Clinical features of immature leukemias in children.

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), mixed phenotypic acute leukemia (MPAL), and acute myeloid leukemia with minimal differentiation (AML-M0) all originate from immature hematopoietic progenitor cells and have a poor prognosis. We investigated the clinical characteristics of these immature leukemias in 17 children (ETP-ALL: 8, MPAL: 5, AML-M0: 4) at seven institutions. Clinical and laboratory findings were comparable across disease types. Eleven and six patients received ALL- and AML-oriented induction chemotherapy, with six and four achieving complete remission (CR), respectively. Five additional patients achieved CR after salvage with the other type of chemotherapy. Eight patients received hematopoietic cell transplantation (HCT) in first CR, and six survived without relapse. However, six of seven patients who did not receive HCT during first CR relapsed; all underwent HCT later, and only three survived. The 5-year event-free survival (EFS) and overall survival (OS) rate were 37% and 69%, respectively. Patients who achieved CR after induction chemotherapy and received HCT in first CR had favorable EFS and OS. Notably, all patients who received HCT in first CR survived 5 years after diagnosis. Appropriate induction chemotherapy and HCT in first CR could improve the outcome of immature leukemias.

Clinical features of children with polycythemia vera, essential thrombocythemia, and primary myelofibrosis in Japan: A retrospective nationwide survey.

Background: Philadelphia-negative (Ph-negative) myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are exceptionally rare during childhood. Thus, clinical features of pediatric Ph-negative MPNs remain largely unknown. This study was therefore performed to address this. Methods: We performed a retrospective study to collect clinical information of children diagnosed with Ph-negative MPNs from 2000 to 2016 using questionnaires in qualified institutions in Japan. The results obtained from the questionnaire survey were then combined with those from the national registry data. Results: Among 50 children identified, five had PV, 44 had ET, and one had PMF. Median age at diagnosis was 14.0, 9.0, and 0 years, respectively. Male to female ratio was 4:1, 21:23, and 1:0, respectively. Detection rates of the JAK2 V617F variant were 0/5 in PV and 9/39 in ET. Frequencies of complications, such as thrombosis and subsequent leukemia, were lower than complication frequencies in adults. We identified two children who developed subsequent leukemia, which has not been reported previously, and one of them died. Conclusion: This is the first nationally representative survey of pediatric Ph-negative MPNs. Given its rarity, an international collaboration with comprehensive genetic analyses might be needed to fully elucidate the clinical and genetic features.

Clinical characteristics of pediatric patients with myeloid sarcoma without bone marrow involvement in Japan.

Myeloid sarcoma (MS) is a rare neoplastic condition that is often described in association with acute myeloid leukemia (AML). MS in childhood has received little attention, particularly in Japan. We carried out a nationwide retrospective analysis of Japanese children diagnosed with MS without bone marrow involvement. Inclusion criteria were diagnosis of MS at younger than 20 years of age between January 1, 2000 and December 31, 2013. There was a predominance of males (8:2), and the median age at MS diagnosis was 4 years. Sites of involvement varied and included skin (n = 3), head and/or neck (n = 2), and multiple sites (n = 2). Karyotypes were evaluated in seven patients, with one individual carrying t(8;21) and t(9;11). Four patients developed bone marrow involvement 2-55 months after diagnosis of MS. All patients received chemotherapy for de novo AML and two individuals received HSCT in first remission. Seven of ten patients survived for 50-152 months (median, 93 months) without disease after initial chemotherapy. This retrospective study confirmed that pediatric MS without bone marrow involvement in Japan is a very rare disease. MS patients responded favorably to therapies for de novo AML, and HSCT in first remission was not indicated for all patients.

High-dose Cepharanthin for pediatric chronic immune thrombocytopenia in Japan.

BACKGROUND: A nationwide, multicenter and observational study was retrospectively conducted to evaluate the clinical utility of Cepharanthin (CEP) for pediatric patients with chronic immune thrombocytopenia (ITP). METHODS: Clinical and laboratory data for 46 Japanese patients aged <16 years who were diagnosed as having chronic ITP in 14 hospitals during 2001-2011, and were treated with CEP for >12 months, were analyzed. RESULTS: Median daily CEP dose was 1 mg/kg (range, 0.12-2 mg/kg). Median platelet count prior to CEP was 20.5 × 109 /L (IQR, 8.3-53.0 × 109 /L), and then significantly increased to 58.5 × 109 /L (IQR, 22.8-115.0 × 109 /L) and 69.0 × 109 /L (IQR, 23.0-134.0 × 109 /L) at 12 and 24 months of treatment, respectively. No life-threatening bleeds or moderate-severe adverse events were reported. Of 38 patients who received both corticosteroids (CS) and CEP, 17 patients (45%) were weaned from CS, and 15 patients (39%) attained the reduced dose of CS. The duration from the start of CEP to the stopping of CS was a median of 413 days (range, 49-1734 days) in patients who were weaned from CS. CONCLUSIONS: CEP alone or combined with CS was useful for the management of pediatric chronic ITPs.

Analyses of Genetic and Clinical Parameters for Screening Patients With Inherited Thrombocytopenia with Small or Normal-Sized Platelets.

BACKGROUND: Childhood thrombocytopenias include immune thrombocytopenic purpura (ITP) and inherited thrombocytopenia; the former is caused by autoantibodies to platelets, whereas the latter can be distinguished by platelet size and underlying genetic mutations. Due to limited methods for the definite diagnosis of ITP, genetic and clinical parameters are required for diagnosing inherited thrombocytopenias with small or normal-sized platelets. PROCEDURE: In total, 32 Japanese patients with thrombocytopenia with small or normal-sized platelets from 29 families were enrolled. All the patients were under 20 years of age, with family histories of early-onset thrombocytopenia and/or poor response to conventional therapies for ITP. Genotypes and clinical parameters were retrospectively evaluated according to the disease type. RESULTS: Twelve cases of inherited thrombocytopenia were observed. We identified chromosomal deletions within the WASP gene in two patients with Wiskott-Aldrich syndrome; a missense mutation in a patient with X-linked thrombocytopenia; and mutations in the RUNX1 gene of five patients with familial platelet disorder with propensity to acute myelogenous leukemia, and in the ANKRD26 gene of four patients with autosomal dominant thrombocytopenia-2. All 12 carried germline mutations, three of which were de novo. Furthermore, we observed significantly elevated serum thrombopoietin (TPO) levels and dysplasia of megakaryocytes in patients carrying the RUNX1 and ANKRD26 mutations. CONCLUSIONS: Genetic analyses and detection of TPO levels and dysmegakaryopoiesis were clinically useful for screening patients with inherited thrombocytopenias, irrespective of the family history. We hypothesize that the WASP, RUNX1, and ANKRD26 genes are important for normal TPO signaling and the network underlying thrombopoiesis.

De novo childhood myelodysplastic/myeloproliferative disease with unique molecular characteristics.

Myelodysplastic/myeloproliferative uclassifiable (MDS/MPN-U) is a rare myeloid neoplasm characterized by myelodysplasia and myeloproliferation at the time of initial presentation, which is usually a diagnosis of exclusion. The molecular pathogenesis of MDS/MPN-U patients remains to be elucidated. Among five patients diagnosed with MDS/MPN-U, three patients harboured RUNX1 (AML1) mutations; one carried somatic mosaicism of RUNX1 mutation with JAK2(V617F) mutation and one had dual RUNX1 and FLT3-internal tandem duplication mutations with progression to acute myeloid leukaemia (AML). Germline mutation of TP53 was detected as a sole genetic lesion in one patient. JAK2(V617F) and somatic mosaicism of KRAS and TET2 mutations co-existed in one patient. Otherwise, no alterations were detected in PTPN11, NRAS, CBL and ASXL1 genes. ETV6-PDGFRB fusion transcript was not detected in all patients. Four patients recieved haematopoietic stem cell transplantation (HSCT); three patients relapsed and one achieved complete remission after three donor lymphocyte infusions. Our findings suggest that the mutational spectrum observed in childhood MDS/MPN-U is quite different from that seen in juvenile myelomonocytic leukaemia and, to some extent, resemble chronic myelomonocytic leukaemia. Moreover, two patients had constitutional alterations of genes frequently found in AML. Further investigations are required to define the roles of these genetic alterations in the pathogenesis of childhood MDS/MPN-U.

Heterozygous ITGA2B R995W mutation inducing constitutive activation of the αIIbß3 receptor affects proplatelet formation and causes congenital macrothrombocytopenia.

Congenital macrothrombocytopenia is a genetically heterogeneous group of rare disorders. αIIbß3 has not been implicated in these conditions. We identified a novel, conserved heterozygous ITGA2B R995W mutation in 4 unrelated families. The surface expression of platelet αIIbß3 was decreased to 50% to 70% of control. There was spontaneous PAC-1 and fibrinogen binding to resting platelets without CD62p expression. The activation state of αIIbß3 in 293T cells was higher for αIIb-W995 than for ß3-H723 but was weaker than for ß3-N562. FAK was spontaneously phosphorylated in αIIb-W995/ß3-transfected 293T cells. These results indicate that αIIb-W995/ß3 has a constitutive, activated conformation but does not induce platelet activation. αIIb-W995/ß3-transfected CHO cells developed membrane ruffling and abnormal cytoplasmic protrusions. The increased size and decreased number of proplatelet tips in αIIb-W995/ß3-transduced mouse fetal liver-derived megakaryocytes indicate defective pro-platelet formation. We propose that activating mutations in ITGA2B and ITGB3 represent the etiology of a subset of congenital macrothrombocytopenias.

[Acute lymphoblastic leukemia in a pediatric patient with Marfan's syndrome].

We report a rare case of acute lymphoblastic leukemia (ALL) in a 7-year-old boy with Marfan's syndrome. He was diagnosed as having Marfan's syndrome by clinical findings at the age of 2 years, and the diagnosis was confirmed by the detection of gene mutation in FBN1. He was referred to our hospital because of the swelling of cervical lymph nodes at the age of 7 years. Findings on bone marrow examination demonstrated T lymphoblastic ALL. He obtained complete remission after induction therapy, and had no serious side effects including cardiotoxicity during chemotherapy. He has remained in continuous complete remission for 34 months following diagnosis. To our knowledge, only three cases of leukemia in patients with Marfan's syndrome were reported previously. We speculate that increased activity of TGF-ß, which is known as a tumor suppressor factor, in patients with Marfan's syndrome may diminish the risk of developing leukemia, although such a thesis was not proven in this case.

Chronological diffusion-weighted imaging changes and mutism in the course of rotavirus-associated acute cerebellitis/cerebellopathy concurrent with encephalitis/encephalopathy.

Rotavirus is one of the most common causes of gastroenteritis in children and is known to accompany some neurological disorders such as encephalitis/encephalopathy and seizures. Although cerebellar disorders sometime occur as a complication of rotavirus gastroenteritis in Japan, few reports have addressed these issues. Here, we report three cases of insulted cerebellums in addition to encephalitis/encephalopathy associated with rotavirus. Similar to posterior fossa syndrome after surgery, mutism was a notable symptom that lasted about 1 month. Brain diffusion-weighted imaging (DWI) revealed chronological changes, i.e., marked hyperintensity in the bilateral dentate nucleus followed by the vermis and cerebellar hemisphere. The bilateral dentate nucleus is known to be a key lesion site for mutism, and these clinical and radiological findings may be tightly connected in rotavirus-associated cerebellitis/cerebellopathy.

How do the clinical features of brain tumours in childhood progress before diagnosis?

OBJECTIVES: To investigate the progression of the clinical features from symptom onset to diagnosis in children with brain tumours. DESIGN: Retrospective case note review. PATIENTS: Sixty children with brain tumours: 27 patients from Nagoya University Hospital diagnosed between February 2004 and April 2008, and 33 patients from Anjo Kosei Hospital diagnosed between April 1995 and December 2008. RESULTS: Various symptoms and signs were observed. The most common initial symptoms or signs were vomiting (24.1%), headache (17.2%), unsteadiness (10.3%), and paresis (10.3%). Sixteen patients were diagnosed based on the initial symptom or sign alone; six, at routine medical check-ups or had perinatal diagnosis; and the remaining 38, based on one or more additional features following the initial symptom. Nine of the 10 patients with headache as the initial symptom subsequently developed either vomiting (in seven) or unsteadiness with cranial nerve palsies (in two). Twelve of the 14 patients with vomiting as the initial symptom subsequently developed headache (in three), unsteadiness (in five), or other manifestations of increased intracranial pressure (in four). The remaining 14 had varied initial symptoms and combinations of symptoms and signs associated with the tumour location. The median pre-diagnosis symptomatic interval was 20.5 days. There was no significant difference in the median symptomatic interval between patients with headache or vomiting as the initial symptom and those with any neurological sign. CONCLUSION: Paediatric brain tumours present with various initial symptoms and signs. Many are diagnosed as additional symptoms or signs develop. The clinical features exhibit several patterns of progression, which are related to the tumour location.

Identification of the first in cis mutations in MYH9 disorder.

Here, we report the first in cis mutations in exon 1 of the MYH9 gene in a patient with MYH9 disorder. The patient was a 5-yr-old girl with macrothrombocytopenia and conspicuous cytoplasmic inclusion bodies in neutrophils. Immunofluorescence analysis of neutrophil non-muscle myosin heavy chain-II A (NMMHC-IIA) indicated several cytoplasmic spots of NMMHC-IIA aggregates that were circular to oval in shape (type II pattern). Mutational analysis showed two mutations, c.99G > T and c.103C > G, which would result in p.W33C and p.P35A, respectively, in exon 1 of the MYH9 gene. In addition, concurrent mutations were present on the same chromosome. Inclusion bodies are usually faint or mostly invisible in MYH9 disorders with a mutation in exon 1. In this case, double mutations might have caused the large myosin protein aggregation and accumulation. Although not observed in this patient, the development of Alport manifestations should be monitored by careful follow-up.

Serial diffusion-weighted imaging of neonatal herpes encephalitis: a case report.

We reported a patient with neonatal herpes simplex encephalitis in whom diffusion-weighted imaging was performed repeatedly. Diffusion-weighted imaging at 20h after the onset of seizures revealed scattered small spotty high intensity lesions in both hemispheres and a high intensity area in the left fronto-temporal lobe. There was no abnormal finding on conventional magnetic resonance imaging. Second diffusion-weighted imaging 72h after the onset revealed expanded scattered high intensity lesions in the bilateral hemisphere, a high intensity area in the left fronto-temporal lobe, and a new high intensity area in the right temporal lobe. There was no report on neonatal herpes simplex encephalitis that showed scattered high intensities in diffusion-weighted imaging. Scattered small high intensities on diffusion-weighted imaging may suggest endothelial cell infection with swelling and small vessel necrosis. Early diffusion-weighted imaging will be valuable for early detection and diagnosis of neonatal herpes simplex encephalitis.