RESUMO
OBJECTIVES: The transglutaminase (TG) antibody test is accurate in identifying celiac disease in symptomatic children. We sought to determine the positive predictive value of this test in asymptomatic children at genetic risk for celiac disease. STUDY DESIGN: Asymptomatic children with a genetic risk for celiac disease were studied to investigate the relationships between TG antibody titer, small bowel histology, growth, and clinical features. Small bowel biopsy histology was graded by using the system of Marsh. RESULTS: Of 30 children with a positive TG antibody test result, 21 (70%) had definite (Marsh score 2 or 3) and 4 (13%) had possible (Marsh score 1) biopsy evidence of celiac disease. TG antibody titer correlated with Marsh score (r = 0.569, P <.01). There was an inverse correlation between Marsh score and height z score (r = -0.361, P =. 05). CONCLUSIONS: In this group of asymptomatic children screened because of a genetic risk, TG antibodies have a positive predictive value of 70% to 83% for biopsy evidence of celiac disease and may identify children before clinical features of celiac disease develop.
Assuntos
Autoanticorpos/análise , Doença Celíaca/enzimologia , Doença Celíaca/genética , Predisposição Genética para Doença , Transglutaminases/imunologia , Adolescente , Doença Celíaca/diagnóstico , Criança , Pré-Escolar , Feminino , Humanos , Intestino Delgado/enzimologia , Intestino Delgado/imunologia , Intestino Delgado/patologia , Masculino , Valor Preditivo dos Testes , Radioimunoensaio , Estatísticas não ParamétricasRESUMO
OBJECTIVE: To compare the health outcomes, costs, and incremental cost-effectiveness of universal neonatal screening for sickle cell disease (SCD) with screening targeted to African Americans. STUDY DESIGN: A cost-effectiveness analysis was done by using a Markov simulation model that considered the costs and outcomes associated with the prevention and treatment of sepsis in those with sickle cell anemia and sickle beta(0)-thalassemia. Three strategies were compared: (1) no screening, (2) targeted screening of African Americans, and (3) universal screening for SCD. RESULTS: In the base case analysis, targeted screening of African Americans compared with no screening cost $6709 per additional year of life saved, and universal screening compared with targeted screening cost $30,760 per additional year of life saved. In a sensitivity analysis, the cost per additional year of life saved with universal screening compared with targeted screening was positively correlated with the delivery rate of targeted screening and was inversely related to the proportion of African Americans in the population. CONCLUSIONS: Targeted screening of African American newborns for SCD compared with no screening is always cost-effective. Universal screening compared with targeted screening always identifies more infants with disease, prevents more deaths, and is cost-effective given certain delivery rates for targeted screening and proportions of African Americans in the population.
Assuntos
Anemia Falciforme/prevenção & controle , Triagem Neonatal , Anemia Falciforme/diagnóstico , Anemia Falciforme/etnologia , População Negra , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Humanos , Recém-Nascido , Cadeias de Markov , Triagem Neonatal/economia , Triagem Neonatal/métodos , Avaliação de Resultados em Cuidados de Saúde , Sensibilidade e Especificidade , Estados Unidos/epidemiologiaRESUMO
The etiology of NIDDM is still controversial, with both insulin resistance and decreased insulin secretion postulated as potential important factors. African-Americans and Hispanics have a two- to threefold excess risk of developing NIDDM compared with non-Hispanic whites. Yet little is known concerning the prevalence of insulin resistance and secretion defects in minorities, especially in African-Americans in population-based studies. Fasting and 2-h post-glucose load glucose and insulin levels, insulin-mediated glucose disposal (insulin sensitivity index) (S(I)), glucose effectiveness (S(G)), and first-phase insulin response (acute insulin response [AIR]) were determined in nondiabetic African-Americans (n= 288), Hispanics (n= 363), and non-Hispanic whites (n= 435) as part of the Insulin Resistance Atherosclerosis Study. Subjects received a standard 2-h oral glucose tolerance test on the first day and an insulin-modified frequently sampled intravenous glucose tolerance test on the second day. African-Americans and Hispanics were more obese than non-Hispanic whites. Both African-Americans and Hispanics had higher fasting and 2-h insulin concentrations and AIR but lower S(I) than non-Hispanic whites. No ethnic difference was observed in S(G). After further adjustments for obesity, body fat distribution, and behavioral factors, African-Americans continued to have higher fasting and 2-h insulin levels and AIR, but lower S(I) than non-Hispanic whites. In contrast, after adjustment for these covariates, no significant ethnic differences in S(I) or fasting insulin levels were observed between Hispanics and non-Hispanic whites. Hispanics continued to have higher 2-h insulin levels and AIRs than those in non-Hispanic whites. In this report, the association between S(I) and upper body adiposity (waist-to-hip, ratio) was similar in each ethnic group. Both nondiabetic African-Americans and Hispanics have increased insulin resistance and higher AIR than nondiabetic non-Hispanic whites, suggesting that greater insulin resistance may be in large part responsible for the higher prevalence of NIDDM in these minority groups. However, in Hispanics. the greater insulin resistance may be due to greater adiposity and other behavioral factors.