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1.
Artigo em Inglês | MEDLINE | ID: mdl-38644588

RESUMO

BACKGROUND: Data on cost-effectiveness of first-line infliximab in paediatric patients with Crohn's disease are limited. Since biologics are increasingly prescribed and accompanied by high costs, this knowledge gap needs to be addressed. AIM: To investigate the cost-effectiveness of first-line infliximab compared to conventional treatment in children with moderate-to-severe Crohn's disease. METHODS: We included patients from the Top-down Infliximab Study in Kids with Crohn's disease randomised controlled trial. Children with newly diagnosed moderate-to-severe Crohn's disease were treated with azathioprine maintenance and either five induction infliximab (biosimilar) infusions or conventional induction treatment (exclusive enteral nutrition or corticosteroids). Direct healthcare consumption and costs were obtained per patient until week 104. This included data on outpatient hospital visits, hospital admissions, drug costs, endoscopies and surgeries. The primary health outcome was the odds ratio of being in clinical remission (weighted paediatric Crohn's disease activity index<12.5) during 104 weeks. RESULTS: We included 89 patients (44 in the first-line infliximab group and 45 in the conventional treatment group). Mean direct healthcare costs per patient were €36,784 for first-line infliximab treatment and €36,874 for conventional treatment over 2 years (p = 0.981). The odds ratio of first-line infliximab versus conventional treatment to be in clinical remission over 104 weeks was 1.56 (95%CI 1.03-2.35, p = 0.036). CONCLUSIONS: First-line infliximab treatment resulted in higher odds of being in clinical remission without being more expensive, making it the dominant strategy over conventional treatment in the first 2 years after diagnosis in children with moderate-to-severe Crohn's disease. TRIAL REGISTRATION NUMBER: NCT02517684.

2.
J Pediatr Gastroenterol Nutr ; 77(5): 628-633, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37494540

RESUMO

OBJECTIVES: Fatigue is a common symptom in children with inflammatory bowel disease (IBD). Diagnostic tests to evaluate biological causes of fatigue commonly include markers of inflammation and hemoglobin (Hb), yet functional parameters have been inadequately studied in pediatric IBD. In this study, we compared fatigued and non-fatigued children with IBD from both a biological and functional point of view. METHODS: A cross-sectional study of 104 pediatric IBD patients with mild to moderately active IBD was conducted. Fatigued children were defined as those with a Pediatric Quality of Life Inventory Multidimensional Fatigue Scale z score <-2.0. Non-fatigued children had a z score ≥-2.0. Disease-specific quality of life (measured with IMPACT-III score), C-reactive protein (CRP), fecal calprotectin (FC), hemoglobin z score (Hb z score), and physical activity tests including 6-minute walking distance z score (6MWD z score) and triaxial accelerometry (TA) were evaluated. RESULTS: Fatigued children (n = 24) had a significant lower IMPACT-III score than non-fatigued children (n = 80). Hb z scores, CRP, FC, and 6MWD z scores were not significantly different between groups. TA was performed in 71 patients. Wear time validation requirements were met in only 31 patients. Fatigued patients spent significant shorter median time in moderate-to-vigorous activity than non-fatigued patients (18.3 vs 37.3 minutes per day, P = 0.008). CONCLUSION: Biological parameters did not discriminate fatigued from non-fatigued patients. TA possibly distinguishes fatigued from non-fatigued patients; the potential association may provide a target for interventions to combat fatigue and improve quality of life.


Assuntos
Doenças Inflamatórias Intestinais , Qualidade de Vida , Humanos , Criança , Estudos Transversais , Doenças Inflamatórias Intestinais/diagnóstico , Exercício Físico , Proteína C-Reativa/análise , Fadiga/etiologia , Complexo Antígeno L1 Leucocitário , Hemoglobinas/metabolismo
3.
J Pediatr ; 256: 113-119.e4, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36563900

RESUMO

OBJECTIVE: To determine whether intravenous (IV) or oral iron suppletion is superior in improving physical fitness in anemic children with inflammatory bowel disease (IBD). STUDY DESIGN: We conducted a clinical trial at 11 centers. Children aged 8-18 with IBD and anemia (defined as hemoglobin [Hb] z-score < -2) were randomly assigned to a single IV dose of ferric carboxymaltose or 12 weeks of oral ferrous fumarate. Primary end point was the change in 6-minute walking distance (6MWD) from baseline, expressed as z-score. Secondary outcome was a change in Hb z-score from baseline. RESULTS: We randomized 64 patients (33 IV iron and 31 oral iron) and followed them for 6 months. One month after the start of iron therapy, the 6MWD z-score of patients in the IV group had increased by 0.71 compared with -0.11 in the oral group (P = .01). At 3- and 6-month follow-ups, no significant differences in 6MWD z-scores were observed. Hb z-scores gradually increased in both groups and the rate of increase was not different between groups at 1, 3, and 6 months after initiation of iron therapy (overall P = .97). CONCLUSION: In this trial involving anemic children with IBD, a single dose of IV ferric carboxymaltose was superior to oral ferrous fumarate with respect to quick improvement of physical fitness. At 3 and 6 months after initiation of therapy, no differences were discovered between oral and IV therapies. The increase of Hb over time was comparable in both treatment groups. TRIAL REGISTRATION: NTR4487 [Netherlands Trial Registry].


Assuntos
Anemia Ferropriva , Anemia , Doenças Inflamatórias Intestinais , Humanos , Criança , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/etiologia , Compostos Férricos/uso terapêutico , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológico , Maltose/uso terapêutico , Ferro/uso terapêutico , Hemoglobinas , Administração Oral , Resultado do Tratamento
4.
J Pediatr Gastroenterol Nutr ; 75(6): e111-e115, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36136124

RESUMO

OBJECTIVES: Thioguanine (TG) has been shown as a safe alternative in adults with inflammatory bowel disease (IBD) who did not tolerate conventional thiopurines [azathioprine (AZA)/mercaptopurine]. However, data in pediatric IBD are scarce. Therefore, we aimed to assess the safety of TG as maintenance therapy. METHODS: A retrospective, multicenter cohort study of children with IBD on TG was performed in the Netherlands. TG-related adverse events (AE) were assessed and listed according to the common terminology criteria for AE. RESULTS: Thirty-six children with IBD (median age 14.5 years) on TG (median dose 15 mg/day) were included in 6 centers. Five AE occurred during follow-up [pancreatitis (grade 3), hepatotoxicity (grade 3) (n = 2), Clostridium difficile infection (grade 2), and abdominal pain (grade 2)]. All patients (n = 8) with a previously AZA-induced pancreatitis did not redevelop pancreatitis on TG. CONCLUSIONS: In pediatric IBD, TG seems a safe alternative in case of AZA-induced pancreatitis. Further research assessing long-term TG-related safety and efficacy is needed.


Assuntos
Doenças Inflamatórias Intestinais , Pancreatite , Humanos , Adulto , Criança , Adolescente , Tioguanina/efeitos adversos , Estudos Retrospectivos , Estudos de Coortes , Mercaptopurina/efeitos adversos , Azatioprina/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico , Doença Crônica , Imunossupressores/efeitos adversos
5.
Gut ; 71(1): 34-42, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33384335

RESUMO

OBJECTIVE: In newly diagnosed paediatric patients with moderate-to-severe Crohn's disease (CD), infliximab (IFX) is initiated once exclusive enteral nutrition (EEN), corticosteroid and immunomodulator therapies have failed. We aimed to investigate whether starting first-line IFX (FL-IFX) is more effective to achieve and maintain remission than conventional treatment. DESIGN: In this multicentre open-label randomised controlled trial, untreated patients with a new diagnosis of CD (3-17 years old, weighted Paediatric CD Activity Index score (wPCDAI) >40) were assigned to groups that received five infusions of 5 mg/kg IFX at weeks 0, 2, 6, 14 and 22 (FL-IFX), or EEN or oral prednisolone (1 mg/kg, maximum 40 mg) (conventional). The primary outcome was clinical remission on azathioprine, defined as a wPCDAI <12.5 at week 52, without need for treatment escalation, using intention-to-treat analysis. RESULTS: 100 patients were included, 50 in the FL-IFX group and 50 in the conventional group. Four patients did not receive treatment as per protocol. At week 10, a higher proportion of patients in the FL-IFX group than in the conventional group achieved clinical (59% vs 34%, respectively, p=0.021) and endoscopic remission (59% vs 17%, respectively, p=0.001). At week 52, the proportion of patients in clinical remission was not significantly different (p=0.421). However, 19/46 (41%) patients in the FL-IFX group were in clinical remission on azathioprine monotherapy without need for treatment escalation vs 7/48 (15%) in the conventional group (p=0.004). CONCLUSIONS: FL-IFX was superior to conventional treatment in achieving short-term clinical and endoscopic remission, and had greater likelihood of maintaining clinical remission at week 52 on azathioprine monotherapy. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT02517684).


Assuntos
Doença de Crohn/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Infliximab/uso terapêutico , Adolescente , Anti-Inflamatórios/uso terapêutico , Azatioprina/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Imunossupressores/uso terapêutico , Masculino , Prednisolona/uso terapêutico , Indução de Remissão , Índice de Gravidade de Doença
6.
Clin Exp Med ; 22(3): 465-476, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34542781

RESUMO

Conflicting data about inflammatory bowel disease [IBD] and immunosuppressants are risk factors for severe COVID-19 confuse patients and healthcare providers. Clinical reports with longer follow-up are lacking. A retrospective search was performed for severe COVID-19 (hospital admission and/or mortality) one year after the SARS-CoV-2 outbreak in an IBD cohort from one of the most affected Dutch regions. Cohort characteristics were explored by value-based healthcare data, including immunotherapy. COVID-19 cases were detected by ICD-10 codes and further examined for IBD determinants (including medication) and COVID-19 characteristics (intensive care admission, respiratory support, treatment, mortality). The national mortality register was consulted, ensuring detection of patients that died without admission. Results were compared with regional and national general population registries. The IBD cohort consisted of 1453 patients (51% Crohn's disease, 54% women, 39.9% using immunotherapy), including children. Biologics use increased during the study. Eight cases (0.55%) had severe COVID-19: seven were hospitalized (0.48%, 95% confidence interval [CI] 0.21-1.04), and two died (0.14%, CI 0.002-0.55). Six patients had comorbidity, one used immunotherapy, and four had no medication. Both deceased patients were older than 80 years, had severe comorbidity, but used no immunotherapy. Hospitalization occurred significantly more in the IBD cohort than regionally (0.18%, CI 0.17-0.19, p = 0.015), but not significantly more than nationally (0.28%, CI 0.279-0.284). Mortality was equal in IBD patients, regionally (0.11%, CI 0.10-0.12) and nationally (0.13%, CI 0.125-0.128). Neither IBD nor immunosuppressants are associated with increased risks of severe COVID-19 in an observational study with one-year follow-up.


Assuntos
COVID-19 , Doenças Inflamatórias Intestinais , COVID-19/epidemiologia , Criança , Estudos de Coortes , Feminino , Humanos , Fatores Imunológicos/uso terapêutico , Imunossupressores/efeitos adversos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/epidemiologia , Masculino , Estudos Retrospectivos , SARS-CoV-2
7.
Pediatr Transplant ; 25(6): e14023, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34014017

RESUMO

BACKGROUND: PNP is a malignancy-associated autoimmune mucocutaneous syndrome due to autoantibodies against plakins, desmogleins, and other components of the epidermis and basement membrane of epithelial tissues. PNP-causing malignancies comprise mainly lymphoproliferative and hematologic neoplasms. PNP is extremely rare, especially in children. METHODS: Here, we present the first case of a child who developed PNP on a PTLD after small bowel transplantation because of a severe genetic protein-losing enteropathy. RESULTS: The patient in this case report had a severe stomatitis, striate palmoplantar keratoderma, and lichenoid skin lesions. In addition, she had marked esophageal involvement. She had lung pathology due to recurrent pulmonary infections and ventilator injury. Although we found no evidence of BO, she died from severe pneumonia and respiratory failure at the age of 12 years. CONCLUSION: It is exceptional that, despite effective treatment of the PTLD, the girl survived 5 years after her diagnosis of PNP. We hypothesize that the girl survived relatively long after the PNP diagnosis due to strong T-cell suppressive treatments for her small bowel transplantation.


Assuntos
Intestino Delgado/transplante , Transtornos Linfoproliferativos/complicações , Síndromes Paraneoplásicas/diagnóstico , Pênfigo/diagnóstico , Enteropatias Perdedoras de Proteínas/cirurgia , Criança , Evolução Fatal , Feminino , Humanos , Imunossupressores/uso terapêutico , Gêmeos Monozigóticos
8.
Gastroenterology ; 147(1): 65-68.e10, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24726755

RESUMO

Microvillus inclusion disease (MVID) is a disorder of intestinal epithelial differentiation characterized by life-threatening intractable diarrhea. MVID can be diagnosed based on loss of microvilli, microvillus inclusions, and accumulation of subapical vesicles. Most patients with MVID have mutations in myosin Vb that cause defects in recycling of apical vesicles. Whole-exome sequencing of DNA from patients with variant MVID showed homozygous truncating mutations in syntaxin 3 (STX3). STX3 is an apical receptor involved in membrane fusion of apical vesicles in enterocytes. Patient-derived organoid cultures and overexpression of truncated STX3 in Caco-2 cells recapitulated most characteristics of variant MVID. We conclude that loss of STX3 function causes variant MVID.


Assuntos
Síndromes de Malabsorção/genética , Microvilosidades/patologia , Mucolipidoses/genética , Mutação/genética , Proteínas Qa-SNARE/genética , Biópsia , Células CACO-2 , Duodeno/patologia , Feminino , Humanos , Lactente , Mucosa Intestinal/patologia , Síndromes de Malabsorção/patologia , Masculino , Microvilosidades/genética , Mucolipidoses/patologia , Técnicas de Cultura de Órgãos
9.
PLoS One ; 8(11): e80553, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24260417

RESUMO

BACKGROUND: Mutations in genes encoding cationic trypsinogen (PRSS1), pancreatic secretory trypsin inhibitor (SPINK1) and chymotrypsinogen C (CTRC) are associated with chronic pancreatitis. However, in many patients with a familial chronic pancreatitis pattern suggesting a genetic cause, no mutations in either of these genes can be found, indicating that other, still unknown, associated genes exist. In this respect ATP8B1 is an interesting candidate due to its strong expression in the pancreas, its supposed general function in membrane organization and the higher incidence of pancreatitis in patients with ATP8B1 deficiency. METHODS: We analyzed all 27 ATP8B1 coding exons and adjacent non-coding sequences of 507 chronic pancreatitis patients by direct sequencing. Exons that harbored possible relevant variations were subsequently sequenced in 1,027 healthy controls. RESULTS: In the exonic regions, 5 novel non-synonymous alterations were detected as well as 14 previously described alterations of which some were associated with ATP8B1 deficiency. However, allele frequencies for any of these variations did not significantly differ between patients and controls. Furthermore, several non-synonymous variants were exclusively detected in control subjects and multiple variants in the non-coding sequence were identified with similar frequencies in both groups. CONCLUSIONS: We did not find an association between heterozygous ATP8B1 variants and chronic pancreatitis in our cohort of patients with hereditary and idiopathic chronic pancreatitis.


Assuntos
Adenosina Trifosfatases/genética , Mutação , Pancreatite Crônica/genética , Alelos , Estudos de Casos e Controles , Éxons , Genótipo , Humanos , Íntrons
10.
PLoS One ; 6(8): e23745, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21887309

RESUMO

BACKGROUND: We previously showed that activation of the bile salt nuclear receptor Farnesoid X Receptor (FXR) protects against intestinal inflammation in mice. Reciprocally, these inflammatory mediators may decrease FXR activation. We investigated whether FXR activation is repressed in the ileum and colon of inflammatory bowel disease (IBD) patients in remission. Additionally, we evaluated whether genetic variation in FXR is associated with IBD. METHODS: mRNA expression of FXR and FXR target gene SHP was determined in ileal and colonic biopsies of patients with Crohn's colitis (n = 15) and ulcerative colitis (UC; n = 12), all in clinical remission, and healthy controls (n = 17). Seven common tagging SNPs and two functional SNPs in FXR were genotyped in 2355 Dutch IBD patients (1162 Crohn's disease (CD) and 1193 UC) and in 853 healthy controls. RESULTS: mRNA expression of SHP in the ileum is reduced in patients with Crohn's colitis but not in patients with UC compared to controls. mRNA expression of villus marker Villin was correlated with FXR and SHP in healthy controls, a correlation that was weaker in UC patients and absent in CD patients. None of the SNPs was associated with IBD, UC or CD, nor with clinical subgroups of CD. CONCLUSIONS: FXR activation in the ileum is decreased in patients with Crohn's colitis. This may be secondary to altered enterohepatic circulation of bile salts or transrepression by inflammatory signals but does not seem to be caused by the studied SNPs in FXR. Increasing FXR activity by synthetic FXR agonists may have benefit in CD patients.


Assuntos
Doenças Inflamatórias Intestinais/genética , Receptores Citoplasmáticos e Nucleares/agonistas , Estudos de Casos e Controles , Colite Ulcerativa/genética , Colite Ulcerativa/metabolismo , Colo/metabolismo , Feminino , Expressão Gênica , Variação Genética , Humanos , Íleo/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Masculino , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/análise
11.
Best Pract Res Clin Gastroenterol ; 24(5): 541-53, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20955958

RESUMO

Progressive familial intrahepatic cholestasis (PFIC) type 1, 2 and 3 are due to mutations in ATP8B1, ABCB11 and ABCB4, respectively. Each of these genes encodes a hepatocanalicular transporter, which is essential for the proper formation of bile. Mutations in ABCB4 can result in progressive cholestatic disease, while mutations in ATP8B1 and ABCB11 can result both in episodic cholestasis, referred to as benign recurrent intrahepatic cholestasis (BRIC) type 1 and 2, as well as in progressive cholestatic disease. This suggests a clinical continuum and these diseases are therefore preferably referred to as ATP8B1 deficiency and ABCB11 deficiency. Similarly PFIC type 3 is designated as ABCB4 deficiency. Heterozygous mutations in each of these transporters can also be associated with intrahepatic cholestasis of pregnancy. This review summarizes the pathophysiology, clinical features and current as well as future therapeutic options for progressive familial- and benign recurrent intrahepatic cholestasis as well as intrahepatic cholestasis of pregnancy.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/genética , Adenosina Trifosfatases/genética , Colestase Intra-Hepática/genética , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Ácidos e Sais Biliares/análise , Colestase Intra-Hepática/classificação , Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/etiologia , Colestase Intra-Hepática/fisiopatologia , Colestase Intra-Hepática/terapia , Progressão da Doença , Feminino , Humanos , Mutação , Gravidez , Complicações na Gravidez/etiologia , Complicações na Gravidez/genética , Complicações na Gravidez/terapia , Recidiva , Ácido Ursodesoxicólico/uso terapêutico
12.
J Hepatol ; 52(2): 258-71, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20034695

RESUMO

Bile formation at the canalicular membrane is a delicate process. This is illustrated by inherited liver diseases due to mutations in ATP8B1, ABCB11, ABCB4, ABCC2 and ABCG5/8, all encoding hepatocanalicular transporters. Effective treatment of these canalicular transport defects is a clinical and scientific challenge that is still ongoing. Current evidence indicates that ursodeoxycholic acid (UDCA) can be effective in selected patients with PFIC3 (ABCB4 deficiency), while rifampicin reduces pruritus in patients with PFIC1 (ATP8B1 deficiency) and PFIC2 (ABCB11 deficiency), and might abort cholestatic episodes in BRIC (mild ATP8B1 or ABCB11 deficiency). Cholestyramine is essential in the treatment of sitosterolemia (ABCG5/8 deficiency). Most patients with PFIC1 and PFIC2 will benefit from partial biliary drainage. Nevertheless liver transplantation is needed in a substantial proportion of these patients, as it is in PFIC3 patients. New developments in the treatment of canalicular transport defects by using nuclear receptors as a target, enhancing the expression of the mutated transporter protein by employing chaperones, or by mutation specific therapy show substantial promise. This review will focus on the therapy that is currently available as well as on those developments that are likely to influence clinical practice in the near future.


Assuntos
Canalículos Biliares/fisiopatologia , Hepatopatias/genética , Hepatopatias/terapia , Subfamília B de Transportador de Cassetes de Ligação de ATP/deficiência , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Membro 8 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Adenosina Trifosfatases/deficiência , Adenosina Trifosfatases/genética , Bile/fisiologia , Procedimentos Cirúrgicos do Sistema Biliar , Transporte Biológico Ativo , Resina de Colestiramina/uso terapêutico , Terapia Genética , Humanos , Lipoproteínas/deficiência , Lipoproteínas/genética , Hepatopatias/fisiopatologia , Transplante de Fígado , Modelos Biológicos , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/deficiência , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Mutação , Rifampina/uso terapêutico , Ácido Ursodesoxicólico/uso terapêutico
13.
Hepatology ; 51(1): 286-96, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19918981

RESUMO

UNLABELLED: Deficiency in P-type ATP8B1 is a severe and clinically highly variable hereditary disorder that is primarily characterized by intrahepatic cholestasis. It presents either as a progressive (progressive familial intrahepatic cholestasis type 1 [PFIC1]) or intermittent (benign recurrent intrahepatic cholestasis type 1 [BRIC1]) disease. ATP8B1 deficiency is caused by autosomal recessive mutations in the gene encoding ATP8B1, a putative aminophospholipid-translocating P-type adenosine triphosphatase. The exact pathogenesis of the disease is elusive, and no effective pharmacological therapy is currently available. Here, the molecular consequences of six distinct ATP8B1 missense mutations (p.L127P, p.G308V, p.D454G, p.D554N, p.I661T, and p.G1040R) and one nonsense mutation (p.R1164X) associated with PFIC1 and/or BRIC1 were systematically characterized. Except for the p.L127P mutation, all mutations resulted in markedly reduced ATP8B1 protein expression, whereas messenger RNA expression was unaffected. Five of seven mutations resulted in (partial) retention of ATP8B1 in the endoplasmic reticulum. Reduced protein expression was partially restored by culturing the cells at 30 degrees C and by treatment with proteasomal inhibitors, indicating protein misfolding and subsequent proteosomal degradation. Protein misfolding was corroborated by predicting the consequences of most mutations onto a homology model of ATP8B1. Treatment with 4-phenylbutyrate, a clinically approved pharmacological chaperone, partially restored defects in expression and localization of ATP8B1 substitutions G308V, D454G, D554N, and in particular I661T, which is the most frequently identified mutation in BRIC1. CONCLUSION: A surprisingly large proportion of ATP8B1 mutations resulted in aberrant folding and decreased expression at the plasma membrane. These effects were partially restored by treatment with 4-phenylbutyrate. We propose that treatment with pharmacological chaperones may represent an effective therapeutic strategy to ameliorate the recurrent attacks of cholestasis in patients with intermittent (BRIC1) disease.


Assuntos
Adenosina Trifosfatases/genética , Colestase/genética , Fenilbutiratos/farmacologia , Dobramento de Proteína/efeitos dos fármacos , Adenosina Trifosfatases/química , Adenosina Trifosfatases/efeitos dos fármacos , Células Cultivadas , Proteínas de Membrana/metabolismo , Mutação de Sentido Incorreto , Complexo de Endopeptidases do Proteassoma/metabolismo
14.
Hepatology ; 50(6): 1783-95, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19937698

RESUMO

UNLABELLED: Wilson disease (WD) is an autosomal recessive copper overload disorder of the liver and basal ganglia. WD is caused by mutations in the gene encoding ATP7B, a protein localized to the trans-Golgi network that primarily facilitates hepatic copper excretion. Current treatment comprises reduction of circulating copper by zinc supplementation or copper chelation. Despite treatment, a significant number of patients have neurological deterioration. The aim of this study was to investigate the possibility that defects arising from some WD mutations are ameliorated by drug treatment aimed at improvement of protein folding and restoration of protein function. This necessitated systematic characterization of the molecular consequences of distinct ATP7B missense mutations associated with WD. With the exception of p.S1363F, all mutations tested (p.G85V, p.R778L, p.H1069Q, p.C1104F, p.V1262F, p.G1343V, and p.S1363F) resulted in reduced ATP7B protein expression, whereas messenger RNA abundance was unaffected. Retention of mutant ATP7B in the endoplasmic reticulum, increased protein expression, and normalization of localization after culturing cells at 30 degrees C, and homology modeling suggested that these proteins were misfolded. Four distinct mutations exhibited residual copper export capacity, whereas other mutations resulted in complete disruption of copper export by ATP7B. Treatment with pharmacological chaperones 4-phenylbutyrate (4-PBA) and curcumin, a clinically approved compound, partially restored protein expression of most ATP7B mutants. CONCLUSION: These findings might enable novel treatment strategies in WD by directly enhancing the protein expression of mutant ATP7B with residual copper export activity. 1795.).


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Transporte de Cátions/genética , Curcumina/farmacologia , Degeneração Hepatolenticular/tratamento farmacológico , Mutação , Fenilbutiratos/farmacologia , Dobramento de Proteína/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal , Adenosina Trifosfatases/química , Proteínas de Transporte/química , Proteínas de Transporte de Cátions/química , Linhagem Celular Tumoral , Cobre/metabolismo , Proteínas de Transporte de Cobre , ATPases Transportadoras de Cobre , Degeneração Hepatolenticular/genética , Humanos , Metalochaperonas , Chaperonas Moleculares/química , Conformação Proteica
15.
Proc Natl Acad Sci U S A ; 106(24): 9709-14, 2009 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-19478059

RESUMO

ATP8B1 deficiency is caused by autosomal recessive mutations in ATP8B1, which encodes the putative phospatidylserine flippase ATP8B1 (formerly called FIC1). ATP8B1 deficiency is primarily characterized by cholestasis, but extrahepatic symptoms are also found. Because patients sometimes report reduced hearing capability, we investigated the role of ATP8B1 in auditory function. Here we show that ATP8B1/Atp8b1 deficiency, both in patients and in Atp8b1(G308V/G308V) mutant mice, causes hearing loss, associated with progressive degeneration of cochlear hair cells. Atp8b1 is specifically localized in the stereocilia of these hair cells. This indicates that the mechanosensory function and integrity of the cochlear hair cells is critically dependent on ATP8B1 activity, possibly through maintaining lipid asymmetry in the cellular membranes of stereocilia.


Assuntos
Adenosina Trifosfatases/fisiologia , Audição/fisiologia , Adenosina Trifosfatases/genética , Animais , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Camundongos , Camundongos Mutantes , Órgão Espiral/patologia , Proteínas de Transferência de Fosfolipídeos
16.
Hepatology ; 43(1): 51-3, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16374853

RESUMO

Benign recurrent intrahepatic cholestasis (BRIC) is characterized by episodic cholestasis and pruritus without anatomical obstruction. Effective medical treatment is not available. We report complete and long-lasting disappearance of pruritus and normalization of serum bile salt concentrations in cholestatic BRIC patients within 24 hours after endoscopic nasobiliary drainage (NBD). Relative amounts of phospholipids and bile salts in bile collected during NBD appeared to be normal, but phospholipids other than phosphatidylcholine (especially sphingomyelin) were increased. In conclusion, we propose that temporary endoscopic nasobiliary drainage should be considered in cholestatic BRIC patients.


Assuntos
Colestase Intra-Hepática/terapia , Drenagem/métodos , Adulto , Bile/química , Ácidos e Sais Biliares/análise , Endoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nariz , Fosfolipídeos/análise , Recidiva
17.
J Hepatol ; 41(5): 758-63, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15519648

RESUMO

BACKGROUND AND AIMS: Wilson disease is an hereditary disorder of copper metabolism, caused by mutations in the ATP7B gene, and leading to hepatic or neurologic disease. We examined whether H1069Q, the most common ATP7B mutation, is associated with a specific phenotype. METHODS: Genotyping results in 70 Dutch patients were related to clinical presentation. Subsequently a meta-analysis for genotype-phenotype correlation was performed on all patients available from literature, combined with the current Dutch group, a total of 577 patients. RESULTS: The Dutch patients homozygous or heterozygous for the H1069Q mutation presented more frequently with neurologic disease (63% and 43% vs. 15%), and at a later age (20.9 and 15.9 vs. 12.6 years) than patients without the H1069Q mutation. In the meta-analysis the odds-ratio for neurologic presentation in homozygous or heterozygous H1069Q vs. non-H1069Q patients was 3.50 (95% CI 2.01-6.09) and 2.13 (95% CI 1.18-3.83), respectively. Age at presentation was 21.1, 19.2 and 16.5 years, respectively, corresponding to a weighted mean difference (WMD) of 4.41 (95% CI 1.56-7.26) for homozygous H1069Q vs. heterozygous patients and 6.68 (95% CI 4.33-9.38) for homozygous H1069Q vs. non-H1069Q patients. CONCLUSIONS: Our results indicate that the H1069Q mutation is associated with a late and neurologic presentation.


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Transporte de Cátions/genética , Degeneração Hepatolenticular/genética , Degeneração Hepatolenticular/fisiopatologia , Mutação Puntual , Idade de Início , ATPases Transportadoras de Cobre , Genótipo , Humanos , Sistema Nervoso/fisiopatologia , Fenótipo
18.
Nat Genet ; 36(4): 400-4, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15052268

RESUMO

ARC syndrome (OMIM 208085) is an autosomal recessive multisystem disorder characterized by neurogenic arthrogryposis multiplex congenita, renal tubular dysfunction and neonatal cholestasis with bile duct hypoplasia and low gamma glutamyl transpeptidase (gGT) activity. Platelet dysfunction is common. Affected infants do not thrive and usually die in the first year of life. To elucidate the molecular basis of ARC, we mapped the disease to a 7-cM interval on 15q26.1 and then identified germline mutations in the gene VPS33B in 14 kindreds with ARC. VPS33B encodes a homolog of the class C yeast vacuolar protein sorting gene, Vps33, that contains a Sec1-like domain important in the regulation of vesicle-to-target SNARE complex formation and subsequent membrane fusion.


Assuntos
Artrogripose/genética , Colestase/genética , Nefropatias/genética , Fusão de Membrana/fisiologia , Proteínas de Membrana/genética , Proteínas de Membrana/fisiologia , Mutação , Proteínas/genética , Proteínas de Transporte Vesicular , Western Blotting , Linhagem Celular , Cromossomos Humanos Par 15 , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Masculino , Fusão de Membrana/genética , Proteínas de Membrana/química , Plasmídeos , Proteínas/química , Proteínas SNARE , Síndrome
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