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1.
J Lab Clin Med ; 136(6): 482-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11128750

RESUMO

Oral contraceptives and postmenopausal estrogen replacement therapy are recognized as risk factors for the development of porphyria cutanea tarda (PCT) in women. The recommended clinical practice is to withhold estrogen therapy in women who have had phlebotomy therapy for PCT and are clinically and biochemically normal. We tested the safety and efficacy of transdermal estrogen replacement therapy in 7 women previously treated for PCT and compared them with 19 non-porphyric control subjects treated with transdermal or oral estrogens. Gonadotrophic hormone levels, estrogen levels, liver function studies, body iron stores, urine porphyrin excretion, and cytochrome P4501A2 (CYP1A2) activity were monitored for 1 year. Four of the women previously treated for PCT completed the study. None had evidence of a porphyric relapse. CYP1A2 activity, measured by three different methods, did not differ between study subjects receiving estrogens, patients with active PCT, and non-porphyric control subjects, nor did CYP1A2 activity change during the study period. Gonadotrophic hormone levels fell and estrogen levels rose in all women receiving estrogens. The administration of estrogens by the transdermal route appeared to be safe in the small number of subjects we studied and should be considered for women previously treated for PCT.


Assuntos
Terapia de Reposição de Estrogênios/efeitos adversos , Porfiria Cutânea Tardia/etiologia , Porfiria Cutânea Tardia/terapia , Administração Cutânea , Adulto , Cafeína/sangue , Estudos de Casos e Controles , Citocromo P-450 CYP1A2/metabolismo , Feminino , Humanos , Fígado/enzimologia , Menopausa , Pessoa de Meia-Idade , Flebotomia , Porfiria Cutânea Tardia/metabolismo , Recidiva , Fatores de Risco , Segurança
2.
N Engl J Med ; 343(21): 1529-35, 2000 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-11087882

RESUMO

BACKGROUND: Hemochromatosis occurs in approximately 5 white people per 1000 and is usually due to homozygosity for mutations in the HLA-linked HFE gene. Although screening has been proposed, the proportion of homozygotes with conditions related to hemochromatosis is uncertain. METHODS: We studied the prevalence of disease-related conditions among relatives of probands with hemochromatosis. We identified probands who presented to a clinic with signs or symptoms of hemochromatosis or who had elevated transferrin-saturation values. We identified homozygous relatives, mainly siblings, on the basis of HLA identity with the proband and by HFE genotyping. Disease-related conditions were cirrhosis, hepatic fibrosis, elevated amino-transferase values, and hemochromatotic arthropathy. RESULTS: We identified 214 homozygous relatives of 291 homozygous probands. Of the 113 men in this group (mean age, 41 years), 96 (85 percent) had iron overload, and 43 (38 percent) had at least one disease-related condition. Of the 52 men over 40 years of age, 27 (52 percent) had at least one disease-related condition. Of the 101 female homozygous relatives (mean age, 44 years), 69 (68 percent) had iron overload, and 10 (10 percent) had at least one disease-related condition. Of the 43 women over 50 years of age, 7 (16 percent) had at least one disease-related condition. If the proband had a disease-related condition, relatives who were men were more likely to have morbidity than if the proband had no disease-related condition. CONCLUSIONS: A substantial number of homozygous relatives of patients with hemochromatosis--more commonly men than women--have conditions related to hemochromatosis that have yet to be detected clinically.


Assuntos
Hemocromatose/complicações , Hemocromatose/genética , Sobrecarga de Ferro/etiologia , Adulto , Família , Feminino , Hemocromatose/classificação , Homozigoto , Humanos , Sobrecarga de Ferro/diagnóstico , Cirrose Hepática/diagnóstico , Cirrose Hepática/etiologia , Cirrose Hepática/genética , Masculino , Pessoa de Meia-Idade , Prevalência , Transaminases/sangue , Transferrina/análise
3.
Blood ; 95(5): 1565-71, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10688809

RESUMO

Inherited and acquired factors have been implicated in the pathogenesis of porphyria cutanea tarda (PCT), a disorder characterized by a photosensitive dermatosis and hepatic siderosis. This study, comprising 108 patients with PCT, was intended to define the role of hemochromatosis gene (HFE) mutations in the expression of PCT and to determine the contribution of acquired factors including alcohol, hepatitis C virus (HCV), and estrogen. The 2 known HFE mutations, cysteine 282 tyrosine (Cys282Tyr) and histidine 63 asparagine (His63Asp), were detected by polymerase chain reaction, and anti-HCV immunoglobulin G was detected serologically. Liver biopsies were graded for iron content, inflammation, and fibrosis. Estimates of alcohol and estrogen use were based on a questionnaire. Of the PCT patients tested, 19% were homozygous for the Cys282Tyr mutation; controls were equal to 0.5%. The compound heterozygous genotype was detected in 7% of the PCT patients; controls were less than 1%. The transferrin saturation, serum ferritin, and liver iron burden of all PCT patients were higher than those of nonporphyric controls. The highest values were found in PCT patients homozygous for the Cys282Tyr mutation. Of the patients studied, 59% were HCV positive (compared with 1.8% of the population), and 46% consumed more than 70 g of alcohol daily. Of the female patients, 63% were ingesting estrogens. Hepatic damage was most marked in patients with the Cys282Tyr/Cys282Tyr genotype who had HCV and drank heavily. Homozygosity for the Cys282Tyr mutation and HCV are the greatest risk factors for expression of PCT, and in most patients, more than 1 risk factor was identified. It was common for patients with HCV to consume alcohol. Patients with PCT should be screened for HFE mutations and for HCV. (Blood. 2000;95:1565-1571)


Assuntos
Hemocromatose/genética , Porfiria Cutânea Tardia/genética , Adolescente , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Biópsia , Pré-Escolar , Comorbidade , Estrogênios/efeitos adversos , Estrogênios/fisiologia , Feminino , Ferritinas/sangue , Predisposição Genética para Doença , Testes Genéticos , Genótipo , Hemocromatose/epidemiologia , Hemocromatose/metabolismo , Hemocromatose/patologia , Hepatite C/epidemiologia , Humanos , Ferro/análise , Fígado/química , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Mutação Puntual , Reação em Cadeia da Polimerase , Porfiria Cutânea Tardia/epidemiologia , Porfiria Cutânea Tardia/etiologia , Porfiria Cutânea Tardia/metabolismo , Porfiria Cutânea Tardia/patologia , Transferrina/análise
4.
N Engl J Med ; 335(24): 1799-805, 1996 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-8943161

RESUMO

BACKGROUND: Ten percent of whites are heterozygous for the HLA-linked hemochromatosis mutation. We performed a cross-sectional analysis of 1058 genotyped heterozygotes to define the effects of age and sex on the phenotype. METHODS: The heterozygous genotype was assigned to 505 male and 553 female members of 202 pedigrees, each with an HLA-typed homozygous proband. We measured serum iron, transferrin saturation, and ferritin in all heterozygotes and in 321 genetically normal subjects (unaffected family members or spouses of family members). Liver biopsies were performed in a subgroup of heterozygotes. RESULTS: The mean serum iron concentrations and transferrin-saturation values were higher in heterozygotes than in normal subjects and did not increase with age. Initial transferrin-saturation levels exceeding the threshold associated with the homozygous genotype were found in 4 percent of male and 8 percent of female heterozygotes. The geometric mean serum ferritin concentration was higher in heterozygotes than in normal subjects and increased with age. Higher-than-normal values were found in 20 percent of male and 8 percent of female heterozygotes. The clinical and biochemical expression of hemochromatosis was more marked in heterozygotes with paternally transmitted mutations than in those with maternally transmitted mutations. Liver-biopsy abnormalities were generally associated with alcohol abuse, hepatitis, or porphyria cutanea tarda. CONCLUSIONS: The phenotype of persons heterozygous for hemochromatosis differs from that of normal subjects, but complications due to iron overload alone in these heterozygotes are extremely rare.


Assuntos
Hemocromatose/sangue , Heterozigoto , Transferrina/análise , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biópsia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Ferritinas/sangue , Hemocromatose/genética , Hemocromatose/patologia , Teste de Histocompatibilidade , Humanos , Lactente , Ferro/sangue , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Valores de Referência
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