RESUMEN
Intestinal barrier immaturity, or "leaky gut," is the proximate cause of susceptibility to necrotizing enterocolitis in preterm neonates. However, the impact of intestinal microbiota development on intestinal mucosal barrier maturation has not been evaluated in this population. In this study, we investigated a longitudinally sampled cohort of 38 preterm infants < 33 weeks gestation monitored for intestinal permeability (IP) and fecal microbiota during the first 2 weeks of life. Rapid decrease in IP indicating intestinal barrier function maturation correlated with significant increase in community diversity. In particular, members of the Clostridiales and Bifidobacterium were highly transcriptionally active, and progressively increasing abundance in Clostridiales was significantly associated with decreased intestinal permeability. Further, neonatal factors previously identified to promote intestinal barrier maturation, including early exclusive breastmilk feeding and shorter duration antibiotic exposure, associate with the early colonization of the intestinal microbiota by members of the Clostridiales, which altogether are associated with improved intestinal barrier function in preterm infants.
RESUMEN
A central goal of the Academy of Breastfeeding Medicine is the development of clinical protocols, free from commercial interest or influence, for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.
Asunto(s)
Alimentación con Biberón/métodos , Lactancia Materna/métodos , Recien Nacido Prematuro , Unidades de Cuidado Intensivo Neonatal , Madres/educación , Alta del Paciente , Adulto , Protocolos Clínicos , Femenino , Humanos , Lactante , Fórmulas Infantiles , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido , Madres/psicología , Alta del Paciente/normas , Educación del Paciente como Asunto , Embarazo , Apoyo SocialRESUMEN
OBJECTIVE: To test the hypothesis that feeding and antibiotic exposures affect intestinal barrier maturation in preterm infants, we serially measured intestinal permeability (IP) biomarkers in infants <33 weeks gestation (gestational age [GA]) during the first 2 weeks of life. STUDY DESIGN: Eligible infants <33 weeks GA were enrolled within 4 days of birth in a prospective study of IP biomarkers (NCT01756040). Study participants received the nonmetabolized sugars lactulose/rhamnose enterally on study days 1, 8, and 15 and lactulose/rhamnose were measured in urine by high-performance liquid chromatography. Serum zonulin and fecal alpha-1-anti-trypsin, 2 other IP markers, were measured by semiquantitative Western blot and ELISA, respectively. RESULTS: In a cohort of 43 subjects, the lactulose/rhamnose ratio was increased on day 1 and decreased over 2 weeks, but remained higher in infants born at ≤28 weeks of gestation compared with IP in infants born at >28 weeks of gestation. Exclusive breastmilk feeding was associated with more rapid maturation in intestinal barrier function. A cluster analysis of 35 subjects who had urine samples from all time points revealed 3 IP patterns (cluster 1, normal maturation: n = 20 [57%]); cluster 2, decreased IP during the first week and subsequent substantial increase: n = 5 [14%]); and cluster 3, delayed maturation: n = 10 [29%]). There were trends toward more prolonged antibiotic exposure (P = .092) and delayed initiation of feeding ≥4 days (P = .064) in infants with abnormal IP patterns. CONCLUSIONS: Intestinal barrier maturation in preterm infants is GA and postnatal age dependent, and is influenced by feeding with a maturational effect of breastmilk feeding and possibly by antibiotic exposures. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01756040.
Asunto(s)
Antibacterianos/administración & dosificación , Recién Nacido de muy Bajo Peso/metabolismo , Absorción Intestinal/fisiología , Leche Humana/metabolismo , Análisis de Varianza , Antibacterianos/farmacocinética , Biomarcadores/análisis , Estudios de Casos y Controles , Desarrollo Infantil/fisiología , Métodos de Alimentación , Femenino , Estudios de Seguimiento , Edad Gestacional , Humanos , Lactante , Fórmulas Infantiles , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Lactosa/administración & dosificación , Lactosa/farmacocinética , Masculino , Permeabilidad/efectos de los fármacos , Estudios Prospectivos , Ramnosa/administración & dosificación , Ramnosa/farmacocinéticaRESUMEN
We previously demonstrated that intestinal myofibroblasts from immature tissue produce excessive IL-8 in response to Escherichia coli lipopolysaccharide (LPS) compared to cells from mature tissue. However, it is unknown whether other cytokines and TLR agonists contribute to this developmentally regulated response. The aim of this study was to further characterize differences in inflammatory signaling in human primary intestinal fibroblasts from fetal (FIF) and infant (IIF) tissue and examine their potential to activate the adaptive immune response in vitro. Cytokine profiles of LPS-stimulated FIF and IIF were assessed by cytokine profile array. IL-8, IL-6, and IL-10 production in response to TLR2, TLR2/6, TLR4, and TLR5 agonists was determined by quantitative ELISA. The potential of activated myofibroblasts to activate adaptive immunity was determined by measuring surface class II MHC expression using flow cytometry. LPS-stimulated FIF produced a distinct proinflammatory cytokine profile consisting of MCP-1, GRO-alpha, IL-6, and IL-8 expression. FIF produced significant IL-8 and IL-6 in response to TLR4 agonist. IIF produced significant levels of IL-8 and IL-6 in the presence of TLR5 and TLR2 agonists. IFN-γ-treated FIF expressed greater HLA-DR levels compared to unstimulated controls and IFN-γ- and LPS-treated IIF. Activated FIF produce a more diverse inflammatory cytokine profile and greater levels of IL-8 and IL-6 in response to TLR4 stimulation compared to IIF. FIF express class II MHC proteins associated with activation of the adaptive immune response. These data suggest that FIF may contribute to bacterial-associated gut inflammation in the immature intestine.
Asunto(s)
Mucosa Intestinal/metabolismo , Intestinos/inmunología , Miofibroblastos/metabolismo , Células Cultivadas , Citocinas/metabolismo , Citocinas/farmacología , Fibroblastos/metabolismo , Expresión Génica , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Lipopolisacáridos/inmunología , Lipopolisacáridos/farmacología , Miofibroblastos/efectos de los fármacos , Receptor Toll-Like 2/agonistas , Receptor Toll-Like 2/metabolismoRESUMEN
BACKGROUND: Intestinal myofibroblasts contribute to immune regulation in adults with inflammatory bowel disease but have not been characterised in neonatal intestinal inflammatory diseases. AIMS: To compare lipopolysaccharide (LPS)-stimulated interleukin-8 (IL-8) production between human foetal and mature intestinal myofibroblasts in vitro. METHODS: Foetal, neonatal and adult cells were stimulated with increasing concentrations of E. coli LPS. In LPS stimulated foetal myofibroblasts, Toll-like receptor 4 mRNA expression was assessed by real-time PCR whilst Toll-like receptor 4 receptor activity was determined using anti-Toll-like receptor 4 antibody. Mitogen activated protein kinase pathway activity was assessed using chemical inhibitors and Western blotting. IL-8 production was measured by quantitative ELISA. RESULTS: IL-8 production by LPS stimulated foetal myofibroblasts occurred in a dose dependent manner. Toll-like receptor 4 expression was constitutive and Toll-like receptor 4 receptor blockade reduced IL-8 production by 42% (P=0.0262). C-Jun N-terminal kinase, p38 and NF-κB inhibitors significantly attenuated LPS stimulated IL-8 production by 42%, 33% and 2%, respectively. Mitogen activated protein kinase activity was confirmed by the presence of phosphorylated proteins on Western blots. CONCLUSION: These data demonstrate increased IL-8 production by foetal myofibroblasts that is partially mediated by Toll-like receptor 4, mitogen activated protein kinase and NF-κB cell signalling pathways. Intestinal myofibroblasts cells may contribute to the dysregulated inflammatory response in the immature intestine and may form targets that lead to new therapies to prevent neonatal intestinal inflammatory bowel diseases.
Asunto(s)
Fibroblastos/metabolismo , Interleucina-8/biosíntesis , Mucosa Intestinal/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Receptor Toll-Like 4/metabolismo , Adulto , Animales , Escherichia coli , Humanos , Técnicas Inmunológicas , Recién Nacido , Intestinos/inmunología , Lipopolisacáridos , Ratones , Proteínas Quinasas Activadas por Mitógenos/genética , FN-kappa B/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/genéticaRESUMEN
OBJECTIVE: To determine whether neonatal intensive care unit (NICU) admission hypothermia is associated with an intrauterine inflammatory response. METHODS: We analyzed a cohort of 309 very low birthweight infants to determine relationships between admission hypothermia, chorioamnionitis, and serum and cerebrospinal fluid (CSF) interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α. RESULTS: Admission hypothermia <36°C occurred in 72% of patients <26 weeks and 44% of patients ≥26 weeks gestational age. NICU admission hypothermia was not associated with histologic chorioamnionitis or with elevated serum cytokine concentrations. CSF IL-6 concentrations ≥6.3 pg/mL were associated with admission hypothermia in infants <26 weeks' gestation. Clinical chorioamnionitis was associated with a lower risk of admission hypothermia, while cesarean section delivery was associated with increased risk. CONCLUSIONS: NICU admission hypothermia is common among preterm infants and is not associated with the fetal inflammatory response syndrome. Hypothermia is less common in the setting of clinical chorioamnionitis and more common in cesarean section deliveries, identifying two groups in whom extra attention to appropriate thermoregulation is warranted.
Asunto(s)
Corioamnionitis/sangre , Corioamnionitis/líquido cefalorraquídeo , Citocinas/sangre , Citocinas/líquido cefalorraquídeo , Hipotermia/sangre , Hipotermia/líquido cefalorraquídeo , Corioamnionitis/etiología , Estudios de Cohortes , Femenino , Humanos , Hipotermia/etiología , Recién Nacido , Recién Nacido de muy Bajo Peso , Unidades de Cuidado Intensivo Neonatal , Cuidado Intensivo Neonatal , Interleucina-1beta/sangre , Interleucina-1beta/líquido cefalorraquídeo , Interleucina-6/sangre , Interleucina-6/líquido cefalorraquídeo , Masculino , Admisión del Paciente , Embarazo , Estudios Prospectivos , Factores de Riesgo , Síndrome de Respuesta Inflamatoria Sistémica/sangre , Síndrome de Respuesta Inflamatoria Sistémica/líquido cefalorraquídeo , Síndrome de Respuesta Inflamatoria Sistémica/etiología , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/líquido cefalorraquídeoRESUMEN
The study objective was to determine whether Ureaplasma respiratory tract colonization of preterm infants <33 wk gestation is associated with an increased risk for necrotizing enterocolitis (NEC). One or more tracheal or nasopharyngeal aspirates for Ureaplasma culture and PCR were obtained during the first week of life from 368 infants <33 wk gestation enrolled from 1999 to 2003 or from 2007 to 2009. NEC Bell stage ≥ 2 was confirmed by radiological criteria, and pathology, if available. Cord serum samples were analyzed for IL-6 and IL-1ß concentrations, and placentas were reviewed for histological chorioamnionitis in the first cohort. NEC was confirmed in 29 of 368 (7.9%) of the combined cohorts. The incidence of NEC was 2.2-fold higher in Ureaplasma-positive (12.3%) than Ureaplasma-negative (5.5%) infants <33 wk (OR, 2.43; 95% CI, 1.13-5.2; p = 0.023) and 3.3-fold higher in Ureaplasma-positive (14.6%) than Ureaplasma-negative (4.4%) infants ≤ 28 wk (OR, 3.67; 95% CI, 1.36-9.93; p = 0.01). Age of onset, hematologic parameters at onset, and NEC severity were similar between Ureaplasma-positive and negative infants. Cord serum IL-6 and IL-1ß concentrations were significantly higher in Ureaplasma-positive than in Ureaplasma-negative NEC-affected infants. Ureaplasma may be a factor in NEC pathogenesis in preterm infants by contributing to intestinal mucosal injury and/or altering systemic or local immune responses.
Asunto(s)
Enterocolitis Necrotizante/microbiología , Recien Nacido Prematuro , Infecciones del Sistema Respiratorio/microbiología , Infecciones por Ureaplasma/microbiología , Ureaplasma/patogenicidad , Análisis de Varianza , Técnicas Bacteriológicas , Baltimore , Distribución de Chi-Cuadrado , Enterocolitis Necrotizante/epidemiología , Enterocolitis Necrotizante/inmunología , Femenino , Sangre Fetal/inmunología , Edad Gestacional , Humanos , Incidencia , Recien Nacido con Peso al Nacer Extremadamente Bajo , Recién Nacido , Recién Nacido de muy Bajo Peso , Mediadores de Inflamación/sangre , Interleucina-1beta/sangre , Interleucina-6/sangre , Masculino , Oportunidad Relativa , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/inmunología , Medición de Riesgo , Factores de Riesgo , Ureaplasma/genética , Ureaplasma/aislamiento & purificación , Infecciones por Ureaplasma/epidemiología , Infecciones por Ureaplasma/inmunologíaRESUMEN
BACKGROUND: Persistent respiratory tract colonization with Ureaplasma spp. in preterm infants is a significant risk factor for the development of the chronic lung disorder, bronchopulmonary dysplasia (BPD). Surfactant protein-A (SP-A), a lung collectin critical for bacterial clearance and regulating inflammation, is deficient in the preterm lung. In an experimental Ureaplasma-pneumonia model, infected SP-A deficient mice exhibited delayed bacterial clearance and an exaggerated inflammatory response compared to infected wild-type mice. The objective was to analyze the role of SP-A in Ureaplasma clearance in vitro. SUBJECTS AND METHODS: We analyzed SP-A binding to Ureaplasma isolates and SP-A-mediated ureaplasmal phagocytosis and killing by cultured RAW 264.7 macrophages. RESULTS: Calcium-dependent SP-A binding was similar among Ureaplasma isolates tested. Pre-incubation of RAW 264.7 cells with SP-A (10-50 µg/ml) enhanced phagocytosis of fluorescein-isothiocyanate (FITC)-labeled Ureaplasma. Surfactant protein-A also increased ureaplasmacidal activity of RAW 264.7 cells by 2.1-fold over 4 h. Pre-incubation of RAW 264.7 cells with 10 µg/ml SP-A reduced lipopolysaccharide (LPS) (100 ng/ml) and Ureaplasma (10(6) color changing units/ml)-stimulated release of tumor necrosis factor-α (TNF-α) by 46% and 43%, respectively, but did not affect transforming growth factor ß(1) (TGFß(1)) release. CONCLUSIONS: These in vitro data confirm that SP-A is important in host defense to perinatally-acquired Ureaplasma infection.