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Prostaglandin E2 attenuates airway pathology in asthmatic patients and exerts a protective effect in antigen-sensitized mice when administered systemically. We aimed to establish the consequences of intranasal PGE2 administration on airway reactivity to aeroallergens in mice and reveal the underlying immunoinflammatory mechanisms. PGE2 was administered either daily during a 10-day exposure to house dust mite (HDM) extracts or for limited intervals. Airway hyperreactivity was measured by whole-body and invasive plethysmography. The phenotypes of lung immune cells and cytokine production were analysed by flow cytometry and ELISA, respectively. Airway hyperreactivity was sustainably reduced only when PGE2 administration was restricted to the initial 5 days of exposure to HDM. Lung inflammation, IL-4 production, and airway mast cell activity were also prevented under this early short-term treatment with PGE2. Interestingly, a Th2 response was already committed on day 5 of exposure to HDM. This was paralleled by GM-CSF and osteopontin upregulation and a decreased number of plasmacytoid dendritic and T regulatory cells, as well as a trend towards reduced IL-10 expression. Local PGE2 administration prevented the increase of airway IL-13 and osteopontin and kept lung plasmacytoid dendritic cell counts close to baseline. GM-CSF and Tregs were unaffected by the treatment. These findings suggest that the protection provided by PGE2 is a result of the modulation of early lung immunomodulatory mechanisms, and possibly a shift in the balance of dendritic cells towards a tolerogenic profile.
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Contaminantes Atmosféricos/inmunología , Antígenos Dermatofagoides/inmunología , Dinoprostona/uso terapéutico , Factores Inmunológicos/uso terapéutico , Hipersensibilidad Respiratoria/prevención & control , Administración Intranasal , Animales , Quimiocina CCL2/metabolismo , Citocinas/biosíntesis , Dinoprostona/administración & dosificación , Dinoprostona/farmacología , Esquema de Medicación , Femenino , Citometría de Flujo , Factores Inmunológicos/administración & dosificación , Factores Inmunológicos/farmacología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Mastocitos/efectos de los fármacos , Mastocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Hipersensibilidad Respiratoria/inducido químicamente , Hipersensibilidad Respiratoria/inmunología , Células Th2/inmunologíaRESUMEN
The fecal immunochemical test (FIT) is the most widely used test for colorectal cancer (CRC) screening. RAID-CRC Screen is a new non-invasive test based on fecal bacterial markers, developed to complement FIT by increasing its specificity. The test was previously clinically evaluated in FIT-positive patients (>20 µg of hemoglobin/g of feces, "FIT20"), in which it reduced the proportion of false positive results by 16.3% while maintaining most of FIT20's sensitivity. The aim of this study was to compare the sensitivity and specificity of a CRC screening program using RAID-CRC Screen in addition to FIT20 as a triage test in a European screening population undergoing screening colonoscopy with a CRC screening program with FIT20 alone in the same cohort. A cohort of 2481 subjects aged > 55 years from the German screening colonoscopy program was included. The colonoscopy findings were used as the gold standard in calculating the diagnostic capacity of the tests and included 15 CRC and 257 advanced neoplasia cases. RAID-CRC Screen added to FIT20 provided the same sensitivity as FIT20 alone (66.7%) in detecting CRC and a significantly higher specificity (97.0% vs. 96.1%, p<0.0001). The positive predictive value was 11.9% when using RAID-CRC Screen and 9.5% with FIT20 alone, and the negative predictive value was 99.8% in the two scenarios. For advanced neoplasia detection, the use of RAID-CRC Screen yielded significantly lower sensitivity than with FIT20 alone (17.5% vs. 21.8%, p = 0.0009), and the overall specificity was significantly higher when using RAID-CRC Screen compared with FIT20 alone (98.2% vs. 97.8%, p = 0.0039). Our findings confirm the results obtained in previous clinical studies in a CRC screening setting, showing the potential of RAID-CRC Screen to increase the overall specificity of FIT-based screening.
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Neoplasias Colorrectales , Detección Precoz del Cáncer , Humanos , Detección Precoz del Cáncer/métodos , Neoplasias Colorrectales/diagnóstico , Sensibilidad y Especificidad , Tamizaje Masivo/métodos , Colonoscopía , Sangre Oculta , HecesRESUMEN
Background and aims: Although there are several effective drugs for the treatment of Crohn's disease (CD), almost 70% of patients will require surgical resection during their lifetime. This procedure is not always curative, as endoscopic recurrence occurs in 65%-90% of patients in the first year after surgery. The aetiology of the recurrence is unknown; however, several studies have shown how the resident microbiota is modified after surgery. The aim of this study was to evaluate samples from patients with Crohn's disease before and after an intestinal resection to determine whether there were differences in the abundance of different microbial markers, which may predict endoscopic recurrence at baseline. Methods: In this observational study, a stool sample was obtained from 25 patients with Crohn's disease before undergoing surgery, recruited at three Catalan hospitals. From each sample, DNA was purified and the relative abundance of nine microbial markers was quantified using qPCR. Results: An algorithm composed of four microbial markers (E. coli, F. prausnitzii phylogroup I, Bacteroidetes, and Eubacteria) showed a sensitivity and specificity of 90.91% and 85.71%, respectively, and a positive and negative predictive value of 83.33% and 92.31%, respectively. Conclusion: A microbial signature to determine patients who will have post-surgical recurrence was identified. This tool might be very useful in daily clinical practice, allowing the scheduling of personalized therapy and enabling preventive treatment only in patients who really require it.
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Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) patients have different faecal microbiota profiles compared to healthy controls. Prebiotics intake influences intestinal microbiota composition which in turn influence the growth of short-chain fatty acids (SCFA) producing bacteria. This study aimed to evaluate the capacity of Previpect, a new prebiotic obtained from grapes fibre, to balance the dysbiosis found in patients with intestinal disorders. This was achieved through the analysis of specific bacterial markers and SCFA production using an in vitro fermentation system and comparing the obtained results with those obtained with other commercial prebiotics. Fresh faecal samples from patients with IBD (N = 6), IBS (N = 3), and control subjects (N = 6) were used. Previpect showed high fermentative ability enabling the growth of butyrate producing bacteria and increasing SCFA concentration up to 2.5-fold. Previpect is a promising prebiotic which may be used as a therapeutic strategy towards promotion of intestinal microbiota restoration, microbial healing, and as a preventive supplement for healthy individuals.
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BACKGROUND AND AIMS: Crohn's disease and ulcerative colitis evolve with alternate outbreaks and remissions of variable duration in both cases. Despite the advances, about 10-30% of patients do not respond to the treatment after the induction period. Besides, between 20% to 50% further patients need an optimization of the dose to respond the treatment. Recent studies have pointed gut microbiota can play a role in the anti-TNF treatment response. This study aimed to define a bacterial signature that could be used to predict the response of patients to anti-TNF treatment. METHODS: There were obtained 38 stool samples from 38 IBD patients before starting anti-TNF treatments: Adalimumab, Golimumab or Infliximab. Patients were differentiated in 2 groups: responders and non-responders to biological treatment. From each sample, DNA was purified and used in a qPCR for the quantification of the 8 microbial markers. RESULTS: In this proof of concept, the predictive ability to identify anti-TNF treatment responders was analyzed. An algorithm consisting in the combination of 4 bacterial markers showed a high capacity to discriminate between responders and non- responders. The algorithm proved high sensitivity and specificity reporting values of 93.33% and 100% respectively, with a positive predictive value of 100% and a negative predictive value of 75% for predicting response to biologic treatment. CONCLUSIONS: A specific bacterial signature could beneficiate patients with inflammatory bowel disease predicting the therapeutic effectiveness of an anti-TNF treatment, leading to a personalized therapy, improving the patients' quality of life, saving costs and gaining time in patient improvement.
This study aimed to define a microbial signature that could be used to predict the response of patients to anti-TNF treatment in inflammatory bowel disease. An algorithm consisting in the combination of 4 bacterial markers showed a high capacity to discriminate between responders and nonresponders.
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Heces/microbiología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Microbiota , Factor de Necrosis Tumoral alfa/uso terapéutico , Biomarcadores , Humanos , Enfermedades Inflamatorias del Intestino/psicología , Proyectos Piloto , Prueba de Estudio Conceptual , Calidad de Vida , Resultado del Tratamiento , Inhibidores del Factor de Necrosis TumoralRESUMEN
Inflammatory bowel disease (IBD), including its two main categories (Crohn's disease and ulcerative colitis), has been linked both to gut microbiota and to diet. Bread is a daily food that has a potential capacity as a prebiotic. Our aim was to evaluate different bread-making processes and their effect on fecal colonic microbiota in IBD patients. The microbial composition of several sourdoughs and dough samples was analyzed by high-throughput sequencing of 16S and 18S rRNA genes. Three types of bread, which followed different bread-making processes, were in vitro digested and incubated with feces from IBD patients. Changes in gut microbiota were assessed by a quantitative polymerase chain reaction using specific bacterial sequence targets. Short-chain fatty acid production was also analyzed by gas chromatography. Lactobacillus sanfranciscensis was the dominant lactic acid bacteria species found in sourdough and bread doughs prepared using sourdough, whereas Saccharomyces cerevisiae was the most dominant yeast in all groups, especially in bread doughs before baking. Differences in microbial composition in raw bread doughs were more related to the type of dough and elaboration than to fermentation time lengths. The analysis of in vitro fecal incubations with bread conditions revealed an increase in most bacterial groups analyzed and short-chain fatty acid production, both in Crohn's disease and ulcerative colitis samples. Most remarkable increases in short-chain fatty acid production mirrored higher abundances of Roseburia species. The potential prebiotic properties observed were mainly obtained when using a high quantity of bread, regardless of bread type. Overall, this study highlights the bacterial dynamics within the bread-making process and the potential prebiotic effect in IBD patients.
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BACKGROUND: The challenges for inflammatory bowel disease (IBD) diagnostics are to discriminate it from gut conditions with similar symptoms such as irritable bowel syndrome (IBS), to distinguish IBD subtypes, to predict disease progression, and to establish the risk to develop colorectal cancer (CRC). Alterations in gut microbiota have been proposed as a source of information to assist in IBD diagnostics. Faecalibacterium prausnitzii (F. prausnitzii), its phylogroups, and Escherichia coli (E. coli) have been reported as potential biomarkers, but their performance in challenging IBD diagnostic situations remains elusive. We hypothesize that bacterial biomarkers based in these species may help to discriminate these conditions of complex diagnostics. AIM: To evaluate the usefulness of indices calculated from the quantification of these species as biomarkers to aid in IBD diagnostics. METHODS: A retrospective study of 131 subjects (31 controls (H); 45 Crohn's disease (CD), 25 ulcerative colitis (UC), 10 IBS, and 20 CRC patients) was performed to assess the usefulness of bacterial biomarkers in biopsies. Further, the performance of biomarkers in faeces was studied in 29 stool samples (19 CD, 10 UC). Relative abundances of total F. prausnitzii (FP), its phylogroups (PHGI and PHGII), and E. coli (E) quantification were determined by qPCR. Loads were combined to calculate the FP-E index, the PHGI-E index and the PHGII-E index. Biomarkers accuracy to discriminate among conditions was measured by the area under the receiver operating characteristic curve (AUC). RESULTS: In biopsies, FP-E index was good for discriminating IBS from CD (AUC = 0.752) while PHGII-E index was suitable for discriminating IBS from UC (AUC = 0.632). The FP-E index would be the choice to discriminate IBD from CRC, especially from all UC subtypes (AUC ≥ 0.875), regardless of the activity status of the patient. Discrimination between UC patients that had the longest disease duration and those with CRC featured slightly lower AUC values. Concerning differentiation in IBD with shared location, PHGI-E index can establish progression from proctitis and left-sided colitis to ulcerative pancolitis (AUC ≥ 0.800). PHG I-E index analysis in tissue would be the choice to discriminate within IBD subtypes of shared location (AUC ≥ 0.712), while in non-invasive faecal samples FP or PHGI could be good indicators (AUC ≥ 0.833). CONCLUSION: F. prausnitzii phylogroups combined with E. coli offer potential to discriminate between IBD and CRC patients and can assist in IBD subtypes classification, which may help in solving IBD diagnostics challenges.
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Guidelines recommend routine screening for colorectal cancer (CRC) in asymptomatic adults starting at age 50. The most extensively used noninvasive test for CRC screening is the fecal immunochemical test (FIT), which has an overall sensitivity for CRC of approximately 61.0%-91.0%, which drops to 27.0%-67.0% for advanced adenomas. These figures contain a high false-positive rate and a low positive predictive value. This work aimed to develop a new, noninvasive CRC screening tool based on fecal bacterial markers capable of decreasing FIT false-positive rates in a FIT-positive population. We defined a fecal bacterial signature (RAID-CRC Screen) in a proof-of-concept with 172 FIT-positive individuals and validated the obtained results on an external cohort of 327 FIT-positive subjects. All study participants had joined the national CRC screening program. In the clinical validation of RAID-CRC Screen, a sensitivity of 83.9% and a specificity of 16.3% were obtained for the detection of advanced neoplasm lesions (advanced adenomas and/or CRC). FIT 20 µg/g produced 184 false-positive results. Using RAID-CRC Screen, this value was reduced to 154, thus reducing the false-positive rate by 16.3%. The RAID-CRC Screen test could be implemented in CRC screening programs to allow a significant reduction in the number of colonoscopies performed unnecessarily for FIT-positive participants of CRC screening programs.
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Neoplasias Colorrectales/diagnóstico , Heces/microbiología , Tamizaje Masivo/métodos , Sangre Oculta , Anciano , Algoritmos , Bacterias/clasificación , Bacterias/aislamiento & purificación , Estudios de Cohortes , Colonoscopía , Detección Precoz del Cáncer/métodos , Detección Precoz del Cáncer/estadística & datos numéricos , Reacciones Falso Positivas , Femenino , Humanos , Inmunoquímica , Masculino , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Sensibilidad y Especificidad , EspañaRESUMEN
BACKGROUND: Colorectal cancer is the second commonest cause of cancer mortality. Some countries are implementing colorectal cancer screening to detect lesions at an early stage using non-invasive tools like the faecal immunochemical test. Despite affordability, this test shows a low sensitivity for precancerous lesions and a low positive predictive value for colorectal cancer, resulting in a high false-positive rate. AIM: To develop a new, non-invasive colorectal cancer screening tool based on bacterial faecal biomarkers, which in combination with the faecal immunochemical test, could allow a reduction in the false-positive rate. This tool is called risk assessment of intestinal disease for colorectal cancer (RAID-CRC). METHODS: We performed both the faecal immunochemical test and the bacterial markers analysis (RAID-CRC test) in stool samples from individuals with normal colonoscopy (167), non-advanced adenomas (88), advanced adenomas (30) and colorectal cancer (48). All the participants showed colorectal cancer-associated symptoms. RESULTS: Performance of the faecal immunochemical test for advanced neoplasia (ie advanced adenoma and colorectal cancer) was determined by using the cut-off value established in Catalonia (20 µg haemoglobin/g of faeces) for a population-based screening approach. Sensitivity and specificity values of 83% and 80%, respectively, and positive and negative predictive values of 56% and 94%, respectively, were obtained. When both the immunological and the biological analysis were combined, the corresponding values were 80% and 90% for sensitivity and specificity, respectively, and 70% and 94% for positive and negative predictive values, respectively, resulting in a 50% reduction of the false-positive rate. CONCLUSIONS: RAID-CRC test allows a substantial reduction in the faecal immunochemical test false-positive results (50%) in a symptomatic population. Further validation is indicated in a colorectal cancer-screening scenario.
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Adenoma/diagnóstico , Neoplasias Colorrectales/diagnóstico , Detección Precoz del Cáncer/métodos , Heces/química , Tamizaje Masivo/métodos , Adenoma/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/análisis , Neoplasias Colorrectales/microbiología , Heces/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Adulto JovenRESUMEN
BACKGROUND: Despite its reported pro-inflammatory activity, cyclooxygenase (COX)-2 has been proposed to play a protective role in asthma. Accordingly, COX-2 might be down-regulated in the airway cells of asthmatics. This, together with results of experiments to assess the impact of COX-2 blockade in ovalbumin (OVA)-sensitized mice in vivo, led us to propose a novel experimental approach using house dust mite (HDM)-sensitized mice in which we mimicked altered regulation of COX-2. METHODS: Allergic inflammation was induced in BALBc mice by intranasal exposure to HDM for 10 consecutive days. This model reproduces spontaneous exposure to aeroallergens by asthmatic patients. In order to impair, but not fully block, COX-2 production in the airways, some of the animals received an intranasal antisense oligonucleotide. Lung COX-2 expression and activity were measured along with bronchovascular inflammation, airway reactivity, and prostaglandin production. RESULTS: We observed impaired COX-2 mRNA and protein expression in the lung tissue of selective oligonucleotide-treated sensitized mice. This was accompanied by diminished production of mPGE synthase and PGE2 in the airways. In sensitized mice, the oligonucleotide induced increased airway hyperreactivity (AHR) to methacholine, but a substantially reduced bronchovascular inflammation. Finally, mRNA levels of hPGD synthase remained unchanged. CONCLUSION: Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients. This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened. This approach will provide insights into the differential regulation of inflammation and lung function in asthma, and will help identify pharmacological targets within the COX-2/PG system.
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Hiperreactividad Bronquial/prevención & control , Hiperreactividad Bronquial/fisiopatología , Ciclooxigenasa 2/administración & dosificación , Ciclooxigenasa 2/metabolismo , Polvo , Pulmón/fisiopatología , Oligonucleótidos Antisentido/administración & dosificación , Oligonucleótidos Antisentido/genética , Administración Intranasal , Animales , Ciclooxigenasa 2/genética , Femenino , Pulmón/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , PyroglyphidaeRESUMEN
The experimental administration of PGE(2) for the treatment of asthma dampens clinical symptoms, and similar efficacy has been found in dust mite-induced hypersensitivity reactions in animal models. Here, we investigate the mechanism by which PGE(2) mediates suppression of MC degranulation. We find that the effect of PGE(2) on FcεRI-dependent MC degranulation varies from activating to suppressing, depending on the relative ratio of EP(2) to EP(3) expression on these cells with suppression evident only in cells having increased EP(2) to EP(3) expression. Consistent with a role for EP(2) in suppressing MC responses in vitro, we found that a selective EP(2) agonist, Butaprost, inhibited MC-mediated FcεRI-induced immediate hypersensitivity in a model of PCA. EP(2) engagement on MCs increased cAMP production and inhibited FcεRI-mediated calcium influx. In addition, it also decreased the extent of FcεRI-induced Fyn kinase activity, leading to decreased phosphorylation of key signaling molecules such as Gab2 and Akt. Treatment with an antagonist of cAMP or shRNA down-regulation of PKA (the principal intracellular target of cAMP) reversed the EP(2)-mediated inhibitory effect on MC degranulation and restored calcium influx and phosphorylation of Akt. Collectively, the findings demonstrate that EP(2) suppresses the Fyn-mediated signals that are central to FcεRI-dependent MC degranulation, suggesting that engagement of the EP(2) on MCs may be beneficial in dampening allergic responses.