events. CR was maintained for >22 months after BMT. A t-distributed symmetric neighbor embedding (tSNE) analysis revealed that blinatumomab altered the CD8+ population, as with pre-HSCT use, and markedly reduced the CD8+19dim+/CD8+CD19- ratio (i.e., naïve lymphocyte predominance). Blinatumomab maintenance therapy after HSCT may be considered a safe treatment.

18q Deletion Syndrome Presenting with Late-Onset Combined Immunodeficiency.

Patients with chromosome 18q deletion syndrome generally experience hypogammaglobulinemia. Herein, we describe two patients with chromosome 18q deletion syndrome who presented with late-onset combined immune deficiency (LOCID), which has not been previously reported. Patient 1 was a 29-year-old male with 18q deletion syndrome, who was being managed for severe motor and intellectual disabilities at the Yamabiko Medical Welfare Center for 26 years. Although the patient had few infections, he developed Pneumocystis pneumonia at the age of 28. Patient 2, a 48-year-old female with intellectual disability and congenital malformations, was referred to Tokyo Medical and Dental University Hospital with abnormal bilateral lung shadows detected on her chest radiography. Computed tomography showed multiple lymphadenopathies and pneumonia. A lymph node biopsy of the inguinal region revealed granulomatous lymphadenitis, and a chromosomal examination revealed 18q deletion. Array-based genomic hybridization analysis revealed deletion at 18q21.32-q22.3 for patient 1 and at 18q21.33-qter for patient 2. Immune status work-up of the two patients revealed panhypogammaglobulinemia, decreased number of memory B cells and naïve CD4+ and/or CD8+ cells, reduced response on the carboxyfluorescein diacetate succinimidyl ester T-cell division test, and low levels of T-cell receptor recombination excision circles and Ig κ-deleting recombination excision circles. Consequently, both patients were diagnosed with LOCID. Although patients with 18q deletion syndrome generally experience humoral immunodeficiency, the disease can be further complicated by cell-mediated immunodeficiency, causing combined immunodeficiency. Therefore, patients with 18q deletion syndrome should be regularly tested for cellular/humoral immunocompetence.

Effects of High-Dose Cyclophosphamide on Ultrastructural Changes and Gene Expression Profiles in the Cardiomyocytes of C57BL/6J Mice.

The pathogenesis of cyclophosphamide (CY)-induced cardiotoxicity remains unknown, and methods for its prevention have not been established. To elucidate the acute structural changes that take place in myocardial cells and the pathways leading to myocardial damage under high-dose CY treatments, we performed detailed pathological analyses of myocardial tissue obtained from C57BL/6J mice subjected to a high-dose CY treatment. Additionally, we analysed the genome-wide cardiomyocyte expression profiles of mice subjected to the high-dose CY treatment. Treatment with CY (400 mg/kg/day intraperitoneally for two days) caused marked ultrastructural aberrations, as observed using electron microscopy, although these aberrations could not be observed using optical microscopy. The expansion of the transverse tubule and sarcoplasmic reticulum, turbulence in myocardial fibre travel, and a low contractile protein density were observed in cardiomyocytes. The high-dose CY treatment altered the cardiomyocyte expression of 1210 genes (with 675 genes upregulated and 535 genes downregulated) associated with cell-cell junctions, inflammatory responses, cardiomyopathy, and cardiac muscle function, as determined using microarray analysis (|Z-score| > 2.0). The expression of functionally important genes related to myocardial contraction and the regulation of calcium ion levels was validated using real-time polymerase chain reaction analysis. The results of the gene expression profiling, functional annotation clustering, and Kyoto Encyclopedia of Genes and Genomes pathway functional-classification analysis suggest that CY-induced cardiotoxicity is associated with the disruption of the Ca2+ signalling pathway.

Human Leukocyte Antigen-Haploidentical Haematopoietic Stem Cell Transplantation Using Post-Transplant Cyclophosphamide for Paediatric Haematological Malignancies.

The use of human leukocyte antigen (HLA)-haploidentical haematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCY), which markedly reduces the risk of graft-versus-host disease, has rapidly increased worldwide, even in children. It was initially developed for post-transplant relapse or non-remission at transplant for patients with high-risk haematologic malignancies. However, this strategy is currently used more frequently for standard-risk, transplant-eligible paediatric haematological malignancies. It has recently been recognised in adults that the transplant outcomes after PTCY-based HLA-haploidentical HSCT are comparable with those achieved after HLA-matched HSCT. Therefore, even in children, parental donors who are HLA-haploidentical donors and cord blood are currently considered the next donor candidates when an HLA-matched related or unrelated donor is unavailable. This review addresses the current status of the use of haplo-HSCT with PTCY for paediatric haematologic malignancies and future directions for donor selection (sex, age, ABO blood type, and HLA disparity), donor source, the dose of infused CD34+ cells, optimal conditioning, the concomitant graft-versus-host disease prophylaxis other than PTCY, and the pharmacokinetic study of CY and CY metabolites. These aspects present key solutions for further improvements in the outcomes of haplo-HSCT with PTCY for paediatric haematological malignancies.

TBI, etoposide, and cyclophosphamide conditioning for intermediate-risk relapsed childhood acute lymphoblastic leukemia.

BACKGROUND: In children with intermediate-risk relapsed acute lymphoblastic leukemia (ALL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) has markedly improved the outcome of patients with an unsatisfactory minimal residual disease (MRD) response. Total body irradiation (TBI), etoposide (ETP), and cyclophosphamide (CY) have been shown to be equivalent to or better than TBI + ETP for conditioning, so we hypothesized that even greater survival could be achieved due to recent advances in HSCT and supportive care. PROCEDURE: We prospectively analyzed the efficacy and safety of allo-HSCT with a unified conditioning regimen of TBI + ETP + CY in children with intermediate-risk relapsed ALL, based on MRD in the bone marrow after induction, from the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) ALL-R08-II nationwide cohort (UMIN000002025). RESULTS: Twenty patients with post-induction MRD ≥ 10-3 and two not evaluated for MRD underwent allo-HSCT. Engraftment was confirmed in all patients, and no transplantation-related mortality was observed. The 3-year event-free survival and overall survival rates after transplantation were 86.4% ± 7.3% and 95.5% ± 4.4%, respectively. CONCLUSION: Allo-HSCT based on post-induction MRD with TBI + ETP + CY conditioning was feasible in Japanese children with intermediate-risk relapsed ALL.

Case Report: The leopard sign as a potential characteristic of chronic granulomatous disease-associated colitis, unrelated to colitis severity.

Background: Chronic granulomatous disease (CGD) is an inborn immune disorder in which the phagocytic system cannot eradicate pathogens, and autoinflammation occurs. Approximately half of the patients have associated gastrointestinal symptoms. Although most cases with CGD-associated colitis present nonspecific histology, colonoscopy in some cases shows brownish dots over a yellowish oedematous mucosa, which is termed a "leopard sign". However, the significance of these signs remains unclear. Methods: We collected data from patients with CGD whose colonoscopic findings showed the leopard sign. Results: Three patients with CGD and leopard signs were enrolled in this study. One patient underwent colonoscopy for frequent diarrhoea and weight gain failure, and another for anal fistula. The third patient was without gastrointestinal symptoms and underwent colonoscopy as a screening test before allogeneic haematopoietic cell transplantation (HCT). Endoscopic findings showed a mild leopard sign in the first case; however, non-contiguous and diffuse aphthae were observed throughout the colon. The other two cases were unremarkable except for the leopard sign. All the patients achieved remission with oral prednisolone or HCT. One patient underwent colonoscopy after HCT; results revealed improvements in endoscopy (including the leopard sign) and histological findings. However, another patient underwent colonoscopy after prednisolone treatment; this revealed no change in the leopard sign. Conclusion: The leopard sign in the colon may be a characteristic endoscopic finding of CGD, even in patients who do not develop severe gastrointestinal symptoms; however, it does not reflect the severity of CGD-associated colitis.

[Steroid-refractory gastrointestinal acute graft-versus-host disease treated with vedolizumab and ruxolitinib in a pediatric patient with therapy-related acute myeloid leukemia].

A 12-year-old girl developed Philadelphia chromosome-positive acute myeloid leukemia due to therapy-related myelodysplastic syndrome with monosomy 7 following neuroblastoma treatment. She underwent allogenic bone marrow transplantation from a human leukocyte antigens-DR1 locus-mismatched unrelated donor. However, on day 49 post transplantation, she presented with diarrhea due to gastrointestinal acute graft-versus-host disease (aGVHD), and treatments with prednisolone, budesonide rectal foam, and human mesenchymal stem cells were ineffective. Therefore, vedolizumab was administered from day 100, which improved the symptoms from gut stage 3 to gut stage 1. Consequently, prednisolone was withdrawn without any serious adverse effects. However, the symptoms worsened to gut stage 3 again; therefore, ruxolitinib was administered to achieve complete remission. Vedolizumab exhibits gut-selective action without systemic immunosuppressive activity. Hence, vedolizumab administration before other systemic immunosuppressive agents may be recommended in patients with steroid-refractory gastrointestinal aGVHD. Thus far, only a few reports have been published regarding the administration of vedolizumab and ruxolitinib for steroid-refractory gastrointestinal aGVHD in children. Further evidence should be obtained from patients treated with vedolizumab and ruxolitinib to confirm their effectiveness for pediatric steroid-refractory gastrointestinal aGVHD.

Association between Dysfunction of the Nucleolar Stress Response and Multidrug Resistance in Pediatric Acute Lymphoblastic Leukemia.

Approximately 20% of pediatric patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) relapse or are refractory to chemotherapy despite the low frequency of TP53 mutations. The nucleolar stress response is a P53-activating mechanism via MDM2 inhibition by ribosomal protein L11 (RPL11). We analyzed the role of the nucleolar stress response using BCP-ALL cell lines and patient samples by drug sensitivity tests, Western blotting, and reverse transcription polymerase chain reaction. We revealed that the nucleolar stress response works properly in TP53 wild-type human BCP-ALL cell lines. Next, we found that 6-mercaptopurine, methotrexate, daunorubicin, and cytarabine had anti-leukemic effects via the nucleolar stress response within BCP-ALL treatment. Comparing the samples at onset and relapse in children with BCP-ALL, RPL11 mRNA expression decreased at relapse in seven of nine cases. Furthermore, leukemia cells with relapse acquired resistance to these four drugs and suppressed P53 and RPL11 expression. Our findings suggest that the nucleolar stress response is a novel anti-leukemia mechanism in BCP-ALL. As these four drugs are key therapeutics for BCP-ALL treatment, dysfunction of the nucleolar stress response may be related to clinical relapse or refractoriness. Nucleolar stress response may be a target to predict and improve the chemotherapy effect for pediatric BCP-ALL.

Successful laparoscopy-assisted en bloc resection of bulky omental malignant lymphoma involving the ascending colon and multiple lymph node metastases: Report of a technically demanding case in a pediatric patient.

We herein report a 13-year-old boy with a chief complaint of abdominal pain and a palpable mass. Contrast-enhanced computed tomography (CT) scan showed an abdominal bulky tumor involving the ascending colon causing severe stenosis, with multiple abdominal lymph node metastases detected by positron emission tomography (PET)-CT. Laparoscopic radical resection with right hemicolectomy and lymph node dissection was planned. The bulky tumor was dissected from the retroperitoneum and resected en bloc with the right-side colon and omentum. The preoperatively detected metastatic lymph nodes were resected along with the tumor. A 6-cm longitudinal umbilical incision was made, and the huge tumor was removed, with functional end-to-end anastomosis performed for intestinal reconstruction. The pathological diagnosis was Burkitt-like lymphoma with 11q aberration. The postoperative course was uneventful. Laparoscopy-assisted extirpation is feasible for pediatric solid tumors involving other organs, but indications and procedures should be carefully determined based on preoperative imaging, intraoperative findings and surgeon's skills.

Changes in intracellular activation-related gene expression and induction of Akt contribute to acquired resistance toward nelarabine in CCRF-CEM cell line.

Drug resistance is a major problem in treatment with nelarabine, and its resolution requires elucidation of the underlying mechanisms. We established two nelarabine-resistant subclones of the human T-cell lymphoblastic leukemia cell line CCRF-CEM. The resistant subclones showed changes in the expression of several genes related to nelarabine intracellular activation and inhibition of apoptosis. Activation of the Akt protein upon nelarabine treatment was observed in both subclones. The combination treatment with nelarabine and PI3K/Akt inhibitors was shown to inhibit cell growth. Cross-resistance was observed with ara-C and not with vincristine, daunorubicin, or etoposide treatment. Thus, changes in the expression of cellular activation-related genes, inhibition of apoptosis, and induction of Akt may be involved in the development of nelarabine resistance in the CCRF-CEM cell model. The use of different classes of chemotherapeutic agents and combination therapy with PI3K/Akt pathway inhibitors may be used to overcome resistance to nelarabine.

Successful Salvage of Very Early Relapse in Pediatric Acute Lymphoblastic Leukemia With Inotuzumab Ozogamicin and HLA-haploidentical Peripheral Blood Stem Cell Transplantation With Posttransplant Cyclophosphamide.

Herein, we describe a 14-year-old female patient with B-cell precursor acute lymphoblastic leukemia who relapsed in early consolidation. Minimal residual disease-negative complete remission was obtained after 1 cycle of inotuzumab ozogamicin therapy. She underwent HLA-haploidentical peripheral blood stem cell transplantation after a myeloablative conditioning regimen. Posttransplant cyclophosphamide, tacrolimus, and mycophenolate mofetil were administered for the prophylaxis of graft-versus-host disease. At 23 months, she was in complete remission. Although the administration of inotuzumab ozogamicin followed by haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide has been limited in children, this strategy may be an effective treatment for pediatric refractory acute lymphoblastic leukemia.

[Improvement in platelet count and bleeding symptom during treatment with eltrombopag in a patient with X-linked thrombocytopenia].

Herein, we describe a 13-year-old male adolescent who had chronic thrombocytopenia since infancy. In this case, X-linked thrombocytopenia (XLT) was suspected owing to a family history of chronic thrombocytopenia and small-sized platelets. Moreover, the patient was refractory to immunoglobulin therapy. The Wiskott-Aldrich syndrome protein (WASP) expression analysis revealed a decreased expression. Results showed a missense mutation [c.296A>G (p.Gln99Arg)] in exon 3 of the WASP-interacting protein region. Therefore, a diagnosis of XLT was made. To lift exercise restrictions, we initiated treatment with eltrombopag at a dose of 12.5 µg/day. The platelet count of the patient increased to approximately 50×103/µl after the treatment dose was escalated to 25 µg/day, and bleeding symptoms decreased after the patient resumed exercise. Ultrastructural platelet abnormalities and abnormal platelet aggregation were observed on transmission electron microscopy after the administration of eltrombopag. Therefore, eltrombopag treatment can increase platelet count and reduce bleeding symptoms in patients with XLT.