Genetic Ancestry, Race, and Severity of Acutely Decompensated Cirrhosis in Latin America

BACKGROUND & AIMS

Genetic ancestry or racial differences in health outcomes exist in diseases associated with systemic inflammation (eg, COVID-19). This study aimed to investigate the association of genetic ancestry and race with acute-on-chronic liver failure (ACLF), which is characterized by acute systemic inflammation, multi-organ failure, and high risk of short-term death.

METHODS

This prospective cohort study analyzed a comprehensive set of data, including genetic ancestry and race among several others, in 1274 patients with acutely decompensated cirrhosis who were nonelectively admitted to 44 hospitals from 7 Latin American countries.

RESULTS

Three hundred ninety-five patients (31.0%) had ACLF of any grade at enrollment. Patients with ACLF had a higher median percentage of Native American genetic ancestry and lower median percentage of European ancestry than patients without ACLF (22.6% vs 12.9% and 53.4% vs 59.6%, respectively). The median percentage of African genetic ancestry was low among patients with ACLF and among those without ACLF. In terms of race, a higher percentage of patients with ACLF than patients without ACLF were Native American and a lower percentage of patients with ACLF than patients without ACLF were European American or African American. In multivariable analyses that adjusted for differences in sociodemographic and clinical characteristics, the odds ratio for ACLF at enrollment was 1.08 (95% CI, 1.03-1.13) with Native American genetic ancestry and 2.57 (95% CI, 1.84-3.58) for Native American race vs European American race CONCLUSIONS: In a large cohort of Latin American patients with acutely decompensated cirrhosis, increasing percentages of Native American ancestry and Native American race were factors independently associated with ACLF at enrollment.

Poor Oral Health-Related Quality of Life in Pre- and Post-Liver Transplantation Patients

Background:

Oral health is associated with Chronic Liver Disease (CLD) and may play a relevant role in oral (OHRQoL) and general health-related quality of life (HRQoL) among people with chronic liver disease (CLD).

Objective:

To explore the correlations between OHRQoL and HRQoL in pre- and post-liver transplantation (LT) patients.

Methods:

A cross-sectional study with 189 patients: 63 per group (pre-LT, post-LT, and without liver disease). The Oral Health Impact Profile-14 (OHIP-14), the 36-Item Short-Form Health Survey, and the Work Ability Index (WAI) were used to measure oral health-related quality of life, health-related quality of life, and work ability, respectively. Oral health was evaluated according to the World Health Organization criteria. The relationship between the OHIP-14 and independent variables was analysed by multiple linear regression.

Results:

Pre-LT group presented the highest OHIP-14 total mean score, followed by the post-LT group, compared to the group without liver disease (p=0.001). All HRQoL and WAI mean scores were lower in the pre-LT group than in the other groups (p≤0.013). In the pre-LT group, the OHIP-14 total mean score was negatively correlated with the Mental Health, Physical Functioning, and General Health mean scores (p=0.01) and negatively and significantly (p<0.05) associated with decayed teeth and with poor workability. In the post-TL group, OHRQOL of life was associated with decayed and missing teeth, lower educational level, and poor workability.

Conclusion:

Patients in the pre- and post-LT groups presented poorer OHRQoL compared to patients without liver disease. OHRQoL was strongly correlated with HRQoL in the pre-LT group.

Drought stress and tree size determine stem CO2 efflux in a tropical forest

CO₂ efflux from stems (CO_{2_stem} ) accounts for a substantial fraction of tropical forest gross primary productivity, but the climate sensitivity of this flux remains poorly understood. We present a study of tropical forest CO_{2_stem} from 215 trees across wet and dry seasons, at the world's longest running tropical forest drought experiment site. We show a 27% increase in wet season CO_{2_stem} in the droughted forest relative to a control forest. This was driven by increasing CO_{2_stem} in trees 10-40 cm diameter. Furthermore, we show that drought increases the proportion of maintenance to growth respiration in trees > 20 cm diameter, including large increases in maintenance respiration in the largest droughted trees, > 40 cm diameter. However, we found no clear taxonomic influence on CO_{2_stem} and were unable to accurately predict how drought sensitivity altered ecosystem scale CO_{2_stem} , due to substantial uncertainty introduced by contrasting methods previously employed to scale CO_{2_stem} fluxes. Our findings indicate that under future scenarios of elevated drought, increases in CO_{2_stem} may augment carbon losses, weakening or potentially reversing the tropical forest carbon sink. However, due to substantial uncertainties in scaling CO_{2_stem} fluxes, stand-scale future estimates of changes in stem CO₂ emissions remain highly uncertain.

Nonalcoholic steatohepatitis in posttransplantation liver: Review article

INTRODUCTION

Nonalcoholic steatohepatitis (NASH) associated or not with cirrhosis is the third leading indication for liver transplantation (LT) around the world. After transplants, NASH has a high prevalence and occurs as both recurrent and de novo manifestations. De novo NASH can also occur in allografts of patients transplanted for non-NASH liver disease.

OBJECTIVE

To evaluate recurrent or de novo NASH in post-LT patients.

METHOD

A literature review was performed using search engines of indexed scientific material, including Medline (by PubMed), Scielo and Lilacs, to identify articles published in Portuguese and English until August 2016. Eligible studies included: place and year of publication, prevalence, clinical characteristics, risk factors and survival.

RESULTS

A total of 110 articles were identified and 63 were selected. Most of the studies evaluated recurrence and survival after LT. Survival reached 90-100% in 1 year and 52-100% in 5 years. Recurrence of NAFLD (steatosis) was described in 15-100% and NASH, in 4-71%. NAFLD and de novo NASH were observed in 18-67% and 3-17%, respectively. Metabolic syndrome, diabetes mellitus, dyslipidemia and hypertension were seen in 45-58%, 18-59%, 25-66% and 52-82%, respectively.

CONCLUSION

After liver transplants, patients present a high prevalence of recurrent and de novo NASH. They also show a high frequence of metabolic disorders. Nevertheless, these alterations seem not to influence patient survival.

New Onset Diabetes and Non-Alcoholic Fatty Liver Disease after Liver Transplantation

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is an emerging cause of graft dysfunction after liver transplantation (LT) frequently related to the development of new onset diabetes after LT (NODAT). This study was undertaken to evaluate the frequencies of NODAT and NAFLD after LT, to investigate their major risk factors and the impact of de novo or recurrent NAFLD in graft function.

MATERIAL AND METHODS

119 patients submitted to LT were prospectively evaluated.

RESULTS

After 4 ± 1 years, NODAT, recurrent and de novo NAFLD were observed in 31%, 56% and 43% of the subjects, respectively. Only 3 patients had non-alcoholic steatohepatitis (NASH) without fibrosis. Other risk factors for NAFLD such as arterial hypertension (AHT), metabolic syndrome (MS), hypertriglyceridemia and obesity were seen in 51%, 50%, 35% and 24% of the subjects, respectively. In addition, insulin resistance (IR), assessed by HOMA-IR and β-cell dysfunction, determined by HOMA-β, were observed in 16% and 94% of the patients, respectively. Occurrence of NODAT was associated with male gender, higher waist circumference, higher HOMA-IR and lower HOMA-β values. No correlation was found between NAFLD and NODAT, MS, hypertriglyceridemia, obesity and HOMAIR and HOMA-β levels.

CONCLUSIONS

NODAT, recurrent and de novo NAFLD are common after LT but are not associated with signs of graft dysfunction, possibly due to the low frequency of IR and NASH. No correlation is observed between NAFLD and NODAT, MS, hypertriglyceridemia, obesity and IR. β-cell dysfunction and diabetes, however, are seen in most of the patients, possibly due to calcineurin inhibitor toxicity.

Brazilian society of hepatology recommendations for the diagnosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma is a malignancy of global importance and is associated with a high rate of mortality. Recent advances in the diagnosis and treatment of this disease make it imperative to update the recommendations on the management of the disease. In order to draw evidence-based recommendations concering the diagnosis and management of hepatocellular carcinoma, the Brazilian Society of Hepatology has sponsored a single-topic meeting in João Pessoa (PB). All the invited pannelists were asked to make a systematic review of the literature and to present topics related to the risk factors for its development, methods of screening, radiological diagnosis, staging systems, curative and palliative treatments and hepatocellular carcinoma in noncirrhotic liver. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of those recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present paper is the final version of the reviewed manuscript containing the recommendations of the Brazilian Society of Hepatology.

Antismooth muscle and antiactin antibodies are indirect markers of histological and biochemical activity of autoimmune hepatitis

Reactivity and titers of autoantibodies vary during the course of autoimmune hepatitis (AIH), and some autoantibodies have been associated with disease activity and adverse outcomes after treatment. The aim of this study was to assess the autoantibody behavior in AIH and its significance as predictors of biochemical and histological remission. A total of 117 patients with AIH (mean age 18.6 [4-69] years) were evaluated and tested for autoantibodies at disease onset and successively (mean 3.2 [2-6] times) after a mean follow-up evaluation of 70 [20-185] months. Antismooth muscle (ASMA), antiliver kidney microsome type 1 (anti-LKM1), antiliver cytosol type 1 (anti-LC1), antimitochondrial, antinuclear (ANA), and antiactin antibodies (AAA) were determined at disease onset and 379 other times during the follow-up evaluation through indirect immunofluorescence in rodent tissues, HEp-2 cells, and human fibroblasts. Anti-SLA/LP were assessed 45 times in the follow-up evaluation of 19 patients using enzyme-linked immunosorbent assay (ELISA). Upon admission, AIH types 1 and 2 were observed in 95 and 17 patients, respectively. Five subjects had AIH with anti-SLA/LP as the sole markers. Patients initially negative for AAA did not develop these antibodies thereafter. ANA were detected de novo in six and three subjects with AIH types 1 and 2, respectively. After treatment, only ASMA (>1:80) and AAA (>1:40) were significantly associated with biochemical (76.9% and 79.8%) and histological features (100% and 100%) of disease activity (P < 0.001).

CONCLUSION

With the exception of ANA, the autoantibody profile does not markedly vary in the course of AIH. The persistence of high titers of ASMA and/or AAA in patients with AIH is associated with disease activity.

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 > or =6) and 81% sensitivity and 99% specificity (cutoff > or =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.

Autoimmune hepatitis in Brazil: an overview

Autoimmune hepatitis is an immune cell-mediated chronic liver disease of unknown cause that leads, when untreated, to cirrhosis and liver failure. Importantly, this disease affects not only adults but children as well. Genetic susceptibility is clearly important and the major susceptibility factor identified up to now is the HLA-DRB1 locus, but other genes may play a role as well. HLA-DRB1 alleles present in South American patients differ from those found in patients in other parts of the world. In addition, we have recently identified two chromosomal regions where additional susceptibility factors may be found in Brazilian patients, namely, the class III MHC region and the 5q31 region where the IL-4 and IL-13 genes are located. This review discusses the current knowledge of the pathogenesis of this autoimmune disease occurring in the setting of an immune-privileged organ, the liver, and compares the data on gene polymorphisms studied in Brazil and in other parts of the world.

Phenotypic expression of familial amyloid polyneuropathy in Brazil

Familial amyloid polyneuropathy (FAP) is an inherited amyloidosis mainly associated with transthyretin Val30Met variant. Clinical heterogeneity has been reported in different populations with FAP and Va130Met variant. In order to characterize FAP expression in Brazilians and to compare its features to those reported in other cohorts, 44 Brazilian patients (27 females, median age 36 [23-53] years) with FAP and the Val30Met variant were investigated. Approximately 40% of their family members, with the exception, of parents and siblings, had FAP. Most of the patients had symptoms of peripheral neuropathy at onset. Median age at onset was 32 [20-44] years. Earlier onset was observed in males (27 [20-43] years in males vs. 33 [20-44] years in females, P = 0.02) and in patients whose parents had FAP (31 [20-44] years vs. 40 [37-43] years in patients, respectively with and without affected parents, P = 0.03). Phenotypic expression of FAP in Brazil is similar to the one reported in Portugal, characterized by high disease penetrance, early onset, particularly in males and in subjects with affected parents, and major symptoms of peripheral neuropathy. These data highlight the influence of common genetic factors, shared by both groups of patients, in disease expression.

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

OBJECTIVE

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 gamma-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.

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

OBJECTIVE

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 gamma-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.

Lack of evidence for the pathogenic role of iron and HFE gene mutations in Brazilian patients with nonalcoholic steatohepatitis

The hypothesis of the role of iron overload associated with HFE gene mutations in the pathogenesis of nonalcoholic steatohepatitis (NASH) has been raised in recent years. In the present study, biochemical and histopathological evidence of iron overload and HFE mutations was investigated in NASH patients. Thirty-two NASH patients, 19 females (59%), average 49.2 years, 72% Caucasians, 12% Mulattoes and 12% Asians, were submitted to serum aminotransferase and iron profile determinations. Liver biopsies were analyzed for necroinflammatory activity, architectural damage and iron deposition. In 31 of the patients, C282Y and H63D mutations were tested by PCR-RFLP. Alanine aminotransferase levels were increased in 30 patients, 2.42 1.12 times the upper normal limit on average. Serum iron concentration, transferrin saturation and ferritin averages were 99.4 31.3 g/dl, 33.1 12.7% and 219.8 163.8 g/dl, respectively, corresponding to normal values in 93.5, 68.7 and 78.1% of the patients. Hepatic siderosis was observed in three patients and was not associated with architectural damage (P = 0.53) or with necroinflammatory activity (P = 0.27). The allelic frequencies (N = 31) found were 1.6 and 14.1% for C282Y and H63D, respectively, which were compatible with those described for the local population. In conclusion, no evidence of an association of hepatic iron overload and HFE mutations with NASH was found. Brazilian NASH patients comprise a heterogeneous group with many associated conditions such as hyperinsulinism, environmental hepatotoxin exposure and drugs, but not hepatic iron overload, and their disease susceptibility could be related to genetic and environmental features other than HFE mutations.

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.

Diabetes mellitus-related autoantibodies in childhood autoimmune hepatitis

OBJECTIVE

To determine the frequency and significance of diabetes mellitus (DM)-related autoantibodies in children with autoimmune hepatitis (AIH).

RESEARCH DESIGN AND METHODS

Anti-islet cell antibodies (ICA), insulin autoantibodies (IAA), and anti-glutamic acid decarboxylase (GAD65) antibodies were assessed in 28 children (25 female) with AIH before and after 3-9 years of therapy with azathioprine and prednisone.

RESULTS

There was biochemical and clinical remission of AIH activity in 76% of the children after 1 year of immunosuppressive therapy. Positive ICA and IAA were found in 60.7% and 18.5% of the patients, decreasing to 38.5% and 12% after 3-9 years of therapy. Anti-GAD autoantibodies were present in only one patient who had Graves' disease, high ICA titer, and developed type 1 DM after 3 years. After 3-9 years of follow up, all had normal fasting glycemia, glycosylated hemoglobin (HbA1c), and, with a single exception, normal responses to oral glucose tolerance testing. No increase in the frequencies of HLA antigens was observed in ICA- and IAA-positive patients compared to antibody-negative patients or a control population. The majority of the patients with HLA-DRB1*03 or DRB1*04, however, were positive for ICA (7/10), and three of them had IAA. The frequency of high risk HLA DQB1*0302 or DQB1*02 alleles was low and similar to control frequencies, indicating low-risk for DM despite the presence of DM-related autoimmunity markers.

CONCLUSIONS

AIH in childhood is associated with high frequency of ICA and IAA, with less than expected rates of progression to DM. Immunosuppression reduced ICA and IAA frequency and titers.

Analysis of HLA-A antigens and C282Y and H63D mutations of the HFE gene in Brazilian patients with hemochromatosis

The hemochromatosis gene, HFE, is located on chromosome 6 in close proximity to the HLA-A locus. Most Caucasian patients with hereditary hemochromatosis (HH) are homozygous for HLA-A3 and for the C282Y mutation of the HFE gene, while a minority are compound heterozygotes for C282Y and H63D. The prevalence of these mutations in non-Caucasian patients with HH is lower than expected. The objective of the present study was to evaluate the frequencies of HLA-A antigens and the C282Y and H63D mutations of the HFE gene in Brazilian patients with HH and to compare clinical and laboratory profiles of C282Y-positive and -negative patients with HH. The frequencies of HLA-A and C282Y and H63D mutations were determined by PCR-based methods in 15 male patients (median age 44 (20-72) years) with HH. Eight patients (53%) were homozygous and one (7%) was heterozygous for the C282Y mutation. None had compound heterozygosity for C282Y and H63D mutations. All but three C282Y homozygotes were positive for HLA-A3 and three other patients without C282Y were shown to be either heterozygous (N = 2) or homozygous (N = 1) for HLA-A3. Patients homozygous for the C282Y mutation had higher ferritin levels and lower age at onset, but the difference was not significant. The presence of C282Y homozygosity in roughly half of the Brazilian patients with HH, together with the findings of HLA-A homozygosity in C282Y-negative subjects, suggest that other mutations in the HFE gene or in other genes involved in iron homeostasis might also be linked to HH in Brazil.

Human polyclonal anti-hepatitis B surface antigen immunoglobulin reduces the frequency of acute rejection after liver transplantation for chronic hepatitis B

BACKGROUND

Use of polyclonal anti-hepatitis B surface antigen immunoglobulin (HBIg) has been shown to reduce hepatitis B virus (HBV) recurrence after liver transplantation (LT) and to decrease the frequency of acute cellular rejection (ACR). However, the protective role of HBIg against ACR remains controversial, since HBV infection has been also associated with a lower incidence of ACR.

AIM

To assess the relationship between HBIg immunoprophylaxis and the incidence of rejection after LT.

METHODS

260 patients (158 males, 43 +/- 14 years old) submitted to LT were retrospectively evaluated and divided into three groups, according to the presence of HBsAg and the use of HBIg. Group I was comprised of HBsAg-positive patients (n = 12) that received HBIg for more than 6 months. Group II was comprised of HBsAg-positive patients that historically have not received HBIg or have been treated irregularly for less than 3 months (n = 10). Group III was composed of 238 HBsAg-negative subjects that have not received HBIg.

RESULTS

HBIg-treated patients (group I) had significantly less ACR episodes, when compared to group II and III. No differences between groups II and III were observed.

CONCLUSIONS

Long-term HBIg administration contributes independently to reduce the number of ACR episodes after LT.

Autoimmune hepatitis in Brazilian patients is not linked to tumor necrosis factor alpha polymorphisms at position -308

BACKGROUND/AIMS

Susceptibility to autoimmune hepatitis (AIH) has been linked to different HLA-DR antigens. Recently, AIH type 1 was associated with polymorphisms in the tumor necrosis factor alpha gene promoter (TNFA) at position -308. In this respect, the frequency of the TNFA*2 allele, in linkage disequilibrium with HLA-DRB1*0301, was shown to be significantly increased in whites with AIH type 1. The aim of this study was to assess the role of TNFA alleles in conferring susceptibility to AIH, studying a population where the disease is not primarily associated with HLA-DRB1*03.

METHODS

The determination of HLA-DRB1 and TNFA alleles was performed in 92 patients with AIH type 1, 29 subjects with AIH type 2 and 83 healthy controls by polymerase chain reaction-based techniques.

RESULTS

The distribution of TNFA alleles was similar in patients with AIH types 1 and 2, when compared with controls. In addition, the TNFA*2 allele was identified in patients carrying HLA-DR antigens other than HLA-DRB1*03. Interestingly, higher gammaglobulin levels were observed in TNFA*2 positive patients.

CONCLUSIONS

Our data indicate that susceptibility to AIH remains primarily linked to the HLA-DRB1 locus, and suggest that the association of AIH with TNFA*2 previously observed in whites might be secondary to a linkage disequilibrium with HLA-DRB1*0301.

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.

Familial amyloidotic polyneuropathy type 1 in Brazil is associated with the transthyretin Val30Met variant

Familial amyloidotic polyneuropathy type 1 (FAP1) is an inherited systemic amyloidosis that is secondary to the deposition of transthyretin (TTR) variants in peripheral nerves and in certain visceral organs. More than 50 distinct mutations have already been described in the TTR gene. Yet, the most common mutation found worldwide is a substitution of valine for methionine in position 30 (Val30Met). Currently, the variants of TTR in Brazilian FAP1 patients remain largely unknown and the aim of this study was to analyze the frequency of the TTR Val30Met mutation in such Brazilian subjects.

METHODS

Thirty-two FAP1 patients belonging to 24 different families were studied for the presence of Val30Met variant by PCR-RFLP.

RESULTS

All Brazilian FAP1 subjects studied were positive for the TTR Val30Met variant. As expected, all of them were heterozygous for the mutation.

CONCLUSION

TTR Val30Met mutation was the sole TTR variant found in Brazilian FAP1 patients in this cohort, and it was present even in those subjects without a clear history of Portuguese ancestry.

Genetic heterogeneity in susceptibility to autoimmune hepatitis types 1 and 2

OBJECTIVE

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, p(c) = 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, p(c) < 0.00014), DRB4 (79% vs 43% of controls, p(c) = 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, p(c) < 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.

Primary extranodal non-Hodgkin lymphoma of the extrahepatic bile duct mimmicking Klatskin tumor

This report describes one case of primary non-Hodgkin lymphoma of the extrahepatic biliary tree. The main symptom was obstructive jaundice. Cholangiography demonstrated stricture of the bile duct which resembled the appearance of cholangiocarcinoma. The surgical approach allowed complete ressection. The histopathological analyses showed a centrocitic-centroblastic follicular non-Hodgkin lymphoma. She underwent chemotherapy, developed severe bone marrow hypoplasia, but 48 months after surgery, the patient is doing well.