RESUMEN
Previous studies of chronic hepatitis C virus (HCV) treatment have demonstrated variations in response among racial and ethnic groups including poorer efficacy rates among African American and Hispanic patients. The individualized dosing efficacy vs flat dosing to assess optimaL pegylated interferon therapy (IDEAL) trial enrolled 3070 patients from 118 United States centres to compare treatment with peginterferon (PEG-IFN) alfa-2a and ribavirin (RBV) and two doses of PEG-IFN alfa-2b and RBV. This analysis examines treatment response among the major racial and ethnic groups in the trial. Overall, sustained virologic response (SVR) rates were 44% for white, 22% for African American, 38% for Hispanic and 59% for Asian American patients. For patients with undetectable HCV RNA at treatment week 4, the positive predictive value of SVR was 86% for white, 92% for African American, 83% for Hispanic and 89% for Asian American patients. The positive predictive values of SVR in those with undetectable HCV RNA at treatment week 12 ranged from 72% to 81%. Multivariate regression analysis using baseline characteristics demonstrated that treatment regimen was not a predictor of SVR. Despite wide-ranging SVR rates among the different racial and ethnic groups, white and Hispanic patients had similar SVR rates. In all groups, treatment response was largely determined by antiviral activity in the first 12 weeks of treatment. Therefore, decisions regarding HCV treatment should consider the predictive value of the early on-treatment response, not just baseline characteristics, such as race and ethnicity.
Asunto(s)
Antivirales/administración & dosificación , Etnicidad , Hepatitis C Crónica/tratamiento farmacológico , Grupos Raciales , Adulto , Femenino , Hepacivirus/aislamiento & purificación , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Proteínas Recombinantes , Ribavirina/administración & dosificación , Resultado del Tratamiento , Estados Unidos , Carga ViralRESUMEN
A motional Stark effect (MSE) diagnostic is now installed and operating routinely on the MAST spherical tokamak, with 35 radial channels, spatial resolution of â¼2.5 cm, and time resolution of â¼1 ms at angular noise levels of â¼0.5°. Conventional (albeit very narrow) interference filters isolate π or σ polarized emission. Avalanche photodiode detectors with digital phase-sensitive detection measure the harmonics of a pair of photoelastic modulators operating at 20 and 23 kHz, and thus the polarization state. The π component is observed to be significantly stronger than σ, in reasonably good agreement with atomic physics calculations, and as a result, almost all channels are now operated on π. Trials with a wide filter that admits the entire Stark pattern (relying on the net polarization of the emission) have demonstrated performance almost as good as the conventional channels. MSE-constrained equilibrium reconstructions can readily be produced between pulses.
RESUMEN
Cytokine production has been implicated in the antiviral response to interferon-alpha (IFN-alpha) in hepatitis C and in the development of IFN-alpha-related side effects. We characterized acute changes in serum cytokine levels following administration of a single dose of consensus IFN (IFN-con1) and during continuous treatment of chronic hepatitis C patients. Serum samples were collected at baseline, at multiple times early after IFN administration, and weekly thereafter. Viral RNA titers were assessed by RT-PCR, and viral kinetics were followed. ELISA assays were used to measure IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-16. Serum cytokine levels were low at baseline. IL-6 was detected in patients with hepatitis C but not in healthy control subjects by either ELISA or RT-PCR, indicating that low levels of circulating IL-6 were associated with hepatitis C infection. None of the cytokines measured increased significantly after IFN administration except for IL-6. IL-6 levels rose rapidly, peaked at 6-15 h in a dose-dependent manner, and returned to baseline by 48 h in both patients receiving a single dose of IFN and those receiving continuous treatment. This was confirmed by RT-PCR. Pretreatment IL-6 levels were directly correlated with area under the curve (AUC) for IL-6 during the 24 h after IFN dosing (r = 0.611, p = 0.007). Viral titers decreased within 24-48 h after a single dose of IFN-con1. Changes in hepatitis C RNA titers were not significantly associated with pretreatment IL-6 levels or with changes in IL-6 levels. In conclusion, (1) baseline serum cytokine levels, except for IL-6, were low or within the normal range in patients with hepatitis C, (2) IL-6 levels were detected in some patients with hepatitis C before treatment but not in healthy controls, (3) IL-6 levels increased acutely after a single dose of IFN-alpha, and IL-6 induction was related to baseline IL-6 level, and (4) changes in IL-6 levels did not correlate with the early virologic response to IFN.
Asunto(s)
Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Hepatitis C/inmunología , Interferón Tipo I/uso terapéutico , Interleucina-6/sangre , Citocinas/sangre , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Hepatitis C/virología , Humanos , Interferón-alfa , Interleucina-6/genética , Cinética , Persona de Mediana Edad , ARN Mensajero/biosíntesis , ARN Viral/análisis , Proteínas RecombinantesRESUMEN
A clinical trial was conducted in three centres to assess the effects of long-term use of the injectable contraceptive depot-medroxyprogesterone acetate (DMPA) on lipid metabolism. Fifty women who had used DMPA at a dose of 150 mg every three months for 3 to 9 years were recruited in Bangkok, Christchurch and Mexico City. They were compared to a control group of 120 IUD users. Total cholesterol, LDL-cholesterol, HDL-cholesterol, total triglycerides, apolipoproteins AI, AII and B were measured throughout one injection interval. Significant findings differed between centres. Compared to their own centre controls, DMPA users in Bangkok had higher LDL-cholesterol levels; those in Christchurch had lower HDL-cholesterol, apolipoprotein (apo) AI and apo AI/B ratio and higher apo B levels; those in Mexico City had a lower apo AI/B ratio. Further changes were observed during the injection interval, some of which were correlated to changes in serum MPA levels. It is concluded that long-term use of DMPA induces moderate changes in lipid metabolism which are unfavourable in terms of risk for atherosclerosis. This should be borne in mind when weighing the overall risks and benefits of this contraceptive method for a potential user.