Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Front Oncol ; 12: 829483, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35982971

RESUMO

Introduction: The first-line treatment for advanced hepatocellular carcinoma (HCC) is atezolizumab plus bevacizumab, but its availability is not universal and elderly patients are underrepresented in clinical trials. There is little evidence of efficacy and tolerability in elderly patients under systemic treatment. The aims of this study were to characterize the profile of elderly patients treated with sorafenib, assess their survival and safety profile in order to extrapolate their eligibility for systemic treatment. Methods: Retrospective multicentre study of HCC patients aged ≥75 years old treated with sorafenib from January 2008 to December 2019. Demographic data, baseline characteristics, and variables related to HCC and sorafenib were recorded. Overall survival (OS) and safety were analyzed. Results: The study included 206 patients from 11 hospitals, median age 77.9 years; 71.4% men and 62.6% stage Barcelona Clinic Liver Cancer- C (BCLC-C). The main causes of cirrhosis were hepatitis C (60.7%) and alcohol (14.7%). Most patients (84.5%) started with sorafenib 800mg and 15.5% at lower dosage. Arterial hypertension (AHT) (74.2 vs 62.2%; standardized mean differences (STD): 26) and baseline ECOG-PS>0 (45.3 vs 34.7%; STD: 38.2) differed significantly between patients receiving low and full doses. Median OS was 15.4 months (18.2 in BCLC-B vs 13.6 in BCLC-C). OS was not modified by comorbidities, age or period with more expertise. Conclusions: Sorafenib appears to be safe in elderly patients with HCC. This is the first study to characterize the profile of elderly patients to be considered for systemic treatment. These findings could be used as the reference profile for elderly candidates for atezolizumab-bevacizumab.

2.
Rev Esp Enferm Dig ; 111(2): 161-163, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30569731

RESUMO

The use of new oral anticoagulants such as apixaban is increasing. We present the case of an 85-year-old patient who was diagnosed with mixed profile toxic hepatitis due to apixaban use. An etiological study was negative, except for anti-smooth muscle antibodies, and a liver biopsy ruled out autoimmune hepatitis. The patient was assigned a score of 7 on the CIOMS/RUCAM scale, indicating a probable causality. The liver injury improved after the withdrawal of apixaban. A previous meta-analysis reported that the risk of hepatotoxicity does not increase with the use of apixaban, nor were any cases reported in registry studies. Nonetheless, more than 120 possible cases currently appear in the European pharmacovigilance database (EudraVigilance). We suggest that apixaban should be considered as a possible cause of liver injury.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Inibidores do Fator Xa/efeitos adversos , Pirazóis/efeitos adversos , Piridonas/efeitos adversos , Idoso de 80 Anos ou mais , Biópsia , Doença Hepática Crônica Induzida por Substâncias e Drogas/patologia , Humanos , Fígado/patologia , Masculino
3.
Gastroenterol Hepatol ; 42(3): 150-156, 2019 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30459058

RESUMO

INTRODUCTION: Upper gastroscopy in patients with cirrhosis often reveals non-specific lesions, which are usually oriented as portal hypertensive gastropathy (PHG). However, the diagnosis of PHG can be difficult, both from an endoscopic and histological point of view. The study of CD34 expression, which enhances the endothelial cells of the microvasculature, could help the differential diagnosis. The objectives of this study were to evaluate the correlation between endoscopy and histology in the diagnosis of PHG and to assess the utility of CD34 in the diagnosis of PHG. MATERIAL AND METHODS: The results of immunostaining with CD34 gastric fundus biopsies from 100 cirrhotic patients and 20 controls were compared with the endoscopic images. RESULTS: The correlation between the histology and the endoscopic diagnosis of PHG was very low (kappa=0.15). In addition, the measurement of the diameter of the gastric vessels enhanced by the use of immunohistochemical staining (CD34) did not show good correlation with the endoscopic diagnosis (p=.26) and did not provide relevant information for the histological diagnosis of PHG either. DISCUSSION: The correlation between histology and endoscopy is low for the diagnosis of PHG. The use of immunostaining for CD34 does not seem to improve the diagnostic yield of the histological study.


Assuntos
Antígenos CD34/análise , Hipertensão Portal/complicações , Cirrose Hepática/complicações , Gastropatias/diagnóstico , Gastropatias/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Biópsia , Estudos de Casos e Controles , Diagnóstico Diferencial , Feminino , Fundo Gástrico/irrigação sanguínea , Fundo Gástrico/imunologia , Fundo Gástrico/patologia , Gastroscopia/métodos , Humanos , Hipertensão Portal/metabolismo , Masculino , Pessoa de Meia-Idade , Estômago/patologia , Gastropatias/etiologia , Gastropatias/metabolismo
4.
Oncotarget ; 9(71): 33446-33458, 2018 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-30323890

RESUMO

Epidermal growth factor receptor (EGFR) is a clinically validated target and often overexpressed in some solid tumors. Both EGFR tyrosine kinase inhibitors and ligand-blocking antibodies have been approved for treatment of NSCLC, head and neck cancers and colorectal cancers. However, clinical response is limited and often accompanied by significant toxicities due to normal tissue expression. To improve the effectiveness of targeting EGFR while minimizing the toxicities on normal tissues, we developed a low-affinity anti-EGFR antibody drug conjugate (ADC), RN765C. Potent in vitro cytotoxicity of RN765C, with nanomolar to subnanomolar EC50, was observed on a panel of cancer cell lines expressing moderate to high level of EGFR. In contrast, RN765C was less effective in killing normal human keratinocytes, presumably due to its lower receptor expression. Mechanistically, RN765C has multiple modes of action: inducing payload mediated mitotic arrest and cell death, blocking EGFR pathway signal and mediating antibody dependent cell cytotoxicity. In preclinical studies, a single dose of RN765C at 1.5-3 mg/kg was generally sufficient to induce tumor regression in multiple cell line and patient-derived xenograft models, including those that are resistant to EGFR-directed tyrosine kinase inhibitors. Our data support further investigation of RN765C in the clinic to treat EGFR expressing solid tumors.

5.
Eur J Gastroenterol Hepatol ; 30(12): 1453-1460, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30113926

RESUMO

BACKGROUND AND AIM: Drug-eluting bead transarterial chemoembolization (DEB-TACE) improves the survival of patients with hepatocellular carcinoma (HCC), intermediate stage [i.e. Barcelona Clinic Liver Cancer-B (BCLC-B)]. The aim of our study was to analyse the overall survival (OS) and prognostic factors of patients with HCC treated with DEB-TACE. PATIENTS AND METHODS: Patients' clinical course was recorded from January 2005 to July 2014. The median OS was obtained by the Kaplan-Meier method and compared using the log-rank test. The prognosis factors associated with OS were determined by a multivariate Cox regression analysis and the accuracy of the OS prediction was determined by calculation of the assessment for retreatment with TACE score (ART score). RESULTS: A cohort of 147 consecutive patients treated with DEB-TACE was included. Median age of the patients was 73.4 years. Overall, 68.7% were men, and all had cirrhosis, with 68.8% being hepatisis C virus positive. Moreover, 35.2% were staged as BCLC-A and 60.2% as BCLC-B. After a median follow-up of 19.2 months, 29.3% were alive, 4.3% needed treatment with sorafenib and 56.1% underwent DEB-TACE retreatment. Median OS was 22.8 [95% confidence interval (CI)=19.6-25.9]. After censoring for ascites and more than one nodule, OS was 23.87 (95% CI =20.72-27.01) and 26.89 (95% CI =21.00-32.78), respectively. The risk of death decreased by 22.3% with the number of DEB-TACE sessions (hazard ratio=0.777) and increased by 25.9% with higher Child-Pugh score (hazard ratio=1.259). Overall, 61.2% of the cohort had an ART score between 0 and 1.5. There were no statistical differences in OS between cohort groups with ART of 0-1.5 and at least 2.5. CONCLUSION: The results validate the efficacy and safety of DEB-TACE in patients with HCC and the importance of some prognostic factors for patient survival.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Idoso , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/efeitos adversos , Quimioembolização Terapêutica/efeitos adversos , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Microesferas , Prognóstico , Medição de Risco/métodos , Resultado do Tratamento
6.
Rev Esp Enferm Dig ; 110(3): 166-171, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29320862

RESUMO

INTRODUCTION: At present there is no fully accepted endoscopic classification for the assessment of the severity of portal hypertensive gastropathy (PHG). Few studies have evaluated inter and intra-observer concordance or the degree of concordance between different endoscopic classifications. OBJECTIVES: To evaluate inter and intra-observer agreement for the presence of portal hypertensive gastropathy and enteropathy using different endoscopic classifications. METHODS: Patients with liver cirrhosis were included into the study. Enteroscopy was performed under sedation. The location of lesions and their severity was recorded. Images were videotaped and subsequently evaluated independently by three different endoscopists, one of whom was the initial endoscopist. The agreement between observations was assessed using the kappa index. RESULTS: Seventy-four patients (mean age 63.2 years, 53 males and 21 females) were included. The agreement between the three endoscopists regarding the presence or absence of PHG using the Tanoue and McCormack classifications was very low (kappa scores = 0.16 and 0.27, respectively). CONCLUSIONS: The current classifications of portal hypertensive gastropathy have a very low degree of intra and inter-observer agreement for the diagnosis and assessment of gastropathy severity.


Assuntos
Hipertensão Portal/complicações , Hipertensão Portal/diagnóstico , Gastropatias/diagnóstico , Gastropatias/etiologia , Adulto , Idoso , Endoscopia Gastrointestinal , Feminino , Humanos , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador
7.
Hepatology ; 67(4): 1458-1471, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28714072

RESUMO

The presence of cirrhosis increases the mortality of patients with peptic ulcer bleeding (PUB). Both acute variceal bleeding (AVB) and PUB are associated with substantial mortality in cirrhosis. This multicenter cohort study was performed to assess whether the mortality of patients with cirrhosis with PUB is different from that of those with AVB. Patients with cirrhosis and acute gastrointestinal bleeding were consecutively included and treated with somatostatin and proton pump inhibitor infusion from admission and with antibiotic prophylaxis. Emergency endoscopy with endoscopic therapy was performed within the first 6 hours. 646 patients with AVB and 144 with PUB were included. There were baseline differences between groups, such as use of gastroerosive drugs or ß-blockers. Child-Pugh and Model for End-Stage Liver Disease MELD scores were similar. Further bleeding was more frequent in the AVB group than those in the PUB group (18% vs. 10%; odds ratio [OR] = 0.50; 95% confidence interval [CI] = 0.29-0.88). However, mortality risk at 45 days was similar in both groups (19% in the AVB group vs. 17% in the PUB group; OR = 0.85; 95% CI = 0.55-1.33; P = 0.48). Different parameters, such as Child-Pugh score, acute kidney injury, acute on chronic liver failure, or presence of shock or bacterial infection, but not the cause of bleeding, were related to the risk of death. Only 2% of the PUB group versus 3% of the AVB group died with uncontrolled bleeding (P = 0.39), whereas the majority of patients in either group died from liver failure or attributed to other comorbidities. CONCLUSION: Using current first-line therapy, patients with cirrhosis and acute peptic ulcer bleeding have a similar survival than those with variceal bleeding. The risk of further bleeding is higher in patients with variceal hemorrhage. However, few patients in both groups died from uncontrolled bleeding, rather the cause of death was usually related to liver failure or comorbidities. (Hepatology 2018;67:1458-1471).


Assuntos
Varizes Esofágicas e Gástricas/mortalidade , Hemorragia Gastrointestinal/mortalidade , Cirrose Hepática/mortalidade , Úlcera Péptica/mortalidade , Idoso , Antibioticoprofilaxia/métodos , Causas de Morte , Estudos de Coortes , Endoscopia Gastrointestinal/métodos , Varizes Esofágicas e Gástricas/complicações , Varizes Esofágicas e Gástricas/tratamento farmacológico , Feminino , Hemorragia Gastrointestinal/tratamento farmacológico , Hemorragia Gastrointestinal/etiologia , Humanos , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/complicações , Úlcera Péptica/tratamento farmacológico , Inibidores da Bomba de Prótons/uso terapêutico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Somatostatina/uso terapêutico , Taxa de Sobrevida
8.
Infectio ; 20(3): 123-129, jul.-sep. 2016. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-791161

RESUMO

Actualmente hay pocos datos sobre los resultados obtenidos con tenofovir y entecavir en la práctica clínica. Objetivo: Valorar la respuesta viral y la seguridad de tenofovir y entecavir en un periodo de 5 años. Material y métodos: Estudio observacional en donde se incluyó a todos los pacientes con hepatitis crónica por virus B que iniciaron tratamiento con tenofovir o entecavir desde enero de 2008 hasta diciembre de 2012. Resultados: De un total de 70 pacientes: 42 (60%) en tratamiento con entecavir y 28 (40%) con tenofovir. Un 75,7% eran hombres, con una edad media de 53 (DE 14) años. Un 70% eran caucásicos. Se realizó biopsia hepática en 46 pacientes (F0 8,7%; F1 6,5%; F2 26,1%; F3 43,5% y F4 15,2%). El 51,4% eran naïve. Del grupo de pacientes previamente tratados, un 17,6% había recibido interferón; un 26,4% interferón inicialmente y luego análogos; y un 55,8% otros análogos de los nucleósidos o de los nucleótidos. El tiempo de seguimiento fue de 36 (DE 12) meses. El DNA del VHB inicial medio era de 31.570.006 UI/mL (rango 24-1.100.000.000 UI/mL).Todos ellos, excepto 3, presentaron un DNA indetectable al año del tratamiento. De los 10 con HBeAg+, 2 de ellos presentaron seroconversión. Los valores de creatinina y la estimación del filtrado glomerular (EFG) fueron de 0,9 (DE 0,3) mg/dL y de 93,92 ml/min/1,73 m² (DE 21,92) al inicio y creatinina 0,93 (DE 0,27) mg/dL y EFG 91,7392 ml/min/1,73 m² (DE 21,38) al año de seguimiento. Conclusiones: Entecavir y tenofovir son eficaces y seguros en la práctica clínica en pacientes con hepatitis crónica por virus B.


The current first line treatment for chronic hepatitis B virus is with entecavir andtenofovir. However, there are few data regarding the results obtained from these treatmentsin clinical practice. Objective: To assess viral response and safety of treatment with entecavir and tenofovir in a5-year follow-up. Material and methods: Observational study on patients with chronic hepatitis B virus who begantreatment with tenofovir or entecavir between January 2008 and December 2012. Results: Seventy patients were included; 42 (60%) were treated with entecavir and 28 (40%)with tenofovir. Of these, 75.7% were men, with an average age of 53 (SD ± 14) years, and mostwere white (70%). A liver biopsy was performed on 46 patients (F0 8.7%; F1 6.5%; F2 26.1%;F3 43.5% and F4 15.2%). Of all the patients, 51.4% were treatment naïve, and of the groupof previously treated patients, 17.6% had received interferon; 26.4% had received interferonfollowed by one or more analogues; and 55.8% had received other nucleoside or nucleotideanalogues.The time of follow-up was 36 (SD ± 12) months. The average initial DNA was 31,570,006UI/mL (range 24-1,100,000,000 UI/mL). All except 3 presented undetectable DNA after oneyear of treatment. Ten patients were HBeAg-positive at the beginning of the treatment and 2seroconverted. At the beginning of the treatment, creatinine was 0.9 (SD ± 0.3) mg/dL and theestimated glomerular filtration rate (eGFR) was 93.92 ml/min/1.73 m²(DE 21.92); both keepingstable after a year of treatment (creatinine levels 0.93 SD ± 0.27 mg/dL, eGFR 91.7392 SD± 21.38 ml/min/1.73 m²). Conclusions: Entecavir and tenofovir are safe and effective in clinical practice for the treatmentof chronic hepatitis B virus, both in treatment-naïve patients and in those previously treated.


Assuntos
Humanos , Antivirais/uso terapêutico , Tenofovir , Hepatite B , Hepatite Crônica
9.
Mol Cancer Ther ; 15(5): 958-70, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26944918

RESUMO

The degree of stability of antibody-drug linkers in systemic circulation, and the rate of their intracellular processing within target cancer cells are among the key factors determining the efficacy of antibody-drug conjugates (ADC) in vivo Previous studies demonstrated the susceptibility of cleavable linkers, as well as auristatin-based payloads, to enzymatic cleavage in rodent plasma. Here, we identify Carboxylesterase 1C as the enzyme responsible for the extracellular hydrolysis of valine-citrulline-p-aminocarbamate (VC-PABC)-based linkers in mouse plasma. We further show that the activity of Carboxylesterase 1C towards VC-PABC-based linkers, and consequently the stability of ADCs in mouse plasma, can be effectively modulated by small chemical modifications to the linker. While the introduced modifications can protect the VC-PABC-based linkers from extracellular cleavage, they do not significantly alter the intracellular linker processing by the lysosomal protease Cathepsin B. The distinct substrate preference of the serum Carboxylesterase 1C offers the opportunity to modulate the extracellular stability of cleavable ADCs without diminishing the intracellular payload release required for ADC efficacy. Mol Cancer Ther; 15(5); 958-70. ©2016 AACR.


Assuntos
Anticorpos Monoclonais/química , Antineoplásicos/química , Carbamatos/química , Citrulina/química , Imunoconjugados/química , Valina/química , Animais , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Biomarcadores , Carboxilesterase/química , Carboxilesterase/metabolismo , Desenho de Fármacos , Estabilidade de Medicamentos , Humanos , Imunoconjugados/farmacocinética , Imunoconjugados/farmacologia , Camundongos , Camundongos Knockout , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade
11.
Eur J Gastroenterol Hepatol ; 27(7): 826-33, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26043289

RESUMO

BACKGROUND AND AIMS: The ability of noninvasive methods to predict the development of cirrhosis has not been established. We evaluated the ability of three noninvasive methods [the Forns index, the aspartate aminotransferase-to-platelet ratio index (APRI), and the Non-Invasive Hepatitis-C-related Cirrhosis Early Detection (NIHCED) score] to determine the risk of developing cirrhosis in chronic hepatitis C. METHODS: Consecutive patients with chronic hepatitis C who had undergone liver biopsy between 1998 and 2004 were eligible. We used the three methods to evaluate patients at baseline and at follow-up (4-10 years later). When these methods yielded discordant or indeterminate results, a second liver biopsy was performed. Logistic regression models were fitted for each method to predict whether cirrhosis would appear and to predict long-term mortality from cirrhosis. RESULTS: We included 289 patients in our study. The mean scores at baseline and at follow-up, respectively, were as follows: Forns, 5.47 ± 1.95 and 6.56 ± 2.02; APRI, 1.1 ± 2.33 and 1.4 ± 1.53; and NIHCED, 7.79 ± 11.45 and 15.48 ± 15.28. The area under the receiver operating characteristic curve for predicting cirrhosis was 0.83 for Forns, 0.79 for APRI, and 0.76 for NIHCED. The sensitivity and specificity for predicting cirrhosis, respectively, were 75 and 71% for Forns (cutoff 4.7), 86 and 42% for APRI (cutoff 0.48), and 41 and 82% for NIHCED (cutoff 0). The area under the receiver operating characteristic curve for predicting mortality was 0.86 for Forns, 0.79 for APRI, and 0.84 for NIHCED. CONCLUSION: Indirect noninvasive markers could help identify patients with chronic hepatitis C at risk of progression to cirrhosis.


Assuntos
Aspartato Aminotransferases/sangue , Hepatite C Crônica/complicações , Cirrose Hepática/diagnóstico , Cirrose Hepática/etiologia , Contagem de Plaquetas , gama-Glutamiltransferase/sangue , Adulto , Idoso , Biomarcadores/sangue , Biópsia , Progressão da Doença , Feminino , Seguimentos , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/mortalidade , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Sensibilidade e Especificidade , Espanha
12.
Bioconjug Chem ; 26(4): 650-9, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25643134

RESUMO

The systemic stability of the antibody-drug linker is crucial for delivery of an intact antibody-drug conjugate (ADC) to target-expressing tumors. Linkers stable in circulation but readily processed in the target cell are necessary for both safety and potency of the delivered conjugate. Here, we report a range of stabilities for an auristatin-based payload site-specifically attached through a cleavable valine-citrulline-p-aminobenzylcarbamate (VC-PABC) linker across various sites on an antibody. We demonstrate that the conjugation site plays an important role in determining VC-PABC linker stability in mouse plasma, and that the stability of the linker positively correlates with ADC cytotoxic potency both in vitro and in vivo. Furthermore, we show that the VC-PABC cleavage in mouse plasma is not mediated by Cathepsin B, the protease thought to be primarily responsible for linker processing in the lysosomal degradation pathway. Although the VC-PABC cleavage is not detected in primate plasma in vitro, linker stabilization in the mouse is an essential prerequisite for designing successful efficacy and safety studies in rodents during preclinical stages of ADC programs. The divergence of linker metabolism in mouse plasma and its intracellular cleavage offers an opportunity for linker optimization in the circulation without compromising its efficient payload release in the target cell.


Assuntos
Aminobenzoatos/química , Anticorpos Monoclonais/química , Antineoplásicos/química , Imunoconjugados/química , Oligopeptídeos/química , Neoplasias Pancreáticas/tratamento farmacológico , Aminobenzoatos/sangue , Aminobenzoatos/farmacocinética , Aminobenzoatos/farmacologia , Animais , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Carbamatos/química , Catepsina B/química , Catepsina B/metabolismo , Linhagem Celular Tumoral , Dipeptídeos/química , Sistemas de Liberação de Medicamentos/métodos , Estabilidade de Medicamentos , Feminino , Humanos , Imunoconjugados/sangue , Imunoconjugados/farmacocinética , Imunoconjugados/farmacologia , Camundongos , Camundongos Nus , Modelos Moleculares , Oligopeptídeos/sangue , Oligopeptídeos/farmacocinética , Oligopeptídeos/farmacologia , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/patologia , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Gastroenterol Hepatol ; 38(2): 97-107, 2015 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-25499848

RESUMO

Portal hypertensive gastropathy (GHP) is a complication of portal hypertension usually associated with liver cirrhosis. The pathogenesis is unclear but the presence of portal hypertension is an essential factor for its development. GHP may be asymptomatic or present as gastrointestinal bleeding or iron deficiency anemia. Endoscopic lesions vary from a mosaic pattern to diffuse red spots; the most common location is the fundus. Treatment is indicated when there is acute or chronic bleeding, as secondary prophylaxis. There is insufficient evidence to recommend primary prophylaxis in patients who have never bled. Drugs that decrease portal pressure, such as non-cardioselective beta-blockers, and/or endoscopic ablative treatments, such as argon-beam coagulation, may be used. The role of transarterial intrahepatic portosystemic shunt) or bypass surgery has been insufficiently analyzed. Antral vascular ectasia (EVA) is a rare entity in liver cirrhosis, whose pathophysiology is still unknown. Clinical presentation is similar to that of GHP and endoscopy usually shows red spots in the antrum. Biopsy is often required to differentiate EVA from GHP. There is no effective medical therapy, so endoscopic ablative therapy and, in severe cases, antrectomy are recommended.


Assuntos
Ectasia Vascular Gástrica Antral/etiologia , Hemorragia Gastrointestinal/etiologia , Hipertensão Portal/complicações , Cirrose Hepática/complicações , Anemia Ferropriva/etiologia , Gastrectomia/métodos , Ectasia Vascular Gástrica Antral/fisiopatologia , Ectasia Vascular Gástrica Antral/cirurgia , Hemorragia Gastrointestinal/fisiopatologia , Hemorragia Gastrointestinal/cirurgia , Gastroscopia , Humanos , Derivação Portossistêmica Cirúrgica
14.
Bioconjug Chem ; 25(2): 240-50, 2014 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-24359082

RESUMO

Antibody drug conjugates (ADCs) are becoming an important new class of therapeutic agents for the treatment of cancer. ADCs are produced through the linkage of a cytotoxic small molecule (drug) to monoclonal antibodies that target tumor cells. Traditionally, most ADCs rely on chemical conjugation methods that yield heterogeneous mixtures of varying number of drugs attached at different positions. The potential benefits of site-specific drug conjugation in terms of stability, manufacturing, and improved therapeutic index has recently led to the development of several new site-specific conjugation technologies. However, detailed characterization of the degree of site specificity is currently lacking. In this study we utilize mass spectrometry to characterize the extent of site-specificity of an enzyme-based site-specific antibody-drug conjugation technology that we recently developed. We found that, in addition to conjugation of the engineered site, a small amount of aglycosylated antibody present in starting material led to conjugation at position Q295, resulting in approximately 1.3% of off-target conjugation. Based on our detection limits, we show that Q295N mutant eliminates the off-target conjugation yielding highly homogeneous conjugates that are better than 99.8% site-specific. Our study demonstrates the importance of detailed characterization of ADCs and describes methods that can be utilized to characterize not only our enzyme based conjugates, but also ADCs generated by other conjugation technologies.


Assuntos
Anticorpos/química , Preparações Farmacêuticas/química , Espectrometria de Massas em Tandem/métodos , Transglutaminases/química , Cromatografia Líquida
15.
Chem Biol ; 20(2): 161-7, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23438745

RESUMO

Antibody drug conjugates (ADCs) are a therapeutic class offering promise for cancer therapy. The attachment of cytotoxic drugs to antibodies can result in an effective therapy with better safety potential than nontargeted cytotoxics. To understand the role of conjugation site, we developed an enzymatic method for site-specific antibody drug conjugation using microbial transglutaminase. This allowed us to attach diverse compounds at multiple positions and investigate how the site influences stability, toxicity, and efficacy. We show that the conjugation site has significant impact on ADC stability and pharmacokinetics in a species-dependent manner. These differences can be directly attributed to the position of the linkage rather than the chemical instability, as was observed with a maleimide linkage. With this method, it is possible to produce homogeneous ADCs and tune their properties to maximize the therapeutic window.


Assuntos
Anticorpos/química , Antineoplásicos/química , Imunoconjugados/química , Animais , Anticorpos/imunologia , Meia-Vida , Humanos , Imunoconjugados/farmacocinética , Imunoconjugados/uso terapêutico , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias Leves de Imunoglobulina/química , Cadeias Leves de Imunoglobulina/imunologia , Camundongos , Neoplasias/tratamento farmacológico , Ratos , Transglutaminases/metabolismo , Moduladores de Tubulina/química
16.
Rev Esp Enferm Dig ; 104(5): 242-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22662776

RESUMO

BACKGROUND: hepatocellular carcinoma (HCC) is a very frequent tumor. Screening for the disease is effective, but the prognostic factors are difficult to evaluate. OBJECTIVES: 1. To determine epidemiological data and the clinical course of HCC in our setting. 2. To compare patient survival according to whether screening is performed or not. 3. To evaluate survival prognostic factors. PATIENTS AND METHODS: data on the epidemiology and clinical course of patients diagnosed with HCC were collected on a prospective basis (January 2004-December 2006). Two groups were considered according to whether screening had been performed (group A) or not (group B). RESULTS: a total of 110 patients were diagnosed with HCC (70% males). The most common etiology of cirrhosis was hepatitis C (56.1%), and 69% presented mild liver failure (Child-Pugh grade A). The median follow-up was 1.8 years. Fifty-one percent had been subjected to screening. The diagnosis of HCC was established by imaging techniques in 48.2% of the cases, and by histological criteria in 51.8%. The median tumor size was 23 mm in group A and 28 mm in group B (p = 0.005). Treatment with curative intent was provided in 72% of the cases in group A and in 48% in group B (p = 0.011). The median overall survival was 1.99 years -2.67 years in group A and 1.75 years in group B (p = 0.05). The multivariate analysis of overall survival showed the type of treatment (OR = 2.82 95%CI: 1.3-6.12, p = 0.009) and liver function (OR = 1.71 95%CI: 1.1-2.68, p = 0.020) to be independent predictors of survival. CONCLUSIONS: screening allows the diagnosis of smaller lesions and a higher percentage of curative treatments. The degree of liver function and the provision of curative treatment are independent predictors of survival.


Assuntos
Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/mortalidade , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Detecção Precoce de Câncer , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Estudos Prospectivos , Espanha/epidemiologia , Análise de Sobrevida
17.
J Mol Biol ; 420(3): 204-19, 2012 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-22543237

RESUMO

Bispecific antibodies and antibody fragments are a new class of therapeutics increasingly utilized in the clinic for T cell recruitment (catumaxomab anti-EpCAM/CD3 and blinatumomab anti-CD19/CD3), increase in the selectivity of targeting, or simultaneous modulation of multiple cellular pathways. While the clinical potential for certain bispecific antibody formats is clear, progress has been hindered because they are often difficult to manufacture, may suffer from suboptimal pharmacokinetic properties, and may be limited due to potential immunogenicity issues. Current state-of-the-art human IgG-like bispecific technologies require co-expression of two heavy chains with a single light chain, use crossover domains to segregate light chains, or utilize scFv (single-chain fragment variable)-Fc fusion. We have engineered both human IgG1 and IgG2 subtypes, with minimal point mutations, to form full-length bispecific human antibodies with high efficiency and in high purity. In our system, the two antibodies of interest can be expressed and purified separately, mixed together under appropriate redox conditions, resulting in a formation of a stable bispecific antibody with high yields. With this approach, it is not necessary to generate new antibodies that share a common light chain, therefore allowing the immediate use of an existing antibody regardless of whether it has been generated via standard hybridoma or display methods. We demonstrate the generality of the approach and show that these bispecific antibodies have properties similar to those of wild-type IgGs, and we further demonstrate the utility of the technology with an example of a CD3/CD20 bispecific antibody that effectively depletes B cells in vitro and in vivo.


Assuntos
Anticorpos Biespecíficos/imunologia , Imunoglobulina G/metabolismo , Engenharia de Proteínas/métodos , Animais , Anticorpos Biespecíficos/genética , Anticorpos Biespecíficos/isolamento & purificação , Anticorpos Biespecíficos/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados , Especificidade de Anticorpos , Antígenos CD20/imunologia , Linfócitos B/imunologia , Complexo CD3/imunologia , Cetuximab , Citotoxicidade Imunológica , Feminino , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Mutação Puntual , Ratos , Ratos Sprague-Dawley , Receptores Fc/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Linfócitos T/imunologia
18.
J Biol Chem ; 287(14): 11090-7, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22294692

RESUMO

Target-mediated clearance and high antigen load can hamper the efficacy and dosage of many antibodies. We show for the first time that the mouse, cynomolgus, and human cross-reactive, antagonistic anti-proprotein convertase substilisin kexin type 9 (PCSK9) antibodies J10 and the affinity-matured and humanized J16 exhibit target-mediated clearance, resulting in dose-dependent pharmacokinetic profiles. These antibodies prevent the degradation of low density lipoprotein receptor, thus lowering serum levels of LDL-cholesterol and potently reducing serum cholesterol in mice, and selectively reduce LDL-cholesterol in cynomolgus monkeys. In order to increase the pharmacokinetic and efficacy of this promising therapeutic for hypercholesterolemia, we engineered pH-sensitive binding to mouse, cynomolgus, and human PCSK9 into J16, resulting in J17. This antibody shows prolonged half-life and increased duration of cholesterol lowering in two species in vivo by binding to endogenous PCSK9 in mice and cynomolgus monkeys, respectively. The proposed mechanism of this pH-sensitive antibody is that it binds with high affinity to PCSK9 in the plasma at pH 7.4, whereas the antibody-antigen complex dissociates at the endosomal pH of 5.5-6.0 in order to escape from target-mediated degradation. Additionally, this enables the antibody to bind to another PCSK9 and therefore increase the antigen-binding cycles. Furthermore, we show that this effect is dependent on the neonatal Fc receptor, which rescues the dissociated antibody in the endosome from degradation. Engineered pH-sensitive antibodies may enable less frequent or lower dosing of antibodies hampered by target-mediated clearance and high antigen load.


Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacocinética , Anticolesterolemiantes/farmacologia , Anticolesterolemiantes/farmacocinética , Pró-Proteína Convertases/imunologia , Engenharia de Proteínas , Serina Endopeptidases/imunologia , Animais , Anticorpos Monoclonais Humanizados/sangue , Anticorpos Monoclonais Humanizados/farmacologia , Anticolesterolemiantes/sangue , Anticolesterolemiantes/imunologia , Regiões Determinantes de Complementaridade/química , Meia-Vida , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Lisossomos/metabolismo , Macaca fascicularis , Masculino , Camundongos , Pró-Proteína Convertase 9 , Receptores Fc/metabolismo
19.
Gastroenterol Hepatol ; 35(1): 12-6, 2012 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-22177938

RESUMO

The life expectancy of patients with hepatocellular carcinoma (HCC) has increased in the last few years due to recent treatment advances. However, extrahepatic metastases from tumors, previously described only occasionally, are becoming more frequent in clinical practice. The choice between an active or passive approach to these metastatic lesions can sometimes present clinicians with a difficult dilemma. We discuss the case of a male patient with multifocal HCC and cranial metastasis from a primary liver tumor and who, after surgery and radiotherapy over the metastatic lesion, has survived for more than 3 years.


Assuntos
Neoplasias Encefálicas/secundário , Carcinoma Hepatocelular/secundário , Neoplasias Hepáticas/patologia , Neoplasias Cranianas/secundário , Idoso , Evolução Fatal , Humanos , Masculino , Sobrevida
20.
J Hepatol ; 52(1): 39-44, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19897273

RESUMO

BACKGROUND & AIMS: Secondary bacterial peritonitis in cirrhotic patients is an uncommon entity that has been little reported. Our aim is to analyse the frequency, clinical characteristics, treatment and prognosis of patients with secondary peritonitis in comparison to those of patients with spontaneous bacterial peritonitis (SBP). METHODS: Retrospective analysis of 24 cirrhotic patients with secondary peritonitis compared with 106 SBP episodes. RESULTS: Secondary peritonitis represented 4.5% of all peritonitis in cirrhotic patients. Patients with secondary peritonitis showed a significantly more severe local inflammatory response than patients with SBP. Considering diagnosis of secondary peritonitis, the sensitivity of Runyon's criteria was 66.6% and specificity 89.7%, Runyon's criteria and/or polymicrobial ascitic fluid culture were present in 95.6%, and abdominal computed tomography was diagnostic in 85% of patients in whom diagnosis was confirmed by surgery or autopsy. Mortality during hospitalization was higher in patients with secondary peritonitis than in those with SBP (16/24, 66.6% vs. 28/106, 26.4%) (p<0.001). There was a trend to lower mortality in secondary peritonitis patients who underwent surgery (7/13, 53.8%) than in those who received medical treatment only (9/11, 81.8%) (p=0.21). Considering surgically treated patients, the time between diagnostic paracentesis and surgery was shorter in survivors than in non-survivors (3.2+/-2.4 vs. 7.2+/-6.1 days, p=0.31). CONCLUSIONS: Secondary peritonitis is an infrequent complication in cirrhotic patients but mortality is high. A low threshold of suspicion on the basis of Runyon's criteria and microbiological data, together with an aggressive approach that includes prompt abdominal computed tomography and early surgical evaluation, could improve prognosis in these patients.


Assuntos
Cirrose Hepática/complicações , Cavidade Peritoneal/microbiologia , Peritonite/diagnóstico , Peritonite/terapia , Idoso , Líquido Ascítico/microbiologia , Diagnóstico Diferencial , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Cavidade Peritoneal/diagnóstico por imagem , Peritonite/mortalidade , Prognóstico , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Taxa de Sobrevida , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA