Clarice Pires Abrantes-Lemos

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.

Follow-up of pregnant women with autoimmune hepatitis: the disease behavior along with maternal and fetal outcomes.

Goals To assess maternal and fetal outcomes and clinical management of pregnancy in patients with autoimmune hepatitis (AIH). Background There is a paucity of information about maternal and fetal outcomes, and AIH activity during pregnancy and in the postpartum period. There is no consensus about the administration of azathioprine during pregnancy and breastfeeding. Study Retrospective analysis of 54 pregnancies (3 still in progress) in 39 AIH patients. Results The median age at conception was 24 years, and 68.4% of women had liver cirrhosis. Before conception and in early pregnancy, azathioprine and prednisone were administered in 48.1%, but treatment regimen was usually changed further to 20 mg/d prednisone; and 20.4% were off treatment. There were 36 livebirths, and fetal loss rates were 29.4% (13 miscarriages, 1 stillbirth, and 1 ectopic pregnancy). Preterm birth rate was 11.8%. In 2 cases, there was acute fetal distress; and in 2 others congenital malformations (3.9%). The rate of serious maternal complication was 7.8%, with no deaths. There were no flares in 41.2% pregnancies, but aminotransferase elevations occurred in 54.9%, 31.4% of which were true AIH relapses, only registered in the postpartum period. Conclusions Despite the high fetal miscarriage rate, pregnancy in AIH was safe. Patients needed careful monitoring, especially in the postpartum period because of relapses. There was no evidence of a cause and effect relationship among azathioprine administration and premature births and congenital abnormalities, but more studies are necessary. Higher doses of prednisone may be an alternative option for those who prefer azathioprine withdrawal during pregnancy.

Analysis of major histocompatibility complex and CTLA-4 alleles in Brazilian patients with primary biliary cirrhosis

Background and Aims:  Predisposition to primary biliary cirrhosis (PBC) has been classically linked to HLA‐DRB1 locus. However, the presence of the HLA‐DRB1*08 antigen has been reported in less than one‐third of PBC patients from Northern Europe and Japan. Recently, polymorphisms in the tumor necrosis factor alpha (TNFA) gene promoter at position −308 and in exon 1 of the cytotoxic T lymphocyte antigen‐4 (CTLA‐4) gene at position 49 have been associated with susceptibility to PBC in Caucasians. In addition, the presence of HLA‐DRB1*08 and the TNFA*1 allele was also linked to progression to end‐stage liver disease. The aims of the present study were to investigate the frequencies of HLA‐DR and DQ antigens and TNFA and CTLA‐4 alleles in PBC patients from a different genetic background, as well as to assess the role of TNFA alleles and HLA‐DR antigens in disease progression.

Applicability of the IAIHG scoring system to the diagnosis of antimitochondrial/anti‐M2 seropositive variant form of autoimmune hepatitis

Background and Aims:  According to the International Autoimmune Hepatitis Group (IAIHG) criteria, circulating antimitochondrial antibodies (AMA) do not support the diagnosis of autoimmune hepatitis (AIH). The aims of this study were to characterize a subset of patients with AIH who have AMA and antiM2 seropositivity, and to assess the applicability of the revised scoring system of the IAIHG in the diagnosis of this variant form of AIH.

Prevalence of immune disturbances and chronic liver disease in family members of patients with primary biliary cirrhosis

Background and Aims:  Primary biliary cirrhosis (PBC) has been reported in up to 4–6% of first degree relatives of patients with the disease. In addition, immune abnormalities, including hypergammaglobulinemia, autoantibodies and increased frequency of autoimmune disorders, were reported in family members of PBC patients. The aim of the present study was to investigate the prevalence of PBC in relatives of patients with PBC, and to investigate the occurrence of chronic liver disease (CLD) and immune abnormalities in these subjects.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immune-mediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Prevalence of non-organ-specific autoantibodies in a rural community from northeastern Brazil: a population-based study

Non-organ-specific autoantibodies (NOSA) are well-recognized diagnostic markers of autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC), but can also be observed in patients with viral hepatitis as well as in healthy subjects. The aim of this study was to evaluate the prevalence of NOSA in subjects living in a rural community in Brazil and to correlate their occurrence with the presence of liver disease. Seven hundred twenty-five apparently healthy subjects were randomly selected for assessment of antinuclear (ANA), anti-smooth muscle (SMA), antimitochondrial (AMA), anti-liver/kidney microsome type 1, and anti-liver cytosol type 1 antibodies. Subjects with those NOSA were evaluated for the presence of AIH, PBC, and viral hepatitis. Reactivities for all NOSA, SMA, ANA, and AMA were detected, respectively, in 14, 10, 4, and 0.1% of subjects, with a mean titer of 1:40. NOSA-positive subjects were significantly older and more frequently females. No correlation was observed between the occurrence of NOSA and PBC, AIH, or viral hepatitis. The prevalence of NOSA in Brazilians was 14%. They were usually low titer. NOSA were more frequently observed in females and older subjects and their presence was not correlated with the presence of AIH, PBC, or viral hepatitis.

Imunodiagnóstico da esquistossomose mansônica com baixa carga parasitária

Presently, the schistosomiasis mansoni with low worm burden is frequent, thus immunologic assays of interest for the field diagnosis of Schistosoma mansoni light infections were evaluated here. Assays not assessed before (group I) and those requiring better validation (group II) for the screening of light infections were included in this study. In the group I, the immunofluorescence assays for the detection of lgM antibodies to worm antigens (IgM IFAw) and IgG antibodies to egg antigens (IgG IFAe) gave high levels of sensitivity, specificity, efficiency and predictive value of positive. However, the immunoenzymatic assays for the detection of IgM antibodies to worm antigens (IgM ELISAw) and to egg antigens (IgM ELISAe) had lower levels than the former assays. The assays from the group II designed mostly for the detection of IgG antibodies to same parasite antigens showed good diagnostic performance. The data obtained here contributed to evidenciate at least three category of immunoassays, and we concluded that those from the category I are suitable for seroepidemiologic purposes by keeping their diagnostic features unchanged even varying significantly the intensity of S. mansoni infection.

Bone disease in primary biliary cirrhosis: Lack of association with distal renal tubular acidosis

Background and Aims: Primary biliary cirrhosis (PBC) might be complicated by osteoporosis, whose etiology remains unknown but seems to be multifactorial. Prevalence rates of 30% to 60% for distal renal tubular acidosis (DRTA) have been reported in PBC patients, generally as incomplete DRTA. Although it is undisputed that a reduced bone mineral density (BMD) is the expected outcome among patients who have been suffering from longstanding chronic metabolic acidosis, it is unclear if incomplete DRTA is also associated with metabolic bone disease in PBC patients. The present study was undertaken to compare the BMD of PBC patients with and without DRTA.

Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients

BACKGROUND Porphyria cutanea tarda is the most common form of porphyria, characterized by the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several reports associated HFE gene mutations of hereditary hemochromatosis with porphyria cutanea tarda worldwide, although up to date only one study has been conducted in Brazil. OBJECTIVES Investigation of porphyria cutanea tarda association with C282Y and H63D mutations in the HFE gene. Identification of precipitating factors (hepatitis C, HIV, alcoholism and estrogen) and their link with HFE mutations. METHODS An ambispective study of 60 patients with PCT was conducted during the period from 2003 to 2012. Serological tests for hepatitis C and HIV were performed and histories of alcohol abuse and estrogen intake were investigated. HFE mutations were identified with real-time PCR. RESULTS Porphyria cutanea tarda predominated in males and alcohol abuse was the main precipitating factor. Estrogen intake was the sole precipitating factor present in 25% of female patients. Hepatitis C was present in 41.7%. All HIV-positive patients (15.3%) had a history of alcohol abuse. Allele frequency for HFE mutations, i.e., C282Y (p = 0.0001) and H63D (p = 0.0004), were significantly higher in porphyria cutanea tarda patients, compared to control group. HFE mutations had no association with the other precipitating factors. CONCLUSIONS Alcohol abuse, hepatitis C and estrogen intake are prevalent precipitating factors in our porphyria cutanea tarda population; however, hemochromatosis in itself can also contribute to the outbreak of porphyria cutanea tarda, which makes the research for HFE mutations necessary in these patients