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1.
Dis Esophagus ; 36(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36892169

RESUMO

Recent guidelines recommend screening for patients with chronic gastroesophageal reflux disease who have three or more additional risk factors for Barrett's esophagus (BE). Failure to screen high-risk individuals represents a missed opportunity in esophageal adenocarcinoma prevention and early detection. We aimed to determine the frequency of upper endoscopy and prevalence of BE and esophageal cancer in a cohort of United States veterans who possessed four or more risk factors for BE. All patients at VA New York Harbor Healthcare System with at least four risk factors for BE between 2012 and 2017 were identified. Procedure records were reviewed for upper endoscopies performed between January 2012 and December 2019. Multivariable logistic regression was used to determine risk factors associated with undergoing endoscopy and factors associated with BE and esophageal cancer. 4505 patients with at least four risk factors for BE were included. 828 patients (18.4%) underwent upper endoscopy, of which 42 (5.1%) were diagnosed with BE and 11 (1.3%) with esophageal cancer (10 adenocarcinoma; 1 squamous cell carcinoma). Among individuals who underwent upper endoscopy, risk factors associated with undergoing endoscopy included obesity (OR, 1.79; 95% CI, 1.41-2.30; P < 0.001) and chronic reflux (OR, 3.86; 95% CI, 3.04-4.90; P < 0.001). There were no individual risk factors associated with BE or BE/esophageal cancer. In this retrospective analysis of patients with 4 or more risk factors for BE, fewer than one-fifth of patients underwent upper endoscopy, supporting the need for efforts aimed at improving BE screening rates.


Assuntos
Adenocarcinoma , Esôfago de Barrett , Neoplasias Esofágicas , Refluxo Gastroesofágico , Veteranos , Humanos , Esôfago de Barrett/diagnóstico , Esôfago de Barrett/epidemiologia , Esôfago de Barrett/complicações , Estudos Retrospectivos , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/etiologia , Fatores de Risco , Adenocarcinoma/diagnóstico , Adenocarcinoma/epidemiologia , Adenocarcinoma/etiologia , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/epidemiologia , Esofagoscopia/efeitos adversos
2.
Dig Dis Sci ; 67(10): 4886-4894, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35022906

RESUMO

BACKGROUND: Chemoprevention for colorectal neoplasia has attracted growing interest, with multiple medications investigated. Metformin may decrease the overall incidence of cancer in patients with diabetes and may decrease the incidence of colorectal cancer. AIMS: We aimed to determine the impact of metformin use on the behavior of colorectal adenomas in a US veteran population. METHODS: All patients with at least two high-quality colonoscopies between January 1997 and December 2013 at Veterans Affairs New York Harbor Healthcare System were identified. Outpatient prescription records were used to determine metformin exposure, and colonoscopy findings were recorded. Multivariable logistic regression was used to determine factors associated with adenoma detection on baseline and interval colonoscopy. RESULTS: In total, 1869 patients with two successive colonoscopies (median 4.5 years) were included. Four hundred and sixty patients had metformin exposure prior to baseline and/or interval colonoscopy. Overall adenoma detection rate was 59.7% at baseline and 45.9% at interval colonoscopy. On multivariable analysis, metformin use was associated with decreased adenoma prevalence at baseline (OR 0.68; 95% CI 0.51-0.92; p = 0.015). Metformin did not impact adenoma incidence at interval colonoscopy whether prescribed before baseline (OR 1.26; 95% CI 0.60-2.67), after baseline (OR 1.25; 95% CI 0.91-1.72), or before and after baseline (OR 1.14; 95% CI 0.82-1.58). CONCLUSIONS: In this retrospective analysis of an average-risk cohort, metformin use was associated with a decreased prevalence of colorectal adenomas at baseline colonoscopy. This inverse association did not persist on interval colonoscopy. Prospective studies are needed to evaluate potential chemoprotective effects of metformin over time.


Assuntos
Adenoma , Pólipos do Colo , Neoplasias Colorretais , Metformina , Adenoma/diagnóstico , Adenoma/epidemiologia , Adenoma/prevenção & controle , Pólipos do Colo/tratamento farmacológico , Colonoscopia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/prevenção & controle , Detecção Precoce de Câncer , Humanos , Metformina/uso terapêutico , Estudos Retrospectivos , Fatores de Risco
3.
Dig Dis Sci ; 67(1): 85-92, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33611689

RESUMO

BACKGROUND: An endoscopist's adenoma detection rate (ADR) is inversely related to interval colorectal cancer risk and cancer mortality. Previous studies evaluating the impact of gastroenterology fellow participation in colonoscopy on ADR have generated conflicting results. AIMS: We aimed to determine the impact of fellow participation, duration of fellowship training, and physician sex on ADR and advanced ADR (AADR). METHODS: We retrospectively analyzed average-risk patients undergoing screening colonoscopy at Veterans Affairs New York Harbor Healthcare System Brooklyn Campus and Kings County Hospital Center. Review of colonoscopy and pathology reports were performed to obtain adenoma-specific details, including the presence of advanced adenoma and adenoma location (right vs. left colon). RESULTS: There were 893 colonoscopies performed by attending only and 502 performed with fellow participation. Fellow participation improved overall ADR (44.6% vs. 35.4%, p < 0.001), right-sided ADR (34.1% vs. 25.2%, p < 0.001), and AADR (15.3% vs. 8.3%, p < 0.001); however, these findings were institution-specific. Year of fellowship training did not impact overall ADR or overall AADR, but did significantly improve right-sided AADR (p-value for trend 0.03). Female attending physicians were associated with increased ADR (47.1% vs. 37.0%, p = 0.0037). Fellow sex did not impact ADR. CONCLUSIONS: Fellow participation in colonoscopy improved overall ADR and AADR, and female attending physicians were associated with improved ADR. Year of fellowship training did not impact overall ADR or AADR.


Assuntos
Adenoma , Pólipos do Colo , Colonoscopia/métodos , Neoplasias Colorretais , Bolsas de Estudo , Gastroenterologia , Ensino , Adenoma/diagnóstico , Adenoma/epidemiologia , Adenoma/cirurgia , Pólipos do Colo/diagnóstico , Pólipos do Colo/epidemiologia , Pólipos do Colo/cirurgia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/prevenção & controle , Detecção Precoce de Câncer/métodos , Educação/métodos , Educação/estatística & dados numéricos , Bolsas de Estudo/métodos , Bolsas de Estudo/organização & administração , Bolsas de Estudo/estatística & dados numéricos , Feminino , Gastroenterologia/educação , Gastroenterologia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Ensino/organização & administração , Ensino/estatística & dados numéricos , Estados Unidos
4.
Cancer Epidemiol Biomarkers Prev ; 30(1): 114-122, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33008872

RESUMO

BACKGROUND: Recent data suggest that subcutaneous adiposity represents an independent prognostic marker in cancer. We aimed to determine whether subcutaneous adiposity estimated by the subcutaneous adiposity tissue index (SATI) was associated with mortality in esophageal cancer. METHODS: We conducted a retrospective analysis of a prospectively enrolled cohort from 2009 to 2015 with esophageal cancer at two major cancer centers. CT scans for initial staging were used to quantify adiposity and skeletal muscle areas. Subjects were categorized as above or below median SATI using sex-specific values. Sarcopenia was defined using previously established skeletal muscle area cutoffs. Cox proportional hazards modeling was performed to determine associations between SATI and all-cause mortality. RESULTS: Of the original 167 patients, 78 met inclusion criteria and had CT images available. Mean age was 67 years, 81.8% had adenocarcinoma, and 58.9% had stage 3 or 4 disease. Median follow-up time was 29.5 months. Overall 5-year survival was 38.9% [95% confidence interval (CI), 26.8-50.7]. Lower body mass index, higher Charlson comorbidity score, and more advanced stage were independently associated with low SATI. Patients with low SATI had increased mortality (unadjusted HR 2.23; 95% CI, 1.20-4.12), even when adjusted for sarcopenia or for percent weight loss. In a multivariable model including age, histology, stage, and receipt of curative surgery, the association between low SATI and mortality was attenuated (adjusted HR 1.64; 95% CI, 0.81-3.34). CONCLUSIONS: Low subcutaneous adiposity as estimated by SATI may be associated with increased mortality in esophageal cancer. IMPACT: Interventions to reduce loss of subcutaneous fat may improve survival in esophageal cancer.


Assuntos
Adenocarcinoma/mortalidade , Adiposidade , Neoplasias Esofágicas/mortalidade , Redução de Peso , Idoso , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sarcopenia/diagnóstico por imagem , Sarcopenia/mortalidade , Sarcopenia/patologia
5.
ACG Case Rep J ; 6(12): e00295, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32161774

RESUMO

Acute esophageal necrosis or "black esophagus" is a rare clinical entity characterized by necrosis of the esophageal mucosa resulting from low-flow hemodynamic states. The disease commonly presents with upper gastrointestinal hemorrhage, and the diagnosis is based on the presence of circumferential black appearance of the distal esophagus with variable proximal involvement and sparing of mucosa distal to the esophagogastric junction. The disease is associated with a high mortality rate, and treatment is supportive. We describe a case of acute esophageal necrosis associated with acute postendoscopic retrograde cholangiopancreatography pancreatitis.

6.
Ann Clin Lab Sci ; 47(3): 354-356, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28667040

RESUMO

Iron pill gastritis has been shown to be associated with superficial gastric erosion and deposition of iron in lamina propria and gastric antral glands. However, iron absorption in gastric parietal and chief cells is rare. We present a case of a 62-year-old man with iron deficiency anemia. His past medical history is significant for Billroth II surgery. His medications include ferrous sulphate 325mg. Esophagogastroduodenoscopy showed diffuse circumferential abnormal mucosa at the gastro-jejunal anastomosis. The mucosa was erythematous and violaceous. Biopsy showed reactive gastropathy with iron deposits predominantly in macrophages, parietal cells, and chief cells. These findings were confirmed by iron stain and later by electron micrography of the gastric mucosa that showed iron deposits in mitochondria and cytoplasm of the parietal and chief cells.


Assuntos
Anemia Ferropriva/etiologia , Celulas Principais Gástricas/metabolismo , Gastrite/induzido quimicamente , Gastroenterostomia/efeitos adversos , Ferro/metabolismo , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/metabolismo , Anemia Ferropriva/patologia , Celulas Principais Gástricas/efeitos dos fármacos , Celulas Principais Gástricas/patologia , Mucosa Gástrica/patologia , Humanos , Ferro/administração & dosagem , Ferro/efeitos adversos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Células Parietais Gástricas/efeitos dos fármacos , Células Parietais Gástricas/metabolismo , Células Parietais Gástricas/patologia
7.
AAPS J ; 19(1): 254-263, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27739010

RESUMO

Host cell proteins are manufacturing process-related impurities that may co-purify with the product despite extensive efforts to optimize the purification process. The risks associated with these impurities can vary and may be patient and/or therapeutic dependent. Therefore, it is critical to monitor and control the levels of these impurities in products and their potential impact on safety and efficacy. Lebrikizumab is a humanized immunoglobulin G4 monoclonal antibody (mAb) that binds specifically to soluble interleukin 13. This mAb is currently in phase III clinical development for the treatment of asthma. Following initial phase III studies, the material used in lebrikizumab clinical trials was found to have a process-related impurity identified as Chinese hamster ovary phospholipase B-like 2 (PLBL2) which co-purified with lebrikizumab. The immunogenic potential of PLBL2 and its potential impact on the immunogenicity of lebrikizumab in clinical studies were therefore evaluated. Data from the clinical studies demonstrated that ∼90% of subjects developed a specific and measurable immune response to PLBL2. Given the high incidence of antibodies to PLBL2 as well as the comparable safety profile observed between placebo- and drug-treated subjects, no correlation between safety events and anti-PLBL2 antibodies could be made. Additionally, no impact on the incidence of anti-lebrikizumab antibodies was observed, suggesting the lack of an adjuvant effect from PLBL2. Interim analysis from ongoing phase III studies using material with substantially reduced levels of PLBL2 with patients having had longer exposure shows significantly less and dose-dependent frequency of immune responses to PLBL2.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos/sangue , Asma/tratamento farmacológico , Contaminação de Medicamentos , Lisofosfolipase/imunologia , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/uso terapêutico , Asma/sangue , Asma/imunologia , Células CHO , Ensaios Clínicos Fase III como Assunto , Cricetinae , Cricetulus , Humanos , Lisofosfolipase/sangue
8.
Therap Adv Gastroenterol ; 9(6): 806-814, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27803735

RESUMO

BACKGROUND: Esophageal cancer remains associated with poor outcomes, yet little is known regarding factors that influence survival. Aspirin use prior to cancer diagnosis may influence outcomes. We aimed to assess the effects of prediagnosis aspirin use in patients with esophageal cancer. METHODS: We conducted a prospective cohort study of newly-diagnosed esophageal cancer patients at two tertiary care centers. We assessed history of prediagnosis aspirin use, and prospectively followed patients and assessed mortality, cause of death, and development of metastases. RESULTS: We enrolled 130 patients, the majority of whom were male (81.5%) and had adenocarcinoma (80.8%). Overall, 57 patients (43.9%) were regular aspirin users. In unadjusted analyses, we found no difference in all-cause mortality between aspirin users and nonusers. In multivariate analyses, prediagnosis aspirin use was not associated with all-cause mortality [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.48-1.57] or esophageal cancer-specific mortality (HR 1.07, 95% CI 0.52-2.21). Prediagnosis aspirin use was associated with a significantly increased risk of interval metastasis (HR 3.59, 95% CI 1.08-11.96). CONCLUSIONS: In our cohort of esophageal cancer patients, prediagnosis aspirin use was not associated with all-cause or cancer-specific mortality. However, risk of interval metastatic disease was increased among those who took aspirin regularly prediagnosis. Future studies are warranted to assess whether aspirin influences the molecular characteristics of esophageal tumors, with potential prognostic and therapeutic implications.

9.
BMJ Case Rep ; 20152015 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-25948859

RESUMO

Despite the widespread use of herbal and dietary supplements (HDS), serious cases of hepatotoxicity have been reported. The popular herbal weight loss supplement, Hydroxycut, has previously been implicated in acute liver injury. Since its introduction, Hydroxycut has undergone successive transformations in its formulation; yet, cases of liver injury have remained an ongoing problem. We report a case of a 41-year-old Hispanic man who developed acute hepatocellular liver injury with associated nausea, vomiting, jaundice, fatigue and asterixis attributed to the use of a newer formulation of Hydroxycut, SX-7 Clean Sensory. The patient required hospitalisation and improved with supportive therapy. Despite successive transformations in its formulation, potential liver injury appears to remain an ongoing problem with Hydroxycut. Our case illustrates the importance of obtaining a thorough medication history, including HDS, regardless of new or reformulated product marketing efforts.


Assuntos
Fármacos Antiobesidade/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Suplementos Nutricionais/efeitos adversos , Preparações de Plantas/efeitos adversos , Adulto , Química Farmacêutica , Humanos , Masculino
10.
Gastroenterology ; 149(3): 567-76.e3; quiz e13-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25917785

RESUMO

BACKGROUND & AIMS: Barrett's esophagus (BE) with low-grade dysplasia (LGD) can progress to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). Radiofrequency ablation (RFA) has been shown to be an effective treatment for LGD in clinical trials, but its effectiveness in clinical practice is unclear. We compared the rate of progression of LGD after RFA with endoscopic surveillance alone in routine clinical practice. METHODS: We performed a retrospective study of patients who either underwent RFA (n = 45) or surveillance endoscopy (n = 125) for LGD, confirmed by at least 1 expert pathologist, from October 1992 through December 2013 at 3 medical centers in the United States. Cox regression analysis was used to assess the association between progression and RFA. RESULTS: Data were collected over median follow-up periods of 889 days (interquartile range, 264-1623 days) after RFA and 848 days (interquartile range, 322-2355 days) after surveillance endoscopy (P = .32). The annual rates of progression to HGD or EAC were 6.6% in the surveillance group and 0.77% in the RFA group. The risk of progression to HGD or EAC was significantly lower among patients who underwent RFA than those who underwent surveillance (adjusted hazard ratio = 0.06; 95% confidence interval: 0.008-0.48). CONCLUSIONS: Among patients with BE and confirmed LGD, rates of progression to a combined end point of HGD and EAC were lower among those treated with RFA than among untreated patients. Although selection bias cannot be excluded, these findings provide additional evidence for the use of endoscopic ablation therapy for LGD.


Assuntos
Adenocarcinoma/prevenção & controle , Esôfago de Barrett/cirurgia , Ablação por Cateter/métodos , Neoplasias Esofágicas/prevenção & controle , Esofagoscopia , Conduta Expectante/métodos , Adenocarcinoma/diagnóstico , Esôfago de Barrett/diagnóstico , Progressão da Doença , Neoplasias Esofágicas/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
11.
Rev. bras. med. fam. comunidade ; 7(Suplemento 1): 45-45, jun. 2012.
Artigo em Português | LILACS | ID: biblio-880799

RESUMO

Introdução: Pretendemos estabelecer uma cultura de paz em uma escola estadual de Natal com várias ocorrências de violência dos alunos contra professores. O aikido é uma arte marcial japonesa que promove por meio de técnicas corporais, etiqueta e disciplina uma "cultura de paz" melhorando o estado de atenção plena e entendimento mútuo. A meditação é uma prática que pode fornecer a melhoria do estado emocional com resultados favoráveis na cognição e na tolerância ao estresse. Objetivo: estudamos os efeitos psicológicos nos docentes da prática de Aikido e de meditação por uma semana em uma escola pública de Natal para promoção de uma cultura de paz. Método: Pesquisa-ação (Thiollent,2005) com entrevistas não-estruturadas de 40 professores antes e após a intervenção de uma semana de práticas contemplativas. Resultados: Os resultados das entrevistas dos professores mostraram um cotidiano estressante com bullying de alunos em sala de aula e com uma intensa carga horária de trabalho. Após a intervenção mais de 80% dos docentes apontaram aumento de tolerância ao estresse e melhoria de atenção e do equilíbrio emocional. Conclusão: observamos que o aikido e a meditação foram efetivos na melhoria do estado emocional e no aumento de tolerância ao estresse de professores. No entanto, investigações com número maior de sujeitos e com estudo prospectivo de longa duração das práticas contemplativas são necessários para avaliar a mediação de conflitos e pacificação dos alunos.


Assuntos
Conscientização , Artes Marciais , Meditação , Docentes
12.
Am J Gastroenterol ; 106(11): 1994-2000, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21912436

RESUMO

OBJECTIVES: Routine screening for hepatocellular carcinoma (HCC) is recommended in chronic hepatitis B (HBV) patients with cirrhosis and select non-cirrhotic HBV populations including Asian males ages 40 and older and females ages 50 and older. However, many younger HBV patients develop HCC and there have been few studies examining this group. Additionally, studies of HCC in the Asian immigrant population in the United States have been limited. The objective of this study was to determine the associated risk factors for the development of early-onset (males and females under ages 40 and 50, respectively) and late-onset HCC in immigrants with chronic HBV in the United States. METHODS: Clinical, demographic, and laboratory data were retrospectively collected on all Asian immigrants with HBV at Bellevue Hospital Center from 2003 to 2009. Patients with HCC were identified within this cohort. Features of early-onset and late-onset HCC cases were compared with age-matched HBV controls without HCC. RESULTS: We identified 168 cases of HCC in Asians with HBV. In all, 74% (124/168) of cases were late-onset, and 26% (44/168) were early-onset. When comparing the 124 late-onset HCC cases with 199 age-matched HBV controls, gender (odds ratio (OR)=4.4; P<0.05) and cirrhosis (OR=9.6; P<0.05) or surrogate labs (i.e., platelets, international normalized ratio, total bilirubin, albumin) were found to be associated with HCC development. When comparing the 44 early-onset HCC cases with 432 age-matched HBV controls, family history of HCC (OR=2.7; P<0.05), and smoking history (OR=3.4; P<0.05) were independently associated risk factors in addition to gender (OR=2.7; P<0.05), and cirrhosis (OR=19.5; P<0.05) or surrogate labs. In all, 54.8% of late-onset HCC cases were cirrhotic and 29.5% of early-onset HCC cases were cirrhotic. CONCLUSIONS: HCC occurs in Asian immigrant HBV patients younger than currently recommended screening guidelines. A large majority of these early-onset patients did not have cirrhosis at the time of their HCC diagnosis; therefore, factors other than cirrhosis need to be considered when evaluating HCC risk in young patients. Factors associated with HCC development across all ages include cirrhosis and male gender, while family history and smoking history may identify younger Asian immigrant HBV patients at risk for HCC. Prospective validation, including cost-effectiveness evaluation, is necessary, but our results suggest that younger Asian HBV patients, especially those with a smoking history or family history of HCC, appear to have an increased risk for HCC and should be considered for enrollment in early screening programs regardless of their age.


Assuntos
Povo Asiático , Carcinoma Hepatocelular/etnologia , Hepatite B Crônica/complicações , Cirrose Hepática/complicações , Neoplasias Hepáticas/etnologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bilirrubina/sangue , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Estudos de Casos e Controles , Feminino , Humanos , Coeficiente Internacional Normatizado , Cirrose Hepática/sangue , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Contagem de Plaquetas , Estudos Retrospectivos , Fatores de Risco , Albumina Sérica , Fatores Sexuais , Fumar , Fatores de Tempo , Estados Unidos/epidemiologia , Adulto Jovem
13.
J Pharm Biomed Anal ; 55(5): 1041-9, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21466939

RESUMO

Protein therapeutics may elicit an anti-therapeutic antibody (ATA) response in patients. This response depends on a number of factors including patient population, disease state, route of delivery or characteristics specific to the product. Therapeutics for immunological indications often target relatively young and healthy patients with hyperactive immune systems who have periodic flares and remissions. The hyperactive immune system of these patients can add several levels of bioanalytical complexity due to the presence of cross reactive molecules such as autoantibodies. In addition, the long-term chronic dosing regimen often necessary in this patient population can increase their risks of immunogenicity against the therapeutic and lead to safety concerns. Therefore, development of a sensitive and drug-tolerant ATA method is important. Bridging ATA assays are usually very sensitive and drug-tolerant methods for immunogenicity assessment; however these methods are particularly vulnerable to any factor that is able to bridge the conjugated therapeutics used as reagents and can generate false positive signal. Although there are many potential interfering factors in serum, rheumatoid factors (RFs), autoantibodies associated with rheumatoid arthritis (RA), are of particular concern in this type of assay. MTRX1011A is a non-depleting anti-CD4 monoclonal antibody therapeutic that was clinically tested in RA patients. This paper will discuss the bioanalytical challenges encountered during development of a clinical ATA assay for MTRX1011A. These challenges highlight interference due to patient disease state, in this case presence of RF in RA patients, as well as specific molecule-related interference caused by an engineered mutation in the Fc region of MTRX1011A designed to enhance its binding to the neonatal Fc receptor (FcRn). We will discuss the characterization work used to identify the cross-reactive epitope and our strategy to overcome this interference during development of an effective ATA assay to support clinical evaluation of MTRX1011A.


Assuntos
Anticorpos/química , Técnicas de Química Analítica/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Imunoensaio/métodos , Fragmentos de Imunoglobulinas/análise , Receptores Fc/química , Fator Reumatoide/análise , Artrite Reumatoide/imunologia , Biotina/química , Antígenos CD4/química , Ensaios Clínicos Fase I como Assunto , Epitopos/química , Humanos , Sistema Imunitário , Imunoglobulina G/análise , Imunoglobulina M/análise , Mutação , Receptores Fc/genética
14.
Exp Eye Res ; 85(4): 425-30, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17714704

RESUMO

Neovascular age-related macular degeneration (AMD) is the leading cause of blindness in older adults in the Western world. Ranibizumab (Lucentis), a humanized antibody fragment directed against vascular endothelial growth factor (VEGF-A), was recently approved by the US Food and Drug Administration (FDA) for the treatment of neovascular AMD. The objective of this study was to characterize the binding affinity and pharmacological activity of ranibizumab for 3 biologically active forms of VEGF-A: VEGF165, VEGF121, and VEGF110. The apparent equilibrium binding affinity of ranibizumab for VEGF-A molecules was determined by Biacore analysis; the biological activity of VEGF-A was demonstrated in a human umbilical vein endothelial cell (HUVEC) proliferation-inhibition assay. Inhibition of VEGF-A-induced vascular permeability by ranibizumab was assessed in vivo using hairless guinea pigs and a modified Miles assay. Ranibizumab was capable of binding to recombinant human VEGF165, VEGF121, and VEGF110 (KD < or = 192 pM), inhibiting VEGF-A-induced HUVEC proliferation in a concentration-dependent manner. Ranibizumab also exerted potent dose-dependent inhibition (IC(50) of 0.4-1.2 nM) of the vascular permeability-enhancing activity of VEGF165, VEGF121, and VEGF110 in the Miles assay. In conclusion, these results show that ranibizumab is capable of binding to and specifically inhibiting the activities of 3 biologically active forms of VEGF-A. As VEGF-A plays a pivotal role in the pathogenesis of neovascular AMD, ranibizumab activity, as demonstrated in this study, supports its clinical utility in the treatment of this disease.


Assuntos
Inibidores da Angiogênese/farmacologia , Anticorpos Monoclonais/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais Humanizados , Permeabilidade Capilar/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Cobaias , Humanos , Ranibizumab , Proteínas Recombinantes/metabolismo , Pele/irrigação sanguínea , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/farmacologia
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