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Biomedical subjects

Catherine Johanet

Publications and source records attributed to Catherine Johanet.

12 recordsLinked to original sources
PubMed2005

Outcome of infants with celiac disease.

AIMS: Determine the proportion of infants whose celiac disease (CD) was confirmed in childhood and evaluate their prognosis in adulthood. PATIENTS AND METHODS: The diagnosis of CD was established between 1971 and 1982 in 84 infants based on intestinal biopsy data; a gluten-free diet was prescribed and the cohort followed prospectively. RESULTS: Thirty-six infants were followed less than 5 years. A second biopsy was performed in 25. Mucosa had healed in 13 and remained atrophic in 12. Three children developed partial villous atrophy between 6 and 12 years of age in spite of the gluten-free diet. Forty-five patients underwent a gluten challenge between 5 and 10 years of age: in 41 histological lesions relapsed, in two mucosa remained normal and clinical and immunological relapse developed in two. Among those 45 patients, 18 were examined after 18 years follow-up: the exclusion diet was resumed in four, overt clinical relapse developed in four and four experienced intermittent gastrointestinal disorders. All biopsies performed during a period of normal diet showed villous atrophy (except in one patient) without correlation with clinical symptoms. CONCLUSION: The diagnosis of celiac disease in infants was confirmed in nearly all cases in childhood. When they reached adulthood, these patients had few symptoms but their histological lesions persisted. These data are in favor of a lifelong exclusion diet.

Adolescent↗
PubMed2005

Remission with ursodeoxycholic acid of type 1 autoimmune hepatitis resistant to azathioprine and steroids.

Combination therapy with steroids and azathioprine is the reference treatment for autoimmune hepatitis, but potential adverse effects are numerous and intolerance can occur. We report a patient with a well-documented type 1 autoimmune hepatitis intolerant to corticosteroids and azathioprine therapy, in whom eight years of ursodeoxycholic acid monotherapy was associated with biochemical and histological remission.

Adrenal Cortex Hormones↗
PubMed2005

Could post-liver transplantation course be helpful for the diagnosis of so called cryptogenic cirrhosis?

Cryptogenic cirrhosis (CC) is diagnosed in 5-30% of cirrhotic patients overall and 7% of patients who undergo liver transplantation for cirrhosis. In our series of patients transplanted for CC, pre-transplant clinical and histological data and the post-transplant course were reexamined in an attempt to identify the aetiology. Among the 881 patients transplanted in our centre between 1987 and 2000, 28 patients with a median age of 46 yr (range: 18-69) at transplantation were initially classified as having CC. Two patients were excluded because of intense ischaemic lesions caused by chemoembolization prevented histological analysis of the native liver (n = 1) and because of cryptic HBV infection (n = 1). Among the remaining 26 patients, four groups were individualized: (i) patients with chronic inflammatory liver disease with autoimmune features (n = 14, 54%); (ii) patients with features suggestive of non-alcoholic fatty liver disease (n = 3, 11.5%); (iii); patients with incomplete septal cirrhosis (ISC) and vascular liver disease (n = 3), and (iv) patients with unresolved CC (n = 6, 23%). In the autoimmune liver disease group, the median International Autoimmune Hepatitis score was 12.5 (range: 11-19) after reevaluation and review of the post-transplantation course was helpful to confirm the diagnosis with the occurrence of active graft hepatitis in nine patients, with autoantibodies in five patients. The vascular group was characterized by lesions of obliterative portal venopathy and ISC in all native livers. Diagnosis of NAFLD was based on the clinical background of obesity and/or type 2 diabetes and the presence of steatosis or steatohepatitis in native livers and graft biopsies. A definite aetiological diagnosis can be achieved in the majority of patients initially diagnosed with CC. Autoimmune liver disease emerged as the main aetiology (14 of 26 patients, 54%) and frequently recurred on the grafted liver (nine cases). In all cases a precise diagnosis is obviously of practical interest for better management of post-transplant survey and treatment.

Adolescent↗
PubMed2004

Diagnosing celiac disease: a comparison of human tissue transglutaminase antibodies with antigliadin and antiendomysium antibodies.

OBJECTIVE: To evaluate and compare the sensitivity and specificity of the new serologic marker human antitissue transglutaminase antibodies (IgA anti-tTG) with those of antiendomysium (IgA EMA) and antigliadin antibodies (IgA and IgG AGA) for the diagnosis of celiac disease (CD). METHODS: The level of IgA antibodies to tTG in serum was determined by an enzyme-linked immunosorbent assay (ELISA) test using recombinant human tTG as the antigen; IgA EMA, by indirect immunofluorescence; and IgA and IgG AGA, by ELISA. Sixty-eight serum samples from 59 patients with CD were studied-30 patients had untreated CD, 22 were on gluten-free diets, and 16 had been reintroduced to gluten-and compared with serum samples from 116 children examined for failure to thrive, short stature, various digestive diseases, or other non-CD conditions. RESULTS: Twenty-eight of 30 patients with CD had anti-tTG (the 2 patients whose results were negative were 1 patient with IgA deficiency and 1 infant); 27 of 30 patients had IgA EMA (1 child was IgA anti-tTG positive and IgA EMA negative); 18 of 30 had IgA AGA; and 28 of 30 had IgG AGA. On gluten-free diets, 4 of 22 patients had anti-tTG but none had IgA EMA or IgA AGA. On normal diets, 15 of 15 children who had relapsed had anti-tTG; 9, IgA EMA; 4, IgA AGA; and 8, IgG AGA (1 child did not relapse). In subjects without CD, 3 of 116 had anti-tTG; 12, IgG AGA; and 1, IgA AGA, but none had IgA EMA. In the 3 children who had anti-tTG, CD could be excluded. The positive predictive value of IgA anti-tTG was 90% and the negative predictive value, 98%. In comparison, results for IgA EMA were 100% and 97%, IgA AGA 94% and 90%, and IgG AGA 70% and 98%, respectively. CONCLUSION: The presence of human anti-tTG is a reliable indicator for the diagnosis and follow-up of CD.

Adolescent↗
PubMed2004

Heterogeneous nuclear ribonucleoprotein A2/B1 identified as an autoantigen in autoimmune hepatitis by proteome analysis.

Our aim was to characterize antinuclear antibody (ANA) targets in type 1 autoimmune hepatitis (AIH1) using a proteomic tool. ANA-positive sera from 29 patients with AIH1 and 14 negative controls were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The principal antigens identified were a 30 kDa triplet band which was recognized by 79% of patient sera and 14% of control sera, and a 36 kDa antigen which was recognized by 52% and 14% of sera, respectively. The latter antigen was studied in more detail using two-dimensional electrophoresis (2-DE) and mass spectrometry (MS). Its identification corresponded to heterogeneous nuclear ribonucleoprotein A2/B1. This paper presents the first description of this protein as an antigen in AIH1.

Adolescent↗
PubMed2004

Immune response to lipopolysaccharide in primary biliary cirrhosis and autoimmune diseases.

A bacteriological aetiology is suspected to be the triggering factor in primary biliary cirrhosis. We studied lipid A, the toxic and immunogenic moiety of gram-negative bacteria lipopolysaccharide, which accumulates abnormally in Kupffer cells, hepatocytes, and biliary epithelial cells in primary biliary cirrhosis patients. Anti-lipid A antibody levels from serum samples from 36 primary biliary cirrhosis patients, drawn before and after ursodeoxycholic acid treatment, were compared to those from patients with other liver diseases (n=236), non-hepatic diseases (n=249), and healthy subjects (n=75). In primary biliary cirrhosis patients, the prevalence of IgM anti-lipid A antibodies was higher before than after ursodeoxycholic acid therapy (64% vs 22%, respectively; P<0.001). Patients with anti-lipid A antibodies had significantly higher IgM levels than those without antibodies (8.7+/-1.1 g/l vs 4.4+/-0.8 g/l, P<0.02). Total IgM levels were correlated with anti-lipid A antibody levels (r=0.65, P<0.02). After therapy, the serum IgM levels decreased significantly (P<0.03). These results indicate that bacterial antigens may participate in the observed increase of serum IgM levels, and support an aetiological role of a gut-derived endotoxin antigen in the pathogenesis of primary biliary cirrhosis.

Adult↗
PubMed2004

Combined search for anti-beta2-glycoprotein I and anticardiolipin antibodies in antiphospholipid syndrome: contribution to diagnosis.

In this study we sought to assess (1) the diagnostic value of a combined search for anti-beta(2)-glycoprotein (abeta(2)-GPIs) and anticardiolipin antibodies (aCLs) in primary (APS I) and secondary (APS II) antiphospholipid syndrome and (2) the influence of the beta(2)-GPI preparation in the ELISA's results. abeta(2)-GPI and aCL concentrations were assessed in 70 patients with APS and compared with those in 65 patients with systemic lupus erythematosus (SLE) without clinical features of APS. In APS patients (38 with APS I, 32 with APS II), the diagnosis had to have been made at least 3 years earlier; in subjects with SLE, the diagnosis had to have been made at least 5 years earlier. All serum samples were tested for abeta(2) -GPI with the use of an in-house ELISA with an abeta(2) -GPI preparation from human plasma. Samples negative for abeta(2) -GPI were controlled with 2 additional beta(2)-GPI preparations, 1 from human serum and 1 from bovine serum. In APS, abeta(2)-GPIs were more frequent than in SLE (76% and 15%, respectively; P <.0001), mainly with IgG isotype and with significantly higher levels than those found in SLE. The specificity for APS was 92% for IgG abeta(2)-GPIs and 68% for IgG aCLs. The highest association with APS was found for the combination of the 2 markers (odds ratio 29; 95% confidence interval 10-76; P <.0001). Among the APS patients, 6 were positive for aCL only and remained negative regardless of which beta 2 -GPI preparation was used; 1 patient was aCL-negative and only positive with human beta 2 -GPI. These data emphasize the heterogeneity of the APS immunologic profile and the diagnostic possibilities of both antibodies.

Adult↗
PubMed2004

Features and outcome of autoimmune hepatitis type 2 presenting with isolated positivity for anti-liver cytosol antibody.

BACKGROUND AND AIMS: Autoimmune hepatitis (AIH) type 2 is identified by the presence in the serum of anti-liver/kidney microsome type 1 autoantibody. Anti-liver cytosol autoantibody has been reported in children with autoimmune liver disorders mostly in association with anti-liver/kidney microsome reactivity. However, its role as a sole marker of AIH type 2 is debated. We describe here a series of 18 children and adolescents (15 girls, 3 boys) with AIH with serum anti-liver cytosol type 1 (aLC1) as the only autoimmune marker. METHODS: A retrospective review was conducted from 3 pediatric hepatology units of all children with an autoimmune liver disease associated with aLC1 as found by immunofluorescence and/or immunodiffusion or immunoblotting. RESULTS: Age at first symptoms ranged from 11 months to 14 years; 12 children presented with acute hepatitis, 1 with progressive jaundice, and 5 were asymptomatic. Anti-liver/kidney microsome, antimitochondria, and anti-actin autoantibodies were not detected. Signs of cirrhosis were present in 11 children. Immunosuppressive treatment was effective in all except 2 children who had subfulminant hepatic failure and who required liver transplantation. Sixteen patients (14 with their native liver) currently are alive; 14 patients still are on immunosuppressive therapy after 1 to 22 years. According to the international scoring system for the diagnosis of AIH, 16 patients corresponded to a definite diagnosis and 2 corresponded to a probable diagnosis. CONCLUSIONS: The presence of aLC1 in children with acute or chronic liver disease of unknown origin strongly supports a diagnosis of AIH and is an indication for early immunosuppressive therapy.

Adolescent↗
PubMed2003

Characterization of the B cell response of patients with anti-liver cytosol autoantibodies in type 2 autoimmune hepatitis.

Anti-liver cytosol type 1 (LC1) autoantibody is detected in 30% of sera from patients with type 2 autoimmune hepatitis (AIH), and is the only circulating autoantibody in 10% of cases. Human formiminotransferase cyclodeaminase (FTCD) has been shown to be the specific liver antigen recognized by anti-LC1 autoantibodies. The aim of this study was to identify the dominant epitope on human FTCD and to analyze antigenic-site sequences for clues on the development of AIH. Recombinant proteins and peptides covering the entire cDNA of human FTCD were tested against anti-LC1 autoantibodies. Conformational epitopes were found throughout the protein but linear epitopes were found exclusively in the C-terminal 146 amino acids. Two groups of sera with different reactivities were found: 69%of the sera recognized two specific linear epitopes at positions 428-434 (NTPEEKD) and 440-447 (LQEGLRRA) of human FTCD; others reacted only with a discontinuous epitope between the amino acids at position 395 and 528. FTCD autoantibody production is thus a polyclonal-antigen-driven B cell response. Autoantibodies against conformational or discontinuous epitopes were found in all patients and two-thirds also recognized linear epitopes on human FTCD.

Ammonia-Lyases↗
PubMed2003

Identification of rat targets of anti-soluble liver antigen autoantibodies by serologic proteome analysis.

BACKGROUND: Anti-soluble liver antigen (SLA) autoantibodies are specific for autoimmune hepatitis type 1 and are the only immunologic marker found in 15-20% of hepatitis cases previously considered cryptogenic. Anti-SLA antibodies react with the 100 000g supernatant from rat liver homogenate, but the molecular targets remain controversial. METHODS: We characterized anti-SLA targets by one- and two-dimensional immunoblotting analysis. The recognized proteins were identified by peptide mass fingerprint analysis after matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. RESULTS: Three proteins of 35 kDa and pI 6.0, 50 kDa and pI between 6.0 and 6.5, and 58 kDa and pI between 6.5 and 7.0 were stained more intensely by anti-SLA positive-sera than by control sera. After in-gel tryptic digestion, MALDI-TOF analysis of the generated peptides enabled the clear identification of N-hydroxyarylamine sulfotransferase, isoforms of alpha-enolase, and isoforms of catalase. CONCLUSIONS: Possible antigens for anti-SLA antibodies include a sulfotransferase, alpha-enolase(s), and catalase(s). Two-dimensional electrophoresis combined with mass spectrometry offers a versatile tool to identify molecular targets of autoantibodies and thus to improve diagnostic tools and the understanding of the immune process.

Animals↗