RESUMEN
Lungs from older adult organ donors are often unused because of concerns for increased mortality. We examined associations between donor age and transplant outcomes among 8860 adult lung transplant recipients using Organ Procurement and Transplantation Network and Lung Transplant Outcomes Group data. We used stratified Cox proportional hazard models and generalized linear mixed models to examine associations between donor age and both 1-year graft failure and primary graft dysfunction (PGD). The rate of 1-year graft failure was similar among recipients of lungs from donors age 18-64 years, but severely ill recipients (Lung Allocation Score [LAS] >47.7 or use of mechanical ventilation) of lungs from donors age 56-64 years had increased rates of 1-year graft failure (p-values for interaction = 0.04 and 0.02, respectively). Recipients of lungs from donors <18 and ≥65 years had increased rates of 1-year graft failure (adjusted hazard ratio [HR] 1.23, 95% CI 1.01-1.50 and adjusted HR 2.15, 95% CI 1.47-3.15, respectively). Donor age was not associated with the risk of PGD. In summary, the use of lungs from donors age 56 to 64 years may be safe for adult candidates without a high LAS and the use of lungs from pediatric donors is associated with a small increase in early graft failure.
Asunto(s)
Rechazo de Injerto/etiología , Enfermedades Pulmonares/cirugía , Trasplante de Pulmón , Complicaciones Posoperatorias , Disfunción Primaria del Injerto/etiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Rechazo de Injerto/diagnóstico , Rechazo de Injerto/mortalidad , Supervivencia de Injerto , Humanos , Enfermedades Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Disfunción Primaria del Injerto/diagnóstico , Disfunción Primaria del Injerto/mortalidad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Adulto JovenRESUMEN
Chronic lung allograft dysfunction (CLAD) is the major factor limiting long-term success of lung transplantation. Polymorphisms of surfactant protein D (SP-D), an important molecule within lung innate immunity, have been associated with various lung diseases. We investigated the association between donor lung SP-D polymorphisms and posttransplant CLAD and survival in 191 lung transplant recipients consecutively transplanted. Recipients were prospectively followed with routine pulmonary function tests. Donor DNA was assayed by pyrosequencing for SP-D polymorphisms of two single-nucleotide variations altering amino acids in the mature protein N-terminal domain codon 11 (Met(11) Thr), and in codon 160 (Ala(160) Thr) of the C-terminal domain. CLAD was diagnosed in 88/191 patients, and 60/191 patients have died. Recipients of allografts that expressed the homozygous Met(11) Met variant of aa11 had significantly greater freedom from CLAD development and better survival compared to those with the homozygous Thr(11) Th variant of aa11. No significant association was noted for SP-D variants of aa160. Lung allografts with the SP-D polymorphic variant Thr(11) Th of aa11 are associated with development of CLAD and reduced survival. The observed genetic differences of the donor lung, potentially with their effects on innate immunity, may influence the clinical outcomes after lung transplantation.
Asunto(s)
Rechazo de Injerto/mortalidad , Enfermedades Pulmonares/complicaciones , Trasplante de Pulmón/efectos adversos , Polimorfismo Genético/genética , Complicaciones Posoperatorias , Proteína D Asociada a Surfactante Pulmonar/genética , Donantes de Tejidos , Adulto , Enfermedad Crónica , Femenino , Estudios de Seguimiento , Rechazo de Injerto/etiología , Humanos , Inmunidad Innata , Enfermedades Pulmonares/genética , Enfermedades Pulmonares/cirugía , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Prospectivos , Estudios Retrospectivos , Tasa de Supervivencia , Trasplante Homólogo , Adulto JovenRESUMEN
Hypoalbuminemia predicts disability and mortality in patients with various illnesses and in the elderly. The association between serum albumin concentration at the time of listing for lung transplantation and the rate of death after lung transplantation is unknown. We examined 6808 adults who underwent lung transplantation in the United States between 2000 and 2008. We used Cox proportional hazard models and generalized additive models to examine multivariable-adjusted associations between serum albumin and the rate of death after transplantation. The median follow-up time was 2.7 years. Those with severe (0.5-2.9 g/dL) and mild hypoalbuminemia (3.0-3.6 g/dL) had posttransplant adjusted mortality rate ratios of 1.35 (95% CI: 1.12-1.62) and 1.15 (95% CI: 1.04-1.27), respectively. For each 0.5 g/dL decrease in serum albumin concentration the 1-year and overall mortality rate ratios were 1.48 (95% CI: 1.21-1.81) and 1.26 (95% CI: 1.11-1.43), respectively. The association between hypoalbuminemia and posttransplant mortality was strongest in recipients with cystic fibrosis and interstitial lung disease. Hypoalbuminemia is an independent risk factor for death after lung transplantation.
Asunto(s)
Hipoalbuminemia/etiología , Hipoalbuminemia/mortalidad , Trasplante de Pulmón/efectos adversos , Trasplante de Pulmón/mortalidad , Complicaciones Posoperatorias , Albúmina Sérica/deficiencia , Adulto , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Tasa de SupervivenciaRESUMEN
The supplemental oxygen flow rate is a common bedside measure of gas exchange impairment. We aimed to determine whether a titrated oxygen requirement (TOR) predicted mortality in idiopathic pulmonary fibrosis (IPF). We examined 104 adults with IPF enrolled in a prospective cohort study and a validation cohort of 151 adults with a variety of interstitial lung diseases (ILDs). The TOR was defined as the lowest oxygen flow rate required to maintain an oxyhaemoglobin saturation of 96% while standing. Cox proportional hazards models and time-dependent receiver operating characteristic curves were used to examine survival time. A higher TOR was associated with a greater mortality rate independent of forced vital capacity and 6-min walk test results in IPF (adjusted hazard ratio (per 1 L·min(-1)) 1.16, 95% CI 1.06-1.27). The TOR was at least as accurate as pulmonary function and 6-min walk testing at predicting 1-yr mortality. Findings were similar in other ILDs. The TOR is a simple, inexpensive bedside measurement that aids prognostication in IPF.
Asunto(s)
Fibrosis Pulmonar Idiopática/mortalidad , Fibrosis Pulmonar Idiopática/terapia , Terapia por Inhalación de Oxígeno/mortalidad , Terapia por Inhalación de Oxígeno/métodos , Índice de Severidad de la Enfermedad , Anciano , Femenino , Humanos , Fibrosis Pulmonar Idiopática/fisiopatología , Enfermedades Pulmonares Intersticiales/mortalidad , Enfermedades Pulmonares Intersticiales/fisiopatología , Enfermedades Pulmonares Intersticiales/terapia , Masculino , Persona de Mediana Edad , Terapia por Inhalación de Oxígeno/normas , Resistencia Física/fisiología , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Intercambio Gaseoso Pulmonar/fisiología , Reproducibilidad de los Resultados , Factores de Riesgo , Resultado del Tratamiento , Capacidad Vital/fisiología , CaminataRESUMEN
Despite the standardization of pathologic grading of acute rejection in transbronchial lung biopsies following lung transplantation, the reproducibility of pathologic diagnosis has not been adequately evaluated. To determine the interobserver variability for pathologic grading of acute rejection, 1566 biopsies from 845 subjects in the Lung Allograft Rejection Gene Expression Observational study were regraded by a pathology panel blinded to the original diagnosis and compared to the grade of acute rejection assigned by individual center pathologists. The study panel confirmed 49.1% of center pathologists' A0 grades, but upgraded 5.7% to A1 and 2.7% to grade ≥ A2 rejection; 42.5% were regraded as AX. Of 268 grade A1 samples, 21.2% were confirmed by the pathology panel; 18.7% were upgraded to ≥ A2 and 35.8% were downgraded to A0 with 24.3% being regraded as AX. Lastly, 53.5% of ≥ A2 cases were confirmed, but 15.7% were downgraded to grade A0 and 18.4% cases to A1, while 12.4% were regraded as AX. The kappa value for interobserver agreement was 0.183 (95%CI 0.147-0.220, p < 0.001). The results for B grade interpretation were similar. Suboptimal sampling is common and a high degree of variability exists in the pathologic interpretation of acute rejection in transbronchial biopsies.
Asunto(s)
Rechazo de Injerto/patología , Trasplante de Pulmón/efectos adversos , Trasplante de Pulmón/patología , Pulmón/patología , Enfermedad Aguda , Adulto , Biopsia/métodos , Bronquios , Errores Diagnósticos , Femenino , Rechazo de Injerto/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del ObservadorRESUMEN
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.
Asunto(s)
Etnicidad , Fibrosis Pulmonar/epidemiología , Grupos Raciales , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Trasplante de Pulmón , Masculino , Persona de Mediana Edad , Pronóstico , Fibrosis Pulmonar/cirugía , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia/tendencias , Estados Unidos/epidemiologíaRESUMEN
Minority patients have worse outcomes than nonminority patients in a variety of pulmonary diseases. We aimed to compare the survival of Black and Hispanic patients to that of others with idiopathic pulmonary fibrosis (IPF). We performed a retrospective cohort study of patients with IPF who were evaluated for lung transplantation at our center. Kaplan-Meier survival curves and Cox proportional hazards models were used to compare survival between groups. Black and Hispanic patients had spirometry, lung volumes and diffusion capacity that were similar to others, but had worse exercise capacity. Minority patients had a significantly increased risk of death compared to others independent of transplantation status (hazard ratio = 3.3, 95% CI 1.2-8.9, p = 0.02). Differences in exercise capacity, pulmonary hemodynamics and socioeconomic factors appeared to account for some of the differences in survival. Black and Hispanic patients with IPF had an increased risk of death following referral for lung transplantation. This finding may be due to differences in disease progression and/or differences in access to medical care among minority patients. Future studies should confirm our findings in a larger cohort. The elimination of racial and ethnic disparities in outcome should be a priority for clinicians and researchers in this field.
Asunto(s)
Etnicidad , Trasplante de Pulmón/mortalidad , Trasplante de Pulmón/fisiología , Fibrosis Pulmonar/cirugía , Grupos Raciales , Anciano , Presión Sanguínea , Estudios de Cohortes , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
STUDY OBJECTIVES: To examine whether relative hypoperfusion to the apical one third of the lungs as determined by lung scintigraphy predicts a favorable functional outcome following bilateral lung volume reduction surgery (LVRS). METHODS: We performed a retrospective analysis of 128 patients who underwent bilateral LVRS. An apical perfusion fraction (AP%), defined as the percentage of total lung perfusion to the apical one third of both lungs, was derived for each patient by quantitative scintigraphy technique. Pulmonary function testing and 6-min walk test (6MWT) data were obtained preoperatively and 3 to 6 months postoperatively. RESULTS: The mean (+/- SD) improvement in FEV(1) was 309 +/- 240 mL, 209 +/- 293 mL, and 116 +/- 224 mL for patients with an AP% of
Asunto(s)
Pulmón/fisiopatología , Neumonectomía , Enfisema Pulmonar/cirugía , Prueba de Esfuerzo , Femenino , Volumen Espiratorio Forzado , Humanos , Pulmón/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Enfisema Pulmonar/diagnóstico por imagen , Enfisema Pulmonar/fisiopatología , Cintigrafía , Radiofármacos , Estudios Retrospectivos , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Resultado del Tratamiento , Relación Ventilacion-PerfusiónRESUMEN
BACKGROUND: Malignancy is a well-recognized complication of solid-organ transplantation. Although a variety of malignancies have been reported in lung transplant recipients, a paucity of information exists regarding the incidence and clinical course of bronchogenic carcinoma in this patient population. METHODS: We conducted a retrospective cohort study of our lung transplant experience at the University of Pennsylvania. RESULTS: We identified 6 patients with bronchogenic carcinoma detected at the time of, or developing after, transplantation. The incidence of bronchogenic carcinoma was 2.4%. All patients with lung cancer had a history of smoking, with an average of 79 +/- 39 pack-years. A total of 5 patients had chronic obstructive pulmonary disease, and 1 had idiopathic pulmonary fibrosis. Lung cancers were all of non-small-cell histology and first developed in native lungs. Three patients had bronchogenic carcinoma at the time of surgery. The remaining 3 patients were diagnosed between 280 and 1,982 days post-transplantation. Of the 6 patients, 4 presented with a rapid course suggestive of an infectious process. The 1- and 2-year survival rates after diagnosis were 33% and 17%, respectively. CONCLUSION: Lung transplant recipients are at risk for harboring or developing bronchogenic carcinoma in their native lungs. Rapid progression to locally advanced or metastatic disease commonly occurs, at times mimicking an infection. Bronchogenic carcinoma should be considered in the differential diagnosis of pleuroparenchymal processes involving the native lung.
Asunto(s)
Carcinoma Broncogénico/etiología , Carcinoma de Pulmón de Células no Pequeñas/etiología , Inmunosupresores/efectos adversos , Neoplasias Pulmonares/etiología , Trasplante de Pulmón , Fumar/efectos adversos , Carcinoma Broncogénico/diagnóstico , Carcinoma Broncogénico/epidemiología , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/epidemiología , Estudios de Cohortes , Femenino , Humanos , Incidencia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
STUDY OBJECTIVES: To characterize the course of patients with advanced sarcoidosis who have been listed for lung transplantation and to identify prognostic factors for death while they are on the waiting list. DESIGN: Retrospective cohort study. SETTING: Tertiary-care university hospital. PATIENTS: Forty-three patients with sarcoidosis who have been listed for lung transplantation at the University of Pennsylvania Medical Center. METHODS: A multivariable explanatory analysis using a Cox proportional hazards model was performed to determine risk factors that are independently associated with mortality while patients await transplantation. RESULTS: Twenty-three of the 43 patients (53%) died while awaiting transplantation. The survival rate of listed patients (as determined by the Kaplan-Meier method) was 66% at 1 year, 40% at 2 years, and 31% at 3 years. In a univariate analysis, the following factors were significantly associated with death on the waiting list: PaO(2) < or = 60 mm Hg (relative risk [RR], 3.4; 95% confidence interval [CI], 1.2 to 9.3); mean pulmonary artery pressure > or = 35 mm Hg (RR, 3.2; 95% CI, 1.1 to 9.5); cardiac index < or = 2 L/min/m(2) (RR, 2.8; 95% CI, 1.2 to 6.6), and right atrial pressure (RAP) > or = 15 mm Hg (RR, 7.6; 95% CI, 3.0 to 19.3). Multivariable analysis revealed that RAP > or = 15 mm Hg was the only independent prognostic variable (RR, 5.2; 95% CI, 1.6 to 16.7; p = 0.006). Twelve patients underwent lung transplantation. Survival after transplantation determined by the Kaplan-Meier method was 62% at both 1 and 2 years, and 50% at 3 years. CONCLUSIONS: Patients with advanced sarcoidosis awaiting lung transplantation have a high mortality rate with a median survival of < 2 years. Mortality is most closely linked to elevated RAP. While earlier referral may diminish the mortality rate of patients on the waiting list for transplantation, further improvements in posttransplantation outcomes will be necessary to ensure that this procedure truly bestows a survival benefit.
Asunto(s)
Trasplante de Pulmón , Sarcoidosis Pulmonar/mortalidad , Listas de Espera , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Sarcoidosis Pulmonar/cirugíaRESUMEN
A 50-year-old woman underwent single lung transplantation for advanced chronic obstructive pulmonary disease. Shortly after the procedure, it was discovered that the donor suffered from both a renal cell carcinoma and a spindle-cell sarcoma of the ascending aorta, which had metastasized to the spleen. The patient was emergently listed for a retransplantation and underwent bilateral lung transplantation after a new donor became available 4 days after the initial transplantation procedure. After 24 months, the patient is without evidence of malignancy. This case illustrates the role of immediate retransplantation for patients who have inadvertently received thoracic organs from donors harboring occult malignancies.
Asunto(s)
Servicios Médicos de Urgencia , Trasplante de Pulmón , Donantes de Tejidos , Adulto , Enfermedades de la Aorta/patología , Carcinoma de Células Renales/patología , Femenino , Humanos , Neoplasias Renales/patología , Persona de Mediana Edad , Neoplasias Primarias Múltiples/patología , Reoperación , Sarcoma/patología , Sarcoma/secundario , Neoplasias del Bazo/patología , Neoplasias del Bazo/secundarioRESUMEN
Obstructive pulmonary diseases are diverse with an extensive differential diagnosis. Most cases can be diagnosed after a systematic evaluation that includes detailed history, physical examination, routine laboratory testing, radiologic and pulmonary physiologic tests. More specific studies are indicated only in a few patients.
Asunto(s)
Enfermedades Pulmonares Obstructivas/diagnóstico , Pruebas de Provocación Bronquial , Broncoscopía , Diagnóstico Diferencial , Prueba de Esfuerzo , Humanos , Enfermedades Pulmonares Obstructivas/etiología , Mediciones del Volumen Pulmonar , EspirometríaAsunto(s)
Alveolitis Alérgica Extrínseca/diagnóstico , Disnea/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Alveolitis Alérgica Extrínseca/patología , Aspergilosis Broncopulmonar Alérgica/diagnóstico , Aspergilosis Broncopulmonar Alérgica/patología , Pulmón de Criadores de Aves/diagnóstico , Pulmón de Criadores de Aves/patología , Diagnóstico Diferencial , Femenino , Humanos , Pulmón/diagnóstico por imagen , Pulmón/patología , Persona de Mediana EdadRESUMEN
BACKGROUND: There is controversy regarding the transplant procedure of choice in chronic obstructive pulmonary disease. We reviewed our intermediate-term outcomes with single lung transplantation (SLT) versus bilateral lung transplantation (BLT). METHODS: We retrospectively reviewed 130 patients with chronic obstructive pulmonary disease: 84 underwent SLT, 46 BLT. The mean age was 51.1 +/- 1.2 years for those who underwent BLT and 56.2 +/- 0.7 years for those who underwent SLT (p < 0.0001). Male patients represented 65% of the BLT group and 46% of the SLT group (p = 0.04). Spirometry and 6-minute walk tests were obtained preoperatively and at 3- to 6-month intervals. Posttransplant survival and survival from time of onset of bronchiolitis obliterans syndrome were calculated by Kaplan-Meier method. The mean follow-up was 32.4 months. RESULTS: The 90-day mortality rate was 13.0% For BLT and 15.5% for SLT (p = 0.71). Actuarial survival rates at 1, 3, and 5 years were 82.6%, 74.6%, and 61.9% for BLT and 72.2%, 63.4%, and 57.4% for SLT; the favorable survival trend with BLT did not achieve statistical significance. There were no differences in preoperative spirometry or 6-minute walk tests. The improvements in forced expiratory volume in one second, forced vital capacity (FVC), and 6 MWT were significantly greater following BLT. The incidence of bronchiolitis obliterans syndrome was 22.4% in SLT and 22.2% in BLT; survival following onset of bronchiolitis obliterans syndrome was similar. CONCLUSIONS: For patients with chronic obstructive pulmonary disease, BLT is associated with superior lung function, exercise tolerance, and a trend toward enhanced survival. Younger candidates may be best suited for BLT. Given the limited donor lungs, SLT remains the preferred alternative for all other patients.
Asunto(s)
Enfermedades Pulmonares Obstructivas/cirugía , Trasplante de Pulmón/métodos , Complicaciones Posoperatorias/etiología , Bronquiolitis Obliterante/etiología , Bronquiolitis Obliterante/mortalidad , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Volumen Espiratorio Forzado , Humanos , Enfermedades Pulmonares Obstructivas/mortalidad , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/mortalidad , Estudios Retrospectivos , Espirometría , Tasa de Supervivencia , Capacidad VitalRESUMEN
Pulmonary embolism (PE) is a common disorder that is accompanied by significant morbidity and mortality. Although anticoagulation is the standard treatment for PE, thrombolytic therapy, with its ability to produce rapid clot lysis, has long been considered an attractive alternative. Although many studies have been performed over the past three decades, however, the indications for the use of thrombolytic agents in patients with PE remain controversial. In this article, we review the medical literature and provide evidence-based guidelines for the use of thrombolytic therapy. We will also discuss the practical aspects of PE thrombolysis.
Asunto(s)
Anticoagulantes/uso terapéutico , Fibrinolíticos/uso terapéutico , Embolia Pulmonar/tratamiento farmacológico , Terapia Trombolítica , Toma de Decisiones , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoAsunto(s)
Obstrucción de las Vías Aéreas/etiología , Artralgia/etiología , Disnea/etiología , Granulomatosis con Poliangitis/diagnóstico , Sinusitis/etiología , Adulto , Obstrucción de las Vías Aéreas/diagnóstico , Artralgia/diagnóstico , Broncoscopía , Diagnóstico Diferencial , Progresión de la Enfermedad , Disnea/diagnóstico , Femenino , Granulomatosis con Poliangitis/complicaciones , Humanos , Radiografía Torácica , Recurrencia , Sinusitis/diagnóstico , Tomografía Computarizada por Rayos XAsunto(s)
Trasplante de Pulmón , Selección de Paciente , Complicaciones Posoperatorias , Rechazo de Injerto , Asignación de Recursos para la Atención de Salud , Humanos , Trasplante de Pulmón/métodos , Trasplante de Pulmón/mortalidad , Trasplante de Pulmón/fisiología , Trasplante de Pulmón/tendencias , Calidad de Vida , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
Recombinant adenoviruses are currently being evaluated as gene transfer vectors for the treatment of airway diseases. Recent evidence indicates that gene transfer to differentiated airway epithelial cells is inefficient. We hypothesized that apical membrane glycoconjugates, such as the transmembrane mucin MUC1, reduce the efficiency of adenovirus-mediated gene transfer. To address this, studies were performed in primary bronchial epithelial and Madin Darby canine kidney (MDCK) cells transduced to express human MUC1. Colocalization of MUC1 and an adenoviral lacZ transgene in the bronchial epithelial cells revealed that at several multiplicities of infection, the percentage of cells expressing lacZ was five-fold less in MUC1-expressing cells. Moreover, lacZ expression was three- to eight-fold lower in MUC1-expressing than in control MDCK cells, demonstrating that MUC1 interferes with gene transfer and is not merely a phenotypic marker of a cell that is refractory to adenovirus infection. Neuraminidase pretreatment of cells to remove sialic acid residues prior to viral adsorption increased the efficiency of gene transfer two- to five-fold in human airway and MDCK cells, and in a xenograft model of human airway. This effect was also observed in cultured cells that do not express MUC1, suggesting that other sialylated glycoconjugates impact on the efficiency of gene transfer. An inhibitory effect of negatively charged glycoconjugates on adenovirus binding was further supported by the finding that adsorption of adenovirus with a polycation significantly increased gene transfer efficiency. These data demonstrate for the first time that sialoglycoconjugates on epithelial cells reduce the efficiency of adenovirus-mediated gene transfer.
Asunto(s)
Bronquios/metabolismo , Regulación de la Expresión Génica , Técnicas de Transferencia de Gen , Mucina-1/genética , Adenoviridae , Animales , Células Cultivadas , Perros , Epitelio/metabolismo , Vectores Genéticos , Glicoconjugados/genética , Glicoconjugados/metabolismo , Humanos , Mucina-1/metabolismoRESUMEN
Airway epithelium is subject to injury during inflammation and exposure to a variety of inhaled and infectious agents. Little is known about the expression of integrins during human airway epithelial regeneration and differentiation after injury. We therefore characterized integrin subunit expression after mechanical injury in an in vivo xenograft model of human bronchial epithelium. On the migrating cells at the edges of surface epithelial wounds, there was increased expression of the alpha v-, beta 5-, beta 6-, and alpha 5-integrin subunits. During the later phase of repair, the increased expression of alpha v-, beta 5-, and beta 6-subunits persisted, but the expression of the beta 8-subunits was restricted to basal cells. In addition, there was a redistribution of the alpha 2- and alpha 6-collagen/laminin-binding integrins to suprabasal epithelial layers. There was no expression of the beta 3- or alpha 4-integrin subunit on reparative epithelium. A similar upregulation of alpha v-, beta 5-, and beta 6-integrin receptor subunits was observed in areas of undifferentiated airway from cystic fibrosis patients. Injured epithelium was found to be significantly more susceptible to gene transfer with a recombinant adenovirus, suggesting that the increased integrin expression has implications for the acquisition of adenovirus infections and for lung-directed gene therapy.