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D Guyader

Publications and source records attributed to D Guyader.

At least 19 recordsLinked to original sources
PubMed2004

Non-invasive assessment of hepatic iron stores by MRI.

BACKGROUND: MRI has been proposed for non-invasive detection and quantification of liver iron content, but has not been validated as a reproducible and sensitive method, especially in patients with mild iron overload. We aimed to assess the accuracy of a simple, rapid, and easy to implement MRI procedure to detect and quantify hepatic iron stores. METHODS: Of 191 patients recruited, 17 were excluded and 174 studied, 139 in a study group and 35 in a validation group. All patients underwent both percutaneous liver biopsy with biochemical assessment of hepatic iron concentration (B-HIC) and MRI of the liver with various gradient-recalled-echo (GRE) sequences obtained with a 1.5 T magnet. Correlation between liver to muscle (L/M) signal intensity ratio and liver iron concentration was calculated. An algorithm to calculate magnetic resonance hepatic iron concentration (MR-HIC) was developed with data from the study group and then applied to the validation group. FINDINGS: A highly T2-weighted GRE sequence was most sensitive, with 89% sensitivity and 80% specificity in the validation group, with an L/M ratio below 0.88. This threshold allowed us to detect all clinically relevant liver iron overload greater than 60 micromol/g (normal value <36 micromol/g). With other sequences, an L/M ratio less than 1 was highly specific (>87%) for raised hepatic iron concentration. With respect to B-HIC range analysed (3-375 micromol/g), mean difference and 95% CI between B-HIC and MR-HIC were quite similar for study and validation groups (0.8 micromol/g [-6.3 to 7.9] and -2.1 micromol/g [-12.9 to 8.9], respectively). INTERPRETATION: MRI is a rapid, non-invasive, and cost effective technique that could limit use of liver biopsy to assess liver iron content. Our MR-HIC algorithm is designed to be used on various magnetic resonance machines.

Algorithms↗
PubMed2001

Histologic features of the liver in insulin resistance-associated iron overload. A study of 139 patients.

The aim of the present study was to describe histologic features of the liver in insulin resistance-associated hepatic iron overload (IR-HIO), defined as the association of metabolic disorders and hepatic iron overload. We included 139 patients in the study on the basis of one or more metabolic disorders and liver iron overload unrelated to usual causes. Liver biopsy specimens were reviewed, and histologic data were compared with those of a previously published, well-defined population with genetic hemochromatosis. Iron overload was characterized by a mixed pattern with iron deposits in hepatocytes and sinusoidal cells. Steatosis was present in 59.7% of patients with inflammation in 32.4% of cases. Periportal fibrosis was found in 67.4% of patients. These patients were older, had higher sinusoidal iron scores, and had a higher prevalence of steatosis and inflammation than patients without fibrosis. Iron overload in IR-HIO was histologically different from that in genetic hemochromatosis.

Adult↗
PubMed2000

Determination of non-transferrin-bound iron in genetic hemochromatosis using a new HPLC-based method.

BACKGROUND/AIMS: Non-transferrin-bound iron may play a major pathogenic role in iron overload diseases due to its high hepatic uptake and potential damaging effect. The aim of this study was to evaluate the relevance of measuring serum non-transferrin-bound iron levels in genetic hemochromatosis using a new high performance liquid chromatography-based method. METHODS: This method includes a presaturation step of transferrin with cobalt(II) in order to avoid secondary deplacement of non-transferrin-bound iron toward transferrin during the assay. Six genetic hemochromatotic patients were followed serially during venesection treatment. RESULTS/CONCLUSIONS: The results indicate: (i) that this new method permits detection of non-transferrin-bound iron when transferrin is not fully saturated, (ii) that non-transferrin-bound iron levels persist almost until the completion of treatment, (iii) that non-transferrin-bound iron levels are well correlated with transferrin saturation for a given patient, and (iv) that despite some individual variations, a transferrin saturation value lower than 35% usually corresponds to the disappearance of non-transferrin-bound iron.

Adult↗
PubMed2000

Clinical aspects of hemochromatosis.

Hemochromatosis is one of the most frequent genetic diseases among the white populations, affecting one in three hundred persons. Its diagnosis has been radically transformed by the discovery of the HFE gene. In a given individual, the diagnosis can, from now on, be ascertained on the sole association of a plasma transferrin saturation (TS) over 45% and homozygosity for the C282Y mutation. Liver biopsy is only required to search for cirrhosis whenever there is hepatomegaly and/or serum ferritin >1000 ng/ml and/or elevated serum AST. Family screening is mandatory, primarily centered on the siblings. The treatment remains based on venesection therapy which improves many features of the disease (one of the most refractory, however, being the joint signs) and permits normal life expectancy provided the diagnosis is established prior to the development of cirrhosis or of insulin-dependent diabetes. In view of the prevalence, the non-invasive diagnosis, the spontaneous severity and the efficacy of a very simple therapy, hemochromatosis should benefit from population screening. This screening could be based, first, on the assessment of transferrin saturation, followed - when elevated - by the search for the C282Y mutation. The discovery of the HFE gene has also paved the road for the individualization of other types of iron overload syndromes which are not HFE-related.

HLA Antigens↗
PubMed2000

Respective value of alkaline phosphatase, gamma-glutamyl transpeptidase and 5' nucleotidase serum activity in the diagnosis of cholestasis: a prospective study of 80 patients.

We studied the value of alkaline phosphatase (AP), gamma-glutamyl transpeptidase (GGT), and 5'-nucleotidase (5'-NU) activities in the diagnosis of intrahepatic (IHC) versus extra-hepatic cholestasis (EHC). Eighty patients were included prospectively. All presented with cholestasis as defined by a concomitant increase in at least two of three cholestatic enzymes (AP, GGT, 5'-NU), a low cytolytic ratio (alanine aminotransferase/AP [xN/xN] < or = 5), and no evidence for associated liver tumor. We compared 43 patients with IHC due to chronic liver disease to 37 patients with EHC due to main bile duct obstruction. Fasting blood samples for activity determination (AP, GGT, 5'-NU) were taken before performing liver biopsy in cases of IHC and before endoscopic or surgical management in cases of EHC. Enzyme activities were compared using univariate and multivariate analysis. AP (276 IU/L [35-3,140] vs. 123 IU/L [37-699]: p < 0.0001), GGT (595 IU/L [98-5,200] vs. 211 IU/L [38-925]; p < 0.0001), and 5'-NU (32 IU/L [10-142] vs. 16 IU/L [4-107]: p < 0.0003) were significantly higher in EHC when compared to IHC. Only in GGT and 5'-NU activities were independent variables significantly linked to the mechanism of cholestasis. In IHC, the ratio GGT/5'-NU (xN/xN) was significantly lower than in EHC (2.8 [0.7-7.2] vs. 3.7 [1.8-10.5]: p < 0.006). A threshold of GGT/5'-NU < 1.9 had a sensitivity of 40% and a specificity of 100% for the diagnosis of IHC. Although such hepatobiliary enzymes cannot be regarded as diagnostic, they can provide useful information to orientate the clinician in the diagnosis of cholestasis.

Adolescent↗
PubMed2000

[Quantification of iron overload].

Iron overload involves primarily hepatocytes in case of digestive hyperabsorption (hemochromatosis and dyserythropoiesis) and macrophages in case of transfusional excess. Serum iron and transferrin saturation are poorly correlated with the degree of iron overload. Serum ferritin is a better reflect of iron stores but numerous clinical conditions, unrelated to variations of iron load, can increase the serum level. Biochemical determination of liver iron overload is the gold standard of iron quantification and well correlated to the level of iron burden appreciated by the amount of iron removed by venesection, but its determination necessitates a liver biopsy and is dependant of sampling error in case of heterogeneous iron deposits (cirrhosis). The sensitivity of computed tomography is insufficient, beeing unable to detect iron overload below 5 times the normal liver iron load, especially in case of associated steatosis. Magnetic resonance imaging is a valuable tool when using T2 weighted gradient echo sequences on 1.5 Tesla magnet and permits non invasive iron overload quantification.

Biopsy↗
PubMed1999

Insulin resistance-associated hepatic iron overload.

BACKGROUND & AIMS: Hepatic iron overload has been reported in various metabolic conditions, including the insulin-resistance syndrome (IRS) and nonalcoholic steatohepatitis (NASH). The aim of this study was to show that such hepatic iron overload is part of a unique and unrecognized entity. METHODS: A total of 161 non-C282Y-homozygous patients with unexplained hepatic iron overload were included. We determined the age; sex; presence of IRS (1 or more of the following: body mass index of >25, diabetes, or hyperlipidemia); serum iron tests and liver iron concentration (LIC; reference value, <36 micromol/g); liver function test results; C282Y and H63D HFE mutations; and liver histological status. RESULTS: Patients were predominantly male and middle-aged. Most (94%) had IRS. Transferrin saturation was increased in 35% (median, 42%; range, 13%-94%). LIC ranged from 38 to 332 micromol/g (median, 90 micromol/g), and LIC/age ratio ranged from 0.5 to 4.8 (median, 1.8). Allelic frequencies of both HFE mutations were significantly increased compared with values in normal controls (C282Y, 20% vs. 9%; H63D, 30% vs. 17%), only because of a higher prevalence of compound heterozygotes. Patients with no HFE mutations had similar degrees of iron overload as those with other genotypes, except for compound heterozygotes, who had slightly more iron burden. Steatosis was present in 25% of patients and NASH in 27%. Portal fibrosis (grades 0-3) was present in 62% of patients (grade 2 or 3 in 12%) in association with steatosis, inflammation, and increased age. Sex ratio, IRS, transferrin saturation, and LIC did not vary with liver damage. Serum ferritin concentration, liver function test results, and fibrosis grade were more elevated in patients with steatosis and NASH than in others, but LIC and allelic frequencies of HFE mutations were similar. CONCLUSIONS: This study shows that patients with unexplained hepatic iron overload are characterized by a mild to moderate iron burden and the nearly constant association of an IRS irrespective of liver damage.

Adult↗
PubMed1999

A genotypic study of 217 unrelated probands diagnosed as "genetic hemochromatosis" on "classical" phenotypic criteria.

BACKGROUND/AIMS: The HFE gene is a crucial candidate gene for hemochromatosis. The aims of this study were to assess the HFE genotypic profile in a large series of unrelated probands diagnosed as having phenotypic hemochromatosis, to characterize the sub-group of patients who were not homozygous for the major C282Y mutation, and to report the iron status of the detected HFE-identical siblings. METHODS: In 217 patients, the phenotypic diagnosis of hemochromatosis was based on strict bioclinical and/or histological criteria, and their genotypic profile (C282Y and H63D mutations) was determined. RESULTS: 1) 209 of the 217 probands were C282Y +/+. In 33 cases, an HFE-identical sibling was identified. Two of them had neither a clinical nor a biochemical phenotypic profile of hemochromatosis in the absence of any external factor which might have attenuated this expression. 2) Eight patients (seven males) were not C282Y +/+. Their genotypic profiles were: (C282Y +/-): six cases (four were H63D +/- and two H63D -/-); (C282Y -/-): two cases (one was H63D +/+, one H63D +/-). Phenotypic expression consisted of six cases of mild liver siderosis (among whom were the four compound heterozygotes and one case of alcoholic cirrhosis) and two severe cases of hepatic iron overload (one with alcoholic cirrhosis). Three HFE-identical siblings were identified, none of them presenting with iron excess. CONCLUSIONS: In our population: 1) The classical phenotypic criteria fitted, in 96.3% of cases, with a homogeneous genotypic entity defined by homozygosity for the C282Y mutation. Incomplete penetrance of the homozygous status was shown by the absence of the hemochromatosis phenotypic profile in 6% of the HFE-identical siblings. 2) A minority (3.7%) were not homozygous for C282Y. These were essentially men with mild iron overload, and might present with distinct iron overload entity(ies) as suggested by the presence in three of an HFE-identical sibling with absence of iron overload.

Adult↗
PubMed1999

Lack of effect of propranolol in the prevention of large oesophageal varices in patients with cirrhosis: a randomized trial. French-Speaking Club for the Study of Portal Hypertension.

OBJECTIVE: Beta-blockers have been shown to reduce portal pressure in patients with cirrhosis and limit the development of portosystemic shunts in portal hypertensive animals. Thus, a randomized double-blind trial was conducted to evaluate propranolol in the prevention of the development of large oesophageal varices in patients with cirrhosis without varices or with small varices. METHODS: One hundred and two patients received long-acting propranolol (160 mg/day) and 104 patients received a placebo. At inclusion, there was no significant difference between the two groups in terms of clinical characteristics or biochemical tests. At 2 years, the size of varices was estimated on video recordings. RESULTS: One-third of the patients were lost to follow-up, and 95%/97% of the remaining patients were compliant in the propranolol and placebo groups, respectively. At 2 years, the proportion of patients with large varices was 31% in the propranolol group and 14% in the placebo group (P< 0.05). Three and four patients bled in the propranolol and placebo groups, respectively, and nine and ten died, respectively. CONCLUSION: This trial suggests that propranolol administration cannot be recommended for the prevention of the development of large oesophageal varices in patients with cirrhosis; thus other studies are needed in selected subgroups of patients.

Adrenergic beta-Antagonists↗
PubMed1999

In patients with cirrhosis, serum albumin determination should be carried out by immunonephelometry rather than by protein electrophoresis.

OBJECTIVE: Serum albumin is a key parameter for prognosis in cirrhosis. We compared levels of serum albumin determined by both protein electrophoresis and immunonephelometry, with special reference to the Child-Pugh classification. DESIGN AND METHODS: One hundred and thirty-one patients, including 39 with cirrhosis, were included prospectively during 2 months. The aetiology of cirrhosis was mainly alcoholism (67%) and hepatitis C virus (HCV) (18%). Serum albumin was determined simultaneously by electrophoresis (Hydrasys SEBIA following protein determination by the biuret reaction) and by immunonephelometry (BECKMAN Nephelometer). Values were compared by non-parametric tests. RESULTS: For the whole population, electrophoretic and immunonephelometric values correlated (p = 0.85; P < 0.0001), but electrophoresis significantly overestimated serum albumin by a median 1.6 g/l (P < 0.0001) with a large spread in values (range, -3.9 to 12.7). Median overestimation in cirrhosis was 2.6 g/l (P < 0.0001; range, -2.0 to 10.2) and 1.0 g/l (P < 0.0001; range, -3.9 to 12.7) in patients without cirrhosis (difference, P < 0.02). For 6/39 (15.4%) patients with cirrhosis, this overestimation led to an underestimation in the Child-Pugh classification. CONCLUSION: In our experience, electrophoresis can lead to serum albumin values which are significantly different compared to those obtained by immunonephelometry. This discrepancy may lead to an incorrect Child-Pugh classification. Therefore, in the follow-up of cirrhotic patients, serum albumin should be determined by immunonephelometry.

Adult↗
PubMed1999

Magnetic resonance iron-free nodules in genetic hemochromatosis.

OBJECTIVE: In hemochromatosis, areas of normal hepatic magnetic resonance (MR) signal intensity indicate the presence of iron-free-nodules, which are strongly suspected of being neoplastic. The goal of the study was to define the prevalence and the nature of these iron-free MR nodules at the time of diagnosis in 116 patients included in a prospective study assessing the accuracy of MR imaging (MRI) in the quantification of liver iron overload. METHODS: Seventy-nine of the 116 patients had homozygous hemochromatosis on a phenotypic basis. Fifteen-millimeter-thick contiguous slices were performed using T1- and T2-weighted gradient echo sequences with a 0.5 Tesla magnet. RESULTS: Six of 79 homozygous hemochromatotic patients had one or more MR iron-free nodules. Five of the six patients proved to have malignant tumors. Four of six iron-free nodules were hepatocellular carcinoma (5% in the hemochromatosis group and 17.5% in hemochromatotic patients with severe fibrosis). CONCLUSIONS: The present data confirm the high prevalence of liver cancer at the time of diagnosis, mainly in cirrhotic patients greater than 45 years of age, and indicate that, when performing MRI for liver iron quantification, a complete hepatic MRI examination is preferable to a simple signal measurement in patients at risk for hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1999

[Importance of liver puncture biopsy and endoscopic retrograde cholangiography in patients with chronic anicteric unexplained cholestasis. A retrospective study in 79 patients].

AIM: To determine the diagnostic value of systematic liver needle biopsy and endoscopic retrograde cholangiography in patients with unexplained chronic anicteric cholestasis. METHODS: Seventy nine patients presented with anicteric cholestasis for over 6 months as defined by: a concomitant increase in at least 2 of 3 cholestatic enzymes (GGT, alkaline phosphatase, 5'nucleotidase); a low cytolytic ratio (ALT/AP (xN/xN) < or = 5); and negative test results (normal ultrasound scan; no antimitochondrial antibodies, viral, drug-induced, or toxic hepatitis, or known ulcerative cholitis). Based on liver biopsy and endoscopic retrograde cholangiography, 5 groups were determined; group A: normal liver biopsy and endoscopic retrograde cholangiography; group B: primary sclerosing cholangitis with histological biliary lesions; group C: primary sclerosing cholangitis with normal histology; group D: histologic biliary lesions alone; group E: other (aspecific histologic lesions, isolated anomalies of intrahepatic bile ducts on endoscopic retrograde cholangiography). RESULTS: Diagnosis of cholestasis was fortuitous in 43% of cases. Group A: 5 patients had normal liver biopsy and endoscopic retrograde cholangiography; group B (10 patients): 5 with destructive cholangitis, 5 with degenerative cholangitis, associated with portal fibrosis in 90%; group C: none of the patients had primary sclerosing cholangitis with normal histology; group D: 39 patients {idiopathic ductopenia (1), Caroli's disease (1), benign recurrent cholestasis (1), regenerative nodular hyperplasia (4), destructive cholangitis without ductopenia (7), degenerative cholangitis (15), ductular proliferation (10)}; group E: 24 patients with aspecific histologic lesions, and one patient with isolated anomalies of the intrahepatic bile ducts on endoscopic retrograde cholangiography. CONCLUSIONS: In the present population: a) 13% presented with intense cholangitis and primary sclerosing cholangitis on endoscopic retrograde cholangiography; b) 49% presented with various histologic biliary lesions without primary sclerosing cholangitis. We conclude that in chronic anicteric cholestasis of unexplained origin, first choice work-up should include liver biopsy, and endoscopic retrograde cholangiography should only be performed when intense histologic cholangitis is observed.

Adolescent↗
PubMed1999

[The diagnosis of hemochromatosis in the era of the gene].

The discovery of the hemochromatosis gene has deeply changed and simplified the diagnosis of the disease. In a given individual, establishing the diagnosis relies, from now on, on a simple blood sample showing the couple: elevated transferrin saturation and homozygous C282Y mutation (= C282Y +/+). Liver biopsy should only be performed when iron overload is massive in order to detect cirrhosis (or bridging fibrosis), i.e. in a prognostic view. Practically, liver biopsy is confined to the following two situations: when the C282Y +/+ patient exhibits hepatomegaly and/or an increase in serum transaminases and/or a serum ferritin level above 1,000 micrograms/L; whenever, despite a strong bio-clinical suspicion of iron overload, genetic testing does not show the expected homozygosity for C282Y. At the family level, evaluating the risk for hemochromatosis is now "instantaneous" thanks to genetic testing. One must, however, keep in mind in interpreting the data of the family members that: clinical expression of the homozygous status is not constant; heterozygosity for C282Y does not per se lead to significant iron overload, but may constitute a co-factor exacerbating (or increasing the risk of) other hepatic or non hepatic diseases. Heterozygosity exposes also to the risk of homozygosity among the offspring; this knowledge of C282Y status must be balanced by the negative impact from the standpoint of possible societal genetic discrimination.

Family Health↗
PubMed1998

Noninvasive prediction of fibrosis in C282Y homozygous hemochromatosis.

BACKGROUND & AIMS: The diagnosis of hemochromatosis is now possible for C282Y homozygous patients using noninvasive molecular genetic tests. The aim of this study was to define noninvasive factors predictive of severe fibrosis (bridging fibrosis or cirrhosis) to avoid unnecessary liver biopsies in such patients. METHODS: Clinical and biological data were recorded at the time of diagnosis in 197 French C282Y homozygous patients, 52 (26%) of whom had severe fibrosis. Variables significantly linked to severe fibrosis using univariate analysis were entered into a multivariate stepwise analysis. These variables were combined to obtain a simple index allowing for prediction of severe fibrosis. RESULTS: Serum ferritin, hepatomegaly, and serum aspartate aminotransferase were selected using multivariate analysis. Their combination applied to the 96 patients with ferritin level of </=1000 microgram/L, normal aspartate aminotransferase values, and absence of hepatomegaly showed that no severe fibrosis was encountered in this subgroup of patients. The results were validated in 113 C282Y homozygous patients in Canada with a good reproducibility of negative prediction but a poor reproducibility of the positive prediction of severe fibrosis. CONCLUSIONS: In C282Y homozygous patients, the diagnosis of severe fibrosis relies on liver biopsy, but absence of severe fibrosis can be accurately predicted in most patients on the basis of simple clinical and biochemical variables.

Adult↗