Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Immunity ; 40(4): 582-93, 2014 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-24745334

RESUMEN

Although in normal lamina propria (LP) large numbers of eosinophils are present, little is known about their role in mucosal immunity at steady state. Here we show that eosinophils are needed to maintain immune homeostasis in gut-associated tissues. By using eosinophil-deficient ΔdblGATA-1 and PHIL mice or an eosinophil-specific depletion model, we found a reduction in immunoglobulin A(+) (IgA(+)) plasma cell numbers and in secreted IgA. Eosinophil-deficient mice also showed defects in the intestinal mucous shield and alterations in microbiota composition in the gut lumen. In addition, TGF-ß-dependent events including class switching to IgA in Peyer's patches (PP), the formation of CD103(+) T cells including Foxp3(+) regulatory (Treg), and also CD103(+) dendritic cells were disturbed. In vitro cultures showed that eosinophils produce factors that promote T-independent IgA class switching. Our findings show that eosinophils are important players for immune homeostasis in gut-associated tissues and add to data suggesting that eosinophils can promote tissue integrity.


Asunto(s)
Células Dendríticas/inmunología , Eosinófilos/metabolismo , Intestinos/inmunología , Células Plasmáticas/inmunología , Linfocitos T Reguladores/inmunología , Animales , Antígenos CD/metabolismo , Diferenciación Celular/genética , Células Cultivadas , Eosinófilos/inmunología , Factores de Transcripción Forkhead , Homeostasis , Inmunidad Mucosa , Inmunoglobulina A/metabolismo , Cambio de Clase de Inmunoglobulina/genética , Cadenas alfa de Integrinas/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Microbiota/genética , Ganglios Linfáticos Agregados/inmunología
2.
Clin Exp Rheumatol ; 36(1): 136-139, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28850025

RESUMEN

OBJECTIVES: Monoclonal antibodies are important in the treatment of rheumatoid arthritis (RA). This is the first trial to monitor the effect of adalimumab dose escalation in persistently active RA. The aim of this study was to identify the response to adalimumab to improve the basis for making decision in relation to actual drug capacity in serum. METHODS: The disease activity of RA patients was assessed with CDAI and DAS28 before administration of additional 40 mg adalimumab one week after standard injection. Serum samples were analysed using the recoveryELISA technology, a combination of sandwich ELISA and competitive assay. The recoveryELISA measure the concentrations of free TNF-α, drug level, and the remaining active adalimumab in the patients' sera. An adalimumab concentration of 5.0-10.0 g/mL was defined as the targeted therapeutic window. RESULTS: Five of 8 patients achieved moderate EULAR response by dose escalation. The results of the free adalimumab and TNF-α neutralisation measurements allowed a separation of the cohort (n=17) into three groups. Group 1 represents 18% of the patients with free adalimumab level higher 30.0 µg/mL and TNF-α neutralisation above 95%. Group 2 (47%) consists of patients within the therapeutic window with balanced free adalimumab and TNF-α neutralisation values. Group 3 contains 35% of the cohort with low concentrations of free adalimumab and lowest remaining TNF-α-neutralisation capacity. Anti-drug antibodies were detected in four patients but did not prevent response to treatment. CONCLUSIONS: Drug and antigen monitoring using recoveryELISA may support dose decision to avoid unnecessary switch in medication or possible overtreatment.


Asunto(s)
Adalimumab/administración & dosificación , Antirreumáticos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Monitoreo de Drogas/métodos , Ensayo de Inmunoadsorción Enzimática , Adalimumab/efectos adversos , Adalimumab/sangre , Adulto , Anciano , Antirreumáticos/efectos adversos , Antirreumáticos/sangre , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/inmunología , Cálculo de Dosificación de Drogas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prueba de Estudio Conceptual , Factores de Tiempo , Resultado del Tratamiento , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/inmunología
3.
Transfus Med Hemother ; 41(5): 381-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25538541

RESUMEN

BACKGROUND: In general, patients with significant anti-Ig-A do not tolerate intravenous (i.v.) administration of normal blood products. Here, we present our experiences in the induction of immune tolerance (IIT) and long-term treatment in a series of such patients affected in such a way. The question whether blood components from IgA-deficient donors are required will be discussed. METHODS: Ten adult patients (4 females and 6 males; age ranging from 36 to 75 years) with anti-IgA were included in this study. All patients required long-term treatment with blood components. One patient had IgA deficiency and paroxysmal nocturnal hemoglobinuria (PNH), and all other patients had common variable immunodeficiency (CVID). The particle gel immunoassay was used for the detection of anti-IgA. Immune tolerance to IgA was induced by controlled subcutaneous (s.c.) and/or i.v. infusions of IgG preparations. RESULTS: Prior to IIT, anti-IgA was detectable in plasma samples of all patients and significantly diminished or abolished by controlled s.c. and/or i.v. infusions of IgG. Multiple transfusions with normal blood components could be repeatedly performed with the patient suffering from PNH without any complications. As long as i.v. IgG (IVIgG) infusions were consequently administered as individually required (intervals 2-8 weeks), none of the patients developed reactions during observation (up to 10 years). However, interruption of treatment and re-exposure to IVIgG resulted in adverse reactions. CONCLUSION: Patients with significant anti-IgA can be safely desensitized and tolerate long-term IgG substitutions independent of the IgA concentration of the used blood component.

4.
Nat Med ; 11(10): 1118-24, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16186818

RESUMEN

The direct assessment of T helper (T(H))-cell responses specific for antigens is essential to evaluate pathogenic and protective immunity. Presently, analysis and isolation of antigen-specific T(H) cells is restricted to cells that produce cytokines, or can be performed only with a rare selection of specific peptide major histocompatibility complex class II (MHC II) multimers. Here we report a new method that enables the assessment and isolation of T(H) cells specific for a defined antigen according to CD154 expression induced after stimulation in vitro. We show that antigen-induced CD154 expression is highly sensitive and specific for human and mouse antigen-specific T(H) cells. Moreover, the isolation of antigen-specific CD154(+) T(H) cells necessitates only surface staining with antibodies, thereby enabling the fast generation of antigen-specific T(H) cell lines. Our approach allows assessment of T(H) cells with a defined specificity for the combined quantitative and qualitative analysis of T(H)-cell immunity as well as for the isolation of specific T(H) cells for targeted cellular immunotherapies.


Asunto(s)
Antígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Ligando de CD40/metabolismo , Separación Celular/métodos , Animales , Ligando de CD40/análisis , Citometría de Flujo , Regulación de la Expresión Génica , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Especificidad por Sustrato
5.
Platelets ; 23(3): 184-94, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21913810

RESUMEN

Autoimmune thrombocytopenic purpura (ITP) is characterized by an abnormally low platelet count and bleeding risks. The exact triggering event remains elusive. Oxidative stress may play a role in several autoimmune diseases. A direct link between platelets in ITP and oxidative stress has not yet been addressed. The intracellular platelet antioxidant capacity (AOC) in ITP patients in the active phase (n = 24) and remission (n = 12), and 44 healthy controls were analysed with 2',7'-dichlorodihydrofluorescein diacetate, and in combination with hydrogen peroxide. Enzyme activities (EA) of serum glutathione peroxidase (GPx), glutathione reductase (GRed) and catalase (CAT) were investigated colourimetrically in patients and controls. The AOC of ITP patients in the active phase was drastically reduced, with significantly high mean fluorescence intensity values. Higher GPx activity was observed in both active phase and remission in comparison to healthy controls (p < 0.001), with greater activity observed in active ITP than remission (p = 0.001). However, GRed EA was not elevated indicating that reduced glutathione (GSH) is not comparably recovered as consumed, leading to a decreased bioavailability of GSH and increased oxidative stress. These results suggest that oxidative stress is implicated in active ITP and may play a crucial role in its pathophysiology.


Asunto(s)
Antioxidantes/metabolismo , Plaquetas/metabolismo , Estrés Oxidativo , Oxidorreductasas/sangre , Púrpura Trombocitopénica Idiopática/sangre , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fluoresceínas/química , Hemorragia/sangre , Hemorragia/etiología , Hemorragia/terapia , Humanos , Peróxido de Hidrógeno/química , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Púrpura Trombocitopénica Idiopática/complicaciones , Púrpura Trombocitopénica Idiopática/terapia
6.
Transfus Med Hemother ; 39(3): 221-223, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22851939

RESUMEN

BACKGROUND: Management of patients with autoimmune hemolytic anemia (AIHA) and reticulocytopenia remains challenging. CASE REPORTS: Two patients with decompensated AIHA who were receiving immunosuppressive drugs were treated with erythropoietin (EPO). Administration of EPO increased reticulocyte counts and hemoglobin concentrations in both cases. One patient completely recovered following a short course of treatment. Hemolysis could be compensated in the second patient using only mild doses of immunosuppressive drugs in combination with EPO. CONCLUSION: The administration of EPO should be considered in patients with therapy-refractory AIHA, particularly in the presence of reticulocytopenia.

7.
J Clin Invest ; 132(9)2022 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-35499083

RESUMEN

BACKGROUNDHyaluronan (HA), an extracellular matrix glycosaminoglycan, has been implicated in the pathophysiology of COVID-19 infection, pulmonary hypertension, pulmonary fibrosis, and other diseases, but is not targeted by any approved drugs. We asked whether hymecromone (4-methylumbelliferone [4-MU]), an oral drug approved in Europe for biliary spasm treatment that also inhibits HA in vitro and in animal models, could be repurposed as an inhibitor of HA synthesis in humans.METHODSWe conducted an open-label, single-center, dose-response study of hymecromone in healthy adults. Subjects received hymecromone at 1200 (n = 8), 2400 (n = 9), or 3600 (n = 9) mg/d divided into 3 doses daily, administered orally for 4 days. We assessed safety and tolerability of hymecromone and analyzed HA, 4-MU, and 4-methylumbelliferyl glucuronide (4-MUG; the main metabolite of 4-MU) concentrations in sputum and serum.RESULTSHymecromone was well tolerated up to doses of 3600 mg/d. Both sputum and serum drug concentrations increased in a dose-dependent manner, indicating that higher doses lead to greater exposures. Across all dose arms combined, we observed a significant decrease in sputum HA from baseline after 4 days of treatment. We also observed a decrease in serum HA. Additionally, higher baseline sputum HA levels were associated with a greater decrease in sputum HA.CONCLUSIONAfter 4 days of exposure to oral hymecromone, healthy human subjects experienced a significant reduction in sputum HA levels, indicating this oral therapy may have potential in pulmonary diseases where HA is implicated in pathogenesis.TRIAL REGISTRATIONClinicalTrials.gov NCT02780752.FUNDINGStanford Medicine Catalyst, Stanford SPARK, Stanford Innovative Medicines Accelerator program, NIH training grants 5T32AI052073-14 and T32HL129970.


Asunto(s)
Ácido Hialurónico , Himecromona , Administración Oral , COVID-19 , Europa (Continente) , Matriz Extracelular/metabolismo , Humanos , Ácido Hialurónico/metabolismo , Himecromona/administración & dosificación , Himecromona/efectos adversos
8.
Nat Rev Drug Discov ; 20(1): 64-81, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33199880

RESUMEN

Academic research plays a key role in identifying new drug targets, including understanding target biology and links between targets and disease states. To lead to new drugs, however, research must progress from purely academic exploration to the initiation of efforts to identify and test a drug candidate in clinical trials, which are typically conducted by the biopharma industry. This transition can be facilitated by a timely focus on target assessment aspects such as target-related safety issues, druggability and assayability, as well as the potential for target modulation to achieve differentiation from established therapies. Here, we present recommendations from the GOT-IT working group, which have been designed to support academic scientists and funders of translational research in identifying and prioritizing target assessment activities and in defining a critical path to reach scientific goals as well as goals related to licensing, partnering with industry or initiating clinical development programmes. Based on sets of guiding questions for different areas of target assessment, the GOT-IT framework is intended to stimulate academic scientists' awareness of factors that make translational research more robust and efficient, and to facilitate academia-industry collaboration.


Asunto(s)
Investigación Biomédica/normas , Descubrimiento de Drogas , Industria Farmacéutica/normas , Terapia Molecular Dirigida , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/metabolismo , Humanos
9.
J Rheumatol ; 42(11): 2029-37, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26373561

RESUMEN

OBJECTIVE: Although heart failure (HF) is a major cause of premature mortality, there is little information regarding its prevalence and associated risk factors in patients with rheumatoid arthritis (RA). In this study, we evaluated the prevalence of HF in a community-based RA cohort. Further, we investigated the effect of RA activity and present treatment on HF rate and cardiac structure. METHODS: A diagnostic workup for HF according to the European Society of Cardiology recommendations was performed in 157 patients with RA fulfilling the American College of Rheumatology/European League Against Rheumatism criteria (68% women, age 61 ± 13 yrs) from our outpatient clinic and in 77 age- and sex-matched controls. RESULTS: The prevalence of HF in patients with RA (24%) was unexpectedly high and differed significantly from the control sample (6%, p = 0.001). Diastolic HF was the dominant type (23% vs 6%), and clinical symptoms alone were of low diagnostic value. Active RA (28-joint Disease Activity Score ≥ 2.6: OR 3.4, 95% CI 1.3-9.8) was an independent risk factor of HF, as well as systemic inflammation (erythrocyte sedimentation rate > 16 mm/h: OR 5.4, 95% CI 2.1-16; C-reactive protein > 10 mg/l: OR 2.6, 95% CI 0.8-8.0) and RA duration > 10 years (OR 2.6, 95% CI 1.2-5.8). HF in RA was associated with concentric hypertrophy (48% vs 17%, p < 0.001) and reduced longitudinal strain (-17.2% vs -19.7%, p < 0.001). However, the prevalence of HF was equivalent between the treatment groups [conventional synthetic disease-modifying antirheumatic drugs (DMARD) 25%, tumor necrosis factor inhibitors 22%, other biological DMARD 27%]. CONCLUSION: Recognition of all diastolic HF in RA requires a complex diagnostic approach. Active rather than inactive RA places patients at a higher risk for HF, whereas influence of RA treatment on HF risk needs to be elucidated in further studies.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/epidemiología , Insuficiencia Cardíaca Diastólica/epidemiología , Distribución por Edad , Anciano , Artritis Reumatoide/diagnóstico , Distribución de Chi-Cuadrado , Comorbilidad , Estudios Transversales , Ecocardiografía Doppler/métodos , Femenino , Alemania , Insuficiencia Cardíaca Diastólica/diagnóstico por imagen , Insuficiencia Cardíaca Diastólica/fisiopatología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Prevalencia , Pronóstico , Medición de Riesgo , Índice de Severidad de la Enfermedad , Distribución por Sexo , Estadísticas no Paramétricas , Tasa de Supervivencia , Resultado del Tratamiento
10.
Immunobiology ; 206(5): 496-501, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12607724

RESUMEN

Churg-Strauss-Syndrome (CSS) often takes a mild course and is in many cases treated successfully by glucocorticosteroids (GC) alone. However, there are also several reports demonstrating the necessity of more intensive treatment in life threatening courses with cyclophosphamide and in less severe cases with other immunosuppressive or immunomodulatory drugs like azathioprine, methotrexate or interferon alpha. Relapses of the CSS are detected clinically and serologically and may require cyclophosphamide therapy as well as high-dose GC. We treated 3 cases between 2000 and 2001 that not only experienced a severe relapse (of the heart and the central nervous system) but also proved to be refractory to cyclophosphamide and GC therapy. In the absence of other options we decided to apply TNF-alpha blockers (etanercept in one case and remicade in the two other). This experimental treatment proved to be effective and safe and induced complete remission in one patient and partial remission in the second and at least stopped disease progression in the third. The BVAS 1 markedly improved after additional treatment with TNF-alpha blockers.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Síndrome de Churg-Strauss/tratamiento farmacológico , Inmunoglobulina G/uso terapéutico , Inmunosupresores/uso terapéutico , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Anciano , Síndrome de Churg-Strauss/fisiopatología , Ciclofosfamida/uso terapéutico , Etanercept , Femenino , Glucocorticoides/uso terapéutico , Humanos , Infliximab , Masculino , Metotrexato/uso terapéutico , Persona de Mediana Edad , Prednisolona/uso terapéutico , Inducción de Remisión , Vasculitis/tratamiento farmacológico
11.
Med Law ; 21(2): 395-401, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12184614

RESUMEN

Ethical Islamic considerations concerning current medical infertility treatment are outlined, that allow application of all techniques as far as they are compatible with legal marriage: Homogenic insemination is allowed. Heterogenic insemination is not, although it bears slightly better outcome, because of the imperative Islamic rule not to mingle genealogical lines. Neither is surrogate motherhood because of the legal position of the mother in Islamic shari'a and consequent inheritance rights on the one hand and sociological significance of motherhood on the other. The question arises, which is the mother, the biological or the social. In all cases, special attention should be paid to the professionals involved in the procedures. The danger of embryonic sex selection following preimplantation diagnostics is hinted at, precautions should be taken. These ethical considerations are substantial in Arab countries, including Syria.


Asunto(s)
Ética Médica , Islamismo , Religión y Medicina , Técnicas Reproductivas Asistidas , Femenino , Alemania , Humanos , Siria/etnología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA