RESUMO
OBJECTIVE: The human matrilin-3 T303M (in mouse T298M) mutation has been proposed to predispose for osteoarthritis, but due to the lack of an appropriate animal model this hypothesis could not be tested. This study was carried out to identify pathogenic mechanisms in a transgenic mouse line by which the mutation might contribute to disease development. METHODS: A mouse line carrying the T298M point mutation in the Matn3 locus was generated and features of skeletal development in ageing animals were characterized by immunohistology, micro computed tomography, transmission electron microscopy and atomic force microscopy. The effect of transgenic matrilin-3 was also studied after surgically induced osteoarthritis. RESULTS: The matrilin-3 T298M mutation influences endochondral ossification and leads to larger cartilage collagen fibril diameters. This in turn leads to an increased compressive stiffness of the articular cartilage, which, upon challenge, aggravates osteoarthritis development. CONCLUSIONS: The mouse matrilin-3 T298M mutation causes a predisposition for post-traumatic osteoarthritis and the corresponding knock-in mouse line therefore represents a valid model for investigating the pathogenic mechanisms involved in osteoarthritis development.
Assuntos
Artrite Experimental/genética , Osteoartrite do Joelho/genética , Osteogênese/genética , Animais , Artrite Experimental/diagnóstico por imagem , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Cartilagem Articular/metabolismo , Cartilagem Articular/ultraestrutura , Colágeno/ultraestrutura , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Proteínas Matrilinas/genética , Meniscectomia , Meniscos Tibiais/cirurgia , Camundongos , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/patologia , Mutação Puntual , Microtomografia por Raio-XRESUMO
Mice devoid of PrP are resistant to scrapie and fail to replicate the agent. Introduction of transgenes expressing PrP into such mice restores susceptibility to scrapie. We find that truncated PrP devoid of the five copper binding octarepeats still sustains scrapie infection; however, incubation times are longer and prion titers and protease-resistant PrP are about 30-fold lower than in wild-type mice. Surprisingly, brains of terminally ill animals show no histopathology typical for scrapie. However, in the spinal cord, infectivity, gliosis, and motor neuron loss are as in scrapie-infected wild-type controls. Thus, while the region comprising the octarepeats is not essential for mediating pathogenesis and prion replication, it modulates the extent of these events and of disease presentation.
Assuntos
Predisposição Genética para Doença/genética , Príons/genética , Príons/metabolismo , Sequências Repetitivas de Aminoácidos/genética , Scrapie/genética , Animais , Química Encefálica , Transplante de Tecido Encefálico , Núcleo Caudado/citologia , Núcleo Caudado/cirurgia , Ectoderma/citologia , Ectoderma/transplante , Transplante de Tecido Fetal , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Príons/análise , Putamen/citologia , Putamen/cirurgia , Scrapie/patologia , Deleção de Sequência/genética , Baço/química , TransgenesRESUMO
Antioxidants such as vitamin E protect unsaturated fatty acids of LDL against oxidation. In the ex vivo model used, LDL was exposed to Cu2+ ions, a potent prooxidant capable of initiating the oxidation of LDL. The lag time, indicating the delay of conjugated diene formation in LDL due to antioxidant protection, was measured in 54 cystic fibrosis (CF) patients with plasma alpha-tocopherol levels below (Group A, n = 30) or above (Group B, n = 24) 15.9 mumol/L (mean - 2 SD of Swiss population). Patients were reevaluated after 2 months on 400 IU/d of oral RRR-alpha-tocopherol. In group A, alpha-tocopherol concentrations in LDL increased significantly from 3.2 +/- 1.6 mol/mol LDL to 8.2 +/- 2.8 mol/mol (P < 0.001) and lag times increased from 79 +/- 33 min to 126 +/- 48 min (P < 0.001), whereas in the vitamin E sufficient group B no further increase neither in LDL alpha-tocopherol concentrations or in lag times was observed. LDL oleic acid concentrations were higher, and linoleic acid concentrations were lower in patients than in controls. After efficient vitamin E supplementation, lag times were positively related to LDL alpha-tocopherol (P < 0.01) and negatively to LDL linoleic and arachidonic acid content (P < 0.001). The maximum rate of oxidation correlated positively with linoleic and arachidonic acid concentrations, as did the maximum conjugated diene absorbance. These results indicate that LDL resistance to oxidation is impaired in vitamin E deficient CF patients but can be normalized within 2 months when alpha-tocopherol is given in sufficient amounts. Linoleic and arachidonic acid content exhibit a major influence on the LDL resistance to oxidation.
Assuntos
Antioxidantes/administração & dosagem , Fibrose Cística/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Vitamina E/administração & dosagem , Adulto , Cobre/farmacologia , Fibrose Cística/complicações , Ácidos Graxos/sangue , Humanos , Oxirredução , Vitamina E/sangue , Vitamina E/uso terapêutico , Deficiência de Vitamina E/complicações , Deficiência de Vitamina E/tratamento farmacológicoRESUMO
We investigated the effect of correcting beta-carotene deficiency in cystic fibrosis (CF) patients on two parameters of lipid peroxidation. The resistance to oxidation of low density lipoprotein (LDL) was measured by the lag time preceding the onset of conjugated diene formation during exposure to copper(II) ions, and lipid peroxide formation was quantitated by malondialdehyde concentrations in plasma (TBA/HPLC method). Simultaneously, alpha-tocopherol and beta-carotene concentrations were determined in LDL and in plasma. Thirty-four CF patients were investigated before and after 3 months of oral beta-carotene supplementation. Beta-carotene concentrations increased (p < 0.0001) in plasma (mean +/- SD) (0.09 +/- 0.06 vs. 1.07 +/- 0.86 mumol/l) and in LDL (0.02 +/- 0.02 vs. 0.31 +/- 0.28 mol/mol), without significant changes in alpha-tocopherol, either in plasma (24.7 +/- 5.9 vs. 25.4 +/- 7.6) or in LDL (8.47 +/- 2.95 vs. 9.05 +/- 4.13). Lag times, being shorter (p < 0.05) in patients than in controls, increased from 48.5 +/- 21.3 to 69.1 +/- 27.9 min (p < 0.001) and plasma MDA concentrations, being greater (p < 0.0001) in patients than in controls, decreased from 0.95 +/- 0.32 to 0.61 +/- 0.15 mumol/l (p < 0.0001). At 3 months, lag times and MDA concentrations did not any longer differ between patients and controls. These data suggest that excess lipid peroxidation occurring in beta-carotene deficiency can be limited and normalized during efficient beta-carotene supplementation in CF patients.
Assuntos
Carotenoides/deficiência , Carotenoides/uso terapêutico , Fibrose Cística/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Peróxidos Lipídicos/sangue , Lipoproteínas LDL/sangue , Criança , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos de Coortes , Fibrose Cística/tratamento farmacológico , Feminino , Humanos , Lipoproteínas LDL/efeitos dos fármacos , Masculino , Malondialdeído/sangue , Oxirredução , Valores de Referência , Análise de Regressão , Vitamina E/sangue , beta CarotenoRESUMO
To substitute for exocrine pancreatic insufficiency, patients with cystic fibrosis (CF) take pancreatic enzymes (PE) originating from porcine pancreas. Five different pancreatic enzyme preparations used by our patients contained 0.5-1.4 microg selenium per g tablet. In patients taking PE in doses that were gradually increased to improve fat absorption during a 48-month period, the effects of PE dose on erythrocyte selenium-dependent glutathione peroxidase (SeGSH-Px) activities and plasma selenium concentrations were studied. At baseline, erythrocyte SeGSH-Px activities were significantly lower in patients (p=.01), while plasma selenium concentrations did not differ between patients and healthy subjects. When PE dose and, consequently, selenium intake from PE was increased, erythrocyte SeGSH-Px activities (p < .001) and plasma selenium concentrations (p=.02) increased. Changes in SeGSH-Px activities during the initial 8 months correlated with those in selenium intake from PE (r=0.67, p < .001). Plasma selenium concentrations plateaued at 12 months and erythrocyte SeGSH-Px activities did so at 36 months, when patients had reached SeGSH-Px activities similar to those of healthy subjects. At 48 months, patients took an average lipase dose of 17400 U x kg(-1) x d(-1) and selenium dose from PE of 0.53 microg x kg(-1) x d(-1). We conclude that selenium content of PE preparations has a significant effect on SeGSH-Px activity in patients with CF. This form of selenium supply needs to be taken into account when selenium supplements are given to patients with CF.
Assuntos
Fibrose Cística/tratamento farmacológico , Enzimas/farmacologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Glutationa Peroxidase/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Extratos Pancreáticos/farmacologia , Selênio/sangue , Administração Oral , Adolescente , Adulto , Criança , Pré-Escolar , Estudos Transversais , Fibrose Cística/sangue , Fibrose Cística/metabolismo , Relação Dose-Resposta a Droga , Esquema de Medicação , Ativação Enzimática/efeitos dos fármacos , Eritrócitos/metabolismo , Feminino , Glutationa Peroxidase/análise , Humanos , Lactente , Lipase/administração & dosagem , Lipase/química , Lipase/farmacologia , Estudos Longitudinais , Masculino , Extratos Pancreáticos/administração & dosagem , Extratos Pancreáticos/química , Pancreatina/administração & dosagem , Pancreatina/química , Pancreatina/farmacologia , Pancrelipase , Selênio/análiseRESUMO
Polyunsaturated fatty acids of biomembranes are a major target of lipid peroxidation. In vitamin E deficiency an efficient delivery of a high oral loading dose of all-rac-alpha-tocopheryl acetate to erythrocyte membranes could provide an early onset antioxidative effect. We investigated short-term changes in erythrocyte alpha-tocopherol after a single oral dose of 100 mg all-rac-alpha-tocopheryl acetate/kg in 10 vitamin E-deficient cystic fibrosis (CF) patients. Over 24 h, erythrocyte alpha-tocopherol increased 68% to 420% of preloading concentrations. With two exceptions, peak values were achieved 12 or 24 h after administration, which was 3-18 h later than peak plasma concentrations. Separate median-based curve estimates for the changes in erythrocyte alpha-tocopherol for five patients with and five without associated cholestatic liver disease were obtained. Cross-sectional test results revealed significantly lower erythrocyte alpha-tocopherol for the 9- and 24-h observations for patients with cholestatic liver disease compared with those without. Oral all-rac-alpha-tocopheryl acetate can be rapidly incorporated into erythrocyte membranes in vitamin E-deficient CF patients.
Assuntos
Colestase Intra-Hepática/sangue , Fibrose Cística/sangue , Eritrócitos/química , Deficiência de Vitamina E/sangue , Vitamina E/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Colestase Intra-Hepática/complicações , Estudos Transversais , Fibrose Cística/complicações , Seguimentos , Humanos , Lactente , Distribuição Aleatória , Deficiência de Vitamina E/complicaçõesRESUMO
Biochemical vitamin E deficiency and low plasma lipids are frequent findings in patients with cystic fibrosis (CF). The response to a single oral dose of all-rac-alpha-tocopheryl acetate [100 IU (100 mg)/kg body wt] was studied over 24 h in 25 CF patients with exocrine pancreatic insufficiency and in 23 healthy individuals. Patients received pancreatic enzymes together with the vitamin E test dose. At baseline, plasma alpha-tocopherol concentrations correlated with cholesterol concentrations; both were lower in patients than in control subjects, as were erythrocyte alpha-tocopherol concentrations (all P < 0.0001). Plasma and erythrocyte alpha-tocopherol concentrations were significantly higher than baseline concentrations from 3 and 6 h onward, respectively, and peaked most frequently at 6 and 12 h, respectively, in both patients and control subjects. Maximum increases and areas under the concentration time curves for plasma alpha-tocopherol concentrations were smaller in patients than in control subjects (P < 0.0001). When ratios of plasma alpha-tocopherol to cholesterol (to correct for differences in cholesterol concentrations) or erythrocyte alpha-tocopherol concentrations were applied, patients were shown to respond as efficiently as control subjects. On the basis of these results, we recommend vitamin E supplements in doses high enough to achieve vitamin E status in CF patients well within the range of healthy individuals; these supplements should be given with appropriate amounts of pancreatic enzymes. However, for long-term supplementation much lower doses than those used in this test situation may be sufficient.
Assuntos
Antioxidantes/farmacocinética , Colesterol/sangue , Fibrose Cística/sangue , Vitamina E/análogos & derivados , Vitamina E/sangue , alfa-Tocoferol/análogos & derivados , Absorção , Administração Oral , Adulto , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Transporte Biológico , Criança , Fibrose Cística/complicações , Fibrose Cística/metabolismo , Relação Dose-Resposta a Droga , Eritrócitos/metabolismo , Feminino , Humanos , Lipase/uso terapêutico , Lipídeos/sangue , Masculino , Extratos Pancreáticos/uso terapêutico , Pancrelipase , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/farmacocinética , Vitamina E/uso terapêutico , Deficiência de Vitamina E/sangue , Deficiência de Vitamina E/tratamento farmacológico , Deficiência de Vitamina E/etiologiaRESUMO
To investigate the efficacy of three different vitamin E preparations for optimizing vitamin E status in cystic fibrosis (CF patients long-term, 29 patients (aged 0.7-29.8 y) were randomly assigned to receive 400 IU of either RRR-alpha-tocopherol (A: 268 mg, n = 10) or all rac-alpha-tocopheryl acetate as a fat-soluble (B: 400 mg, n = 10) or water-miscible preparation (C: 400 mg, n = 9) and were followed for 6 wk. In the whole study group, plasma alpha-tocopherol concentrations increased from baseline (10.5 +/- 4.6 micromol/L) to 3 wk (25.7 +/- 6.5 micromol/L; P < 0.001), but not further between 3 and 6 wk; concentrations at 3 and 6 wk did not differ from those of age-matched control subjects (23.6 +/- 3.9 micromol/L). There was no significant difference in the increase from baseline to 6 wk among preparations A (17.75 +/- 8.43 micromol/L), B (14.0 +/- 9.4 micromol/L), and C (15.5 +/- 7.1 micromol/L). Because of differences in body weight, the dose administered ranged from 5.5 to 47.4 IU x kg-1 x d-1; it correlated positively with the increase in plasma alpha-tocopherol concentrations (P < 0.001). There was no significant difference in the increase in plasma alpha-tocopherol concentrations between patients with CF-associated liver disease (n = 8) who received 10.2 +/- 3.8 IU x kg-1 x d-1 and those without liver disease taking comparable doses. We conclude that CF patients can be efficiently supplemented with 400 IU/d of any one of the three vitamin E preparations and plasma values of healthy control subjects can be achieved.
Assuntos
Antioxidantes/farmacocinética , Fibrose Cística/sangue , Deficiência de Vitamina E/prevenção & controle , Vitamina E/análogos & derivados , Vitamina E/sangue , Vitamina E/farmacocinética , alfa-Tocoferol/análogos & derivados , Administração Oral , Adolescente , Adulto , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Criança , Pré-Escolar , Colesterol/sangue , Fibrose Cística/complicações , Fibrose Cística/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Lactente , Hepatopatias/complicações , Hepatopatias/metabolismo , Masculino , Fatores de Tempo , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/uso terapêutico , Deficiência de Vitamina E/etiologiaRESUMO
Vitamin C status and possible associations with the disease process in cystic fibrosis (CF) patients were investigated. Plasma vitamin C concentrations in patients from two different mid-European populations (Swiss, n = 62; Austrian, n = 60) taking no or low-dose vitamin C from multivitamin supplements did not differ from each other or from control subjects (n = 34). Vitamin C concentrations decreased with age (5.05 mumol.L-1, y-1). When followed up for 12 mo, patients had the highest plasma vitamin C concentrations in February and the lowest in May and August (P < 0.01); the decrease in vitamin C was accompanied by increases in plasma malondialdehyde (P < 0.001) and tumor necrosis factor alpha concentrations (P < 0.01). During supplementation with vitamin E for 2 mo or beta-carotene for 12 mo vitamin C concentrations did not change. They correlated inversely with white blood cell count (r = -0.36, P = 0.008), bands (r = -0.36, P = 0.02), alpha 1-acid glycoprotein (r = -0.45, P = 0.002), interleukin 6 (r = -0.46, P = 0.0006), and neutrophil elastase/alpha 1-proteinase inhibitor complexes (r = -0.34, P = 0.02). In patients with vitamin C concentrations < 40 mumol/L, all indexes of inflammation were relatively high, whereas those with concentrations > 80 mumol/L (upper quartile of control subjects) showed clearly lower values. These results are consistent with the hypothesis that by scavenging oxygen free radicals vitamin C interacts with an inflammation-amplifying cycle of activation of alveolar macrophages and neutrophils, release of proinflammatory cytokines and oxygen free radicals, and inactivation of antiproteases.
Assuntos
Ácido Ascórbico/sangue , Fibrose Cística/sangue , Pneumopatias/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Fibrose Cística/etiologia , Fibrose Cística/fisiopatologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Lactente , Inflamação/sangue , Inflamação/etiologia , Inflamação/fisiopatologia , Interleucina-6/sangue , Elastase de Leucócito/sangue , Peroxidação de Lipídeos/fisiologia , Pneumopatias/etiologia , Pneumopatias/fisiopatologia , Masculino , Malondialdeído/sangue , Estado Nutricional , Orosomucoide/análise , Orosomucoide/metabolismo , Estações do Ano , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/metabolismo , Vitamina E/administração & dosagem , Vitamina E/farmacologia , beta Caroteno/administração & dosagem , beta Caroteno/sangue , beta Caroteno/farmacologiaRESUMO
In the mature human newborn infant, only pancreatic alpha-amylase shows a very low but highly inducible activity. Other digestive enzymes, although not yet at adult levels, increase rapidly with age. Intestinal absorptive functions develop already during early and mid-pregnancy and are mostly at adult levels in the newborn infant. Fat absorption is usually low in the premature infant and increases rapidly during the first month.
Assuntos
Feto/enzimologia , Absorção Intestinal , Intestinos/embriologia , Amilases/metabolismo , Gorduras na Dieta/metabolismo , Dipeptidases/metabolismo , Dissacaridases/metabolismo , Humanos , Recém-Nascido , Lipase/metabolismoRESUMO
The prion, the transmissible agent that causes spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease, is believed to be devoid of nucleic acid and to be identical to PrPSc (prion protein: scrapie form), a modified form of the normal host protein PrPC (prion protein: cellular form) which is encoded by the single copy gene Prnp. The 'protein only' hypothesis proposes that PrPSc, when introduced into a normal host, causes the conversion of PrPC into PrPSc; it therefore predicts that an animal devoid of PrPC should be resistant to prion diseases. The authors generated homozygous Prnp(o/o) ('PrP knockout') mice and showed that, after inoculation with prions, these mice remained free from scrapie for at least two years while wild-type controls all died within six months. There was no propagation of prions in the Prnp(o/o) animals. Surprisingly, heterozygous Prnp(o/+) mice, which express PrPC at about half the normal level, also showed enhanced resistance to scrapie despite high levels of infectious agent and PrPSc in the brain at an early stage. After introduction of murine PrP transgenes, Prnp(o/o) mice became highly susceptible to mouse--but not to hamster--prions, while the insertion of Syrian hamster PrP transgenes rendered the mice susceptible to hamster prions but much less susceptible to mouse prions. These complementation experiments enabled the application of reverse genetics. The authors prepared animals transgenic for genes encoding PrP with amino terminal deletions of various lengths and found that PrP that lacks 48 amino proximal amino acids (which comprise four of the five octa repeats of PrP) is still biologically active.
Assuntos
Camundongos Transgênicos , Doenças Priônicas , Animais , Bovinos , Síndrome de Creutzfeldt-Jakob/etiologia , Encefalopatia Espongiforme Bovina/etiologia , Humanos , Imunidade Inata , Camundongos , Doenças Priônicas/etiologia , Doenças Priônicas/imunologia , Príons/genética , Príons/fisiologia , Scrapie/etiologia , OvinosRESUMO
A retrospective analysis of the case histories of 176 infants and children with documented coeliac disease born between 1953 and 1975 revealed the following data: Gluten was introduced into the diet of 49% of these patients at an age of 3 to 4 months. The interval between the introduction of gluten and the appearance of first symptoms was very variable and independent of age, occurring within 4 weeks in 32% and within 2 weeks in 20% of cases. In 13% this interval was 6 to 13 months. 91% of cases presented during the first year of life. Signs were also variable, the most frequent combination being failure to thrive, abnormal stools, anorexia vomiting and abdominal distension. In young infants symptoms tended to be more severe, whilst in children older than 2 years stunting of growth was the most frequent single clinical finding.
Assuntos
Doença Celíaca/etiologia , Glutens/efeitos adversos , Doença Celíaca/complicações , Criança , Pré-Escolar , Transtornos do Crescimento/etiologia , Humanos , Lactente , Mucosa Intestinal/patologia , Intestino Delgado , Estudos RetrospectivosRESUMO
Since 1976, various activity indices for Crohn's disease have been developed but none has been suitable for use in the paediatric age group. Therefore, the German-Swiss Study Group on Crohn's Disease in Children and Adolescents decided to develop their own paediatric Crohn's disease activity index (PCDAI) by multiple regression analysis of prospectively collected data. The result was a simple index consisting of two clinical (appetite, number of stools/week) and four laboratory variables (erythrocyte sedimentation rate, serum iron and alpha 2-globulin concentrations and bands as percentage of white blood cells). Applying the index to patients who were followed-up, it could be demonstrated that the changes in PCDAI inversely reflected the changes in weight and that the surgical removal of the inflamed parts of the gut reduced the disease activity index to levels comparable to those obtained in patients after successful, exclusively conservative, treatment. Low disease activity was maintained for at least three years.
Assuntos
Doença de Crohn/fisiopatologia , Adolescente , Adulto , Apetite , Peso Corporal , Criança , Pré-Escolar , Doença de Crohn/diagnóstico , Fezes , Feminino , Humanos , Masculino , Análise de RegressãoAssuntos
Ácidos Graxos/análise , Fezes/análise , Síndromes de Malabsorção/metabolismo , Nitrogênio/análise , Pancreatopatias/metabolismo , Adolescente , Doença Celíaca/metabolismo , Criança , Pré-Escolar , Doença de Crohn/metabolismo , Fibrose Cística/metabolismo , Gorduras na Dieta/metabolismo , Feminino , Humanos , Lactente , Absorção Intestinal , Masculino , Proteínas/metabolismoAssuntos
Doença Celíaca , Glutens/efeitos adversos , Adolescente , Adulto , Doença Celíaca/dietoterapia , Doença Celíaca/etiologia , Criança , Pré-Escolar , Doença Crônica , Humanos , LactenteAssuntos
Gastroenteropatias/dietoterapia , Animais , Doença Celíaca/etiologia , Colite Ulcerativa/dietoterapia , Doença de Crohn/dietoterapia , Diarreia/etiologia , Dissacaridases/deficiência , Glutens/efeitos adversos , Humanos , Intolerância à Lactose , Síndromes de Malabsorção/dietoterapia , Leite , Proteínas do Leite/metabolismo , Pancreatopatias/dietoterapia , Nutrição Parenteral , Amido/metabolismo , Complexo Sacarase-Isomaltase/deficiênciaRESUMO
The criteria for the diagnosis of coeliac disease are the evidence of a well characterized and typical, albeit not pathognomonic lesion of the proximal small bowel mucosa in untreated patients as well as the unequivocal rapid response to a gluten free diet (GFD). The instruction and the motivation of the patients in GFD aims at an early and positive establishment of dietary habits, based on an adequate choice of gluten free foods. As coeliac disease is genetically determined, GFD should be maintained life long. The results of long term evaluations of relapses in coeliac patients confirm this postulate by demonstrating that only 6.5% of the patients show no mucosal alteration upon gluten ingestion, even after years on GFD, and that another group (12-18%) will deteriorate very slowly over years. Routine gluten challenges in patients, whose initial diagnosis was established according to the discussed criteria, seem therefore unjustified, as they represent a serious challenge of established dietary and life habits for the vast majority of patients without any positive issue for them.