Gilda Porta

Simplified criteria for the diagnosis of autoimmune hepatitis

Diagnosis of autoimmune hepatitis (AIH) may be challenging. However, early diagnosis is important because immunosuppression is life‐saving. Diagnostic criteria of the International Autoimmune Hepatitis Group (IAIHG) were complex and purely meant for scientific purposes. This study of the IAIHG aims to define simplified diagnostic criteria for routine clinical practice. Candidate criteria included sex, age, autoantibodies, immunoglobulins, absence of viral hepatitis, and histology. The training set included 250 AIH patients and 193 controls from 11 centers worldwide. Scores were built from variables showing predictive ability in univariate analysis. Diagnostic value of each score was assessed by the area under the receiver operating characteristic (ROC) curve. The best score was validated using data of an additional 109 AIH patients and 284 controls. This score included autoantibodies, immunoglobulin G, histology, and exclusion of viral hepatitis. The area under the curve for prediction of AIH was 0.946 in the training set and 0.91 in the validation set. Based on the ROC curves, two cutoff points were chosen. The score was found to have 88% sensitivity and 97% specificity (cutoff ≥6) and 81% sensitivity and 99% specificity (cutoff ≥7) in the validation set. Conclusion: A reliable diagnosis of AIH can be made using a very simple diagnostic score. We propose the diagnosis of probable AIH at a cutoff point greater than 6 points and definite AIH 7 points or higher. (HEPATOLOGY 2008.)

Genetic heterogeneity in susceptibility to autoimmune hepatitis types 1 and 2

OBJECTIVES:Susceptibility to autoimmune hepatitis (AIH) type 1 has been associated with DRB1*03, DRB1*04, and DRB3 alleles in European and North-American whites, with DRB1*04 in Japan, and with DRB1*04 and DRB1*13 in Latin America. Very few studies have been performed on AIH type 2. The aim of the present study was to evaluate the association of AIH types 1 and 2 with HLA-DR and DQ loci.METHODS:We performed HLA-DRB and -DQB1 typing by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) in 139 AIH patients. Most had AIH type 1 associated with circulating anti-smooth muscle antibody with F-actin specificity or antinuclear antibody. Twenty-eight patients presented AIH type 2 with anti-liver/kidney microsome type 1 or anti-liver cytosol type 1 antibodies.RESULTS:We observed a significant increase of DRB1*13 (70%vs 26% of controls, p < 0.00001) and DRB3 (93%vs 69% of controls, p < 0.00001) in AIH type 1 patients. Analysis of patients without DRB1*13 disclosed a secondary association with DRB1*03 (70%vs 30% of controls, p= 0.0001) and either the DRB1*13 or the DRB1*03 alleles were present in the majority of these patients (91%vs 48% of controls, p= 0.001). Comparison of DRB1*13- and DRB1*03-positive subjects revealed that the former alleles conferred susceptibility to younger patients with AIH type 1. DQB1 typing showed a significant increase in DQB1*06 (68%vs 41% of controls, p= 0.00007) in strong linkage disequilibrium with DRB1*13, and a decrease in DQB1*0301 (8%vs 47% of controls, pc= 0.0003). On the other hand, HLA typing of patients with AIH type 2 disclosed a significant increase in the DRB1*07 (68%vs 20% of controls, pc < 0.00014), DRB4 (79%vs 43% of controls, pc= 0.004), and DQB1*02 (86%vs 42%, p= 0.00002) alleles. After exclusion of DRB1*07, a secondary association with HLA-DRB1*03 was further observed in these patients (78%vs 30%, p= 0.007) and most of them had either DRB1*07 or DRB1*03 (93%vs 44% of controls, pc < 0.0001).CONCLUSIONS:Our data indicate that predisposition to AIH types 1 and 2 is associated, respectively, with the DRB1*13 or DRB1*03 and DRB1*07 or DRB1*03 alleles, and suggest that protection against type 1 disease may be conferred by DQB1*0301. In addition, the cluster of DRB1*13 in children with AIH type 1 also supports the concept that different HLA alleles might influence the onset of the disease.

Clinical distinctions and pathogenic implications of type 1 autoimmune hepatitis in Brazil and the United States

BACKGROUND/AIMS Type 1 autoimmune hepatitis has a strong genetic predisposition that varies among different ethnic groups. Our aims were to determine if the clinical manifestations differed between patients with type 1 autoimmune hepatitis from Brazil and the United States and if classical disease could be associated with region-specific susceptibility markers. METHODS The clinical manifestations and genetic risk factors of 161 patients from the United States were compared to those of 115 patients from Brazil. RESULTS The patients from Brazil had earlier disease onset, lower frequency of concurrent immune diseases, higher serum levels of aspartate aminotransferase and gamma-globulin, greater occurrence of smooth muscle antibodies, and lower frequency of antinuclear antibodies than the patients from the United States. Human leukocyte antigen (HLA) DR13 and DRB1*1301 occurred more commonly in the Brazilian patients and HLA DR4 less often. Normal subjects from each country had similar frequencies of HLA DR13 and DR3. CONCLUSIONS Type 1 autoimmune hepatitis in Brazil has different features at presentation than the disease in Caucasoid patients from the United States, and it is associated with HLA DR13. Background populations in each country have similar frequencies of HLA DR13 and DR3, and region-specific etiologic factors may determine the HLA association.

Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection in children and adolescents.

BACKGROUND & AIMS This multi-center study aimed to prospectively evaluate the safety and efficacy of a genotype-based Pegylated Interferon alfa-2a/Ribavirin therapy in treatment-naïve hepatitis C virus (HCV), positive HCV serology, and quantifiable HCV RNA, infected children. METHODS Eighteen children with genotypes 2 and 3 patients (group A) were assigned to medication for 24weeks, and 47 children with genotypes 1, 4, 5 and 6 patients (group B) for 48weeks. RESULTS Early response at week 12 was observed in 83% of group A patients and in 57% of group B patients (p<0.05). End of treatment response was achieved in 94% of patients in group A and in 57% in group B (p<0.001). Sustained virologic response was maintained in 89% of patients in group A and in 57% of patients in group B (p<0.01). Ten patients stopped prematurely the treatment, 2 for serious adverse event (acute hepatitis and thyrotoxicosis), and 8 because of no virologic response at week 24. Peginterferon alfa-2a and Ribavirin dose was adjusted in 15 patients (23%), 11 for neutropenia (17%), and 3 patients (5%), for anemia, respectively. Treatment-related adverse events included fever and flu-like symptoms (54%), irritability-depression-change of mood (34%), vomiting (23%), abdominal pain (38%), loss of appetite (21.5%) and dermatitis (29%). No influence on height growth was observed. CONCLUSIONS Pegylated inteferon alfa-2a and Ribavirin treatment allowed to achieve SVR in 57% of pediatric patients with genotypes 1, 4, 5 and 6, and in 94% of genotypes 2 and 3. These results show an improved SVR as compared to reference series in adults with similar regimen.

Analysis of HLA haplotypes in autoimmune hepatitis type 1: identifying the major susceptibility locus

Susceptibility to autoimmune hepatitis type I (AIH-1) has been associated with HLA-DR3, DR52, and DR4 antigens in Caucasian and Oriental patients. However, in Brazil, disease susceptibility is primarily linked to DR13 and DR52. In this highly admixed population, we find different DR13-associated haplotypes, presenting a unique opportunity to discriminate relevant genes within a tightly linked genomic region. To identify the primary susceptibility locus, we sequenced DR13 alleles of 39 patients with AIH-1 and 22 controls. Patients were almost exclusively DRB1*1301, but half of controls typed DRB1*1302. HLA-DQ haplotypes were varied. Oligotyping of DRB3 locus of all patients and also within the HLA-DR13 positive group showed an allele distribution comparable to controls, confirming that the stronger association lies in the DRB1 locus. On the other hand, if DRB1*1301 is the major susceptibility factor in our sample, the only amino acid different from DRB1*1302 in position 86, corresponding to pocket 1 in the peptide-presenting groove, may be important. We propose that peptide presentation leading to pathogenesis of AIH-1 may be quite stringent, but will also be affected by other strong genetic or environmental susceptibility factors, which would explain the various HLA molecules associated to the disease in the different populations.

Guidelines for the Management of Mucopolysaccharidosis Type I

Mucopolysaccharidosis type I (MPS I) is the prototype of the MPS disorders, a subgroup of lysosomal storage diseases. The incidence of MPS I in Brazil is unknown, but a retrospective population study in Australia conducted between 1980 and 1996 yielded an overall prevalence of 1 in 22 500 for all MPS types. 1 In British Columbia, cases ascertained between 1952 and 1986 determined that the frequency of MPS type I Hurler, the most severe form of the disease, was approximately 1 in 144 000 newborns, 2 a result similar to that found in The Netherlands. 3 A recent analysis of data collected by the Society for Mucopolysaccharides in the United Kingdom in patients with MPS I found a prevalence of 1.07 per 100 000 births. 4 MPS I is characterized by a deficiency in a-L-iduronidase enzyme activity, leading to buildup and urinary excretion of high levels of glycosaminoglycans (GAGs), specifically dermatan and heparan sulfates. The disease is genetically determined and shows autosomal recessive inheritance. 5,6 MPS

Autoimmune hepatitis, HLA and extended haplotypes.

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease. Characteristic liver-infiltrating immune cells in portal and periportal areas, hypergammaglobulinemia and typical autoantibodies indicate an ongoing autoimmune reaction against liver self antigens, which lead to irreversible cellular damage and ultimately to severe hepatic failure. A significant part of adult, but not pediatric AIH patients, exhibit concurrent autoimmune diseases, further strengthening the immunological etiology of the disease. Genetic susceptibility to autoimmune hepatitis is strongly associated with HLA-DRB1 alleles. In Caucasian European and North American patients, AIH-1 is associated with the presence of DRB1*0301, DRB3*0101 and DRB1*0401 alleles, while AIH-2 is associated with DRB1*0301 or DRB1*07. In Brazil, the primary susceptibility allele for AIH-1 is DRB1*1301, but a secondary association with DRB1*0301 has also been identified. We looked for additional susceptibility factors in the extended MHC region. We genotyped 107 AIH-1 children and up to 326 healthy subjects for TNFA G-308A, TNFA G-238A, LTA A+252G, LTA A+80C, NFKBIL1 T-63A, BAT1 C-348T, BAT1 G-22C, MICA, and HLA-B polymorphisms. The TNFA-308 A allele was significantly increased in AIH-1 when compared with healthy controls, confirming data from other studies. Linkage disequilibrium analysis was carried out. The ancestral haplotype comprising TNFA-308A, TNFA-238G, LTA+252G, LTA+80C, NFKBIL1-63A, BAT1-348C, BAT1-22C, HLA-B*08, MICA*08 was more common in DRB1*03 positive patients than in controls (40% vs. 14%), showing a seven-fold increased risk for the disease [OR=7.8 (95%CI 2.04-29.9.2, p=0.0021). In contrast, the remaining patients carrying DRB1*03 exhibited varied haplotypes. Finally, a variety of class III haplotypes was also present in HLA-DRB1*13 patients, without a predominant pattern. The most common of the 98 haplotypes present in patients were completely absent in controls. The extended haplotype analysis in this sample of AIH-1 patients highlights not only the genetic diversity present in the Brazilian population, but is also in accordance with the previously documented microdiversity within the MHC region. The present knowledge of AIH suggests that the same or a very similar disease can be induced by yet unknown, but different, triggers followed by presentation on different HLA-DR molecules of the epitopes derived from the corresponding autoantigens, characterizing a much more complex disease than previously thought.

Cytotoxic T lymphocyte antigen–4 gene polymorphisms do not confer susceptibility to autoimmune hepatitis types 1 and 2 in Brazil

OBJECTIVES:Susceptibility to autoimmune hepatitis (AIH) has been linked to different HLA-DR antigens in distinct populations. Recently, an A–G polymorphism in exon 1 of the cytotoxic T lymphocyte antigen-4 (CTLA-4) gene was associated with predisposition to AIH type 1 (AIH-1) in white individuals in North America. This polymorphism has been associated with several other autoimmune diseases, presumably because of its effect in the expression of CTLA-4, an adhesion molecule that downregulates peripheral T cell responses. The aims of this study were to assess the frequency of CTLA-4 genotypes in Brazilian patients with AIH-1 and AIH type 2 (AIH-1), as well as to investigate the influence of these genotypes in disease expression.METHODS:Determination of CTLA-4 genotypes was carried out in 106 patients with AIH-1, 26 subjects with AIH-2, and 67 healthy control subjects by polymerase chain reaction (PCR)–based techniques.RESULTS:No difference in the distribution of CTLA-4 genotypes was observed in subjects with AIH-1 and AIH-2 as compared to healthy controls. Patients with AIH-1 and AIH-2 with the GG genotype exhibited lower γ-globulin and ALT levels, respectively.CONCLUSIONS:Susceptibility to AIH-1 and AIH-2 in Brazilian patients is not influenced by exon 1 CTLA-4 gene polymorphisms at position 49.

The Endoscopic and Surgical Management of Portal Hypertension in Children: Analysis of 123 Cases

Since 1973, 178 children with portal hypertension (PH) have been seen at Instituto da Criança of the University of São Paulo Medical School. Fifty-five of these children were excluded from this analysis for various reasons, including no treatment required, death before treatment, or incomplete data. From the remaining 123 children with esophageal varices, only 96 (76.1%) of them had at least one episode of upper gastrointestinal hemorrhage. Eighty-eight children were submitted to injection sclerotherapy; 26 treated prophylactically, and 62 for treatment of previous bleeding. Eleven (42.3%) children from the prophylactic group bled from esophageal varices during the treatment. They were all successfully managed thereafter. Satisfactory results were achieved in 53 (85.4%) children in the therapeutic group. Twenty-eight (45.1%) children had at least one episode of bleeding after beginning of sclerotherapy, 19 of whom eventually had successful control of the variceal bleeding. From 1973 to 1984, distal splenorenal shunt (DSS) was the procedure of choice for the treatment of bleeding esophageal varices. Forty-two children have undergone DSS during this period. Only one child was shunted prophylactically. Since 1985, injection sclerotherapy has been the first choice for the treatment and only seven children with sclerotherapy failure have since been treated by DSS. Characteristically these children had very similar splenoportographic pattern with huge esophageal and gastric varices and deviation of portal vein blood flow toward the left gastric vein.(ABSTRACT TRUNCATED AT 250 WORDS)

FREQUENCY OF CONCURRENT AUTOIMMUNE DISORDERS IN PATIENTS WITH AUTOIMMUNE HEPATITIS: EFFECT OF AGE, GENDER, AND GENETIC BACKGROUND

Background Concurrent autoimmune disorders (CAIDs) have been shown to occur in 22% to 34% of the patients with autoimmune hepatitis (AIH). Their presence has been linked to female gender, older age, and to certain HLA antigens, namely HLA-A11, DRB1*04, and DRB4*01. Aims To assess the frequency and nature of CAID in Brazilian patients with AIH types 1 (AIH-1) and 2 (AIH-2) and to investigate the influence of age, gender, and genetic background in their occurrence. Patients and Methods The presence and nature of CAID was studied in 143 patients [117 females, median age 11 (1.3 to 69)] with AIH-1 (n=125) and AIH-2 (n=28). HLA typing and tumor necrosis factor α gene promoter and exon 1 cytotoxic T lymphocyte associated antigen 4 (CTLA-4) gene polymorphisms were determined by polymerase chain reaction-based techniques. Results The frequency of CAID was similar in patients with AIH-1 (14%) and AIH-2 (18%), but their nature was shown to vary. Arthritis was seen in half of the patients (n=8) with CAID and AIH-1 and in none of those with AIH-2. Subjects with AIH-1 and CAID were shown to be older [24 (1.3 to 61) vs. 11 (1.3 to 69) y, P=0.02] and to have more often circulating antinuclear antibody (76% vs. 40%, P=0.008) and less frequently antiactin antibodies (33% vs. 75%, P=0.008) when compared with their counterparts without CAID. No particular HLA-DR and DQ alleles, as well as tumor necrosis factor α and CTLA-4 genotypes, were associated with CAID. Conclusions The nature, but not the frequency, of CAID was shown to vary in AIH-1 and AIH-2. In subjects with AIH-1, CAID was linked to older subjects and to the presence of antinuclear antibody. No predisposition to CAID was associated to HLA-DRB1*04 or DDB4*01 alleles. The observed lower frequency of CAID could be attributed to the lower age of disease onset in Brazilians and to differences in HLA-encoded susceptibility to AIH-1 observed in South America.