RESUMEN
Fe status is difficult to assess in the presence of infections. To assess the role of the acute- phase response (APR) and other predictors of serum ferritin and transferrin receptor, we conducted a cross-sectional study among pulmonary tuberculosis (PTB) patients in Mwanza, Tanzania. The acute- (serum ferritin) phase protein, serum alpha1-antichymotrypsin (ACT) and serum ferritin and serum soluble transferrin receptor (sTfR) were measured, and data on smoking, soil and alcohol intake, and infection status were collected. Linear regression analysis was used to assess the role of elevated serum ACT and other predictors of serum ferritin and serum sTfR. Of 655 patients, 81.2 % were sputum positive (PTB+) and 47.2 % HIV+. Mean serum ACT was 0.72 g/l, with 91.1 % above 0.4 g/l. Among females and males, respectively, geometric mean serum ferritin was 140.9 and 269.1 microg/l (P < 0.001), and mean serum sTfR 4.3 and 3.8 mg/l (P < 0.001). Serum sTfR was increased 0.5 mg/l and log serum ferritin increased linearly with serum ACT >0.4 g/l. PTB+ and HIV infection, alcohol drinking and smoking were the positive predictors of serum ferritin, and female sex, soil eating, Schistosoma mansoni and hookworm infection were the negative predictors. Similarly, smoking and HIV infection were the negative predictors of serum sTfR, and female sex, soil eating and PTB+ were the positive predictors. Serum ferritin and serum sTfR are affected by the APR, but may still provide information about Fe status. It may be possible to develop algorithms, based on the markers of the APR and Fe status, to assess the Fe status among the patients with tuberculosis or other infections eliciting an APR.
Asunto(s)
Reacción de Fase Aguda/sangre , Hierro/sangre , Tuberculosis Pulmonar/sangre , Reacción de Fase Aguda/inmunología , Adolescente , Adulto , Análisis de Varianza , Biomarcadores/sangre , Distribución de Chi-Cuadrado , Estudios Transversales , Femenino , Ferritinas/sangre , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Infecciones por VIH/microbiología , Helmintiasis/sangre , Helmintiasis/inmunología , Helmintiasis/microbiología , Humanos , Masculino , Estado Nutricional , Pica/sangre , Receptores de Transferrina/sangre , Esquistosomiasis/sangre , Esquistosomiasis/inmunología , Esquistosomiasis/microbiología , Tanzanía , Transferrina/análisis , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/microbiología , Adulto Joven , alfa 1-Antiquimotripsina/sangreRESUMEN
The study aimed to describe morbidity patterns due to intestinal schistosomiasis in adults living in two villages along the southern shores of Lake Victoria, Mwanza District, Tanzania. Nine hundred and fifty persons from Msozi and 497 from Sangabuye, aged between 14 and 87 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIP) A and B were considered normal and C-F as distinct periportal fibrosis (PPF). The frequency of PPF was higher in Msozi (41.5%) than in Sangabuye (16.7%) (P<0.001) and was associated with high prevalence and intensity of Schistosoma mansoni infection. PPF was shown to be more common in males than females. Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common among males than females. Hepatomegaly and splenomegaly were frequently encountered in both villages. The LIPs were positively correlated to size of SBWT and PVD but not to size of left liver lobe or spleen. In the study communities the risk of developing PPF differed greatly among individuals depending on various risk factors especially alcohol consumption.
Asunto(s)
Cirrosis Hepática/parasitología , Schistosoma mansoni , Esquistosomiasis mansoni/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Métodos Epidemiológicos , Femenino , Agua Dulce/parasitología , Humanos , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/epidemiología , Masculino , Persona de Mediana Edad , Salud Rural , Esquistosomiasis mansoni/diagnóstico por imagen , Esquistosomiasis mansoni/epidemiología , Tanzanía/epidemiología , UltrasonografíaRESUMEN
Iron deficiency is widespread in sub-Saharan Africa, but its predictors are not fully understood. We conducted a cross-sectional study among adults around Lake Victoria to describe iron status and asses the role of dietary and infectious predictors. Linear regression analyses were used to assess the role of infections and intake of meat, fish, fruit/vegetables, alcoholic beverages, and soil on hemoglobin and serum ferritin, while controlling for elevated serum alpha(1)-antichymotrypsin (ACT). Among 1498 participants, the mean age was 33.3 (14-87) y with 53.9% females. More than one-half ate fish daily, 6% ate fruit/vegetables daily, and only 11% ate meat weekly. One-third consumed alcoholic beverages and one-fifth of females consumed soil. Hookworm (80.3%), Schistosoma mansoni (64.7%), and HIV (7.3%) infection were common. Anemia was found in 48.2% of females (<120 g/L hemoglobin) and 40.1% of males (<130 g/L hemoglobin), and 22.3% of females and 7.0% of males had depleted iron stores (serum ferritin <12 microg/L). In multivariate analyses, alcoholic beverage consumption and HIV were positive, whereas soil eating and hookworm infection were negative predictors of serum ferritin. Alcoholic beverage consumption was a positive predictor of hemoglobin, and soil eating, HIV, and hookworm infection were negative predictors. Intakes of meat, fish, and fruit or vegetables were not predictors. Elevated serum ACT was a predictor of both hemoglobin and serum ferritin. Anemia and depleted iron stores were common, whereas iron overload was rare. In conclusion, the associations between alcoholic beverage intake and hemoglobin and iron status suggest that alcoholic beverages may contain micronutrients essential to erythropoiesis. The role of alcoholic beverage intake and other determinants of hemoglobin and iron status in low-income populations needs to be better elucidated.
Asunto(s)
Bebidas Alcohólicas , Hemoglobinas/metabolismo , Hierro/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bebidas Alcohólicas/estadística & datos numéricos , Anemia Ferropénica/epidemiología , Femenino , Ferritinas/sangre , Infecciones por Uncinaria/sangre , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/parasitología , Humanos , Masculino , Persona de Mediana Edad , Caracteres Sexuales , Tanzanía/epidemiologíaRESUMEN
BACKGROUND: New, simple, and better-performing diagnostic tools are needed for the diagnosis of tuberculosis (TB). Much effort has been invested in developing an antibody-based test for TB, but to date, no such test has performed with sufficient sensitivity and specificity. A key question remaining is the extent to which the disappointing performance of current tests is associated with a high background prevalence of latent TB. METHODS: We compared Mycobacterium tuberculosis-specific ESAT-6 and CFP-10 antibody responses in a total of 565 human serum samples from M. tuberculosis-uninfected donors and donors with latent infection, as well as samples from patients with active TB. Our study included samples from 4 countries, representing environments with low, intermediate, and high TB incidences. RESULTS: We demonstrated significant increases in antibody levels in latently infected contacts, compared with M. tuberculosis-uninfected individuals, and in patients with active TB disease, compared with latently infected contacts. Furthermore, we found a striking increase in the magnitude of the antibody responses in samples obtained from infected Ethiopian individuals (with and without disease), compared with Danish and Brazilian infected individuals; this was presumably the result of higher exposure levels. CONCLUSIONS: Our study confirms the presence of ESAT-6 and CFP-10 antibodies in patients with TB, and we demonstrate that significant antibody responses are not restricted to active TB disease but can reflect latent infection, particularly in areas with high levels of exposure to M. tuberculosis. This finding is important for the understanding of the poor discriminatory power of current serodiagnostic tests in regions of endemicity, and it may have major implications on the future development of serologic tests.
Asunto(s)
Especificidad de Anticuerpos/inmunología , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Mycobacterium tuberculosis/inmunología , Fragmentos de Péptidos/inmunología , Tuberculosis/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Formación de Anticuerpos/inmunología , Brasil , Dinamarca , Etiopía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Serológicas , Tanzanía , Tuberculosis/diagnósticoRESUMEN
Genetic susceptibility towards clinical tuberculosis has been proposed in several population studies. We investigated whether polymorphisms in the candidate genes encoding solute carrier 11a1 protein (SLC11A1 formerly NRAMP1), mannose-binding lectin (MBL2) and Vitamin D receptor (VDR) were associated with tuberculosis in an East-African setting. Four hundred and forty-three culture positive pulmonary tuberculosis patients and 426 controls from Mwanza district in the northern part of Tanzania were prospectively included. Polymorphisms in the candidate genes were detected by different PCR-based techniques. A significant association between pulmonary tuberculosis and a microsatellite marker in the 5'(CA)n locus in the SLC11A1 gene compared with controls (38% versus 30% odds ratio 1.45, 95% CI: 1.06-1.9, P=0.014) was observed. The association was apparent only in HIV negative tuberculosis patients. No association with tuberculosis was seen with 3 other SLC11A1 loci investigated, which previously have been associated with tuberculosis in other populations or with MBL2 and VDR polymorphisms. The tuberculosis associated microsatellite marker was situated on different SLC11A1 haplotypes. In this cohort a microsatellite marker in the 5'(CA)n locus situated in the SLC11A1 gene was associated with tuberculosis. The observed association was seen only in HIV negative patients suggesting that this genetic susceptibility for tuberculosis may be surpassed by co-infections.