RESUMEN
Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract that might lead to progressive bowel damage and disability. The exact cause of Crohn's disease is unknown, but evidence points towards multifactorial events causing dysregulation of the innate immune system in genetically susceptible people. Commonly affecting the terminal ileum and proximal colon, Crohn's disease inflammation is often discontinuous and patchy, segmental, and transmural. Identification of characteristic findings on ileocolonoscopy and histology remains the diagnostic gold standard, but complete assessment involves laboratory abnormalities, including micronutrient deficiencies, cross-sectional imaging to identify transmural disease extent, severity and complications, and a psychosocial assessment. Treatment strategies for patients with Crohn's disease now go beyond achieving clinical remission to include deeper targets of endoscopic healing and consideration of adjunctive histological and transmural targets to alter disease progression potentially further. The use of early effective advanced therapies and development of therapies targeting alternative novel pathways with improved safety profiles have resulted in a new era of healing in Crohn's disease management. Future combination of advanced therapies with diet or other biological drugs and small molecules, together with improvements in tight control monitoring tools and predictive biomarkers might continue to improve outcomes for patients with Crohn's disease.
Asunto(s)
Enfermedad de Crohn , Humanos , Enfermedad de Crohn/terapia , Enfermedad de Crohn/tratamiento farmacológico , Íleon/patología , Endoscopía , BiomarcadoresRESUMEN
DESCRIPTION: In the past 3 years, the use of intestinal ultrasound (IUS) for monitoring inflammatory bowel disease in clinical practice has grown substantially in the United States. This American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) aims to review the available evidence and guidance regarding the role of intestinal ultrasound in inflammatory bowel disease care. METHODS: This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important and recently published studies in this field, and it reflects the experiences of the multidisciplinary group of authors composed of adult and pediatric gastroenterologists.
Asunto(s)
Enfermedades Inflamatorias del Intestino , Ultrasonografía , Humanos , Enfermedades Inflamatorias del Intestino/diagnóstico por imagen , Ultrasonografía/métodos , Estados Unidos , Intestinos/diagnóstico por imagenRESUMEN
INTRODUCTION: High rates of screen failure for the minimum Simple Endoscopic Score for Crohn's Disease (SES-CD) plague Crohn's disease (CD) clinical trials. We aimed to determine the accuracy of segmental intestinal ultrasound (IUS) parameters and scores to detect segmental SES-CD activity. METHODS: A single-center, blinded, cross-sectional cohort study of children and young adult patients with CD undergoing IUS and ileocolonoscopy, comparing segmental IUS bowel wall thickness (BWT), hyperemia (modified Limberg score [MLS]), and scores to detect segmental SES-CD activity: (i) SES-CD ≤2, (ii) SES-CD ≥6, and (iii) SES-CD ≥4 in the terminal ileum (TI) only. Primary outcome was accuracy of BWT, MLS, and IUS scores to detect SES-CD ≤2 and SES-CD ≥6. Secondary outcomes were accuracy of TI BWT, MLS, and IUS scores to detect SES-CD ≥4 and correlation with the SES-CD. RESULTS: Eighty-two patients (median [interquartile range] age 16.5 [12.9-20.0] years) underwent IUS and ileocolonoscopy of 323 bowel segments. Segmental BWT ≤3.1 mm had a similar high accuracy to detect SES-CD ≤2 as IUS scores (area under the receiver operating curve [AUROC] 0.833 [95% confidence interval 0.76-0.91], 94% sensitivity, and 73% specificity). Segmental BWT ≥3.6 mm and ≥4.3 mm had similar high accuracy to detect SES-CD ≥6 (AUROC 0.950 [95% confidence interval 0.92-0.98], 89% sensitivity, 93% specificity) in the colon and an SES-CD ≥4 in the TI (AUROC 0.874 [0.79-0.96], 80% sensitivity, and 91% specificity) as IUS scores. Segmental IUS scores strongly correlated with the SES-CD. DISCUSSION: Segmental IUS BWT is highly accurate to detect moderate-to-severe endoscopic inflammation. IUS may be the ideal prescreening tool to reduce unnecessary trial screen failures.
Asunto(s)
Colonoscopía , Enfermedad de Crohn , Ultrasonografía , Humanos , Enfermedad de Crohn/diagnóstico por imagen , Femenino , Masculino , Estudios Transversales , Adolescente , Ultrasonografía/métodos , Adulto Joven , Niño , Índice de Severidad de la Enfermedad , Íleon/diagnóstico por imagen , Íleon/patología , Sensibilidad y Especificidad , Ensayos Clínicos como Asunto , Curva ROCRESUMEN
INTRODUCTION: A significant proportion of patients with acute severe ulcerative colitis (ASUC) require colectomy. METHODS: Patients with ASUC treated with upadacitinib and intravenous corticosteroids at 5 hospitals are presented. The primary outcome was 90-day colectomy rate. Secondary outcomes included frequency of steroid-free clinical remission, adverse events, and all-cause readmissions. RESULTS: Of the 25 patients with ASUC treated with upadacitinib, 6 (24%) patients underwent colectomy, 15 (83%) of the 18 patients with available data and who did not undergo colectomy experienced steroid-free clinical remission (1 patient did not have complete data), 1 (4%) patient experienced a venous thromboembolic event, while 5 (20%) patients were readmitted. DISCUSSION: Upadacitinib along with intravenous corticosteroids may be an effective treatment for ASUC.
RESUMEN
BACKGROUND: Data are limited on the safety and efficacy of combining advanced therapies for refractory patients with IBD. AIM: To evaluate the real-world efficacy and safety of dual advanced therapy (DAT), combining 2 biologics or a biologic with a small molecule, in children and young adults with refractory IBD. METHODS: Primary outcome of this single IBD center cohort was DAT remission (clinical and biomarker remission) at first assessment (T1). Secondary outcomes included remission at T2, if DAT de-intensification (De-I) occurred and T3, if T2 DAT re-intensification (Re-I) occurred. Efficacy and safety outcomes were described. RESULTS: Of the 30 patients [43% female, 30% CD, median age of 18.3 [15.1-19.8] years], all 11 UST + TOFA achieved T1 remission; 6/10 De-I failed at T2; and 4/4 Re-I achieved T3 remission. Of 9 VDZ + TOFA, 6 achieved T1 remission; 5/6 De-I failed at T2; and 1/1 failed T3 Re-I. Of 4 UST + VDZ, 3 achieved T1 remission; 2/3 De-I failed at T2; and 0 had Re-I. Of 5 UST + UPA, 4 achieved T1 remission; 1/5 De-I failed at T2 but recaptured T3 remission post-Re-I. One VDZ + OZA achieved T1 remission and maintained T2 remission post-De-I to OZA monotherapy. At last follow-up, 43% were on original DAT, 17% on one of original DAT, and 40% neither. One UST + TOFA patient developed mild leukopenia and another developed septic arthritis and venous thromboembolism on VDZ + TOFA and prednisone. CONCLUSION: Most children and young adults treated with DAT achieved remission with minimal safety events; however, de-intensification had limited success.
Asunto(s)
Inducción de Remisión , Humanos , Femenino , Masculino , Adolescente , Adulto Joven , Resultado del Tratamiento , Quimioterapia Combinada , Fármacos Gastrointestinales/uso terapéutico , Productos Biológicos/uso terapéutico , Productos Biológicos/efectos adversos , Enfermedad de Crohn/tratamiento farmacológico , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/diagnóstico , Estudios Retrospectivos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológicoRESUMEN
Breaking through the biologic therapy efficacy plateau for inflammatory bowel disease requires the strategic development of personalized biomarkers in the tight control model. After risk stratification early in the disease course, targeted serial monitoring consistently to assess clinical outcomes in response to therapy allows for quick therapeutic adjustments before bowel damage can occur. Point-of-care intestinal ultrasound performed by the treating gastroenterologist is an accurate cross- sectional biomarker that monitors intestinal inflammation in real-time, enhances patient care, and increases shared understanding to help achieve common treatment goals. Combining intestinal ultrasound during a clinic visit with existing serum and stool biomarkers in a home testing setup with electronic health monitoring allows for an optimized, patient-centered personalized treatment algorithm that may improve treatment outcomes. Here, we review the current state, pragmatic considerations, and future implications of point-of-care testing and home testing for noninvasive inflammatory bowel disease monitoring in the tight control model.
Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Colitis Ulcerosa/metabolismo , Enfermedad de Crohn/metabolismo , Humanos , Enfermedades Inflamatorias del Intestino/diagnóstico por imagen , Enfermedades Inflamatorias del Intestino/terapia , Pruebas en el Punto de Atención , UltrasonografíaRESUMEN
Crohn disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) often diagnosed in childhood. A strict monitoring strategy can potentially alter the disease course and facilitate early effective treatment before irreversible bowel damage occurs. Serial colonoscopy in children, the gold standard for monitoring, is impractical. Accurate, real-time, noninvasive markers of disease activity are needed. Intestinal ultrasound is an accurate, noninvasive, real-time, point-of-care, cross-sectional imaging tool used to monitor inflammation in pediatric IBD patients in Europe, Canada, and Australia. It is now emerging in a few expert centers in the United States as a safe, non-radiating, inexpensive, bedside tool used by the treating gastroenterologist for real-time decision-making. Unlike the standard biomarkers of pediatric IBD activity, C-reactive protein, and fecal calprotectin, intestinal ultrasound (IUS) facilitates disease localization, characterizes severity, extent, and accurately detects complications. Perhaps most importantly, IUS may enhance shared understanding and ease the burden of treatment decision-making for both the gastroenterologist and the patient. There is a lack of standardization for bedside IUS among pediatric gastroenterologists. The purpose is to outline a standardized approach to pediatric bedside IUS, including basic equipment requirements and technique, patient selection, preparation and positioning, technical considerations and limitations, documentation of mesenteric and luminal features of IBD, characterization of penetrating disease and strictures, and provide a proposed pediatric IUS monitoring algorithm to guide care.
Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Gastroenterólogos , Enfermedades Inflamatorias del Intestino , Humanos , Niño , Consenso , Enfermedades Inflamatorias del Intestino/complicaciones , Intestinos/diagnóstico por imagen , Enfermedad de Crohn/diagnóstico , Colitis Ulcerosa/diagnóstico , HecesRESUMEN
PURPOSE OF REVIEW: Intestinal ultrasound (IUS) is an emerging non-invasive point-of-care tool utilized by pediatric gastroenterologists for accurately detecting and monitoring inflammatory bowel disease (IBD) activity. In this article, we reviewed the evidence supporting and technique to perform IUS for children with IBD. RECENT FINDINGS: IUS technique can visualize the colon from the distal sigmoid until the cecum and the terminal ileum without the need for bowel preparation, fasting, or sedation in children with IBD. IUS has been shown to be accurate to endoscopy in children with ulcerative colitis and Crohn's disease. IUS may be the most accurate biomarker to follow as a marker of treatment response that is predictive of endoscopic outcomes in children with IBD. Multiple studies have demonstrated that IUS can be performed at the point-of-care for IBD activity assessment in children. Recent studies have demonstrated the accuracy of IUS to endoscopy and magnetic resonance enterography with an ability to be repeated as a monitor of treatment response for tight control monitoring.
Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Humanos , Niño , Sistemas de Atención de Punto , Enfermedades Inflamatorias del Intestino/diagnóstico por imagen , Intestinos , Colitis Ulcerosa/diagnósticoRESUMEN
INTRODUCTION: Dupilumab blocks IL4/IL13 and is used in atopic disease. There are concerns that blockade may lead to inflammatory bowel disease (IBD) inception or activity. Limited data exist on the use of this therapy in patients with IBD; we aimed to describe our experience using dupilumab in IBD to treat concomitant atopic dermatitis (AD) or anti-TNF-induced dermatitis. METHODS: We analyzed the electronic medical records (2018-2022) in a single, tertiary care center to identify patients with IBD on dupilumab. Clinical and demographic data were gathered, including disease location/behavior, personal/family history of atopy, indication for and response to dupilumab, IBD medication history, and adverse events. RESULTS: Seventeen patients (65% Crohn's) were identified with IBD on dupilumab for dermatitis; 9 for severe AD and 8 for a worsened dermatitis, either AD or psoriasiform dermatitis (PD), induced by anti-TNF. They were treated for a median 1.2 [IQR 0.6-2.3] years. All patients had a dermatologic response to dupilumab and remained on dupilumab at last follow-up. No adverse events were identified, including no increase in IBD activity. In those with dermatitis worsened or induced by anti-TNF, all started dupilumab in combination with another biologic: 3 with anti-TNF, 4 with ustekinumab, and 1 with vedolizumab. Seven of the eight had a response to the initial combination of biologics; however, one patient using dupilumab-anti-TNF ultimately changed to combination dupilumab-ustekinumab to achieve resolution of the dermatitis. CONCLUSION: Dupilumab is safe and effective for dermatitis in patients with IBD, both primary atopic dermatitis and dermatitis induced or worsened by anti-TNF.
Asunto(s)
Dermatitis Atópica , Enfermedades Inflamatorias del Intestino , Humanos , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/tratamiento farmacológico , Ustekinumab/uso terapéutico , Inhibidores del Factor de Necrosis Tumoral/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Resultado del Tratamiento , Índice de Severidad de la EnfermedadRESUMEN
GOAL: The goal of this study was to explore the utility of small bowel ultrasound (SBUS) as a noninvasive tool to assess induction response to infliximab (IFX) in pediatric Crohn's disease (CD). BACKGROUND: Inflammatory bowel disease management has shifted to a treat-to-target and tight control strategy utilizing noninvasive serum and fecal markers to monitor disease activity in response to therapy. Bowel wall changes as seen on cross-sectional imaging may be a more accurate marker of treatment success. MATERIALS AND METHODS: Pediatric patients with CD with small bowel involvement initiating IFX were prospectively enrolled. Clinical activity, biomarkers, and SBUS findings were evaluated at baseline (T0) and postinduction at week 14 (T1). The primary outcome was to describe the changes in SBUS parameters pre and post IFX induction and how they associate with clinical and biomarker response. Descriptive statistics summarized the data and univariate analysis tested associations. RESULTS: All 13 CD patients achieved steroid-free clinical remission (P<0.001) and a decrease in C-reactive protein (P=0.01) postinduction. Bowel wall hyperemia (BWH) (P=0.01) and bowel segment length involved (P=0.07) decreased postinduction. Decrease in fecal calprotectin at T1 moderately correlated with a decrease in bowel segment length (r=0.57; P=0.04). No correlation was seen with a change in bowel wall thickness or BWH postinduction. CONCLUSIONS: Our pilot study suggests that SBUS is a feasible, noninvasive tool to measure early treatment response to IFX. BWH, not bowel wall thickness, is the first parameter to change. Larger longitudinal studies are warranted to validate the utility of SBUS as part of a disease monitoring strategy.
Asunto(s)
Enfermedad de Crohn , Fármacos Gastrointestinales , Niño , Enfermedad de Crohn/diagnóstico por imagen , Enfermedad de Crohn/tratamiento farmacológico , Fármacos Gastrointestinales/uso terapéutico , Humanos , Infliximab/uso terapéutico , Proyectos Piloto , Inducción de Remisión , Resultado del TratamientoRESUMEN
Coronavirus disease 2019 (COVID-19) may lead to a severe inflammatory response referred to as a cytokine storm. We describe a case of severe COVID-19 infection in a recently diagnosed pediatric Crohn disease patient successfully treated with tumor necrosis factor-alpha (TNF-α) blockade. The patient presented with 5 days of fever, an erythematous maculopapular facial rash, and abdominal pain without respiratory symptoms. SARS-CoV-2 polymerase chain reaction was positive. Despite inpatient treatment for COVID-19 and a perianal abscess, the patient acutely decompensated, with worsening fever, tachycardia, fluid-refractory hypotension, elevation of liver enzymes, and transformation of the rash into purpura extending from the face to the trunk, upper and lower extremities, including the palmar and plantar surfaces of the hands and feet. Cytokine profile revealed rising levels of interleukin (IL)-6, IL-8, and TNF-α, higher than those described in either inflammatory bowel disease or severe COVID-19 alone. The patient was treated with infliximab for TNF-α blockade to address both moderately to severely active Crohn disease and multisystem inflammatory syndrome in children temporally related to COVID-19. Within hours of infliximab treatment, fever, tachycardia, and hypotension resolved. Cytokine profile improved with normalization of TNF-α, a decrease in IL-6, and IL-8 concentrations. This case supports a role for blockade of TNF-α in the treatment of COVID-19 inflammatory cascade. The role of anti-TNF agents in patients with multisystem inflammatory syndrome in children temporally related to COVID-19 requires further investigation.
Asunto(s)
Infecciones por Coronavirus/tratamiento farmacológico , Enfermedad de Crohn/complicaciones , Enfermedades Genéticas Ligadas al Cromosoma X/complicaciones , Eritrodermia Ictiosiforme Congénita/complicaciones , Infliximab/uso terapéutico , Interleucina-6/sangre , Interleucina-8/sangre , Deformidades Congénitas de las Extremidades/complicaciones , Neumonía Viral/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Anomalías Múltiples , Adolescente , Antirreumáticos/uso terapéutico , Betacoronavirus , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/virología , Humanos , Masculino , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/virología , SARS-CoV-2 , Factor de Necrosis Tumoral alfa/sangreRESUMEN
BACKGROUND: Ustekinumab is an effective therapy for Crohn disease currently approved for adults. Off-label use in the pediatric population is increasing, but its effectiveness in this age group has not been reported. AIMS: The aim of the study was to describe real-world experience with ustekinumab at a tertiary care pediatric inflammatory bowel disease (IBD) center. METHODS: As part of an ongoing observational cohort study of biologic-treated pediatric IBD patients initiated in October 2014, data on demographics, disease behavior, location and activity, treatment, and surgical history were collected for all patients receiving ustekinumab. Disease activity was assessed using the Harvey Bradshaw index or partial Mayo score. Primary outcome was steroid-free remission at 52 weeks. Descriptive statistics summarized the safety and efficacy outcomes, and univariate analyses were performed to examine associations of clinical characteristics with efficacy. RESULTS: Fifty-two children and young adults initiating ustekinumab were analyzed; 81% Crohn Disease, 8% ulcerative colitis, and 11% IBD-unspecified. Median [IQR] age at induction was 16.8 [14-18] years. Patients were followed for a minimum of 12 months. Most patients (81%) failed >1 anti-TNF, and 37% failed anti-TNF and vedolizumab; 10 patients were biologic-naïve. At week 52, 75% were still on ustekinumab, and 50% (bio-exposed) and 90% (bio-naïve) were in steroid-free remission. Two infusion reactions and neither serious adverse events nor serious infections were observed. CONCLUSIONS: Our results suggest that ustekinumab is efficacious and safe in pediatric patients with IBD. Controlled clinical trial data are needed to confirm these observations.
Asunto(s)
Colitis Ulcerosa/tratamiento farmacológico , Enfermedad de Crohn/tratamiento farmacológico , Fármacos Gastrointestinales/uso terapéutico , Ustekinumab/uso terapéutico , Adolescente , Anticuerpos/sangre , Productos Biológicos/uso terapéutico , Niño , Femenino , Fármacos Gastrointestinales/administración & dosificación , Fármacos Gastrointestinales/efectos adversos , Fármacos Gastrointestinales/inmunología , Humanos , Masculino , Uso Fuera de lo Indicado , Inducción de Remisión , Retratamiento , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Centros de Atención Terciaria , Resultado del Tratamiento , Ustekinumab/administración & dosificación , Ustekinumab/efectos adversos , Ustekinumab/inmunología , Adulto JovenRESUMEN
INTRODUCTION: Acute pancreatitis (AP) is understudied in the pediatric population despite increasing incidence. Although many cases are mild and resolve with supportive care, severe acute pancreatitis (SAP) can be associated with significant morbidity and mortality. There is a lack of pediatric-specific predictive tools to help stratify risk of SAP in children. METHODS: A retrospective cohort study of patients with AP or recurrent AP at Cohen Children's Medical Center between 2011 and 2016 was performed. Lipase level and the presence of pediatric systemic inflammatory response syndrome (SIRS) on admission were examined as potential predictors of SAP and length of stay (LOS). A multivariate logistic regression or analysis of covariance was used to conduct the multivariate analysis. RESULTS: Seventy-nine pediatric patients met inclusion criteria. Approximately 37% (29/79) had SIRS on admission, 22% (17/79) developed SAP, and there were no mortalities. In both the univariate and multivariate models, SIRS was a predictor of SAP. Mean (SD) LOS for patients with SIRS compared with without SIRS was 9.6â±â8.3 compared with 6.3â±â6.9 days (Pâ<â0.05). The mean LOS of patients with one or more comorbidity (48%, 38/79) was 10.0â±â9.5 compared with 5.2â±â4.0 days (Pâ<â0.01) for those patients without any comorbidities. Only the presence of comorbidities predicted length of time spent nil per os (NPO; Pâ=â0.0022). Patients with comorbidities stayed an average of 5.6â±â7.6 days NPO, whereas those without comorbidities spent 2.8â±â2.4 days NPO. Lipase was not predictive of SAP, LOS, or length of time spent NPO. CONCLUSIONS: These results support the use of SIRS as a simple screening tool on admission to identify children at risk for the development of SAP. The presence of any comorbidity was predictive of LOS and length of NPO in the multivariate model. This may reflect that comorbidities prolong pancreatitis or influence disposition planning.
Asunto(s)
Tiempo de Internación/estadística & datos numéricos , Lipasa/sangre , Pancreatitis/epidemiología , Síndrome de Respuesta Inflamatoria Sistémica/epidemiología , Adolescente , Estudios de Casos y Controles , Niño , Comorbilidad , Femenino , Humanos , Masculino , Pancreatitis/diagnóstico , Estudios Retrospectivos , Sensibilidad y Especificidad , Síndrome de Respuesta Inflamatoria Sistémica/diagnósticoAsunto(s)
Gastroenterólogos , Estados Unidos , Humanos , Habilitación Profesional , Documentación , UltrasonografíaAsunto(s)
Colitis Ulcerosa , Complicaciones del Embarazo , Colitis Ulcerosa/diagnóstico por imagen , Colitis Ulcerosa/tratamiento farmacológico , Monitoreo de Drogas , Femenino , Humanos , Intestinos , Sistemas de Atención de Punto , Embarazo , Complicaciones del Embarazo/diagnóstico por imagen , Complicaciones del Embarazo/tratamiento farmacológicoAsunto(s)
Técnicas de Laboratorio Clínico/normas , Infecciones por Coronavirus/prevención & control , Endoscopía/normas , Transmisión de Enfermedad Infecciosa de Paciente a Profesional/prevención & control , Pandemias/prevención & control , Neumonía Viral/prevención & control , Cuidados Preoperatorios/normas , Adolescente , Adulto , Anciano , Infecciones Asintomáticas/epidemiología , Betacoronavirus/genética , Betacoronavirus/aislamiento & purificación , COVID-19 , Prueba de COVID-19 , Niño , Técnicas de Laboratorio Clínico/métodos , Técnicas de Laboratorio Clínico/estadística & datos numéricos , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/normas , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ciudad de Nueva York/epidemiología , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Neumonía Viral/virología , Reacción en Cadena de la Polimerasa/estadística & datos numéricos , ARN Viral/aislamiento & purificación , Estudios Retrospectivos , SARS-CoV-2 , Centros de Atención Terciaria/estadística & datos numéricosRESUMEN
BACKGROUND & AIMS: The immunosuppressant rapamycin frequently causes noninfectious diarrhea in organ transplant recipients. We investigated the mechanisms of this process. METHODS: We performed a retrospective analysis of renal transplant recipients treated with rapamycin from 2003 through 2010 at Albany Medical College, collecting data on serum levels of rapamycin. Levels of the Na+/H+ exchanger 3 (NHE3) were measured in human ileal biopsy specimens from patients who did and did not receive rapamycin (controls), in ileum tissues from rats or mice given rapamycin, and in mice with intestine-specific disruption of mammalian target of rapamycin (Mtor) (mTOR(f/f):Villin-cre mice) or Atg7 (Atg7(flox/flox); Villin-Cre). Exchange activity and intestinal water absorption were measured using a pH-sensitive dye and small intestine perfusion, respectively. RESULTS: Episodes of noninfectious diarrhea occurred in organ recipients after increases in serum levels of rapamycin. The expression of NHE3 was reduced in the ileal brush border of patients with diarrhea. In rats and mice, continuous administration of low doses of rapamycin reduced levels of NHE3 in intestinal tissues; this effect was not observed in mice with intestinal deletion of ATG7, indicating that autophagy is required for the reduction. Administration of single high doses of rapamycin to mice, to model the spikes in rapamycin levels that occur in patients with severe diarrheal episodes, resulted in reduced phosphorylation of S6 and AKT in ileal tissues, indicating inhibition of the mTOR complex (mTORC1 and mTORC2). The intestines of mice with intestine-specific deletion of mTOR were dilated and contained large amounts of liquid stools; they also had reduced levels of total NHE3 and NHERF1 compared with control mice. We observed a significant reduction in Na(+)/H(+) exchange activity in ileum tissues from these mice. CONCLUSIONS: Rapamycin inhibition of mTOR reduces levels of NHE3 and Na(+)/H(+) exchange activity in intestinal tissues of patients and rodents. This process appears to require the autophagic activity mediated by ATG7. Loss of mTOR regulation of NHE3 could mediate the development of diarrhea in patients undergoing rapamycin therapy.