RESUMO
Fanconi anemia (FA), a rare genetic disease in which patients' life is compromised mainly by hematological abnormalities and cancer prone, seems to be affected by subtle immune cell irregularities. Knowing that FA presents developmental abnormalities and, based on recent reports, suggesting that natural killer (NK) CD56(dim) and NK CD56(bright) correspond to sequential differentiation pathways, we investigated if there were changes on the total number of NK cells and subsets as well as on T CD4 and T CD8 lymphocytes and their ratio. A large sample of FA patients (n = 42) was used in this work, and the results were correlated to clinical hematological status of these patients. Among FA patients, a decreased proportion of T CD8(+) and NK CD56(dim)CD16(+) cells were observed when compared to healthy controls as well as an imbalance of the subsets NK lymphocytes. Data suggest that FA patients might have a defective cytotoxic response due to the lower number of cytotoxic cells as well as impairment in the differentiation process of the NK cells subsets which may be directly related to impairment of the immune surveillance observed in these patients.
Assuntos
Linfócitos T CD4-Positivos/patologia , Antígeno CD56/imunologia , Linfócitos T CD8-Positivos/patologia , Anemia de Fanconi/patologia , Células Matadoras Naturais/patologia , Receptores de IgG/imunologia , Adolescente , Adulto , Linfócitos T CD4-Positivos/imunologia , Antígeno CD56/genética , Linfócitos T CD8-Positivos/imunologia , Estudos de Casos e Controles , Diferenciação Celular , Linhagem da Célula/imunologia , Criança , Pré-Escolar , Citotoxicidade Imunológica , Anemia de Fanconi/imunologia , Anemia de Fanconi/metabolismo , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Expressão Gênica , Humanos , Vigilância Imunológica , Imunofenotipagem , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Contagem de Linfócitos , Masculino , Receptores de IgG/genéticaRESUMO
Fanconi anemia (FA) is a rare disease, autosomal recessive and X linked, which is clinically prone to development of hematological abnormalities and neoplasms, especially acute myeloid leukemia. In this work IL-10 and TGF-ß levels were measured on FA patients' plasma since they are the regulatory cytokines of TNF-α and INF-γ which had been described to be overexpressed in this genetic disease. Our results show increased IL-10 plasma levels in 25% of FA patients studied, but levels of TGF-ß within the normal range. TNF-α and INF-γ were also measured and found to be increased in 24% and 23% of FA patients, respectively. However, no inverse correlation was observed between augmented levels of IL-10 and TNF or IFN-γ. Patients with elevated levels of TNF-α and INF-γ presented bone marrow hypocellularity. IL-10 levels did not appear to be determinant for bone marrow cellularity. These data suggest that IL-10 is also a feature of Fanconi anemia pathophysiology.
Assuntos
Anemia de Fanconi/sangue , Interleucina-10/sangue , Adolescente , Adulto , Plaquetas/metabolismo , Estudos de Casos e Controles , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Reduced fertility is one clinical manifestation among other well known Fanconi anemia features. Most recipients of allogeneic hematopoietic stem cell transplantation suffer from secondary infertility owing to gonadal damage from myeloablative conditioning. In order to evaluate the rate of pregnancy in Fanconi anemia transplanted patients, we performed a retrospective analysis of female patients transplanted in 15 centers from 1976 to 2008. Among 578 transplanted Fanconi anemia patients, we identified 285 transplanted females of whom 101 patients were aged 16 years or over. Ten became pregnant (4 twice). Before hematopoietic stem cell transplantation all had confirmed Fanconi anemia diagnosis. Median age at transplantation was 12 years (range 5-17 years). Conditioning regimen consisted of cyclophosphamide with or without irradiation. During follow up, 5 of 10 patients presented signs of ovarian failure. Among those, 2 patients spontaneously recovered regular menses, and 3 received hormonal replacement therapy. Pregnancy occurred from four to 17 years after hematopoietic stem cell transplantation. Three patients had preterm deliveries, one patient had a hysterectomy for bleeding. All 14 newborns had normal growth and development without congenital diseases. In conclusion, recovery of normal ovarian function and a viable pregnancy is a realistic but relatively rare possibility even in Fanconi anemia patients following hematopoietic stem cell transplantation. Mechanisms of fertility recovery are discussed.
Assuntos
Anemia de Fanconi/complicações , Transplante de Células-Tronco Hematopoéticas/métodos , Infertilidade , Recuperação de Função Fisiológica , Anemia de Fanconi/terapia , Feminino , Humanos , Recém-Nascido , Infertilidade/etiologia , Masculino , Gravidez , Estudos Retrospectivos , Transplante HomólogoRESUMO
BACKGROUND: Fanconi anemia (FA) is a predominantly autosomal recessive disease with wide genetic heterogeneity resulting from mutations in several DNA repair pathway genes. To date, 21 genetic subtypes have been identified. We aimed to identify the FA genetic subtypes in the Brazilian population and to develop a strategy for molecular diagnosis applicable to routine clinical use. METHODS: We screened 255 patients from Hospital de Clínicas, Universidade Federal do Paraná for 11 common FA gene mutations. Further analysis by multiplex ligation-dependent probe amplification (MLPA) for FANCA and Sanger sequencing of all coding exons of FANCA, -C, and -G was performed in cases who harbored a single gene mutation. RESULTS: We identified biallelic mutations in 128/255 patients (50.2%): 89, 11, and 28 carried FANCA,FANCC, and FANCG mutations, respectively. Of these, 71 harbored homozygous mutations, whereas 57 had compound heterozygous mutations. In 4/57 heterozygous patients, both mutations were identified by the initial screening, in 51/57 additional analyses was required for classification, and in 2/57 the second mutation remained unidentified. We found 52 different mutations of which 22 were novel. CONCLUSION: The proposed method allowed genetic subtyping of 126/255 (49.4%) patients at a significantly reduced time and cost, which makes molecular diagnosis of FA Brazilian patients feasible.
RESUMO
Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive syndrome associated with chromosomal instability, hypersensitivity to DNA cross-linking agents, and predisposition to malignancy. The gene for FA complementation group G (FANCG) was the third FA gene to be cloned, and was found to be identical with human XRCC9, which maps to 9p13. The cDNA is predicted to encode a polypeptide of 622 amino acids, with no sequence similarities to any other known protein or motifs that could point to a molecular function for FANCG/XRCC9. We used single strand conformational polymorphism analysis (SSCP) to screen genomic DNA from a panel of 307 racially and ethnically diverse unrelated FA patients from the International Fanconi Anemia Registry (IFAR) for variants in FANCG. Twenty-seven abnormal SSCP patterns were found; 18 of these variants appear to be pathogenic mutations while nine are likely to be nonpathogenic polymorphisms. Direct sequencing of genomic DNA from seven FA-G probands with one mutant allele not detected in the SSCP study and three additional probands assigned to the FA-G complementation group by retroviral correction with FANCG resulted in the detection of nine additional pathogenic mutations and two common SNPs. Conditions for rapid screening for these mutations by DHPLC for use in a clinical laboratory setting were established. The most common FANCG mutations in the IFAR population were: IVS8-2A>G (seven Portuguese-Brazilian probands), IVS11+1G>C (seven French-Acadian probands), 1794_1803del10 (seven European probands), and IVS3+1G>C (five Korean or Japanese probands). Our data suggest that the Portuguese-Brazilian, French-Acadian, and Korean/Japanese mutations were likely to have been present in a founding member of each of these populations.
Assuntos
Proteínas de Ligação a DNA/genética , Anemia de Fanconi/genética , Variação Genética/genética , Sistema de Registros , Alelos , Cromatografia Líquida de Alta Pressão/métodos , Análise Mutacional de DNA , Etnicidade/genética , Éxons/genética , Anemia de Fanconi/diagnóstico , Proteína do Grupo de Complementação G da Anemia de Fanconi , Testes Genéticos , Humanos , Desnaturação de Ácido Nucleico/genética , Polimorfismo de Nucleotídeo Único/genética , Polimorfismo Conformacional de Fita Simples , Grupos Raciais/genética , Sistema de Registros/estatística & dados numéricosRESUMO
As some patients with Fanconi s anemia (FA) present excessive telomere shortening correlating with poor outcome, we investigated whether human telomerase RNA component (hTERC) mutations also play a role in telomere shortening in 115 FA patients. Only one patient was heterozygous for the G58A polymorphism. No other mutation or deletion was found. We conclude that hTERC gene mutations do not contribute to telomere shortening in FA.
Assuntos
Anemia de Fanconi/genética , Telomerase/genética , Brasil , Etnicidade , Anemia de Fanconi/sangue , Genes Recessivos , Teste de Complementação Genética , Humanos , População BrancaRESUMO
We present the neurological complications evaluated in a series of 1000 patients who underwent hematopoietic stem cell transplantation (HSCT). Central nervous system (CNS) neurological complications, particularly brain hemorrhages, were the most common, followed by seizures and CNS infections. An unusual neurological complication was Wernicke's encephalopathy. Less frequent neurological complications were metabolic encephalopathy, neuroleptic malignant syndrome, reversible posterior leukoencephalopathy syndrome, brain infarct and movement disorders. The most common neurological complication of the peripheral nervous system was herpes zoster radiculopathy, while peripheral neuropathies, inflammatory myopathy and myotonia were very rarely found.
Assuntos
Doenças do Sistema Nervoso Central/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Doenças do Sistema Nervoso Central/classificação , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
Cells from Fanconi anemia (FA) patients are hypersensitive to alkylating agents and radiation traditionally used as conditioning regimens for marrow cell transplantation, and patients experience serious toxicities. To reduce toxicities, we used progressively lower doses of cyclophosphamide (CY) for conditioning. Here, we report the results in 43 FA patients who received marrow transplantation from HLA-matched related donors (37 siblings and 6 other relatives). Conditioning consisted of 15 mg CY/kg/day for 4 days along with Mesna. Methotrexate and cyclosporine were given for graft-versus-host disease (GVHD) prophylaxis. Forty patients (93%) are alive with a median follow-up of 3.7 (range 0.6 to 7.9) years. One patient with primary graft failure was successfully retransplanted. Three of 4 patients with late graft failures were retransplanted, and 2 of those are alive; 1 died before a second marrow graft. Twelve patients including 3 with rejection had cytogenetic abnormalities in their marrow cells before transplantation. Acute grade II-III and chronic GVHD (aGVHD, cGVHD) were seen in 17% and 28.5% of patients, respectively. These results confirm and extend our previous observations that conditioning with 60 mg CY/kg allows for sustained engraftment of HLA-matched related marrow grafts in most FA patients and is associated with low toxicity, low incidences of aGVHD and cGVHD, and excellent long-term survival.
Assuntos
Ciclofosfamida/administração & dosagem , Anemia de Fanconi/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Agonistas Mieloablativos/administração & dosagem , Condicionamento Pré-Transplante/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Doação Dirigida de Tecido , Relação Dose-Resposta a Droga , Feminino , Antígenos HLA/imunologia , Humanos , Masculino , Análise de Sobrevida , Sobreviventes , Transplante Homólogo , Resultado do TratamentoAssuntos
Gânglios da Base/química , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Manganês/metabolismo , Convulsões/etiologia , Adolescente , Gânglios da Base/patologia , Anemia de Fanconi/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Convulsões/patologiaRESUMO
Fanconi anaemia (FA) is a rare genetic disease whose patients have a high predisposition to haematological abnormalities and cancer. Fas expression levels in peripheral blood lymphocytes samples of 73 FA patients were measured to verify if alterations in Fas expression could lead to predisposition/resistance to spontaneous or PHA induced apoptosis, as well as, to reflect some haematological features of this disease. The anti- and pro-apoptotic proteins Bcl-2 and Bax were also evaluated. FA patients samples could be divided into three different groups based on Fas expression: 20 samples had low, 32 normal and 21 increased Fas levels when compared to 41 control samples. No correlation was found between Fas and Bcl-2 expression but a good association was obtained with Bax, in the subgroup with increased Fas expression. The best correlation was seen between Bax expression and apoptosis. Out of the 15 samples with high Bax expression, 11 underwent apoptosis whereas only one out of seven samples with low levels of Bax displayed increased induced apoptosis. Most patients with normal haematological features expressed Fas within normal levels. It is difficult to establish, however, if Fas-expression is involved in the cause or is a consequence of the effects observed.
Assuntos
Apoptose , Anemia de Fanconi/sangue , Leucócitos Mononucleares/patologia , Receptor fas/análise , Adolescente , Adulto , Células Sanguíneas , Estudos de Casos e Controles , Criança , Pré-Escolar , Anemia de Fanconi/patologia , Humanos , Leucócitos Mononucleares/química , Leucócitos Mononucleares/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteína X Associada a bcl-2RESUMO
We present the neurological complications evaluated in a series of 1000 patients who underwent hematopoietic stem cell transplantation (HSCT). Central nervous system (CNS) neurological complications, particularly brain hemorrhages, were the most common, followed by seizures and CNS infections. An unusual neurological complication was Wernicke's encephalopathy. Less frequent neurological complications were metabolic encephalopathy, neuroleptic malignant syndrome, reversible posterior leukoencephalopathy syndrome, brain infarct and movement disorders. The most common neurological complication of the peripheral nervous system was herpes zoster radiculopathy, while peripheral neuropathies, inflammatory myopathy and myotonia were very rarely found.
Apresentamos as complicações neurológicas avaliadas em uma série de 1000 pacientes submetidos ao transplante de células tronco hematopoiéticas (TCTH). As complicações neurológicas do sistema nervoso central foram as mais encontradas, particularmente as hemorragias encefálicas, seguidas por crises convulsivas e por infecções. Uma complicação peculiar foi a encefalopatia de Wernicke. Menos freqüentemente foram encontrados casos de encefalopatia metabólica, síndrome maligna neuroléptica, leucoencefalopatia posterior reversível, infarto cerebral e os distúrbios do movimento. Entre as complicações neurológicas do sistema nervoso periférico a mais encontrada foi a radiculopatia pelo herpes zoster, enquanto que raramente se observaram casos de polineuropatias periféricas, miopatia inflamatória e de miotonia.
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Doenças do Sistema Nervoso Central/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Doenças do Sistema Nervoso Central/classificação , Estudos Retrospectivos , Adulto JovemRESUMO
Hematopoietic progenitor cell transplantation from HLA-identical sibling donors cures 70-90 percent of Severe Aplastic Anemia (sAA) patients. Older age, heavy exposure to transfusions, immunosuppression treatment (IST) with a long interval from diagnosis to transplant and infection at procedure are associated with poor outcomes. We transplanted 18 patients with sAA and at least one risk factor (RF) for poor prognosis (age >35 years, >50 transfusions prior to transplant, unresponsiveness to previous IST and bacterial or fungal infection at transplant) from 2001 to 2005, using cyclophosphamide (CY - 5 patients) or busulfan plus CY (13 patients). Sixteen patients engrafted, two died with no engraftment, three patients had evidence of graft failure at days +67, +524 and +638 (two died and one was rescued with IST). Grade III/IV mucositis occurred in 39 percent but neither aGVHD nor cGVHD were observed. The Kaplan-Meier probability of survival was 75 percent at 2.14 years, with a trend favoring survival by number of RF (1 versus =2 RF) (P = 0.06). These results are comparable to recent data reported with fludarabine-based conditioning in patients with poor prognosis sAA. Due to the small sample size, prospective clinical trials with larger cohorts of patients are needed to confirm the real benefits of fludarabine-based conditioning, and also to define the best agent(s) to be associated with Fludarabine as preparative regimen for sAA patients with poor prognosis.
Transplante de medula óssea de doador irmão HLA-idêntico pode curar 70 por cento-90 por cento dos portadores de anemia aplásica severa (AAs). Pacientes mais idosos, muito transfundidos, longamente tratados com imunossupressão (IS) e com infecções ao tempo do transplante têm pior evolução. Nós transplantamos 18 pacientes com AAs e pelo menos um dos fatores associados a pior prognóstico (idade >35 anos, >50 transfusões antes do transplante, falta de resposta à imunossupressão prévia e infecção bacteriana ou fúngica ao transplante) de 2001 a 2005, com ciclofosfamida (Cy - 5 pacientes) ou bussulfan mais Cy (13 pacientes). Dezesseis pacientes apresentaram pega do enxerto, dois morreram sem pega, três tiveram rejeição aos dias +67, +524 e +638 (dois morreram e um foi resgatado com IS). Mucosite grau III/IV ocorreu em 39 por cento e não observamos DECH aguda ou crônica. A probabilidade de sobrevida pelo método de Kaplan-Meier foi de 75 por cento aos 2,14 anos, e uma tendência a melhor sobrevida foi encontrada entre os portadores de apenas um fator de risco ao transplante (P: .06). Estes resultados são comparáveis a recentes relatos de literatura envolvendo condicionamentos baseados em fludarabina para tratar pacientes com alto risco. Devido à pequena amostra analisada, estudos clínicos prospectivos com maior número de pacientes são necessários, visando comprovar o real benefício dos condicionamentos baseados em fludarabina, definir o melhor agente a ser a ela associado e assim obter o melhor condicionamento para portadores de AAs com fatores de mau prognóstico para o transplante.
Assuntos
Humanos , Anemia Aplástica , Transplante de Medula Óssea , Prognóstico , Transplante HomólogoAssuntos
Adolescente , Humanos , Masculino , Gânglios da Base/química , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Manganês/metabolismo , Convulsões/etiologia , Gânglios da Base/patologia , Anemia de Fanconi/cirurgia , Imageamento por Ressonância Magnética , Convulsões/patologiaRESUMO
Fanconi anaemia (FA) is a rare genetic disease whose patientshave a high predisposition to haematological abnormalities andcancer. Fas expression levels in peripheral blood lymphocytes samples of73 FA patients were measured to verify if alterations in Fas expressioncould lead to predisposition/resistance to spontaneous or PHA inducedapoptosis, as well as, to reflect some haematological features of thisdisease. The anti- and pro-apoptotic proteins Bcl-2 and Bax were alsoevaluated. FA patients samples could be divided into three differentgroups based on Fas expression: 20 samples had low, 32 normal and 21increased Fas levels when compared to 41 control samples. No correlationwas found between Fas and Bcl-2 expression but a good associationwas obtained with Bax, in the subgroup with increased Fasexpression. The best correlation was seen between Bax expression andapoptosis. Out of the 15 samples with high Bax expression, 11 underwentapoptosis whereas only one out of seven samples with low levels ofBax displayed increased induced apoptosis. Most patients with normalhaematological features expressed Fas within normal levels. It is difficultto establish, however, if Fas-expression is involved in the cause or is aconsequence of the effects observed.
Assuntos
Humanos , Anemia de Fanconi , Apoptose , Citometria de Fluxo , LinfócitosRESUMO
Chronic Myeloid Leukemia (CML) is a clonal disease characterized by balanced translocation between chromosomes 9 and 22 (Philadelphia chromosome). The resulting BCR-ABL gene has tyrosine kinase activity which stimulates cellular growth. Imatinib mesylate is a potent and specific inhibitor of all ABL related kinases. Ninety-eight CML patients were treated with imatinib mesylate from October 2000 to January 2003. Disease stage was: late chronic phase resistant or intolerant to alpha-interferon (CP): 28; accelerated phase (AP): 55; blastic phase (BP): 15 patients. Dose: 400 mg for CP and 600 mg for AP or CB. The objectives were to evaluation the efficacy, safety and survival with imatinib mesylate therapy in all phases of CML. The median follow up time was 545 days (range: 7-862), complete hematologic response was 86 percent in CP, 47 percent in AP and 13 percent in BP. Complete cytogenetic response was 61 percent, 24 percent and 0 percent respectively. BCR-ABL was not detected by nested RT-PCR in 9 percent of patients. Grade 3-4 hematologic toxicity was seen in 21 percent of CP, 74 percent of AP and 87 percent of BP patients. Grade 3-4 non-hematologic toxicity was observed in 11 percent of CP, 51 percent of AP and 53 percent of BP patients. Two-year overall survival was 64 percent for all patients, 96 percent for CP and 36 percent for AP patients. All BP patients died within a median of 60 days. Imatinib mesylate induced cytogenetic responses in Brazilian patients with previously treated CML in chronic and accelerated phase. Adverse events are similar to those reported in the literature, except for lower rates of gastrointestinal symptoms and muscle cramps in our study group.
INTRODUÇÃO: A Leucemia Mielóide Crônica (LMC) é uma doença clonal caracterizada pela presença da translocação entre os cromossomos 9 e 22 (cromossomo Philadelphia). O gene resultante BCR-ABL possui atividade de tirosino-quinase, que estimula o crescimento celular. O mesilato de imatinibe é um inibidor potente e específico de todas as quinases relacionadas ao ABL. PACIENTES E MÉTODOS: Noventa e oito pacientes com LMC foram tratados com mesilato de imatinibe de outubro de 2000 a janeiro de 2003: 28 em fase crônica (FC) resistente ou intolerante ao interferon alfa; 55 em fase acelerada (FA) e 55 em crise blástica (CB). Dose: 400 mg para CP e 600 mg para FA ou CB. OBJETIVOS: Avaliação da eficácia, segurança e sobrevida após tratamento da LMC com mesilato de imatinibe. RESULTADOS: Seguimento mediano: 545 dias (variação: 7-862). Resposta hematológica completa ocorreu em 86 por cento dos pacientes em FC, 47 por cento na FA e 13 por cento na CB. Sessenta e um por cento, 24 por cento e 0 por cento dos pacientes em FC, FA e CB, atingiram resposta citogenética completa, respectivamente. Não foram detectados transcritos BCR-ABL por "nested RT-PCR" em 9 por cento dos pacientes. Toxicidade hematológica grau 3-4: 21 por cento na FC, 74 por cento na FA e em 87 por cento na CB. Toxicidade não hematológica grau 3-4: 11 por cento na FC, 51 por cento na FA e 53 por cento na CB. A sobrevida global em dois anos foi de 64 por cento para todos os pacientes, 96 por cento na FC e 36 por cento na FA. Todos os pacientes em CB faleceram numa mediana de 60 dias. CONCLUSÕES: O mesilato de imatinibe induziu respostas citogenéticas completas em pacientes brasileiros com LMC em fase crônica e acelerada. Os eventos adversos nos nossos pacientes foram semelhantes aos relatados em literatura, exceto pela menor incidência de sintomas gastro-intestinais e câimbras.
Assuntos
Humanos , Masculino , Feminino , Leucemia Mielogênica Crônica BCR-ABL Positiva , Mesilatos/administração & dosagem , Mesilatos/uso terapêutico , Proteínas Quinases/uso terapêuticoRESUMO
Anemia Fanconi (AF) é uma síndrome autossômica recessiva, caracterizada por pancitopenia progressiva com hipoplasia de MO, em associação com várias anormalidades constitucionais, tendo como único recurso terapêutico com possibilidade potencial de cura o transplante de medula óssea, e sendo tais pacientes propensos ao desenvolvimento de malignidades hematológicas e carcinoma de células escamosas (CEC) em diversos locais: reto, vagina, cérvice, esôfago, cavidade bucal, faringe ou pele, mas especialmente em cabeça e pescoço. Relatamos aqui três casos de pacientes portadores de AF, que após TMO desenvolveram CEC em língua. Além disso, mencionamos fatores de risco relatados para tal evento, como diagnóstico de AF, condicionamento pré-transplante (quimioterápicos e irradiação), terapia com drogas imunossupressoras para tratamento de doença enxerto contra hospedeiro (DECH) aguda ou crônica, sexo e idade avançada. Além do que, discorremos sobre a existência de três mecanismos postulados que predispõem indivíduos com AF ao desenvolvimento de neoplasia: (1) defeito na reparação do DNA; (2) defeito na detoxificação de radicais de oxigênio; e (3) imunodeficiência.
Fanconis Anemia, first described in 1927, is a rareautonomic recessive disease characterized byprogressive pancytopenia, congenital malformations,spontaneous or chemically induced chromosomebreakage and increased incidence of leukemia andother cancers. The onset of bone marrow hypoplasiaand its hematological manifestations is usually in the3 - 7 year age range. Additionally, we discussed the existence ofthree postulated mechanisms that make individualswith Fanconis anemia susceptible to the developmentof neoplasias: (1) deficiency in the DNA repair system,(2) deficiency in oxygen radical detoxification; and(3) immunodeficiency.
Assuntos
Humanos , Masculino , Pré-Escolar , Criança , Adulto , Alquilantes/administração & dosagem , Transplante de Medula Óssea , Carcinoma de Células Escamosas , Ciclofosfamida , Citogenética , Anemia de FanconiRESUMO
Introdução: A síndrome de Imerslund-Gräsbeck é uma entidade rara, de transmissão autossônica recessiva, caracterizada por anemia megaloblástica e proteinúria assintomática, que se manifesta, geralmente, nos dois primeiros anos de vida. Objetivo: Enfatizar aos pediatras gerais a importância do diagnóstico precoce desta entidade, em vista da alta morbidade causada pela ausência da terapia correta, além da necessidade de realização de triagem e aconselhamento genético dos familiares assintomáticos. Métodos: Os autores descrevem 2 casos de pacientes dos sexos masculino e feminino, com 8 e 10 anos de idade respectivamente, com história de anemia e múltiplas transfusões desde os primeiros anos de vida, que evoluíram para pancitopenia em idade escolar, havendo suspeita de anemia aplástica ou anemia de Fanconi e encaminhamento ao Serviço de Transplante de Medula Óssea - HC-UFPR. Resultados: Presença de pancitopenia com medula óssea megaloblástica em ambos os casos. Parciais de urina demonstraram proteinúria em ambos os casos. Parciais de urina demonstraram proteinúria de 24 horas de 3 e 5,8 g/dl em cada caso. Os estudos citogenéticos foram normais. O tratamento com viitamina B12 intramuscular após o diagnóstico foi efetivo, com resolução do quadro clínico em ambos os casos. Conlcusão: A presença de anemia megaloblástica na infância deve ser sempre acompanhada da investigação de proteinúria, com vistas à caracterização desta entidade rara, porém de diagnóstico simples e tratamento eficaz