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1.
Genes Chromosomes Cancer ; 61(12): 740-746, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35999193

RESUMO

Cutaneous skeletal hypophosphatemia syndrome (CSHS) is caused by somatic mosaic NRAS variants and characterized by melanocytic/sebaceous naevi, eye, and brain malformations, and FGF23-mediated hypophosphatemic rickets. The MEK inhibitor Trametinib, acting on the RAS/MAPK pathway, is a candidate for CSHS therapy. A 4-year-old boy with seborrheic nevus, eye choristoma, multiple hamartomas, brain malformation, pleural lymphangioma and chylothorax developed severe hypophosphatemic rickets unresponsive to phosphate supplementation. The c.182A > G;p.(Gln61Arg) somatic NRAS variant found in DNA from nevus biopsy allowed diagnosing CSHS. We administered Trametinib for 15 months investigating the transcriptional effects at different time points by whole blood RNA-seq. Treatment resulted in prompt normalization of phosphatemia and phosphaturia, catch-up growth, chylothorax regression, improvement of bone mineral density, reduction of epidermal nevus and hamartomas. Global RNA sequencing on peripheral blood mononucleate cells showed transcriptional changes under MEK inhibition consisting in a strong sustained downregulation of signatures related to RAS/MAPK, PI3 kinase, WNT and YAP/TAZ pathways, reverting previously defined transcriptomic signatures. CSHS was effectively treated with a MEK inhibitor with almost complete recovery of rickets and partial regression of the phenotype. We identified "core" genes modulated by MEK inhibition potentially serving as surrogate markers of Trametinib action.


Assuntos
Quilotórax , Hamartoma , Hipofosfatemia , Nevo Pigmentado , Nevo , Raquitismo Hipofosfatêmico , Neoplasias Cutâneas , DNA , GTP Fosfo-Hidrolases/genética , Humanos , Hipofosfatemia/diagnóstico , Hipofosfatemia/genética , Proteínas de Membrana/genética , Quinases de Proteína Quinase Ativadas por Mitógeno , Nevo Pigmentado/diagnóstico , Nevo Pigmentado/genética , Nevo Pigmentado/metabolismo , Fosfatos , Fosfatidilinositol 3-Quinases , Raquitismo Hipofosfatêmico/genética , Neoplasias Cutâneas/genética , Síndrome
2.
Br J Haematol ; 199(2): 171-172, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35929529

RESUMO

Transfusion-dependent Diamond-Blackfan anaemia (DBA) patients rapidly develop iron overload and frequently experience cardiac complications. The report by Lecornec and colleagues offers useful details on indications and the management of deferiprone, a highly efficient chelator in removing excess cardiac iron but associated with a high risk of agranulocytosis in DBA patients. Commentary on: Lecornec et al. Agranulocytosis in patients with Diamond-Blackfan anaemia (DBA) treated with deferiprone for post-transfusion iron overload: A retrospective study of the French DBA cohort. British Journal of Haematology 2022;199:285-288.


Assuntos
Agranulocitose , Anemia de Diamond-Blackfan , Sobrecarga de Ferro , Anemia de Diamond-Blackfan/complicações , Anemia de Diamond-Blackfan/terapia , Quelantes , Deferiprona/uso terapêutico , Humanos , Ferro/uso terapêutico , Sobrecarga de Ferro/complicações , Estudos Retrospectivos
3.
Pediatr Blood Cancer ; 69(6): e29599, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35253359

RESUMO

Neutropenia refers to a group of diseases characterized by a reduction in neutrophil levels below the recommended age threshold. The present study aimed to review the diagnosis and management of neutropenia, including a diagnostic toolkit and candidate underlying genes. This study also aimed to review the progress toward the definition of autoimmune and idiopathic neutropenia rising in infancy or in late childhood but without remission, and provide suggestions for efficient diagnostics, including indications for the bone marrow and genetic testing. The management and treatment protocols for common and unique presentations are also reviewed, providing evidence tailored to a single patient.


Assuntos
Medula Óssea , Neutropenia , Transplante de Medula Óssea , Criança , Humanos , Itália , Oncologia , Neutropenia/diagnóstico , Neutropenia/terapia , Síndrome
4.
Haematologica ; 106(5): 1303-1310, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32241839

RESUMO

Diamond Blackfan anemia (DBA) is predominantly an autosomal dominant inherited red cell aplasia primarily caused by pathogenic germline variants in ribosomal protein genes. DBA due to pathogenic RPL35A variants has been associated with large 3q29 deletions and phenotypes not common in DBA. We conducted a multi-institutional genotype-phenotype study of 45 patients with DBA associated with pathogenic RPL35A germline variants and curated the variant data on 21 additional cases from the literature. Genotype-phenotype analyses were conducted comparing patients with large deletions versus all other pathogenic variants in RPL35A. Twenty-two of the 45 cases had large deletions in RPL35A. After adjusting for multiple tests, a statistically significant association was observed between patients with a large deletion and steroid-resistant anemia, neutropenia, craniofacial abnormalities, chronic gastrointestinal problems, and intellectual disabilities (p<0.01) compared with all other pathogenic variants. Non-large deletion pathogenic variants were spread across RPL35A with no apparent hot spot and 56% of the individual family variants were observed more than once. In this, the largest known study of DBA patients with pathogenic RPL35A variants, we determined that patients with large deletions have a more severe phenotype that is clinically different from those with non-large deletion variants. Genes of interest also deleted in the 3q29 region that could be associated with some of these phenotypic features include LMLN and IQCG. Management of DBA due to large RPL35A deletions may be challenging due to complex problems and require comprehensive assessments by multiple specialists including immunologic, gastrointestinal, and developmental evaluations to provide optimal multidisciplinary care.


Assuntos
Anemia de Diamond-Blackfan , Anemia de Diamond-Blackfan/genética , Estudos de Associação Genética , Humanos , Mutação , Fenótipo , Proteínas Ribossômicas/genética
5.
Pediatr Blood Cancer ; 68(3): e28840, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33274837

RESUMO

BACKGROUND: Fatigue is an important clinical and psychological aspect for a significant number of children affected by immune thrombocytopenia (ITP). To date, few studies have explored fatigue and its relationship with chronic ITP in pediatric age. The aim of the present multicentric pilot study is to determine fatigue perception in a large group of children with chronic ITP and their caregivers using the PedsQL Multidimensional Fatigue Scale (PedsQL MFS), and to compare the results with those of healthy control subjects. PROCEDURE: Children with chronic ITP aged 5-18 years and/or caregivers of children aged 2-18 years were enrolled. Child/adolescent self-report was used for patients aged 5-18 years, and parent proxy-report for patients aged 2-18 years. The questionnaire was offered as online survey. PedsQL MFS is composed of 18 items covering three dimensions: General Fatigue Scale, Sleep/Rest Fatigue Scale, and Cognitive Fatigue Scale. RESULTS: One hundred ninety-one patients affected by chronic ITP and 248 caregivers answered the PedsQL MFS. We have highlighted that lower values of PedsQL MFS scores are obtained in the 13-18 age group. Moreover, sleep/rest fatigue domain appears to be more compromised in all age groups. For all PedsQL MFS scores, pediatric patients with chronic ITP and their caregivers reported statistically significant worse fatigue than healthy children. CONCLUSIONS: This study suggests that fatigue is relevant among children and adolescents affected by chronic ITP. The PedsQL MFS represents an adequate instrument for measuring fatigue in patients with chronic ITP. Therefore, symptoms of fatigue should be routinely assessed in clinical practice.


Assuntos
Cuidadores/psicologia , Fadiga/diagnóstico , Fadiga/psicologia , Púrpura Trombocitopênica Idiopática/complicações , Qualidade de Vida , Adolescente , Adulto , Criança , Pré-Escolar , Fadiga/etiologia , Feminino , Seguimentos , Humanos , Masculino , Percepção , Projetos Piloto , Prognóstico , Inquéritos e Questionários , Adulto Jovem
6.
Int J Mol Sci ; 22(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299101

RESUMO

Children with the new coronavirus disease 2019 (COVID-19) have milder symptoms and a better prognosis than adult patients. Several investigations assessed type I, II, and III interferon (IFN) signatures in SARS-CoV-2 infected adults, however no data are available for pediatric patients. TRIM28 and SETDB1 regulate the transcription of multiple genes involved in the immune response as well as of human endogenous retroviruses (HERVs). Exogenous viral infections can trigger the activation of HERVs, which in turn can induce inflammatory and immune reactions. Despite the potential cross-talks between SARS-CoV-2 infection and TRIM28, SETDB1, and HERVs, information on their expressions in COVID-19 patients is lacking. We assessed, through a PCR real time Taqman amplification assay, the transcription levels of six IFN-I stimulated genes, IFN-II and three of its sensitive genes, three IFN-lIIs, as well as of TRIM28, SETDB1, pol genes of HERV-H, -K, and -W families, and of env genes of Syncytin (SYN)1, SYN2, and multiple sclerosis-associated retrovirus (MRSV) in peripheral blood from COVID-19 children and in control uninfected subjects. Higher expression levels of IFN-I and IFN-II inducible genes were observed in 36 COVID-19 children with mild or moderate disease as compared to uninfected controls, whereas their concentrations decreased in 17 children with severe disease and in 11 with multisystem inflammatory syndrome (MIS-C). Similar findings were found for the expression of TRIM-28, SETDB1, and every HERV gene. Positive correlations emerged between the transcriptional levels of type I and II IFNs, TRIM28, SETDB1, and HERVs in COVID-19 patients. IFN-III expressions were comparable in each group of subjects. This preserved induction of IFN-λs could contribute to the better control of the infection in children as compared to adults, in whom IFN-III deficiency has been reported. The upregulation of IFN-I, IFN-II, TRIM28, SETDB1, and HERVs in children with mild symptoms, their declines in severe cases or with MIS-C, and the positive correlations of their transcription in SARS-CoV-2-infected children suggest that they may play important roles in conditioning the evolution of the infection.


Assuntos
COVID-19/epidemiologia , COVID-19/metabolismo , Retrovirus Endógenos/metabolismo , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , COVID-19/patologia , COVID-19/virologia , Estudos de Casos e Controles , Criança , Retrovirus Endógenos/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Interferons/genética , Interferons/metabolismo , Itália/epidemiologia , Masculino , Proteína 28 com Motivo Tripartido/genética , Proteína 28 com Motivo Tripartido/metabolismo , Interferon lambda
7.
Epidemiol Prev ; 45(6): 522-527, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34841834

RESUMO

BACKGROUND: Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare but severe illness associated with SARS-CoV-2 infection. A dysregulated immune response is recognized as the main pathogenic mechanism. Previous studies demonstrated the presence of SARS-CoV-2 RNA in faeces of almost one-third of patients with COVID-19, while data are currently missing about MIS-C. OBJECTIVES: to evaluate faecal sample positivity to SARS-CoV-2 in MIS-C and to compare the positivity rate between MIS-C and COVID-19 hospitalised children.  DESIGN: observational descriptive study with prospective patient enrollment. SETTING AND PARTICIPANTS: the SARS-CoV-2 positivity was evaluated in stool samples obtained in a prospective series of 63 paediatric patients admitted to Regina Margherita Children's Hospital (Azienda Ospedaliero Universitaria - Città della Salute e della Scienza, Turin, Northern Italy) with diagnosis of MIS-C (N. 31) or COVID-19 (N. 32), during the first year of pandemic emergency. The real-time reverse transcription polymerase chain reaction (real-time RT-PCR), was performed using a validated kit measuring 3 target SARS-CoV-2 genes: E gene, N gene, and ORF1ab gene MAIN OUTCOME MEASURES: SARS-CoV-2 stool positivity and concomitant gastrointestinal symptoms. RESULTS: overall, 16/63 (25%) stool samples revealed the presence of SARS-CoV-2 mRNA. In patients with COVID-19, faecal samples were collected 8 days as median (IQR 7) after the presumed viral exposure and were positive in 12/31 (39%; 95%CI 23.2-56.2); among children with MIS-C, stools were collected 27.5 days as median (IQR 26.25) after presumed contact and the positivity rate was 12.5% (95%CI 4.4-27.0) (4/32). More than 80% of the children with MIS-C presented gastrointestinal symptoms, but the frequency of gastrointestinal symptoms in patients with positive stools for SARS-CoV-2 RNA is not higher than patients tested negative (p=0.092). CONCLUSIONS: MIS-C patients frequently experienced gastrointestinal symptoms, confirming the intestinal involvement in MIS-C already described in the literature. The presence of SARS-CoV-2 mRNA in faecal samples is confirmed in more than 10% of MIS-C patients and stool positivity was also detected many days after presumed first contact with the virus. This data suggests the possibility of tracing SARS-COV-2 also in faeces for a better description of its circulation and spread in the environment.


Assuntos
COVID-19 , COVID-19/complicações , Criança , Fezes , Humanos , Itália/epidemiologia , Estudos Prospectivos , RNA Viral , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica
8.
Br J Haematol ; 190(1): 93-104, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32080838

RESUMO

Diamond-Blackfan anaemia (DBA) is a rare and heterogeneous disease characterised by hypoplastic anaemia, congenital anomalies and a predisposition for malignancies. The aim of this paper is to report the findings from the Italian DBA Registry, and to discuss the Registry's future challenges in tackling this disease. Our 20-year long work allowed the connection of 50 Italian Association of Paediatric Haematology and Oncology (AIEOP) centres and the recruitment of 283 cases. Almost all patients have been characterised at a molecular level (96%, 271/283), finding a causative mutation in 68% (184/271). We confirm the importance of determination of erythrocyte adenosine deaminase activity (eADA) and of ribosomal RNA assay in the diagnostic pipeline and characterisation of a remission state. Patients with mutations in large ribosomal subunit protein (RPL) genes had a significant correlation with the incidence of malformations, higher eADA levels and more severe outcomes, compared to patients with mutations in small ribosomal subunit protein (RPS) genes. Furthermore, as a consequence of our findings, particularly the incidence of malignancies and the high percentage of patients aged >18 years, we stress the importance of collaboration with adult clinicians to guarantee regular multi-specialist follow-up. In conclusion, this study highlights the importance of national registries to increase our understanding and improve management of this complex disease.


Assuntos
Anemia de Diamond-Blackfan/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Fatores de Tempo , Adulto Jovem
9.
J Pediatr ; 219: 196-201.e1, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32037152

RESUMO

OBJECTIVE: To describe the hematologic outcome and long-term survival of patients enrolled in the Shwachman-Diamond syndrome Italian Registry. STUDY DESIGN: A retrospective and prospective study of patients recorded in the Shwachman-Diamond syndrome Italian Registry. RESULTS: The study population included 121 patients, 69 males and 52 females, diagnosed between 1999 and 2018. All patients had the clinical diagnosis confirmed by mutational analysis on the SBDS gene. During the study period, the incidence of SDS was 1 in 153 000 births. The median age of patients with SDS at diagnosis was 1.3 years (range, 0-35.6 years). At the first hematologic assessment, severe neutropenia was present in 25.8%, thrombocytopenia in 25.5%, and anemia in 4.6% of patients. A normal karyotype was found in 40 of 79 patients, assessed whereas the most frequent cytogenetic abnormalities were isochromosome 7 and interstitial deletion of the long arm of chromosome 20. The cumulative incidence of severe neutropenia, thrombocytopenia, and anemia at 30 years of age were 59.9%, 66.8%, and 20.2%, respectively. The 20-year cumulative incidence of myelodysplastic syndrome/leukemia and of bone marrow failure/severe cytopenia was 9.8% and 9.9%, respectively. Fifteen of 121 patients (12.4%) underwent allogeneic stem cell transplantation. Fifteen patients (12.4%) died; the probability of overall survival at 10 and 20 years was 95.7% and 87.4%, respectively. CONCLUSIONS: Despite an improvement in survival, hematologic complications still cause death in patients with SDS. Further studies are needed to optimize type and modality of hematopoietic stem cell transplantation and to assess the long-term outcome in nontransplanted patients.


Assuntos
Doenças Hematológicas/etiologia , Síndrome de Shwachman-Diamond/complicações , Síndrome de Shwachman-Diamond/mortalidade , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Itália , Masculino , Estudos Prospectivos , Sistema de Registros , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
10.
Ann Hematol ; 99(3): 413-420, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31965272

RESUMO

Oral ferrous salts are standard treatment for children with iron deficiency anemia (IDA). The objective of our study was to monitor oral iron therapy in children, aged 3 months-12 years, with IDA. We prospectively collected clinical and hematological data of children with IDA, from 15 AIEOP (Associazione Italiana di Ematologia ed. Oncologia Pediatrica) centers. Response was measured by the increase of Hb from baseline. Of the 107 analyzed patients, 18 received ferrous gluconate/sulfate 2 mg/kg (ferrous 2), 7 ferrous gluconate/sulfate 4 mg/kg (ferrous 4), 7 ferric iron salts 2 mg/kg (ferric), 62 bis-glycinate iron 0.45 mg/kg (glycinate), and 13 liposomal iron 0.7-1.4 mg/kg (liposomal). Increase in reticulocytes was evident at 3 days, while Hb increase appeared at 2 weeks. Gain of Hb at 2 and 8 weeks revealed a higher median increase in both ferrous 2 and ferrous 4 groups. Gastro-intestinal side effects were reported in 16% (ferrous 2), 14% (ferrous 4), 6% (glycinate), and 0 (ferric and liposomal) patients. The reticulocyte counts significantly increased after 3 days from the start of oral iron supplementation. Bis-glycinate iron formulation had a good efficacy/safety profile and offers an acceptable alternative to ferrous iron preparations.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Ferrosos/administração & dosagem , Administração Oral , Adolescente , Anemia Ferropriva/sangue , Criança , Pré-Escolar , Feminino , Compostos Ferrosos/efeitos adversos , Humanos , Lactente , Ferro/administração & dosagem , Ferro/efeitos adversos , Masculino , Estudos Prospectivos
11.
Am J Hematol ; 94(2): 216-222, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30456824

RESUMO

Autoimmune neutropenia of infancy (AIN) is characterized by low risk of severe infection, tendency to spontaneously resolve and typically onset at ≤4-5 years of age; it is due to auto-antibodies whose detection is often difficult. In case of negativity of 4 antineutrophils autoantibody tests, after having excluded ethnic, postinfection, drug induced, or congenital neutropenia, according to the Italian guidelines the patients will be defined as affected by "idiopathic neutropenia" (IN). We describe the characteristics of 85 IN patients enrolled in the Italian neutropenia registry: they were compared with 336 children affected by AIN. The 2 groups were clinically very similar and the main differences were detection age (later in IN), length of disease (longer in IN) and, among recovered patients, age of spontaneous recovery: the median age at resolution was 2.13 years in AINs and 3.03 years in INs (P = .00002). At bivariate analysis among AIN patients earlier detection age (P = .00013), male sex (P = .000748), absence of leucopenia (P = .0045), and absence of monocytosis (P = .0419) were significantly associated with earlier recovery; in the IN group only detection age (P = .013) and absence of monocytosis (P = .0333) were significant. At multivariate analysis detection age and absence of monocytosis were independently significant (P = 6.7e-05 and 4.4e-03, respectively) in the AIN group, whereas in the IN group only detection age stayed significant (P = .013).


Assuntos
Neutropenia/congênito , Fatores Etários , Autoimunidade , Síndrome Congênita de Insuficiência da Medula Óssea , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Itália , Leucopenia , Masculino , Neutropenia/diagnóstico , Neutropenia/epidemiologia , Sistema de Registros , Fatores de Risco , Fatores Sexuais
12.
Hum Mutat ; 39(8): 1102-1111, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29766597

RESUMO

Diamond-Blackfan anemia (DBA) is a rare genetic hypoplasia of erythroid progenitors characterized by mild to severe anemia and associated with congenital malformations. Clinical manifestations in DBA patients are quite variable and genetic testing has become a critical factor in establishing a diagnosis of DBA. The majority of DBA cases are due to heterozygous loss-of-function mutations in ribosomal protein (RP) genes. Causative mutations are fairly straightforward to identify in the case of large deletions and frameshift and nonsense mutations found early in a protein coding sequence, but diagnosis becomes more challenging in the case of missense mutations and small in-frame indels. Our group recently characterized the phenotype of lymphoblastoid cell lines established from DBA patients with pathogenic lesions in RPS19 and observed that defective pre-rRNA processing, a hallmark of the disease, was rescued by lentiviral vectors expressing wild-type RPS19. Here, we use this complementation assay to determine whether RPS19 variants of unknown significance are capable of rescuing pre-rRNA processing defects in these lymphoblastoid cells as a means of assessing the effects of these sequence changes on the function of the RPS19 protein. This approach will be useful in differentiating pathogenic mutations from benign polymorphisms in identifying causative genes in DBA patients.


Assuntos
Anemia de Diamond-Blackfan/genética , Proteínas Ribossômicas/genética , Linhagem Celular , Códon sem Sentido/genética , Biologia Computacional , DNA Complementar/genética , Mutação da Fase de Leitura/genética , Humanos , Mutação/genética , Fenótipo
13.
Br J Haematol ; 183(2): 276-288, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30351444

RESUMO

The inherited thrombocytopenias (IT) are a heterogeneous group of diseases resulting from mutations in more than 30 different genes. Among them, ACTN1-related thrombocytopenia (ACTN1-RT; Online Mendelian Inheritance in Man: 615193) is one of the most recently identified forms. It has been described as a mild autosomal dominant macrothrombocytopenia caused by mutations in ACTN1, a gene encoding for one of the two non-muscle isoforms of α-actinin. We recently identified seven new unrelated families with ACTN1-RT caused by different mutations. Two of them are novel missense variants (p.Trp128Cys and p.Pro233Leu), whose pathogenic role has been confirmed by in vitro studies. Together with the 10 families we have previously described, our cohort of ACTN1-RT now consists of 49 individuals carrying ACTN1 mutations. This is the largest case series ever collected and enabled a critical evaluation of the clinical aspects of the disease. We concluded that ACTN1-RT is the fourth most frequent form of IT worldwide and it is characterized by platelet macrocytosis in all affected subjects and mild thrombocytopenia in less than 80% of cases. The risk of bleeding, either spontaneous or upon haemostatic challenge, is negligible and there are no other associated defects, either congenital or acquired. Therefore, ACTN1-RT is a benign form of IT, whose diagnosis provides affected individuals and their families with a good prognosis.


Assuntos
Actinina/genética , Doenças Hematológicas/genética , Mutação , Trombocitopenia/genética , Adulto , Idoso , Contagem de Células Sanguíneas , Plaquetas/patologia , Criança , Análise Mutacional de DNA/métodos , Eritrócitos Anormais/patologia , Feminino , Doenças Hematológicas/sangue , Doenças Hematológicas/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Linhagem , Agregação Plaquetária , Trombocitopenia/sangue
14.
Haematologica ; 103(3): 417-426, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29269525

RESUMO

Fanconi anemia is a rare disease characterized by congenital malformations, aplastic anemia, and predisposition to cancer. Despite the consolidated role of the Fanconi anemia proteins in DNA repair, their involvement in mitochondrial function is emerging. The purpose of this work was to assess whether the mitochondrial phenotype, independent of genomic integrity, could correlate with patient phenotype. We evaluated mitochondrial and clinical features of 11 affected individuals homozygous or compound heterozygous for p.His913Pro and p.Arg951Gln/Trp, the two residues of FANCA that are more frequently affected in our cohort of patients. Although p.His913Pro and p.Arg951Gln proteins are stably expressed in cytoplasm, they are unable to migrate in the nucleus, preventing cells from repairing DNA. In these cells, the electron transfer between respiring complex I-III is reduced and the ATP/AMP ratio is impaired with defective ATP production and AMP accumulation. These activities are intermediate between those observed in wild-type and FANCA-/- cells, suggesting that the variants at residues His913 and Arg951 are hypomorphic mutations. Consistent with these findings, the clinical phenotype of most of the patients carrying these mutations is mild. These data further support the recent finding that the Fanconi anemia proteins play a role in mitochondria, and open up possibilities for genotype/phenotype studies based on novel mitochondrial criteria.


Assuntos
Proteína do Grupo de Complementação A da Anemia de Fanconi/genética , Anemia de Fanconi/genética , Mitocôndrias , Mutação de Sentido Incorreto , Trifosfato de Adenosina/biossíntese , Adolescente , Núcleo Celular/metabolismo , Criança , Pré-Escolar , Reparo do DNA/genética , Transporte de Elétrons , Proteína do Grupo de Complementação A da Anemia de Fanconi/metabolismo , Feminino , Humanos , Mutação com Perda de Função , Masculino , Fenótipo
15.
Blood ; 125(5): 869-72, 2015 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-25361813

RESUMO

Inherited thrombocytopenias (ITs) are a heterogeneous group of syndromic and nonsyndromic diseases caused by mutations affecting different genes. Alterations of ACTN1, the gene encoding for α-actinin 1, have recently been identified in a few families as being responsible for a mild form of IT (ACTN1-related thrombocytopenia; ACTN1-RT). To better characterize this disease, we screened ACTN1 in 128 probands and found 10 (8 novel) missense heterozygous variants in 11 families. Combining bioinformatics, segregation, and functional studies, we demonstrated that all but 1 amino acid substitution had deleterious effects. The clinical and laboratory findings of 31 affected individuals confirmed that ACTN1-RT is a mild macrothrombocytopenia with low risk for bleeding. Low reticulated platelet counts and only slightly increased serum thrombopoietin levels indicated that the latest phases of megakaryopoiesis were affected. Given its relatively high frequency in our cohort (4.2%), ACTN1-RT has to be taken into consideration in the differential diagnosis of ITs.


Assuntos
Actinina/genética , Plaquetas/metabolismo , Mutação de Sentido Incorreto , Fenótipo , Trombocitopenia/genética , Actinina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Plaquetas/patologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Expressão Gênica , Genótipo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Contagem de Plaquetas , Índice de Gravidade de Doença , Trombocitopenia/metabolismo , Trombocitopenia/patologia , Trombocitopenia/fisiopatologia , Trombopoese/genética , Trombopoetina/sangue
16.
Br J Haematol ; 172(5): 782-5, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26763766

RESUMO

Diamond-Blackfan anaemia (DBA) is an inherited disease characterized by pure erythroid aplasia that has been tagged as a 'ribosomopathy'. We report a multi-centre study focused on the analysis of rRNA processing of 53 Italian DBA patients using capillary electrophoresis analysis of rRNA maturation of the 40S and 60S ribosomal subunits. The ratio of 28S/18S rRNA was higher in patients with mutated ribosomal proteins (RPs) of the small ribosomal subunit. In contrast, patients with mutated RPs of the large ribosomal subunit (RPLs) had a lower 28S/18S ratio. The assay reported here would be amenable for development as a diagnostic tool.


Assuntos
Anemia de Diamond-Blackfan/diagnóstico , RNA Ribossômico/genética , Anemia de Diamond-Blackfan/genética , Estudos de Casos e Controles , Eletroforese Capilar/métodos , Deleção de Genes , Humanos , Mutação
17.
Br J Haematol ; 175(3): 490-495, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27447678

RESUMO

Mycophenolate mofetil (MMF) has been shown to be effective in children with immune thrombocytopenia (ITP) and Evans syndrome (ES), but data from larger series and details on the timing of the response are lacking. We evaluated 56 children treated with MMF for ITP (n = 40) or ES (n = 16), which was primary or secondary to autoimmune lymphoproliferative syndrome -related syndrome (ARS). Thirty-five of the 54 evaluable patients (65%) achieved a partial (18%) or complete (46%) response after a median (range) of 20 (7-137) and 37 (7-192) d, respectively. ITP and ES patients responded in 58% and 81% of cases (P = not significant, ns), with complete response in 32% and 81% (P = 0·01), respectively. 60% and 73% of children with primary disease and ARS responded (P = ns) with complete response in 34% and 68% of cases (P = 0·01), respectively. Six of 35 (17%) children relapsed after a median of 283 d (range 189-1036). Limited toxicity was observed in four patients. The median durations of treatment and follow-up were seven and 12·7 months, respectively. This is the largest reported cohort of patients treated with MMF for ITP/ES. The results show that MMF is effective and safe and provides a relatively quick response, suggesting that it has a potential role as an alternative to more aggressive and expensive second/further-line treatments.


Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Antibióticos Antineoplásicos/uso terapêutico , Ácido Micofenólico/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Trombocitopenia/tratamento farmacológico , Adolescente , Anemia Hemolítica Autoimune/diagnóstico , Antibióticos Antineoplásicos/efeitos adversos , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Lactente , Itália , Masculino , Ácido Micofenólico/efeitos adversos , Razão de Chances , Púrpura Trombocitopênica Idiopática/diagnóstico , Recidiva , Retratamento , Estudos Retrospectivos , Trombocitopenia/diagnóstico , Resultado do Tratamento
18.
Lancet ; 386(10004): 1649-58, 2015 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-26231455

RESUMO

BACKGROUND: The thrombopoietin receptor agonist eltrombopag has been shown to be safe, tolerable, and effective for adults with chronic immune thrombocytopenia. We aimed to investigate the safety and efficacy of eltrombopag for children with chronic immune thrombocytopenia. METHODS: PETIT2 was a two part, randomised, multicentre, placebo-controlled study done at 38 centres in 12 countries (Argentina, Czech Republic, Germany, Hong Kong, Israel, Italy, Russia, Spain, Taiwan, Thailand, UK, and USA). Paediatric patients aged 1-17 years who had chronic immune thrombocytopenia and platelet counts less than 30 × 10(9) per L were randomly assigned (2:1) to receive eltrombopag or placebo. We stratified patients by age into three cohorts (patients aged 12-17 years, 6-11 years, and 1-5 years) before randomly entering them into a 13 week, double-blind period. Randomisation was done by the GlaxoSmithKline Registration and Medication Ordering System and both patients and study personnel were masked to treatment assignments. Patients who were allocated eltrombopag received tablets (except for those aged 1-5 years who received an oral suspension formulation) once per day for 13 weeks. Starting doses for patients aged 6-17 were based on bodyweight, and ethnic origin and ranged between 50 mg/day and 25 mg/day (starting dose for patients aged 1-5 years was 1·2 mg/kg/day or 0·8 mg/kg/day for east Asian patients). Patients who completed the double-blind period entered a 24 week open-label treatment period in which all patients received eltrombopag at either the starting dose (if they were formerly on placebo) or their established dose. The primary outcome was the proportion of patients achieving platelet counts of at least 50 × 10(9) per L in the absence of rescue therapy for 6 or more weeks from weeks 5 to 12 of the double-blind period. The intention-to-treat population included in the efficacy assessment consisted of all patients who were randomly assigned to one of the treatment groups, and the safety population included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01520909. FINDINGS: Beginning in March 15, 2012, 92 patients were enrolled, and the trial was completed on Jan 2, 2014. 63 patients were assigned to receive eltrombopag and 29 were assigned to receive placebo. In the double-blind period, three patients discontinued treatment because of adverse events: two patients in the eltrombopag group withdrew because of increased liver aminotransferases and one in the placebo group withdrew because of abdominal haemorrhage. 25 (40%) patients who received eltrombopag compared with one (3%) patient who received placebo achieved the primary outcome of platelet counts of at least 50 × 10(9) per L for 6 of the last 8 weeks of the double-blind period (odds ratio 18·0, 95% CI, 2·3-140·9; p=0·0004). Responses were similar in all cohorts (eltrombopag vs placebo: 39% vs 10% for patients aged 12-17 years, 42% vs 0% for patients aged 6-11 years, and 36% vs 0% for patients aged 1-5 years). Proportionately fewer patients who received eltrombopag (23 [37%] of 63 patients) had WHO grades 1-4 bleeding at the end of the double-blind period than did those who received placebo (16 [55%] of 29 patients); grades 2-4 bleeding were similar (three [5%] patients who received eltrombopag vs two [7%] patients who received placebo). During the 24-week open-label treatment period, 70 [80%] of 87 patients achieved platelet counts of 50 × 10(9) per L or more at least once. Adverse events that occurred more frequently with eltrombopag than with placebo included nasopharyngitis (11 [17%] patients), rhinitis (10 [16%] patients), upper respiratory tract infection (7 [11%] patients), and cough (7 [11%] patients). Serious adverse events occurred in five (8%) patients who received eltrombopag and four (14%) who received placebo. Safety was consistent between the open-label and double-blind periods. No deaths, malignancies, or thromboses occurred during the trial. INTERPRETATION: Eltrombopag, which produced a sustained platelet response in 40% of patients with chronic immune thrombocytopenia, is a suitable therapeutic option for children with chronic symptomatic immune thrombocytopenia. We identified no new safety concerns and few patients discontinued treatment because of adverse events. FUNDING: GlaxoSmithKline.


Assuntos
Benzoatos/uso terapêutico , Hidrazinas/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirazóis/uso terapêutico , Receptores de Trombopoetina/agonistas , Adolescente , Benzoatos/administração & dosagem , Benzoatos/efeitos adversos , Criança , Pré-Escolar , Doença Crônica , Método Duplo-Cego , Feminino , Humanos , Hidrazinas/administração & dosagem , Hidrazinas/efeitos adversos , Lactente , Masculino , Contagem de Plaquetas , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Resultado do Tratamento
19.
Blood ; 123(8): 1178-86, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-24363402

RESUMO

In autoimmune/lymphoproliferative syndrome (ALPS), defective Fas death receptor function causes lymphadenomegaly/splenomegaly, the expansion of T-cell receptor αß(+) CD4/CD8 double-negative T cells, and frequent development of hematologic autoimmunity. Dianzani autoimmune lymphoproliferative disease (DALD) has a similar phenotype but lacks the expansion of double-negative T cells. This work shows that patients with ALPS and DALD have high serum levels of interleukin 17A (IL-17A), IL-17F, and IL-17AF, which are involved in several autoimmune diseases, and that their T cells show increased secretion of these cytokines upon activation in vitro. The following data indicate that these cytokines may contribute to ALPS and DALD: (1) recombinant IL-17A and IL-17F significantly inhibit Fas-induced cell death in Fas-sensitive T cells from healthy donors; (2) this inhibitory effect is also induced by the patients' serum and is reversed by anti-IL-17A antibodies; (3) IL-17A neutralization substantially increases Fas-induced cell death in T cells from ALPS and DALD patients in vitro; and (4) treatment with anti-IL-17A antibodies ameliorates the autoimmune manifestations and, at a lesser extent, the lymphoproliferative phenotype and prolongs survival in MRLlpr/lpr mice, which are an animal model of ALPS. These data suggest that IL-17A and IL-17F could be targeted therapeutically to improve Fas function in ALPS and DALD.


Assuntos
Apoptose/imunologia , Síndrome Linfoproliferativa Autoimune/imunologia , Interleucina-17/imunologia , Linfócitos T/citologia , Animais , Anticorpos Neutralizantes/imunologia , Síndrome Linfoproliferativa Autoimune/patologia , Células Cultivadas , Criança , Pré-Escolar , Feminino , Humanos , Imunização Passiva , Imunofenotipagem , Interleucina-17/sangue , Masculino , Camundongos , Camundongos Endogâmicos MRL lpr , Fenótipo , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T/imunologia , Adulto Jovem
20.
Blood ; 124(6): e4-e10, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24990887

RESUMO

Abnormalities of platelet size are one of the distinguishing features of inherited thrombocytopenias (ITs), and evaluation of blood films is recommended as an essential step for differential diagnosis of these disorders. Nevertheless, what we presently know about this subject is derived mainly from anecdotal evidence. To improve knowledge in this field, we evaluated platelet size on blood films obtained from 376 patients with all 19 forms of IT identified so far and found that these conditions differ not only in mean platelet diameter, but also in platelet diameter distribution width and the percentage of platelets with increased or reduced diameters. On the basis of these findings, we propose a new classification of ITs according to platelet size. It distinguishes forms with giant platelets, with large platelets, with normal or slightly increased platelet size, and with normal or slightly decreased platelet size. We also measured platelet diameters in 87 patients with immune thrombocytopenia and identified cutoff values for mean platelet diameter and the percentage of platelets with increased or reduced size that have good diagnostic accuracy in differentiating ITs with giant platelets and with normal or slightly decreased platelet size from immune thrombocytopenia and all other forms of IT.


Assuntos
Plaquetas/patologia , Trombocitopenia/sangue , Trombocitopenia/genética , Adolescente , Adulto , Estudos de Casos e Controles , Tamanho Celular , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Perda Auditiva Neurossensorial/sangue , Perda Auditiva Neurossensorial/classificação , Perda Auditiva Neurossensorial/genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Proteínas Motores Moleculares/genética , Mutação , Cadeias Pesadas de Miosina/genética , Púrpura Trombocitopênica Idiopática/sangue , Púrpura Trombocitopênica Idiopática/diagnóstico , Trombocitopenia/classificação , Trombocitopenia/congênito , Adulto Jovem
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