RESUMO
OBJECTIVES: To evaluate whether extremely preterm infants regulate iron status via hepcidin. STUDY DESIGN: In this retrospective analysis of infants from the Preterm Epo Neuroprotection (PENUT) Trial, urine hepcidin (Uhep) normalized to creatinine (Uhep/UCr) was evaluated among infants randomized to erythropoietin (Epo) or placebo. RESULTS: The correlation (r) between Uhep/UCr and serum markers of iron status (ferritin and zinc protoporphyrin-to-heme ratio [ZnPP/H]) and iron dose was assessed. A total of 243 urine samples from 76 infants born at 24-276/7 weeks gestation were analyzed. The median Uhep/UCr concentration was 0.3, 1.3, 0.4, and 0.1 ng/mg at baseline, 2 weeks, 4 weeks, and 12 weeks, respectively, in placebo-treated infants. The median Uhep/UCr value in Epo-treated infants were not significantly different, with the exception of the value at the 2-week time point (median Uhep/UCr, 0.1 ng/mg; P < .001). A significant association was seen between Uhep/UCr and ferritin at 2 weeks (r = 0.63; P < .001) and at 4 weeks (r = 0.41; P = .01) and between Uhep/UCr and ZnPP/H at 2 weeks (r = -0.49; P = .002). CONCLUSIONS: Uhep/UCr values correlate with serum iron markers. Uhep/UCr values vary over time and are affected by treatment with Epo, suggesting that extremely preterm neonates can regulate hepcidin and therefore their iron status. Uhep is suppressed in extremely preterm neonates, particularly those treated with Epo.
Assuntos
Creatinina/urina , Eritropoetina/administração & dosagem , Hepcidinas/urina , Lactente Extremamente Prematuro/metabolismo , Ferro/metabolismo , Biomarcadores/sangue , Ferritinas/sangue , Heme , Humanos , Lactente , Recém-Nascido , Protoporfirinas/sangue , Estudos RetrospectivosRESUMO
The private demand for a hypothetical vaccine that would provide lifetime protection against HIV/AIDS to an uninfected adult was measured in Guadalajara, Mexico, using the concept of willingness to pay (WTP). A 91-question survey instrument was administered by trained enumerators employing contingent valuation techniques to 234 adults, aged 18-60. Our estimates of private demand indicate that individuals anticipate sizable personal benefits from such a vaccine, and that they would be willing to allocate a substantial portion of their income to be protected in this way from HIV infection. A conservative estimate of the mean WTP of adults in the Guadalajara sample is 6358 pesos (669 US dollars) and the median is 3000 pesos (316 US dollars). A multivariate statistical analysis of the determinants of individuals' WTP shows that individuals with higher incomes, with spouses or partners, and with higher perceived risks of becoming infected with HIV are willing to pay more for the vaccine. Older respondents are willing to pay less. These results suggest that there is likely to be a potentially large private market for a HIV/AIDS vaccine in the middle-income developing countries such as Mexico. These findings have important implications both for the level of R&D effort that is devoted to a vaccine and, assuming these efforts are successful, for future policies to make the vaccine available to the public.