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1.
Pediatr Blood Cancer ; 66(6): e27674, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30773805

RESUMO

INTRODUCTION: According to SIOP criteria, every patient presenting with preoperative Wilms tumor (WT) rupture must receive abdominal radiotherapy. Neoadjuvant chemotherapy reduces tumor volume and is responsible for the development of peritumoral capsule formation, which can mask tumor rupture on histological analysis, while it was clinically or radiologically obvious at diagnosis. Yet, there are no protocol recommendations for this particular presentation. OBJECTIVES: Study the agreement between clinicoradiological signs and histological confirmation after neoadjuvant chemotherapy of suspected WT rupture and describe the therapeutic choices arising in consequence. METHODS: Descriptive retrospective study on a monocentric series of patients with WT between June 1991 and August 2017. RESULTS: Out of 71 patients, 28 presented with suspected tumor rupture. We observed good agreement between clinical and radiological signs of suspected rupture (κ coefficient: 0.67). However, we assessed poor agreement between these signs and histological conclusions after neoadjuvant chemotherapy (κ coefficient: 0.27). Only five patients with clinicoradiological signs were overtreated with radiotherapy while tumor rupture had been refuted after histological review. The notion of abdominal trauma and the presence of intraperitoneal effusion seemed to guide collegial decision to overtreat these patients. No statistical difference in survival between patients with and without suspicion of tumor rupture at diagnosis was observed. CONCLUSION: This study highlights the need for recommendations in case of discrepancy between radiological and histological signs of rupture at diagnosis and after neoadjuvant chemotherapy. A study with stronger statistical power is necessary to define criteria that would lead to optimization of treatment in this context.

2.
Br J Haematol ; 183(4): 608-617, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30421536

RESUMO

Neurodegenerative (ND) complications in Langerhans cell histiocytosis (LCH) are a late-onset but dramatic sequelae for which incidence and risk factors are not well defined. Based on a national prospective registry of paediatric LCH patients, we determined the incidence rate of clinical ND LCH (cND-LCH) and analysed risk factors, taking into account disease extent and molecular characteristics. Among 1897 LCH patients, 36 (1·9%) were diagnosed with a cND-LCH. The 10-year cumulative incidence of cND-LCH was 4·1%. cND-LCH typically affected patients previously treated for a multisystem, risk organ-negative LCH, represented in 69·4% of cND-LCH cases. Pituitary gland, skin and base skull/orbit bone lesions were more frequent (P < 0·001) in cND-LCH patients compared to those without cND-LCH (respectively 86·1% vs. 12·2%, 75·0% vs. 34·2%, and 63·9% vs. 28·4%). The 'cND susceptible patients' (n = 671) i.e., children who had experienced LCH disease with pituitary or skull base or orbit bone involvement, had a 10-year cND risk of 7·8% vs. 0% for patients who did not meet these criteria. Finally, BRAFV 600E status added important information among these cND susceptible patients, with the 10-year cND risk of 33·1% if a BRAFV 600E mutation was present compared to 2·9% if it was absent (P = 0·002).

4.
J Surg Case Rep ; 2018(1): rjx260, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29383241

RESUMO

Infantile hepatic hemangioma (IHH) and mesenchymal hamartoma (MH) form the first and second most common benign hepatic tumors in children. In this case report, we present a newborn child in whom a growing hepatic mass was discovered at the age of 7 days. She suffered also from anemia, respiratory and renal failure. No signs of heart disease or cutaneous lesions were detected. Alpha-fetoprotein was elevated for her age (3562.2 ng/ml). Imaging studies showed multifocal large cystic lesions associated with heterogeneous small solid lesions with arterial enhancement of the liver. Non-anatomical liver resection was performed initially and synchronous MH and IHH GLUT-1 positive were discovered in the pathological analysis. Segmental IV hepatic resection and later on selective cysts excision were done for persistent hepatic lesion despite medical treatment. After 14 months of beta-blockers treatment, clinical follow-up shows a healthy child with no residual cystic lesions.

5.
J Med Genet ; 55(3): 173-180, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29070607

RESUMO

BACKGROUND: Development of tumours such as adrenocortical carcinomas (ACC), choroid plexus tumours (CPT) or female breast cancers before age 31 or multiple primary cancers belonging to the Li-Fraumeni (LFS) spectrum is, independently of the familial history, highly suggestive of a germline TP53 mutation. The aim of this study was to determine the contribution of de novo and mosaic mutations to LFS. METHODS AND RESULTS: Among 328 unrelated patients harbouring a germline TP53 mutation identified by Sanger sequencing and/or QMPSF, we could show that the mutations had occurred de novo in 40 cases, without detectable parental age effect. Sanger sequencing revealed two mosaic mutations in a child with ACC and in an unaffected father of a child with medulloblastoma. Re-analysis of blood DNA by next-generation sequencing, performed at a depth above 500X, from 108 patients suggestive of LFS without detectable TP53 mutations, allowed us to identify 6 additional cases of mosaic TP53 mutations, in 2/49 children with ACC, 2/21 children with CPT, in 1/31 women with breast cancer before age 31 and in a patient who developed an osteosarcoma at age 12, a breast carcinoma and a breast sarcoma at age 35. CONCLUSIONS: This study performed on a large series of TP53 mutation carriers allows estimating the contribution to LFS of de novo mutations to at least 14% (48/336) and suggests that approximately one-fifth of these de novo mutations occur during embryonic development. Considering the medical impact of TP53 mutation identification, medical laboratories in charge of TP53 testing should ensure the detection of mosaic mutations.

6.
J Oral Pathol Med ; 46(5): 321-326, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27778394

RESUMO

New targeted cancer therapies such as bisphosphonates, denosumab, and bevacizumab are routinely used in adult for the past decades. Their introduction into pediatric medicine is more recent that means there is a paucity of data on long-term effects on dental development and on the risk of osteonecrosis of jaw. This study aimed to outline adverse effects of new targeted cancer therapies on oral cavity including dental abnormalities observed in pediatric population treated with these molecules and the risk of osteonecrosis of the jaw (ONJ). The impact of bisphosphonates and denosumab on bone remodeling (inhibition of osteoclasts) could interfere with teeth exfoliation and eruption processes, causing a tooth eruption delay. This hypothesis was confirmed, bisphosphonate-treated rats presented tooth eruption delay, and bisphosphonate therapy was associated with a mean delay of 1.67 years in tooth eruption in children with osteogenesis imperfecta. Another study showed that the inhibition of RANK/RANKL by denosumab was associated with a lack of tooth eruption in animals. Several animal studies reported that bisphosphonate could also induce dental abnormalities including defective amelogenesis and dentinogenesis in rats, but there is no evidence of such effects in children; only one case of enamel hypoplasia in a child treated for idiopathic arterial calcification with bisphosphate was reported. To date, there has been no reported case of ONJ in children treated with bisphosphonates, denosumab, or bevacizumab.


Assuntos
Antinematódeos/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Dente/crescimento & desenvolvimento , Animais , Antinematódeos/uso terapêutico , Bevacizumab/efeitos adversos , Bevacizumab/uso terapêutico , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Criança , Denosumab/efeitos adversos , Denosumab/uso terapêutico , Difosfonatos/efeitos adversos , Difosfonatos/uso terapêutico , Humanos , Dente/efeitos dos fármacos , Erupção Dentária/efeitos dos fármacos
7.
J Clin Oncol ; 34(25): 3023-30, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27382093

RESUMO

PURPOSE: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with a broad spectrum of clinical manifestations and outcomes in children. The somatic BRAF(V600E) mutation occurs frequently, but clinical significance remains to be determined. PATIENTS AND METHODS: BRAF(V600E) mutation was investigated in a French LCH cohort. We analyzed associations between mutation status and clinical presentation, extent of disease, reactivation rate, response to therapy, and long-term permanent sequelae. RESULTS: Among 315 patients with successfully determined BRAF status, 173 (54.6%) carried a BRAF(V600E) mutation. Patients with BRAF(V600E) manifested more severe disease than did those with wild-type BRAF. Patients with BRAF(V600E) comprised 87.8% of patients (43 of 49) with multisystem LCH with risk organ involvement (liver, spleen, hematology), 68.6% of patients (35 of 51) with multisystem LCH without risk organ involvement, 43.9% of patients (86 of 196) with single-system LCH, and 42.1% of patients (8 of 19) with lung-involved LCH (P < .001). BRAF(V600E) mutation was also associated with organ involvement that could lead to permanent, irreversible damage, such as neurologic (75%) and pituitary (72.9%) injuries. Compared with patients with wild-type BRAF, patients with BRAF(V600E) more commonly displayed resistance to combined vinblastine and corticosteroid therapy (21.9% v 3.3%; P = .001), showed a higher reactivation rate (5-year reactivation rate, 42.8% v 28.1%; P = .006), and had more permanent, long-term consequences from disease or treatment (27.9% v 12.6%; P = .001). CONCLUSION: In children with LCH, BRAF(V600E) mutation was associated with high-risk features, permanent injury, and poor short-term response to chemotherapy. Further population-based studies should be undertaken to confirm our observations and to assess the impact of BRAF inhibitors for this subgroup of patients who may benefit from targeted therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Histiocitose de Células de Langerhans/tratamento farmacológico , Histiocitose de Células de Langerhans/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Corticosteroides/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Criança , Pré-Escolar , Estudos de Coortes , Resistencia a Medicamentos Antineoplásicos , Feminino , França/epidemiologia , Histiocitose de Células de Langerhans/enzimologia , Histiocitose de Células de Langerhans/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sistema de Registros , Vimblastina/administração & dosagem
8.
Br J Haematol ; 174(6): 887-98, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27273725

RESUMO

The French national cohort of children with Langerhans cell histiocytosis (LCH) has included 1478 patients since it was established in 1983. LCH therapeutic strategies substantially changed in 1998, so we have divided the cohort into two 15-year periods. Starting in 1998, therapy duration increased from 6 to 12 months, repeated induction therapy was performed in cases showing a poor response to the first induction with vinblastine and steroids, and refractory disease in a risk organ (RO+) was treated with cladribine and cytarabine. A total of 483 (33%) patients were enrolled before 1998, and 995 (67%) after 1998. Five-year survival was 96·6% (95% confidence interval: 95·4-97·5%) overall, improving from 92% pre-1998 to 99% post-1998 (P < 0·001 adjusted to disease extent). This change was supported by an increase in 5-year survival from 60% to 92% in the RO+ group. Survival was particularly associated with cladribine and cytarabine among refractory RO+ patients. Disease reactivation was slightly less frequent after 1998, due to better enrolment of single-system patients, extended therapy duration, and more efficient second-line therapy. The crude rates of endocrine and neurological sequelae (the most frequent sequelae) appeared to improve over time, but this difference was not observed when the analysis was stratified by disease extent.


Assuntos
Histiocitose de Células de Langerhans/epidemiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Estudos de Coortes , Terapia Combinada , Feminino , Seguimentos , França/epidemiologia , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/mortalidade , Histiocitose de Células de Langerhans/terapia , Humanos , Lactente , Recém-Nascido , Masculino , Vigilância da População , Padrão de Cuidado , Análise de Sobrevida , Resultado do Tratamento
9.
Bull Cancer ; 103(2): 210-8, 2016 Feb.
Artigo em Francês | MEDLINE | ID: mdl-26774699

RESUMO

Synovial sarcoma (SS) is a rare high-grade malignant mesenchymal tumor affecting children, adolescents, and young adults. Cytogenetically, more than 90% of SS is characterized by the t(X;18)(p11.2;q11.2), translocation resulting in two chimeric fusion genes SYT-SSX1 and SYT-SSX2, confirming histological diagnosis. Pediatric SS arises most often in soft tissues of the extremities (66% of cases), and is a localized tumor without spreading to regional lymph nodes (96% of cases) nor to metastatic sites (94% of cases). Although clinical and radiologic presentation, histologic analysis and tumor biology appear similar in pediatric and adolescent SS, outcome seems better in children than in adolescents, respectively 84% vs 60% of 5years overall survival (OS). If complete resection is the gold standard in SS, other therapeutic modalities differ between pediatric and adult populations, considering SS as an intermediate chemosensitive tumor more frequently by pediatric oncologists. Prognostic factors evaluation (tumor size, site of primary and IRS group) is necessary to establish optimal treatment strategies, with multimodal therapeutic approach in children and adolescents. Thus, recent results about the European prospective EpSSG NRSTS 05 study for children and adolescent patients with localized SS showed a 5years OS >90%. Moreover, recent somatic genetic data about SS open the debate on an appropriate strategy based and stratified on tumor genomic. Multinational prospective pediatric, adolescent and young adult study is necessary to improve optimal and appropriate approach in this rare tumor.


Assuntos
Sarcoma Sinovial , Adolescente , Fatores Etários , Criança , Pré-Escolar , Rearranjo Gênico , Humanos , Proteínas de Fusão Oncogênica/genética , Prognóstico , Doenças Raras/diagnóstico , Doenças Raras/genética , Doenças Raras/mortalidade , Doenças Raras/terapia , Sarcoma Sinovial/diagnóstico , Sarcoma Sinovial/genética , Sarcoma Sinovial/mortalidade , Sarcoma Sinovial/terapia , Carga Tumoral
10.
Eur Urol ; 69(6): 1055-61, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26433572

RESUMO

BACKGROUND: Renal medullary carcinoma (RMC) is a rare and highly aggressive neoplasm that most often occurs in the setting of sickle cell trait or sickle cell disease (SCD). Most patients present with metastatic disease resistant to conventional chemotherapy, and therefore there is an urgent need for molecular insight to propose new therapies. OBJECTIVE: To determine the molecular alterations and oncogenic pathways that drive RMC development. DESIGN, SETTING, AND PARTICIPANTS: A series of five frozen samples of patients with RMC was investigated by means of gene expression profiling, array comparative genomic hybridization, and RNA and whole exome sequencing (WES). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: RNA and DNA sequencing read data were analyzed to detect gene fusions and somatic mutations. Gene fusions mutations were validated by real-time polymerase chain reaction and fluorescence in situ hybridization. Gene expression profiling was analyzed by unsupervised hierarchical clustering and Gene Set Enrichment Analysis (Broad Institute, Cambridge, MA, USA). RESULTS AND LIMITATIONS: We observed inactivation of the tumor suppressor gene SMARCB1 in all tumors. In all four cases developed in patients with SCD, we identified an original mechanism of interchromosomal balanced translocations that disrupt the SMARCB1 sequence and thus contribute to its inactivation. Gene expression profiling revealed that RMC shares common oncogenic pathways with pediatric malignant rhabdoid tumors, another tumor subtype characterized by SMARCB1 deficiency. CONCLUSIONS: RMCs are characterized by an original mechanism of interchromosomal balanced translocations that disrupt the SMARCB1 sequence. WES reveals that RMCs show no other recurrent genetic alteration and an overall stable genome, underscoring the oncogenic potency of SMARCB1 inactivation. PATIENT SUMMARY: Our comprehensive molecular study supports a pivotal role of the tumor suppressor gene SMARCB1 in the development of renal medullary carcinoma. The use of therapeutic strategies based on the biologic effects of its inactivation should now open new perspectives for this typically lethal malignancy.


Assuntos
Carcinoma/genética , Neoplasias Renais/genética , Proteína SMARCB1/genética , Translocação Genética , Adolescente , Adulto , Anemia Falciforme/complicações , Anemia Falciforme/genética , Calpaína/genética , Carcinogênese/genética , Carcinoma/complicações , Criança , Hibridização Genômica Comparativa , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Fusão Gênica , Humanos , Neoplasias Renais/complicações , Proteínas Nucleares/genética , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , RNA Longo não Codificante/genética , Análise de Sequência de RNA , Fatores de Transcrição/genética , Sequenciamento Completo do Exoma
11.
Eur J Hum Genet ; 24(1): 99-105, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25873010

RESUMO

To determine if the at-risk single-nucleotide polymorphism (SNP) alleles for colorectal cancer (CRC) could contribute to clinical situations suggestive of an increased genetic risk for CRC, we performed a prospective national case-control study based on highly selected patients (CRC in two first-degree relatives, one before 61 years of age; or CRC diagnosed before 51 years of age; or multiple primary CRCs, the first before 61 years of age; exclusion of Lynch syndrome and polyposes) and controls without personal or familial history of CRC. SNPs were genotyped using SNaPshot, and statistical analyses were performed using Pearson's χ(2) test, Cochran-Armitage test of trend and logistic regression. We included 1029 patients and 350 controls. We confirmed the association of CRC risk with four SNPs, with odds ratio (OR) higher than previously reported: rs16892766 on 8q23.3 (OR: 1.88, 95% confidence interval (CI): 1.30-2.72; P=0.0007); rs4779584 on 15q13.3 (OR: 1.42, CI: 1.11-1.83; P=0.0061) and rs4939827 and rs58920878/Novel 1 on 18q21.1 (OR: 1.49, CI: 1.13-1.98; P=0.007 and OR: 1.49, CI: 1.14-1.95; P=0.0035). We found a significant (P<0.0001) cumulative effect of the at-risk alleles or genotypes with OR at 1.62 (CI: 1.10-2.37), 2.09 (CI: 1.43-3.07), 2.87 (CI: 1.76-4.70) and 3.88 (CI: 1.72-8.76) for 1, 2, 3 and at least 4 at-risk alleles, respectively, and OR at 1.71 (CI: 1.18-2.46), 2.29 (CI: 1.55-3.38) and 6.21 (CI: 2.67-14.42) for 1, 2 and 3 at-risk genotypes, respectively. Combination of SNPs may therefore explain a fraction of clinical situations suggestive of an increased risk for CRC.


Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 18 , Cromossomos Humanos Par 8 , Neoplasias Colorretais/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Estudos de Casos e Controles , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Feminino , Frequência do Gene , Loci Gênicos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Prospectivos , Fatores de Risco
13.
J Clin Endocrinol Metab ; 99(2): E369-73, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24276449

RESUMO

CONTEXT: HIF2A germline mutations were known to cause congenital polycythemia. Recently, HIF2A somatic mutations were found in several patients with polycythemia and paraganglioma, pheochromocytoma, or somatostatinoma, suggesting the occurrence of a de novo postzygotic HIF2A mutation that has not been demonstrated clearly. PATIENTS: Patient 1 is a woman suffering from polycythemia diagnosed at the age of 16 years. She was operated on for a pheochromocytoma at 45 years and for two abdominal paragangliomas at 59 years. She was also diagnosed with somatostatinoma. Patient 2 is a young boy who suffered from polycythemia since infancy. He underwent surgery for a nonfunctional adrenal paraganglioma at the age of 9 years. METHODS: We sequenced by Sanger and next-generation sequencing the HIF2A gene in DNA extracted from tumors, leukocytes, and buccal cells. RESULTS: In patient 1, we identified a somatic HIF2A mutation (c.1586T>C; p.Leu529Pro) in DNA extracted from both paragangliomas. The mutation was detected as a somatic mosaic in DNA extracted from somatostatinoma and was absent from germline DNA. In patient 2, we found an HIF2A heterozygous mutation (c.1625T>C; p.Leu542Pro) in the paraganglioma, but the mutation was also present as a mosaic in leukocyte DNA and in DNA extracted from buccal cells (3.3 and 8.96% of sequencing reads, respectively). Both mutations disrupt the hydroxylation domain of the HIF2α protein. CONCLUSIONS: Our study shows that HIF2A-related tumors are caused by postzygotic mutations occurring in early developmental stages. Potential germline mosaicism should be considered during the familial genetic counseling when an individual has been diagnosed with HIF2A-related polycythemia-paraganglioma syndrome.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Mosaicismo , Policitemia/genética , Adolescente , Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias das Glândulas Suprarrenais/cirurgia , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Paraganglioma/genética , Paraganglioma/patologia , Paraganglioma/cirurgia , Policitemia/patologia , Síndrome
14.
Ann Biol Clin (Paris) ; 71(4): 489-95, 2013 Jul-Aug.
Artigo em Francês | MEDLINE | ID: mdl-23906582

RESUMO

This work describes a dysfibrinogenemia linked to a new mutation in the gene coding for fibrinogen γ chain. Dysfibrinogenemia was fortuitously discovered in a 9-year old boy consulting for symptoms suggesting meningitis. DNA was extracted from blood, the fibrinogen genes coding for Aα, Bß and γ chains were sequenced, and compared with consensus sequences. Apart from the patient, dysfibrinogenemia and the mutation p.H103N in the γ chain of fibrinogen with heterozygous status were found in his mother, without any symptom. This mutation is unknown in fibrinogen variant databases and seems to affect mostly fibrin polymerisation. The reporting of this new p.H103N mutation in the γ chain has a great interest for improving the knowledge of the fibrinogen gene and its expression. Even if no haemorrhage was observed in this case, the expression of this mutation impaired the function of the molecule, particularly polymerisation, and could induce bleeding during an important surgery.


Assuntos
Afibrinogenemia/genética , Asparagina/genética , Fibrinogênio/genética , Histidina/genética , Mutação/genética , Adenina , Criança , Códon/genética , Citosina , Exantema Súbito/diagnóstico , Fibrinogênios Anormais/genética , Herpesvirus Humano 6/isolamento & purificação , Heterozigoto , Humanos , Achados Incidentais , Masculino , Polimorfismo Genético/genética
15.
Pediatr Blood Cancer ; 60(11): 1759-65, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23813854

RESUMO

BACKGROUND: Mediastinal involvement (MI) in Langerhans cell histiocytosis (LCH) has been rarely reported. Here, we describe the clinical, radiological, and biological presentation, and the outcome of childhood LCH with MI. METHOD: From the French LCH register, which includes 1,423 patients aged less than 18 years, we retrieved the medical charts of patients with mediastinal enlargement detected on chest X-rays. RESULTS: Thirty-seven patients were retrieved, including 18 males; median age of diagnosis was 0.7 years, and median follow-up time was 6.2 years. The prevalence of MI varied with the age at diagnosis, ranging from 7% below 1 year old to less than 1% at >5 years. Thirteen cases (35%) were diagnosed because of MI-related symptoms, including respiratory distress (N = 4), superior venous cava syndrome (N = 2), and/or cough and polypnea (N = 10). CT scans performed in 32 cases at diagnosis showed tracheal compression (N = 5), cava thrombosis (N = 2), and/or calcification (N = 16). All patients presented multi-system disease at LCH diagnosis, and 35/37 were initially treated with vinblastine and corticosteroids. Death occurred in five cases, due to MI (N = 1) or hematological refractory involvement (N = 4). The overall 5-year survival was 87.1%, and immunodeficiency was not detected as a sequel. CONCLUSIONS: MI in LCH mainly occurs in young children, and diagnosis was based on CT showing thymus enlargement and calcifications.


Assuntos
Histiocitose de Células de Langerhans/patologia , Linfonodos/patologia , Timo/patologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , França , Humanos , Lactente , Masculino , Mediastino/patologia
17.
Hum Mutat ; 32(6): 590-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21309041

RESUMO

X-linked Sideroblastic Anemia (XLSA) is the most common genetic form of sideroblastic anemia, a heterogeneous group of disorders characterized by iron deposits in the mitochondria of erythroid precursors. XLSA is due to mutations in the erythroid-specific 5-aminolevulinate synthase (ALAS2) gene. Thirteen different ALAS2 mutations were identified in 16 out of 29 probands with sideroblastic anemia. One third of the patients were females with a highly skewed X-chromosome inactivation. The identification of seven novel mutations in the ALAS2 gene, six missense mutations, and one deletion in the proximal promoter extends the allelic heterogeneity of XSLA. Most of the missense mutations were predicted to be deleterious, and 10 of them, without any published functional characterization, were expressed in Escherichia coli. ALAS2 activities were assayed in vitro. Five missense mutations resulted in decreased enzymatic activity under standard conditions, and two other mutated proteins had decreased activity when assayed in the absence of exogenous pyridoxal phosphate and increased thermosensitivity. Although most amino acid substitutions result in a clearly decreased enzymatic activity in vitro, a few mutations have a more subtle effect on the protein that is only revealed by in vitro tests under specific conditions.


Assuntos
5-Aminolevulinato Sintetase/genética , Anemia Sideroblástica/genética , Mutação de Sentido Incorreto , Adulto , Substituição de Aminoácidos , Criança , Feminino , Expressão Gênica , Doenças Genéticas Ligadas ao Cromossomo X , Heme/biossíntese , Heme/genética , Humanos , Lactente , Ferro/metabolismo , Masculino , Pessoa de Meia-Idade , Conformação Proteica , Protoporfirinas/genética , Inativação do Cromossomo X
18.
PLoS One ; 3(9): e3262, 2008 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-18810271

RESUMO

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare disease that affects mainly young children, and which features granulomas containing Langerhans-type dendritic cells. The role of several human herpesviruses (HHV) in the pathogenesis of LCH was suggested by numerous reports but remains debated. Epstein-barr virus (EBV, HHV-4), & Cytomegalovirus (CMV, HHV-5) can infect Langerhans cells, and EBV, CMV and HHV-6 have been proposed to be associated with LCH based on the detection of these viruses in clinical samples. METHODOLOGY: We have investigated the prevalence of EBV, CMV and HHV-6 infection, the characters of antibody response and the plasma viral load in a cohort of 83 patients and 236 age-matched controls, and the presence and cellular localization of the viruses in LCH tissue samples from 19 patients. PRINCIPAL FINDINGS: The results show that prevalence, serological titers, and viral load for EBV, CMV and HHV-6 did not differ between patients and controls. EBV was found by PCR in tumoral sample from 3/19 patients, however, EBV small RNAs EBERs -when positive-, were detected by in situ double staining in bystander B CD20+ CD79a+ lymphocytes and not in CD1a+ LC. HHV-6 genome was detected in the biopsies of 5/19 patients with low copy number and viral Ag could not be detected in biopsies. CMV was not detected by PCR in this series. CONCLUSIONS/SIGNIFICANCE: Therefore, our findings do not support the hypothesis of a role of EBV, CMV, or HHV-6 in the pathogenesis of LCH, and indicate that the frequent detection of Epstein-barr virus (EBV) in Langerhans cell histiocytosis is accounted for by the infection of bystander B lymphocytes in LCH granuloma. The latter observation can be attributed to the immunosuppressive micro environment found in LCH granuloma.


Assuntos
Infecções por Herpesviridae/complicações , Infecções por Herpesviridae/epidemiologia , Histiocitose de Células de Langerhans/complicações , Histiocitose de Células de Langerhans/epidemiologia , Adolescente , Adulto , Antígenos CD1/biossíntese , Antígenos CD20/biossíntese , Antígenos CD79/biossíntese , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Citomegalovirus/metabolismo , Infecções por Herpesviridae/diagnóstico , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 6/metabolismo , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/virologia , Humanos , Imunossupressores/farmacologia , Lactente
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