Nowadays, medical care for patients with hemophilia has progressed. On the other hand, medical care for carriers of hemophilia is still insufficient, despite the fact that more than 20% of them are considered to meet the diagnostic criteria of hemophilia. Conventionally, the aim of carrier testing is to assess the possibility of having a child with hemophilia. Accordingly, only 20% of patients with hemophilia have female relatives who had their factor VIII or IX concentration measured in our institution. Henceforth, factor assays should be performed for all carriers and female relatives suspected of being carriers to protect themselves from bleeding. For perinatal management, cooperation among experts in various fields is important. Concerning the mode of delivery, it has been reported that cesarean section (CS) is associated with a reduced risk of intracranial hemorrhage (ICH) in newborns with hemophilia compared with spontaneous vaginal delivery. However, there are some cases of ICH caused by CS, and mothers undergoing CS also have the risk of bleeding. Under these circumstances, we should sufficiently discuss the mode of delivery with the expectant mother and her family, and this should be mutually agreed upon by the family and the medical team. The risk of ICH is lower in hemophiliac infants whose mothers are known to be carriers. From this viewpoint, medical care should be expanded for carriers and females suspected of being carriers. Medical care for carriers should include not only carrier testing but also sharing knowledge of hemophilia, psychosocial care, and medical examination.
Hemophilia A is a congenital bleeding disorder caused by genetic abnormalities of the blood coagulation factor (F)VIII. The QOL of hemophilia patients has been markedly improved by the on-demand or prophylactic replacement therapy with clotting factor agents. However, 20–30% of severe hemophilia A patients who received this replacement therapy, develop anti-FVIII alloantibodies (inhibitors). Once this happens, the hemostatic treatment is very uncertain and difficult. Therefore, the inhibitor development is one of the most serious problems. A hemostatic treatment strategy for hemophilia patients who developed inhibitors is to (i) elucidate the risk factor(s) for inhibitor development and prevent this development, (ii) eradicate the inhibitors, and (iii) establish an effective hemostatic and prophylactic treatment. More recently, the outcome of immune-tolerance induction therapy in Japanese hemophilia A patients who developed inhibitors has been reported. Furthermore, a subcutaneous formulation of available bispecific antibody (emicizumab, Hemlibra®) was approved for hemophilia A patients with or without inhibitors. This product decreases markedly the number of bleeding events. I will review the current status of the inhibitor treatment.
Hemophilia A and B are rare inherited bleeding disorders occurring in 1–5 persons per 10000 individuals in a given population. About 6000 patients with hemophilia are treated with clotting factor concentrates in approximately 1000 medical institutes in Japan. As a result, there is large disparity in patient access to the proper use of various clotting factor concentrates, which have been considerably developed in recent years. In addition to bleeding control, there is a need for the comprehensive care of hemophilia patients with various handicaps such as arthropathy. However, it is difficult for medical institutes, except for hemophilia treatment centers, to offer comprehensive care. Therefore, the Japanese hemophilia network committee (JHNC) was organized by the Japanese Society of Thrombosis and Hemostasis. JHNC is composed of hemophilia comprehensive care centers, hemophilia treatment centers, and other hemophilia care institutes. In collaboration with hemophilia treatment centers and hemophilia care institutes, hemophilia comprehensive care centers will provide comprehensive and personalized care to patients with hemophilia.
Transposable elements (TEs) are “DNA parasites” of the genome, which transpose, proliferate and comprise about 45% of the human genome. The transposition of TEs may harm the genome with the destruction of genes, thereby causing diseases. However, TEs have transcription factor binding sites (TFBSs), and a substantial fraction of them act as enhancers for nearby genes. Thus, TEs are required for genome functions. The adaptational capability of the genome is supported by the flexible use of TFBSs derived from TEs, called “exaptation”. Given that active enhancers are transcribed to RNA, transcribed TEs may reflect part of the “enhancer landscape” of cells. Neuroblastomas (NBs) have a unique stage called 4S in which they regress spontaneously even if stage 4 (st4) shows poor prognosis. A comparison study of st4 and 4S may provide the keys to finding the causes underlying the malignant characteristics of NBs and also the benign behavior of 4S. NBs show a relatively low frequency of gene mutations, so the amount of information obtained by studying NBs is limited. We introduced a method of TE transcriptome analysis, which may show another aspect of genome dysfunctions in TE-derived enhancer systems. Both gene and TE expression data have the power to cluster st4 and 4S clearly. They also brought about subclusters of st4, which show different survival courses. The significance of TE-based NB clusters will be revealed and would open a new age of medical discoveries.
Cellular immunotherapies are promising innovative and effective treatments even for patients who fail to be treated by current standard therapies. In this review, we outlined the advances in cellular immunotherapies for the treatment of pediatric cancer, mainly focusing on the development and clinical application of the chimeric antigen receptor T cell therapy for pediatric solid malignancies.
As well as surgery and chemotherapy, radiotherapy plays an important role in the treatment of pediatric tumors. There are many tumors that are particularly sensitive to radiotherapy in the field of pediatrics, and radiotherapy plays an important role in multidisciplinary treatment. However, growing children are sensitive to radiotherapy, requiring attention to adverse events. Also, it is necessary to consider adverse events specific to children, such as growth and developmental disorders and secondary cancers. To smoothly carry out radiotherapy without giving a sense of fear, collaboration of various types of work is required. The University of Tsukuba Hospital has been working on proton therapy for pediatric tumors since the 1980s. On the basis of our experiences, we will comment on radiotherapy for pediatric tumors.
Background: Occupational exposure to hazardous drugs (HDs) can decrease fertility and result in miscarriages, stillbirths, and cancer in healthcare staff. Several guidelines on the occupational exposure to HDs have been established for the health of hospital workers, but not of the family caregivers of cancer patients.
Methods: We administered high-dose cyclophosphamide (CPM) to 15 hospitalized pediatric cancer patients and analyzed the concentration of CPM in the urine and saliva of mothers attending to these patients, nurses, doctors, nursery staff members, child-life specialists, and cleaning staff members in the ward. Closed-system-drug-transfer devices in addition to safe handling were used to minimize technical exposure. This was approved by IRB of Kyushu University.
Results: The median concentration of CPM in the urine samples from mothers of infant patients (192 ng/10 mL, 0–1,510) was significantly higher than that in the urine samples from mothers of adolescent patients (0 ng/10 mL, 0–58.4) (p=0.005). CPM was also detected in the saliva samples from the attending mothers. On the other hand, CPM was not detected in the urine and saliva samples from all medical staff members.
Conclusion: On the basis of findings in urine and saliva samples, HD exposure was confirmed in attending mothers but not such exposure was found in medical staff members. The frequent mother–patient contact for the care of infants might account for the higher CPM concentrations in infants’ mothers than in adolescents’ mothers. In the pediatric cancer ward, preventive measures for HD exposure in accordance with the management of pediatric patients are needed for family caregivers.
The development of next-generation sequencing technologies has enabled the genome-wide analysis of pediatric T-cell acute lymphoblastic leukemia (T-ALL) and unveiled its clinicopathological features. In recent years, epigenetic profiles of T-ALL such as DNA methylation status have been widely investigated. In this study, we performed methylation array analysis in 79 pediatric T-ALL patients using EPIC methylation arrays. On the basis of DNA methylation profiles, pediatric T-ALL was classified into 4 clusters (Clusters 1–4). Cluster 1 was related to TAL1. Patients in this cluster showed high expression levels of ALDH1A2, a TAL1 downstream gene, and exhibited a late cortical thymocyte profile. Cluster 2 represented the earliest stage of T-cell development (CD4/8 double negative) and was characterized by high DEPTOR expression levels leading to PI3K-AKT activation. Interestingly, DNA methylation profiles were completely opposite between Clusters 1 and 2. In the hypermethylated Cluster 3, mutations of epigenetic regulators and JAK-STAT-related genes were frequently detected. All Cluster 3 patients were alive, but the significance of this finding should be interpreted carefully because of the small sample size (n=11). Cluster 4 was associated with SPI1 and showed the hypomethylated status. In addition to SPI1-related genes, high expression levels of cell-proliferation- and RAS/MAPK-related genes were the characteristic findings. All patients with SPI1 fusion, which we reported to have an extremely dismal prognosis, were classified into Cluster 4 with two dead patients without SPI1 fusions. Thus, Cluster 4 patients represented fatal outcomes regardless of SPI1 fusion. In the future, the elucidation of these genetic and epigenetic profiles might be helpful for a more adequate risk stratification and a new therapeutic strategy for T-ALL.
The blockade of the PD-1 or CTLA-4 pathway is an attractive strategy for immuno-oncology (I-O) therapy for not only adults but also children. Here, we developed a novel therapeutic strategy using alkylating pyrrole-imidazole polyamide (CCC07-01) capable of the simultaneous downregulation of the expressions of the human PD-1, PD-L1 and CTLA-4 genes targeting a common recognition sequence of these genes. CCC07-01 significantly suppressed PD-1, PD-L1 and CTLA-4 mRNA and protein expressions and subsequently showed cell killing activity in several cancer cell lines, whereas it did not show cytotoxic effects on human non-tumorous cells. Fourteen days after CCC07-01 injection, we also observed a significant inhibition of tumor growth and a predominant induction of effector memory CD8 T cells in a study of a human xenograft colon carcinoma model in NGS mice, following the engraftment of human peripheral blood mononuclear cells (PBMCs). The blockade of both PD-1 and CTLA-4 pathways together with preferable cancer cell death induction by a single agent, CCC07-01, may be a promising anticancer therapeutic strategy.
Recent studies using a next-generation sequencer demonstrated that at least 10% of pediatric cancer patients have a germline mutation in a cancer predisposition gene. Modern treatments for patients with Wilms tumor achieved overall survival rates of approximately 90%; however, 24% of the patients suffer from severe chronic health conditions. WT1 is a master gene for kidney development, and its germline mutations cause Wilms tumor as well as chronic kidney disease. In addition to the adverse effects of surgery, radiotherapy and/or chemotherapy, WT1 germline mutations may cause end-stage renal disease, and its prevention is needed to reduce late mortality. Children with Drash or Wilms tumor-aniridia-genitourinary anomalies-range of developmental delays (WAGR) syndrome or 46,XY disorders of sex development (DSD) and a family history of Wilms tumor may have a WT1 germline mutation. After confirming the mutation, surveillance is recommended to detect asymptomatic Wilms tumor. Nephron-preserving surgery for the small tumor may prevent end-stage renal disease. Thus, genetic counseling and genetic testing will lead to the understanding of the precise mechanism underlying late adverse effects, their prevention, and an improved outcome.
It is a great challenge to treat patients with very severe aplastic anemia (VSAA), who lack an HLA-matched related donor, and who fail to respond to immunosuppressive treatment (IST). Although cord blood transplantation (CBT) is a treatment option for hematological malignancies in the absence of a suitable unrelated donor, there is no evidence so far of the effectivity of CBT for aplastic anemia (AA). We performed semiurgent CBT to control recurrent infections in a patient with VSAA, which was refractory to IST and complicated by infections. The conditioning regimen consisted of fludarabine, melphalan, and low-dose total body irradiation, and GVHD prophylaxis consisted of tacrolimus and mycophenolate mofetil. Neutrophil engraftment was achieved on day 16. Complications such as Grade I acute GVHD, hemophagocytic syndrome, and virus-associated hemorrhagic cystitis were observed; however, they were tolerable. CBT could be an alternative treatment option for VSAA in the absence of an unrelated donor.
Acute megakaryoblastic leukemia (AMKL) often develops in neonates, and the prognosis differs depending on the gene mutation. A 0-day-old female with thrombocytopenia was transferred to our hospital. Physical examinations revealed severe hepatosplenomegaly, but no other external malformations. A blood test showed disseminated intravascular coagulation. We suspected that this was caused by an infection and thus we initiated antibiotic therapy and symptomatic treatment. The percentage of blast cells in peripheral blood increased from 2.7% to 11% by day 5. Therefore, bone marrow aspiration was performed. Flow cytometry indicated that the patient had transient abnormal myelopoiesis (TAM) or AMKL. The percentage of blast cells decreased to 2% without specific treatment. We therefore speculated that the patient had TAM without Down syndrome. However, we detected t(1;22)(p13;q13) by chromosome analysis of peripheral blood and therefore diagnosed the patient as having AMKL. Diagnosis of AMKL was complicated by the decrease in the percentage of blast cells, which occurs in TAM. We hope that polymerase chain reaction analysis will become readily available to facilitate the identification of gene mutations and thus differentiate between AMKL and TAM.
A 9-month-old male infant with congenital amegakaryocytic thrombocytopenia underwent unrelated bone marrow transplantation (BMT). Hematological engraftment was prompt, and serial chimerism analyses showed sustained complete chimerism on and after day 91. He developed autoimmune hemolytic anemia (AIHA) on day 56. Prednisolone and intravenous immunoglobulin (IVIG) did not improve his symptoms with persistent transfusion dependence. Treatment with rituximab on day 69, followed by the addition of the mTOR inhibitor everolimus on day 102, resulted in the gradual improvement of his anemia. The incidence of steroid- and IVIG-refractory AIHA has recently been increasing among pediatric patients undergoing hematopoietic stem cell transplantation. Therefore, it is necessary to reassess the treatment algorithm for these patients, such as the incorporation of rituximab or mTOR inhibitors into first-line treatment.
A 14-year-old male was referred to his previous doctor for fever and lumbago. A germ cell tumor (GCT) was observed in the mediastinum complicated by acute megakaryoblastic leukemia (AMKL). On the basis of this rare complication, the patient was diagnosed as having hematological neoplasia associated with primary mediastinal germ cell tumor (HN-PMGCT). He was treated following the JPLSG AML12 protocol for induction chemotherapy and achieved complete remission. His intensive chemotherapy included cisplatin to increase its effectiveness for the GCT, but after the 2nd cycle of intensive chemotherapy, AMKL relapsed and the GCT increased in size, causing dyspnea. To perform advanced therapy, he was transferred to our center. His GCT was resected, and hematopoietic stem cell transplantation (HSCT) was performed immediately after. However, HN-PMGCT recurred in the CNS and marrow approximately one month after the HSCT, resulting in death 117 days after the procedure. This syndrome needs to be studied further to develop new effective treatments.