Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
1.
Hepatology ; 61(3): 823-33, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25418031

RESUMO

UNLABELLED: Hepatitis B virus (HBV) reactivation during immunosuppression can lead to severe acute hepatitis, fulminant liver failure, and death. Here, we investigated hepatitis B surface antigen (HBsAg) genetic features underlying this phenomenon by analyzing 93 patients: 29 developing HBV reactivation and 64 consecutive patients with chronic HBV infection (as control). HBsAg genetic diversity was analyzed by population-based and ultradeep sequencing (UDS). Before HBV reactivation, 51.7% of patients were isolated hepatitis B core antibody (anti-HBc) positive, 31.0% inactive carriers, 6.9% anti-HBc/anti-HBs (hepatitis B surface antibody) positive, 6.9% isolated anti-HBs positive, and 3.4% had an overt HBV infection. Of HBV-reactivated patients, 51.7% were treated with rituximab, 34.5% with different chemotherapeutics, and 13.8% with corticosteroids only for inflammatory diseases. In total, 75.9% of HBV-reactivated patients (vs. 3.1% of control patients; P<0.001) carried HBsAg mutations localized in immune-active HBsAg regions. Of the 13 HBsAg mutations found in these patients, 8 of 13 (M103I-L109I-T118K-P120A-Y134H-S143L-D144E-S171F) reside in a major hydrophilic loop (target of neutralizing antibodies [Abs]); some of them are already known to hamper HBsAg recognition by humoral response. The remaining five (C48G-V96A-L175S-G185E-V190A) are localized in class I/II-restricted T-cell epitopes, suggesting a role in HBV escape from T-cell-mediated responses. By UDS, these mutations occurred in HBV-reactivated patients with a median intrapatient prevalence of 73.3% (range, 27.6%-100%) supporting their fixation in the viral population as a predominant species. In control patients carrying such mutations, their median intrapatient prevalence was 4.6% (range, 2.5%-11.3%; P<0.001). Finally, additional N-linked glycosylation (NLG) sites within the major hydrophilic loop were found in 24.1% of HBV-reactivated patients (vs. 0% of chronic patients; P<0.001); 5 of 7 patients carrying these sites remained HBsAg negative despite HBV reactivation. NLG can mask immunogenic epitopes, abrogating HBsAg recognition by Abs. CONCLUSION: HBV reactivation occurs in a wide variety of clinical settings requiring immune-suppressive therapy, and correlates with HBsAg mutations endowed with enhanced capability to evade immune response. This highlights the need for careful patient monitoring in all immunosuppressive settings at reactivation risk and of establishing a prompt therapy to prevent HBV-related clinical complications.


Assuntos
Antígenos de Superfície da Hepatite B/genética , Hepatite B Crônica/imunologia , Evasão da Resposta Imune , Terapia de Imunossupressão , Ativação Viral , Adulto , Idoso , Farmacorresistência Viral , Feminino , Glicosilação , Anticorpos Anti-Hepatite B/sangue , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação
2.
Am J Med ; 118(6): 664-70, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15922699

RESUMO

BACKGROUND: Frequent endocrine disorders have been reported after allogeneic stem-cell transplant, but data on adult survivors of autologous transplants are still scarce. METHODS: In this prospective study we investigated early (at 3 months) and late (at 12 months) endocrine dysfunctions in 95 consecutive autologous stem-cell transplant recipients (47 men and 48 women) aged 16 to 55 years. The functions of the hypothalamic-pituitary-gonadal/thyroid/adrenal/somatotroph axis were evaluated. RESULTS: Three months after the transplant, insulin-like growth factor-1 values were below the normal range in 53 patients (56%); 37 of 40 women (93%) of reproductive age experienced precocious ovarian failure; 39 of 46 men (85%) showed high follicular stimulating hormone, and 17 men (37%) showed low testosterone levels. Adrenal insufficiency occurred in 28 patients (30%) during the peritransplant period after corticosteroid withdrawal. Transient subclinical hyperthyroidism was found in 15 patients (16%). Transient "low T(3)" syndrome was revealed in 29 patients (31%). Twelve months after the transplant, insulin-like growth factor-1 values were still low in 36 patients (38%). Menstrual cycles resumed in four women; follicular stimulating hormone, luteinizing hormone, and estradiol levels improved in 10 patients. Testosterone was low in only two men (4%). Seminal analysis revealed azoospermia in 32 (91%) of 35 men examined. Subclinical hypothyroidism was found in 11 patients (12%); eight of them had previously received radiotherapy for the upper half of the body. CONCLUSION: This study documents frequent endocrine disorders during the first year after autologous stem-cell transplant. Despite a tendency to improve, in more than half of the cases, the complications persisted for more than 1 year. Therefore, to diagnose and correct early and late endocrine dysfunctions, endocrine screening is required during the first year in all patients undergoing autografting.


Assuntos
Doenças do Sistema Endócrino/etiologia , Transplante de Células-Tronco/efeitos adversos , Adolescente , Adulto , Síndromes do Eutireóideo Doente , Feminino , Humanos , Hipotireoidismo/etiologia , Fator de Crescimento Insulin-Like I/análise , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Indução de Remissão
3.
Hum Reprod ; 18(7): 1410-6, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12832364

RESUMO

BACKGROUND: Ovarian failure is a frequent complication occurring after haematopoietic stem cell transplantion (SCT), which is generally ascribed to radiation treatment and antiblastic alkylating agents. METHODS: Ovarian morphology and function were studied in reproductive age women 12-24 months after allogeneic SCT (n = 23) received from an HLA identical sibling, or autologous SCT (n = 22). Thirteen allo-transplanted women were suffering from chronic graft-versus-host disease (cGVHD). RESULTS: Menstrual cycles recovered in two and four women in the allo- and auto-SCT groups respectively, being associated with younger age and longer period elapsed from transplant. There was no difference in previous use of alkylating agents between allo- and auto-transplantation, while corticosteroid treatment was longer and more recent in the allo-SCT group. Significantly higher gonadotrophin levels and lower estradiol were seen in the combined group of patients than in controls. In allo-transplanted women, androgens were also significantly lower than in controls. Ovarian and uterine volumes were lower in patients than in controls, and in the allo- than in the auto-transplanted women. Within the allo-SCT group, endocrine function and ovarian and uterine volumes were significantly lower in the patients suffering from cGVHD. CONCLUSIONS: Ovarian failure in SCT recipients is likely to be caused principally by myelo-ablative treatments, but the condition of gonadal and androgen insufficiency can be worsened by an altered immunomodulation in allogeneic setting.


Assuntos
Doença Enxerto-Hospedeiro/complicações , Transplante de Células-Tronco Hematopoéticas , Leucemia/terapia , Insuficiência Ovariana Primária/etiologia , Adulto , Antineoplásicos Alquilantes/efeitos adversos , Feminino , Hormônios Esteroides Gonadais/sangue , Gonadotropinas/sangue , Humanos , Ciclo Menstrual , Pessoa de Meia-Idade , Folículo Ovariano/fisiologia , Projetos Piloto , Insuficiência Ovariana Primária/diagnóstico por imagem , Insuficiência Ovariana Primária/imunologia , Estudos Prospectivos , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...