Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Lancet Gastroenterol Hepatol ; 9(5): 415-427, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38402895

RESUMEN

BACKGROUND: Management strategies and clinical outcomes vary substantially in patients newly diagnosed with Crohn's disease. We evaluated the use of a putative prognostic biomarker to guide therapy by assessing outcomes in patients randomised to either top-down (ie, early combined immunosuppression with infliximab and immunomodulator) or accelerated step-up (conventional) treatment strategies. METHODS: PROFILE (PRedicting Outcomes For Crohn's disease using a moLecular biomarker) was a multicentre, open-label, biomarker-stratified, randomised controlled trial that enrolled adults with newly diagnosed active Crohn's disease (Harvey-Bradshaw Index ≥7, either elevated C-reactive protein or faecal calprotectin or both, and endoscopic evidence of active inflammation). Potential participants had blood drawn to be tested for a prognostic biomarker derived from T-cell transcriptional signatures (PredictSURE-IBD assay). Following testing, patients were randomly assigned, via a secure online platform, to top-down or accelerated step-up treatment stratified by biomarker subgroup (IBDhi or IBDlo), endoscopic inflammation (mild, moderate, or severe), and extent (colonic or other). Blinding to biomarker status was maintained throughout the trial. The primary endpoint was sustained steroid-free and surgery-free remission to week 48. Remission was defined by a composite of symptoms and inflammatory markers at all visits. Flare required active symptoms (HBI ≥5) plus raised inflammatory markers (CRP >upper limit of normal or faecal calprotectin ≥200 µg/g, or both), while remission was the converse-ie, quiescent symptoms (HBI <5) or resolved inflammatory markers (both CRP ≤ the upper limit of normal and calprotectin <200 µg/g) or both. Analyses were done in the full analysis (intention-to-treat) population. The trial has completed and is registered (ISRCTN11808228). FINDINGS: Between Dec 29, 2017, and Jan 5, 2022, 386 patients (mean age 33·6 years [SD 13·2]; 179 [46%] female, 207 [54%] male) were randomised: 193 to the top-down group and 193 to the accelerated step-up group. Median time from diagnosis to trial enrolment was 12 days (range 0-191). Primary outcome data were available for 379 participants (189 in the top-down group; 190 in the accelerated step-up group). There was no biomarker-treatment interaction effect (absolute difference 1 percentage points, 95% CI -15 to 15; p=0·944). Sustained steroid-free and surgery-free remission was significantly more frequent in the top-down group than in the accelerated step-up group (149 [79%] of 189 patients vs 29 [15%] of 190 patients, absolute difference 64 percentage points, 95% CI 57 to 72; p<0·0001). There were fewer adverse events (including disease flares) and serious adverse events in the top-down group than in the accelerated step-up group (adverse events: 168 vs 315; serious adverse events: 15 vs 42), with fewer complications requiring abdominal surgery (one vs ten) and no difference in serious infections (three vs eight). INTERPRETATION: Top-down treatment with combination infliximab plus immunomodulator achieved substantially better outcomes at 1 year than accelerated step-up treatment. The biomarker did not show clinical utility. Top-down treatment should be considered standard of care for patients with newly diagnosed active Crohn's disease. FUNDING: Wellcome and PredictImmune Ltd.


Asunto(s)
Enfermedad de Crohn , Adulto , Humanos , Masculino , Femenino , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/tratamiento farmacológico , Enfermedad de Crohn/complicaciones , Infliximab/uso terapéutico , Azatioprina/uso terapéutico , Biomarcadores , Factores Inmunológicos/uso terapéutico , Inflamación , Complejo de Antígeno L1 de Leucocito
2.
Transplantation ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38409681

RESUMEN

BACKGROUND: Bile chemistry during normothermic ex situ liver perfusion (NESLiP) has been suggested to be an indicator of cholangiopathy. The normal range of biochemical variables in bile of livers undergoing NESLiP has not been defined, nor have published biliary viability criteria been assessed against instances of posttransplant nonanastomotic bile strictures (NASs). METHODS: The bile and perfusate chemistry of 200 livers undergoing NESLiP between February 1, 2018, and October 30, 2023, was compared. In addition, 11 livers that underwent NESLiP and later developed NAS were selected and their bile chemistry was also examined. RESULTS: In livers that did not develop cholangiopathy, concentrations of sodium, potassium, and chloride were slightly higher in bile than in perfusate, whereas the concentration of calcium was slightly lower. Bile was alkali and had a lower glucose concentration than perfusate. Cholangiocyte glucose reabsorption was shown to saturate at high perfusate concentrations and was more impaired in livers donated after circulatory death than in livers donated after brain death. Published criteria failed to identify all livers that went on to develop NASs. CONCLUSIONS: A significant false-negative rate exists with current biliary viability criteria, probably reflecting the patchy and incomplete nature of the development of NASs in the biliary tree. The data presented here provide a benchmark for future assessment of bile duct chemistry during NESLiP.

4.
Transplantation ; 107(6): 1311-1321, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-36728501

RESUMEN

BACKGROUND: Deceased donor livers are prone to biliary complications, which may necessitate retransplantation, and we, and others, have suggested that these complications are because of peribiliary vascular fibrin microthrombi. We sought to determine the prevalence and consequence of occult fibrin within deceased donor livers undergoing normothermic ex situ perfusion (NESLiP) and evaluate a role for fibrinolysis. METHODS: D-dimer concentrations, products of fibrin degradation, were assayed in the perfusate of 163 livers taken after 2 h of NESLiP, including 91 that were transplanted. These were related to posttransplant outcomes. Five different fibrinolytic protocols during NESLiP using alteplase were evaluated, and the transplant outcomes of these alteplase-treated livers were reviewed. RESULTS: Perfusate D-dimer concentrations were lowest in livers recovered using in situ normothermic regional perfusion and highest in alteplase-treated livers. D-dimer release from donation after brain death livers was significantly correlated with the duration of cold ischemia. In non-alteplase-treated livers, Cox proportional hazards regression analysis showed that D-dimer levels were associated with transplant survival ( P = 0.005). Treatment with alteplase and fresh frozen plasma during NESLiP was associated with significantly more D-dimer release into the perfusate and was not associated with excess bleeding postimplantation; 8 of the 9 treated livers were free of cholangiopathy, whereas the ninth had a proximal duct stricture. CONCLUSIONS: Fibrin is present in many livers during cold storage and is associated with poor posttransplant outcomes. The amount of D-dimer released after fibrinolytic treatment indicates a significant occult fibrin burden and suggests that fibrinolytic therapy during NESLiP may be a promising therapeutic intervention.


Asunto(s)
Trasplante de Hígado , Humanos , Trasplante de Hígado/efectos adversos , Fibrina/metabolismo , Preservación de Órganos/métodos , Hígado/irrigación sanguínea , Perfusión/métodos
5.
Nature ; 615(7950): 134-142, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36470304

RESUMEN

Preventing SARS-CoV-2 infection by modulating viral host receptors, such as angiotensin-converting enzyme 2 (ACE2)1, could represent a new chemoprophylactic approach for COVID-19 that complements vaccination2,3. However, the mechanisms that control the expression of ACE2 remain unclear. Here we show that the farnesoid X receptor (FXR) is a direct regulator of ACE2 transcription in several tissues affected by COVID-19, including the gastrointestinal and respiratory systems. We then use the over-the-counter compound z-guggulsterone and the off-patent drug ursodeoxycholic acid (UDCA) to reduce FXR signalling and downregulate ACE2 in human lung, cholangiocyte and intestinal organoids and in the corresponding tissues in mice and hamsters. We show that the UDCA-mediated downregulation of ACE2 reduces susceptibility to SARS-CoV-2 infection in vitro, in vivo and in human lungs and livers perfused ex situ. Furthermore, we reveal that UDCA reduces the expression of ACE2 in the nasal epithelium in humans. Finally, we identify a correlation between UDCA treatment and positive clinical outcomes after SARS-CoV-2 infection using retrospective registry data, and confirm these findings in an independent validation cohort of recipients of liver transplants. In conclusion, we show that FXR has a role in controlling ACE2 expression and provide evidence that modulation of this pathway could be beneficial for reducing SARS-CoV-2 infection, paving the way for future clinical trials.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Receptores Virales , Ácido Ursodesoxicólico , Animales , Humanos , Ratones , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19/metabolismo , COVID-19/prevención & control , Receptores Virales/genética , Receptores Virales/metabolismo , Estudios Retrospectivos , SARS-CoV-2/metabolismo , Tratamiento Farmacológico de COVID-19 , Cricetinae , Transcripción Genética , Ácido Ursodesoxicólico/farmacología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Organoides/efectos de los fármacos , Organoides/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Mucosa Nasal/efectos de los fármacos , Mucosa Nasal/metabolismo , Sistema de Registros , Reproducibilidad de los Resultados , Trasplante de Hígado
6.
Transplantation ; 106(12): 2391-2398, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36044364

RESUMEN

BACKGROUND: Normothermic ex situ liver perfusion is increasingly used to assess donor livers, but there remains a paucity of evidence regarding criteria upon which to base a viability assessment or criteria predicting early allograft function. METHODS: Perfusate variables from livers undergoing normothermic ex situ liver perfusion were analyzed to see which best predicted the Model for Early Allograft Function score. RESULTS: One hundred fifty-four of 203 perfused livers were transplanted following our previously defined criteria. These comprised 84/123 donation after circulatory death livers and 70/80 donation after brain death livers. Multivariable analysis suggested that 2-h alanine transaminase, 2-h lactate, 11 to 29 mmol supplementary bicarbonate in the first 4 h, and peak bile pH were associated with early allograft function as defined by the Model for Early Allograft Function score. Nonanastomotic biliary strictures occurred in 11% of transplants, predominantly affected first- and second-order ducts, despite selection based on bile glucose and pH. CONCLUSIONS: This work confirms the importance of perfusate alanine transaminase and lactate at 2-h, as well as the amount of supplementary bicarbonate required to keep the perfusate pH > 7.2, in the assessment of livers undergoing perfusion. It cautions against the use of lactate as a sole indicator of viability and also suggests a role for cholangiocyte function markers in predicting early allograft function.


Asunto(s)
Bicarbonatos , Trasplante de Hígado , Alanina Transaminasa , Trasplante de Hígado/efectos adversos , Perfusión/efectos adversos , Hígado , Lactatos , Aloinjertos , Preservación de Órganos
7.
Science ; 371(6531): 839-846, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33602855

RESUMEN

Organoid technology holds great promise for regenerative medicine but has not yet been applied to humans. We address this challenge using cholangiocyte organoids in the context of cholangiopathies, which represent a key reason for liver transplantation. Using single-cell RNA sequencing, we show that primary human cholangiocytes display transcriptional diversity that is lost in organoid culture. However, cholangiocyte organoids remain plastic and resume their in vivo signatures when transplanted back in the biliary tree. We then utilize a model of cell engraftment in human livers undergoing ex vivo normothermic perfusion to demonstrate that this property allows extrahepatic organoids to repair human intrahepatic ducts after transplantation. Our results provide proof of principle that cholangiocyte organoids can be used to repair human biliary epithelium.


Asunto(s)
Enfermedades de los Conductos Biliares/terapia , Conductos Biliares Intrahepáticos/fisiología , Conductos Biliares/citología , Tratamiento Basado en Trasplante de Células y Tejidos , Células Epiteliales/citología , Organoides/trasplante , Animales , Bilis , Conductos Biliares/fisiología , Conductos Biliares Intrahepáticos/citología , Conducto Colédoco/citología , Células Epiteliales/fisiología , Vesícula Biliar/citología , Regulación de la Expresión Génica , Humanos , Hígado/fisiología , Trasplante de Hígado , Trasplante de Células Madre Mesenquimatosas , Ratones , Organoides/fisiología , RNA-Seq , Obtención de Tejidos y Órganos , Transcriptoma
9.
Nat Med ; 23(8): 954-963, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28671689

RESUMEN

The treatment of common bile duct (CBD) disorders, such as biliary atresia or ischemic strictures, is restricted by the lack of biliary tissue from healthy donors suitable for surgical reconstruction. Here we report a new method for the isolation and propagation of human cholangiocytes from the extrahepatic biliary tree in the form of extrahepatic cholangiocyte organoids (ECOs) for regenerative medicine applications. The resulting ECOs closely resemble primary cholangiocytes in terms of their transcriptomic profile and functional properties. We explore the regenerative potential of these organoids in vivo and demonstrate that ECOs self-organize into bile duct-like tubes expressing biliary markers following transplantation under the kidney capsule of immunocompromised mice. In addition, when seeded on biodegradable scaffolds, ECOs form tissue-like structures retaining biliary characteristics. The resulting bioengineered tissue can reconstruct the gallbladder wall and repair the biliary epithelium following transplantation into a mouse model of injury. Furthermore, bioengineered artificial ducts can replace the native CBD, with no evidence of cholestasis or occlusion of the lumen. In conclusion, ECOs can successfully reconstruct the biliary tree, providing proof of principle for organ regeneration using human primary cholangiocytes expanded in vitro.


Asunto(s)
Conductos Biliares Extrahepáticos/fisiología , Células Epiteliales/citología , Vesícula Biliar/fisiología , Organoides/fisiología , Regeneración/fisiología , Ingeniería de Tejidos/métodos , Animales , Conductos Biliares Extrahepáticos/citología , Conductos Biliares Extrahepáticos/lesiones , Sistema Biliar/citología , Sistema Biliar/lesiones , Sistema Biliar/fisiología , Trasplante de Células , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Vesícula Biliar/lesiones , Humanos , Técnicas In Vitro , Queratina-19/metabolismo , Queratina-7/metabolismo , Ratones , Organoides/citología , Organoides/efectos de los fármacos , Organoides/metabolismo , Secretina/farmacología , Somatostatina/farmacología , Andamios del Tejido , gamma-Glutamiltransferasa/metabolismo
10.
J Med Imaging Radiat Oncol ; 61(5): 636-642, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28432731

RESUMEN

INTRODUCTION: Hepatic morphology changes are well described in Primary Sclerosing Cholangitis and characterised by a combination of atrophy and hypertrophy changes. This study investigates the relationship between progression of these changes over time and clinical outcome in patients with PSC. METHODS: Fifty-three patients with PSC (mean age 44, 28 males and 25 females) who underwent serial MRI liver studies at least one year apart were identified. The first and the last MRI studies were selected for the retrospective analysis. Three radiologists reviewed and compared both studies for changes in hepatic morphology, specifically atrophy and/or hypertrophy. The imaging findings were correlated with adverse clinical outcomes defined as death or liver transplantation and with serum bilirubin. RESULTS: There was a mean interval of 60 months between MRI examinations and a mean clinical follow-up period thereafter of 22 months. Thirty-three (62.3%) patients had stable hepatic morphology, whilst 20 (37.7%) patients showed hepatic morphology changes (atrophy: 13 patients, 24%; hypertrophy: 16 patients, 30%). Eleven patients (21%) died or underwent liver transplantation. There was a significant correlation between interval hepatic atrophy and adverse clinical outcomes (P = 0.001). Significant correlations were found between increasing serum bilirubin level and interval hepatic atrophy, hepatic hypertrophy and combined changes (P = 0.025, P = 0.022, P = 0.027, respectively). CONCLUSION: Hepatic morphology changes over time in patients with PSC are heterogeneous with some patients developing atrophy and/or hypertrophy whilst other patients remain stable. In this retrospective study, progressive hepatic atrophy showed significant association with adverse clinical outcome defined by either death or liver transplantation.


Asunto(s)
Colangitis Esclerosante/diagnóstico por imagen , Colangitis Esclerosante/patología , Imagen por Resonancia Magnética/métodos , Adulto , Bilirrubina/sangre , Colangitis Esclerosante/mortalidad , Colangitis Esclerosante/cirugía , Progresión de la Enfermedad , Femenino , Humanos , Trasplante de Hígado , Masculino , Estudios Retrospectivos
11.
Eur J Radiol ; 73(2): 404-11, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19251387

RESUMEN

Interventional radiology is continuing to reshape current practice in many specialties of clinical care. It is a relatively new and innovative branch of medicine in which physicians treat diseases non-operatively through small catheters guided to the target by fluoroscopic and other imaging modalities. The aim is to provide image-guided, minimally invasive alternatives to traditional surgical and medical procedures in suitable cohorts of patients. Procedures which previously required major surgery can now be performed by interventional radiologists, sometimes on an outpatient basis, with little patient discomfort. In this review, we highlight the importance of interventional radiology in treating a comprehensive range of obstetric and gynaecological pathologies.


Asunto(s)
Procedimientos Quirúrgicos Ginecológicos/tendencias , Pautas de la Práctica en Medicina/tendencias , Radiografía Intervencional/tendencias , Radiología Intervencionista/tendencias , Femenino , Humanos
12.
Breast ; 15(6): 736-43, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16650993

RESUMEN

For effective use, the diagnostic impact of contrast-enhanced breast MRI (CE MRI) needs to be quantified. This is a retrospective study of 441 women who have undergone CE MRI of the breast from 1 July 1997 to 25 March 2002. Indications for CE MRI studies were diagnostic in 176, monitoring chemotherapy in 126 and study of MRI screening for breast cancer (MARIBS) cases in 139. CE MRI results were confusing or incorrect in 6% of the diagnostic group, 13% of the chemotherapy group and 9% of the MARIBS group. In 18 of 38 of these cases CE MRI stimulated further tests to clarify a clinical query. CE MRI resulted in an increase in confidence or change in clinical plan in 46% of the diagnostic group, 72% of the chemotherapy group and 80% of the MARIBS group. In 44 of 283 of these, CE MRI caused a beneficial change in the clinical plan based on conventional radiology. CE MRI results in a positive diagnostic impact above conventional imaging in a clinically important proportion of patients, but gives some false calls in a smaller proportion (8.6%).


Asunto(s)
Enfermedades de la Mama/diagnóstico , Mama/patología , Medios de Contraste , Gadolinio DTPA , Imagen por Resonancia Magnética , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja , Enfermedades de la Mama/terapia , Estudios de Cohortes , Femenino , Humanos , Mamografía , Persona de Mediana Edad , Reproducibilidad de los Resultados , Estudios Retrospectivos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...