Volcanic ash-driven worsening of mucosal inflammation in an experimental colitis model.

Particulate matter exposure and related chemical changes in drinking water have been associated with health problems and inflammatory disorders. This study aimed to examine the effect of orally administered ash-water dilution on the gut of mice under normal and inflammatory conditions. Balb/c mice received ash-released soluble and dust-suspended components in the drinking water for 14 days. On day 7, animals were intrarectally instilled with TNBS in ethanol or flagellin from Salmonella typhimurium in PBS. At sacrifice, colon segments were collected and histologic damage, mRNA expression and cytokine levels in tissue were evaluated. In addition, these parameters were also evaluated in IL-10 null mice. We found that mice that received 5% w. fine-ash dilution in the drinking water worsened colitis signs. Weight loss, shortening of the colon, tissue edema with mucosa and submucosa cell infiltration and production of pro-inflammatory cytokines and chemokines were enhanced compared to control mice. A more pronounced inflammation was observed in IL-10 null mice. In addition, markers of NLRP3-dependent inflammasome activation were found in animals exposed to ash. In conclusion, ingestion of contaminated water with dust-suspended particulate matter enhanced the inflammatory response in the gut, probably due to alteration of the gut barrier and promoting an intense contact with the luminal content. This study critically appraises the response for fine particulate matter in uncommon illnesses reported for volcanic ash pollution. We suggest actions to enable better prediction and assessment the health impacts of volcanic eruptions.

Control of intestinal inflammation by glycosylation-dependent lectin-driven immunoregulatory circuits.

Diverse immunoregulatory circuits operate to preserve intestinal homeostasis and prevent inflammation. Galectin-1 (Gal1), a ß-galactoside-binding protein, promotes homeostasis by reprogramming innate and adaptive immunity. Here, we identify a glycosylation-dependent "on-off" circuit driven by Gal1 and its glycosylated ligands that controls intestinal immunopathology by targeting activated CD8+ T cells and shaping the cytokine profile. In patients with inflammatory bowel disease (IBD), augmented Gal1 was associated with dysregulated expression of core 2 ß6-N-acetylglucosaminyltransferase 1 (C2GNT1) and α(2,6)-sialyltransferase 1 (ST6GAL1), glycosyltransferases responsible for creating or masking Gal1 ligands. Mice lacking Gal1 exhibited exacerbated colitis and augmented mucosal CD8+ T cell activation in response to 2,4,6-trinitrobenzenesulfonic acid; this phenotype was partially ameliorated by treatment with recombinant Gal1. While C2gnt1-/- mice exhibited aggravated colitis, St6gal1-/- mice showed attenuated inflammation. These effects were associated with intrinsic T cell glycosylation. Thus, Gal1 and its glycosylated ligands act to preserve intestinal homeostasis by recalibrating T cell immunity.

[P-glycoprotein functional activity in peripheral blood lymphocytes in ulcerative colitis]. / Funcionalidad de la glicoproteína P linfocitaria en la colitis ulcerosa.

P-glycoprotein (P-gp), encoded by MDR-1, is a transmembrane efflux pump that has been involved in relevant clinical drug transport. It is expressed in lymphocytes, luminal epithelium of colon and other tissues with barrier function. MDR1 was proposed as a candidate gene for ulcerative colitis. The aim of the present work was to investigate the role of P-gp in therapeutic response of ulcerative colitis by studying its functionality in lymphocytes isolated from peripheral blood. Samples were taken from 27 patients with active colitis classified clinically in refractory (n = 16) and responders (n = 11) to treatment. Rhodamine 123 (a fluorescent P-glycoprotein substrate) efflux was studied by flow cytometry as absence and presence of an inhibitor (verapamil, 100 uM). Data were expressed evaluating the behaviour of two markers defined based on % of cells with maximum (M1)/minimum (M2) intracellular fluorescence, reflecting inactivity/activity of the pump. Results were compared with a group of healthy individuals (n = 68). Significant differences were observed in absence and presence of Verapamil inhibition, when comparing refractory vs. responders (p < 0.05) as well as refractory vs. healthy controls (p < 0.01). No differences were observed when comparing responders vs. controls (p > 0.05) (Kruskal-Wallis test and Dunn post-test). Rhodamine efflux assay was also performed in 12 patients who required therapeutic change; a significant diminish of rhodamine transport (p < 0.01) was observed without inhibitor when patients achieved clinical response. Finally, our results suggest a possible relevant role of P-gp in ulcerative colitis treatment response and a possible usefulness of P-gp functional assay in the early detection of individual therapeutic response.

Interstitial Lung Disease in a Patient Treated with Denosumab.

Denosumab is an antiresorptive agent widely used for treating osteoporosis. Atypical femur fractures, osteonecrosis of the jaw and hypocalcaemia are well-known possible adverse effects of this drug. We present, to our knowledge, the first case report in the English literature of clinically significant interstitial lung disease likely related to denosumab. LEARNING POINTS: Denosumab is a fully human monoclonal antibody which may rarely cause interstitial lung disease (ILD).The findings from this isolated case report of ILD in a patient taking denosumab do not prove causality.Nevertheless, we suggest that patient exposure to denosumab should be considered in a patient with ILD.

Prevalence of primary sclerosing cholangitis in patients with ulcerative colitis and the risk of developing malignancies. A large prospective study.

BACKGROUND/AIM: primary sclerosing cholangitis (PSC) is associated with ulcerative colitis (UC) and seems to be a risk factor for colon cancer. However, taking into account that no data are available in South American population, we analyzed the prevalence of PSC in 1,333 patients with UC and the risk for developing colon cancer. MATERIAL: patients with persistent increases of alkaline phosphatase were studied by cholangiography and liver biopsy. To assess the risk of colon cancer, each patient with PSC and UC was matched with two control patients with UC without PSC of the same age, gender, extent and duration of UC. RESULTS: the whole prevalence of PSC was 2.9% (39 patients) reaching 6.2% in extensive colitis. Seven (18%) out of 39 patients with PSC developed colorectal carcinoma compared with 2 out of 78 (2.6%) in the control group (p=0.006). The cumulative risk of colorectal carcinoma was 11% and 18% after 10 and 20 years in the PSC group compared with 2% and 7% in the control group, respectively (p=0.002). CONCLUSION: this is the first prospective study performed in Latin America showing that the prevalence of PSC in patients with UC is similar to that reported in the Anglo-Saxon population. Patients with UC and PSC have a high risk of colorectal cancer.

Multidrug resistance gene (MDR-1) expression in the colonic mucosa of patients with refractory ulcerative colitis.

BACKGROUND: P-Glycoprotein (P-gp), a product of the MDR-1 gene, is a transmembrane efflux pump involved in drug transport, first described in cancer refractoriness. In the normal bowel P-gp is detectable on superficial epithelial cells, but has not been described in crypt epithelium. The role of P-gp and its intestinal expression in steroid-refractory ulcerative colitis (UC) are controversial. AIM: to compare P-gp immunostaining pattern in colonic epithelial cells of steroid-refractory versus steroid-responder UC patients. METHODS: P-gp was assessed by immunohistochemistry in rectal biopsies obtained from 19 patients with active UC, including pre-surgical samples from 11 refractory patients who underwent colectomy, and 8 responders. We devised a 5-point (0-4) score, according to the percentage of epithelial surface with positive immunostaining in the superficial and crypt epithelium (apical, lateral and cytoplasmic areas). RESULTS: Compared with responders, steroid-refractory patients had significantly higher immunostaining scores in the superficial epithelium, both in apical (2.8+/-0.5 versus 1.1+/-0.5, p=0.023) and cytoplasmic cellular areas (2.7+/-0.5 versus 1.2+/-0.5, p=0.032). Positive immunostaining of the superficial epithelium was frequently detected in refractory patients (apical: 9/11 cases, cytoplasmic: 10/11 cases) but was only observed in 4/8 responders. P-gp was also detected in similar areas of the crypt epithelium in 6/11 refractory patients, while it was infrequent in the group of 8 responders (1 apical 1 case, cytoplasmic 2 cases). Samples from the mucosa of normal ileal pouch-anal anastomoses obtained several years after the surgical procedure had a P-gp immunostaining pattern which was similar to that of rectal samples from patients with refractory UC. CONCLUSIONS: These results suggest a critical role of P-gp overexpression in steroid-refractory UC.

[Non-invasive ventilation in 'do-not-intubate' patients in a chronic disease hospital. One year follow-up study]. / Resultados de la ventilación mecánica no invasiva en pacientes no candidatos a intubación en un hospital de subagudos. Estudio de seguimiento a un año.

UNLABELLED: Elderly patients with multiple morbidity and do not intubate (DNI) orders frequently present with acute respiratory failure. There are data supporting the effectiveness of non-invasive ventilation (NIV) in this context. Our chronic disease hospital developed an integrated care clinical pathway for the use of NIV in acute respiratory failure in the emergency room and wards in 2010. The aim of this study was to assess the outcome of NIV in patients with acute respiratory failure who had a DNI order in a sub-acute care hospital. METHODS: Observational, one year-follow up study. The main variables were in-hospital mortality and one year mortality. Other variables recorded were: demographics, clinical data, functional data, performance of daily life activities, dementia, arterial blood gases and re-admissions. RESULTS: The study included a total of 102 patients, of which 22% were in institutions. The mean age 81±7.47% males, with a Charlson index 3.7±1, and Barthel index 54±31. The overall mortality during the admission was 33% (34 patients). Among those patients ventilated outside the protocol indication, the mortality was significantly greater, at 71% (P>.05). Overall one-year survival rate was 46%. This survival rate was statistically higher in patients with obesity hypoventilation syndrome and a Barthel >50. CONCLUSIONS: NIV is a useful technique in a hospital for chronic patients in an elderly population with a therapeutic ceiling. Despite their disease severity and comorbidity, acceptable survival rates are achieved. A correct case selection is needed. Obesity hypoventilation syndrome and those with Barthel index >50 have a better prognosis.

[Activity index in Crohn's disease]. / Indices de actividad en la enfermedad de Crohn. Revisión crítica y evaluación de su utilidad en el manejo clínico.

The gold standard to quantify Crohn's disease activity is still not defined and a world consensus to unify criteria is necessary. Criticism has been directed towards every existing indexes. We summarize some of the currently used criteria for the assessment of disease activity, point out the controversies and issues that will need further investigations, and discuss their usefulness based on our experience.

[Inhaled colistin in elderly patients with non-cystic fibrosis bronchiectasis and chronic Pseudomonas aeruginosa bronchial infection]. / Tratamiento inhalado con colistina a largo plazo en pacientes ancianos con infección crónica por Pseudomonas aeruginosa y bronquiectasias.

BACKGROUND: Bronchiectasis is a frequent cause of admission for elderly patients and chronic respiratory diseases. Although some guidelines recommend long-term treatment with inhaled antibiotics in non-cystic fibrosis bronchiectasis with chronic Pseudomonas aeruginosa (P. aeruginosa) infection, there is limited evidence supporting these prolonged antibiotic treatments in this population. The aim of this study was to assess the effectiveness of inhaled colistin in elderly patients with bronchiectasis and chronic bronchial P. aeruginosa infection in reducing hospital readmissions. MATERIAL AND METHODS: A prospective, controlled and open label study was conducted on patients with bronchiectasis diagnosed by computed tomography and persistence of P. aeruginosa in sputum after appropriate antimicrobial therapy. All patients received education, and physiotherapy training. The intervention group also received nebulized colistin 1 million IU twice a day for one year. Data were collected on the demographics, clinical and functional characteristics, admissions in previous year, and sputum microbiology. Patients were followed up every two months for one year, with readmissions, microbiological results, functional tests, and deaths being evaluated. RESULTS: The study included 39 patients, of whom 20 received nebulized colistin and 19 conventional therapy. There were no differences between the two groups in baseline clinical and functional characteristics or previous hospital stay. The mean age was 77.7+/-5, Charlson index 2.85, and FEV1% 41.3+/-15. Five patients (25%) stopped the nebulized treatment because of adverse effects. P. aeruginosa was eradicated in 45% of the colistin treated patients, and in only one of the control group (statistically significant), but at the end of the study year, there were no differences in the number of hospital admissions (control group 1.6+/-1.7 and 2.7+/-3 colistin group), or days of stay (19+/-31 and 23+/-20). There were no differences in lung function or clinical symptoms between the two groups No significant changes were observed in P. aeruginosa A antibiotic sensitivity or in sputum flora. CONCLUSIONS: More patients in the treatment group achieved Pseudomonas eradication, but benefits in clinical symptoms, lung function or use of healthcare resources in our elderly patients, could not be demonstrated. Adverse effects were common. Further studies are needed in order to identify factors associated with response, or subgroups of patients with bronchiectasis and chronic infection with P. aeruginosa, who benefit from (expensive) long term treatments with inhaled antibiotics.

Prevalence of primary sclerosing cholangitis in patients with ulcerative colitis and the risk of developing malignancies: a large prospective study / Prevalencia de colangitis esclerosante primaria en pacientes con colitis ulcerosa y el riesgo de desarrollar malignidades: un extenso estudio prospectivo

Background/aim: primary sclerosing cholangitis (PSC) is associated with ulcerative colitis (UC) and seems to be a risk factor for colon cancer. However, taking into account that no data are available in South American population, we analyzed the prevalence of PSC in 1.333 patients with UC and the risk for developing colon cancer. Material: patients with persistent increases of alkaline phosphatase were studied by cholangiography and liver biopsy. To assess the risk of colon cancer, each patient with PSC and UC was matched with two control patients with UC without PSC of the same age, gender, extent and duration of UC. Results: the whole prevalence of PSC was 2.9% (39 patients) reaching 6.2% in extensive colitis. Seven (18 %) out of 39 patients with PSC developed colorectal carcinoma compared with 2 out of 78 (2.6%) in the control group (p=0.006). The cumulative risk of colorectal carcinoma was 11% and 18% after 10 and 20 years in the PSC group compared with 2% and 7% in the control group, respectively (p=0.002). Conclusion: this is the first prospective study performed in Latin America showing that the prevalence of PSC in patients with UC is similar to that reported in the Anglo-Saxon population. Patients with UC and PSC have a high risk of colorectal cancer.

Introducción/objetivos: la colangitis esclerosante primaria (CEP) se asocia a colitis ulcerosa (CU) y parece ser un factor de riesgo para cáncer de colon. Sin embargo, teniendo en cuenta que no existen datos disponibles en población de Sudamérica, nosotros analizamos la prevalencia de CEP en 1.333 pacientes con CU y el riesgo de desarrollar cáncer de colon. Material: los pacientes con fosfatasa alcalina persistentemente elevada fueron estudiados con colangiografía y biopsia hepática. Para determinar el riesgo de cáncer de colon cada paciente con CEP y CU fueron apareados con dos pacientes controles con CU sin CEP de la misma edad, sexo, extensión y duración de la CU. Resultados: la prevalencia total de CEP fue de 2.9% (39 pacientes), alcanzando una prevalencia del 6.2% en colitis extensa. Siete (18%) de 39 pacientes con CEP desarrollaron cáncer colorectal comparado con 2 de 78 en el grupo control (p=0.006). El riesgo acumulado de cáncer colorectal fue 11 y 18% después de 10 y 20 años en el grupo con CEP comparado con 2 y 7% en el grupo control, respectivamente (p=0.002). Conclusión: este es el primer estudio prospectivo realizado en Latinoamérica mostrando que la prevalencia de CEP en pacientes con CU es similar a la reportada en población anglosajona. Los pacientes con CU y CEP tienen un alto riesgo de cáncer colorectal.

Multidrug resistance gene (MDR-1) expression in the colonic mucosa of patients with refractory ulcerative colitis / Expresión del gen de multirresistencia a drogas (MDR-1) en la mucosa colónica de pacientes con colitis ulcerosa refractaria

BACKGROUND: P-Glycoprotein (P-gp), a product of the MDR-1 gene, is a transmembrane efflux pump involved in drug transport, first described in cancer refractoriness. In the normal bowel P-gp is detectable on superficial epithelial cells, but has not been described in crypt epithelium. The role of P-gp and its intestinal expression in steroid-refractory ulcerative colitis (UC) are controversial. AIM: to compare P-gp immunostaining pattern in colonic epithelial cells of steroid-refractory versus steroid-responder UC patients. METHODS: P-gp was assessed by immunohistochemistry in rectal biopsies obtained from 19 patients with active UC, including pre-surgical samples from 11 refractory patients who underwent colectomy, and 8 responders. We devised a 5-point (0-4) score, according to the percentage of epithelial surface with positive immunostaining in the superficial and crypt epithelium (apical, lateral and cytoplasmic areas). RESULTS: Compared with responders, steroid-refractory patients had significantly higher immunostaining scores in the superficial epithelium, both in apical (2.8+/-0.5 versus 1.1+/-0.5, p=0.023) and cytoplasmic cellular areas (2.7+/-0.5 versus 1.2+/-0.5, p=0.032). Positive immunostaining of the superficial epithelium was frequently detected in refractory patients (apical: 9/11 cases, cytoplasmic: 10/11 cases) but was only observed in 4/8 responders. P-gp was also detected in similar areas of the crypt epithelium in 6/11 refractory patients, while it was infrequent in the group of 8 responders (1 apical 1 case, cytoplasmic 2 cases). Samples from the mucosa of normal ileal pouch-anal anastomoses obtained several years after the surgical procedure had a P-gp immunostaining pattern which was similar to that of rectal samples from patients with refractory UC. CONCLUSIONS: These results suggest a critical role of P-gp overexpression in steroid-refractory UC.

Antecedentes. La glicoproteína P (P-gp), un producto del gen MDR-1, es una bomba de eflujo transmembranainvolucrada en el transporte de drogas, descripta por primera vez en el cáncer refractario. En el intestino normal, P-gp se detecta sobre las célulasepiteliales superficiales, pero no se la ha descripto en el epitelio de las criptas. El papel de P-gp y su expresiónintestinal en la colitis ulcerosa (CU) refractaria a esteroides es controvertido. Objetivo. Comparar elpatrón de inmunotinción de P-gp en células epiteliales colónicas de pacientes con CU refractaria vs.respondedora a esteroides. Métodos. Se estudió P-gp por inmunohistoquímica en biopsias rectales obtenidasde 19 pacientes con CU activa, incluyendo muestras prequirúrgicas de 11 pacientes refractarios que fueronsometidos a una colectomía y muestras de 8 respondedores. Ideamos un score de 5 puntos (0-4), según elporcentaje de superficie epitelial con inmunotinción positiva en el epitelio superficial y críptico (áreas apical,lateral y citoplásmica). Resultados. Comparados con los respondedores, los pacientes refractarios a esteroides tenían scores de inmunotinción significativamente mayores en el epitelio superficial, tanto en lasáreas celulares apical (2.8+0.5 vs. 1.1+0.5, p=0.023) como citoplásmica (2.7+0.5 vs. 1.2+0.5, p=0.032). Se detectó frecuentemente inmunotinción positiva en el epitelio superficial en los pacientes refractarios (apical: 9/11 casos, citoplásmica: 10/11 casos), pero la misma se observó sólo en 4/8 respondedores. P-gp también sedetectó en áreas similares del epitelio de las criptas en 6/11 pacientes refractarios, en tanto que fue infrecuenteen el grupo de los 8 respondedores (1 caso en el área apical y 2 en la citoplásmica). Fuerón estudiadasbiopsias de la mucosa de la anastomosis pouch ileal - anal, obtenidas varios años después del procedimeinto quirúrgico, observándose un patrón de...

Índices de actividad en la enfermedad de Crohn: revisión crítica y evaluación de su utilidad en el manejo clínico / Activity indices in Crohn's disease: critical review and evaluation of their usefulness in clinical management

No se ha definido aún un método gold standard para cuantificar la actividad de la enfermedad de Crohn, por lo que es necesario unificar criterios a través de un consenso mundial. Cada uno de los índices descriptos para tal fin han sido criticados. En el presente trabajo realizamos una revisión de los criterios actualmente utilizados para evaluar la actividad de la enfermedad, destacamos las controversias existentes y los temas que aún requieren ser investigados, y analizamos su utilidad en base a nuestra experiencia.

The gold standard to quantify Crohn's disease activity is still not defined and a world consensus to unify criteria is necessary. Criticism has been directed towards every existing indexes. We summarize some of the currently used criteria for the assessment of disease activity, point out the controversies and issues that will need further investigations, and discuss their usefulness based on our experience.