Laura Alencastro de Azevedo

Prevalence of common α-thalassemia determinants in south Brazil: importance for the diagnosis of microcytic anemia

Alpha thalassemia has not been systematically investigated in Brazil. In this study, 493 unrelated individuals from the southernmost Brazilian state of Rio Grande do Sul were screened for deletional forms of α-thalassemia. One hundred and one individuals had microcytic anemia (MCV < 80 fL) and a normal hemoglobin pattern (Hb A 2 < 3.5% and Hb F < 1%). The subjects were screened for - α3.7 , - α4.2 , - α20.5 , — SEA and — MED deletions but only the - α3.7 allele was detected. The - α3.7 allele frequency in Brazilians of European and African ancestry was 0.02 and 0.12, respectively, whereas in individuals with microcytosis the frequency was 0.20. The prevalence of α-thalassemia was significantly higher in individuals with microcytosis than in healthy individuals (p = 0.001), regardless of their ethnic origin. There were also significant differences in the hematological parameters of individuals with - α3.7 / αα, - α3.7 /- α3.7 and β-thalassemia trait compared to healthy subjects. These data suggest that α-thalassemia is an important cause of microcytosis and mild anemia in Brazilians.

UGT1A1, SLCO1B1 , and SLCO1B3 polymorphisms vs. neonatal hyperbilirubinemia: is there an association?

Background:Jaundice is a physiological phenomenon; however, severe hyperbilirubinemia occurs in only 5 to 6% of the healthy newborn population. It has been suggested that genetic variation could enhance the risk of hyperbilirubinemia when coexpressed with other icterogenic conditions.Methods:The study included newborns with a gestational age of greater than 35 wk and weights greater than 2,000 g with indications for phototherapy. The polymorphisms from UGT1A1 (rs8175347), SLCO1B1 (rs4149056 and rs2306283), and SLCO1B3 (rs17680137 and rs2117032) were analyzed by capillary electrophoresis and hydrolysis probes.Results:A total of 167 hyperbilirubinemic infants and 247 control subjects were enrolled. The gender, ABO incompatibility, birth weight, and gestational age differed between the groups, but the allelic and genotypic frequency of the polymorphisms from SLCO1B genes did not. In logistic regression, the ABO incompatibility, gestational age, and polymorphic T allele of rs2117032 remained in the model. The presence of this polymorphism seemed to provide protection from hyperbilirubinemia. The individuals who were homozygous for the G allele of rs2306283 and who were glucose 6-phosphate-dehydrogenase deficient were more frequent among the cases.Conclusion:Although genetic variation accounts for a good part of this condition, the association between different polymorphisms and environmental factors has yet to be explained.

Neonatal screening for hemoglobinopathies: results of a public health system in South Brazil.

AIM The aim of this study was to estimate the prevalence of hemoglobinopathies in South Brazil. METHODS Samples of dried blood spots collected by heel prick in neonates were evaluated by isoeletric focusing and/or high-performance liquid chromatography techniques. All variants were characterized at the molecular level. RESULTS A total of 437,787 samples were evaluated. Among these, 6391 showed an abnormal hemoglobin pattern. These included 48 cases (0.01%) of sickle cell disorders (33 hemoglobin SS [Hb SS], 7 Hb SC, 7 Hb S/beta thalassemia, 1 Hb SD), 1 neonate who was homozygous for beta thalassemia, 6272 (1.4%) newborns who were heterozygous for Hb S, C, or D, and 71 (0.02%) neonates who were carriers for rare hemoglobin variants. Most of these rare variants were identified for the first time in Brazil. CONCLUSIONS Comparing these results with those obtained in other Brazilian regions, we observe a highly heterogeneous distribution. This knowledge is useful in healthcare planning and allocation of resources, as well as identifying at-risk couples, which will assist with disease prevention.

Polymorphic variants of UGT1A1 in neonatal jaundice in southern Brazil.

Alterations in the hepatic conjugation of bilirubin due to uridyl-diphosphate-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms have been proposed as risk factors to neonatal jaundice. Herein, we estimated the frequency of genotypes of the promoter region of UGT1A1 gene in newborns and evaluated its association with severe hyperbilirubinemia. Prospective study of cases and controls including all newborns admitted for phototherapy at HCPA, Brazil, during 9 months; 490 babies were enrolled and PCR was performed. Polymorphic genotypes were detected in 16% of the patients and 7 of the 10 possible genotypes were identified with higher prevalence of polymorphisms in Afro-descendants. In this sample, the variants of UGT1A1 were not associated to severe hyperbilirubinemia; other genic factors should be sought in this high miscegenation area of Brazil.

Prevalence of UGT1A1 Gene Polymorphism in Patients with Hemolytic Anemia in Southern Brazil

The aim of the work was to determine the variation of UGT1A1 genotypes in patients with hemolytic anemia in the southern Brazil. Three hundred twenty-three patients with hemolytic anemia were genotyped for UGT1A1 along with 232 controls. Allelic and genotypic distribution did not differ among studied groups. The TA7/TA7 genotype presented a frequency that ranged from 3.2% to 18.0% (nonsignificant). Alleles TA5 and TA8 were also found in the sample, even though southern Brazil is a major Caucasoid region. Genotype prevalence was very similar to those of African origins, reflecting the diversity of ethnic origins and the high degree of admixture in southern Brazil. Further studies should be conducted to correlate the modulating role of UGT1A1 polymorphism with the clinical conditions of each patient with hemolytic anemia.

Genetic variants underlying vitamin D metabolism and VDR–TGFβ-1–SMAD3 interaction may impact on HCV progression: a study based on dbGaP data from the HALT-C study

Vitamin D deficiency is prevalent in liver disease and vitamin D has been shown to decrease hepatic fibrosis through an anti-TGFβ-1/SMAD3 effect mediated by the vitamin D receptor. Thus, we hypothesized that genetic variants involved in vitamin D metabolism and/or VDR/TGFβ-1/SMAD3 interaction could impact on the progression of chronic HCV. We obtained or imputed genotypes for 40 single nucleotide polymorphisms (SNPs) located in genes implicated in vitamin D metabolism from the HALT-C cohort via dbGaP. The HALT-C study followed 692 chronic HCV patients over 4 years, evaluating clinical outcomes including worsening of fibrosis, hepatic decompensation (gastric/esophageal bleeding, CTP>7, ascites, spontaneous bacterial peritonitis and encephalopathy), development of hepatocellular carcinoma, and liver death. We tested the selected SNPs for association with these outcomes in 681 HALT-C subjects. Eleven SNPs presented tendency towards significance (P<0.05): four SNPs in DHCR7 related to with hepatic decompensation (rs4944957, rs12800438, rs3829251 and rs4945008); two in GC to worsening of fibrosis and liver death (rs7041 and rs222020); two in CYP2R1 to ascites and hepatocellular carcinoma (rs7116978 and rs1562902); two in VDR to gastric/esophageal bleeding and hepatocellular carcinoma (rs4516035 and rs2239186); and one in SMAD3 to worsening of fibrosis and encephalopathy (rs2118610). Only rs1800469 in TGFB1 was statistically associated with hepatic decompensation after Bonferroni’s correction (P<0.00125). In conclusion, rs1800469 in TGFB1 was associated to hepatic decompensation in chronic hepatitis C, while the other 11 described polymorphisms must be evaluated in a larger cohort to determine the possible role of vitamin D in hepatitis C.

Is dietary glycemic load associated with liver fibrosis in hepatitis C

INTRODUCTION Occidental diet and metabolic profile seems to increase hepatic fibrosis (HF) in patients with chronic hepatitis C virus (HCV) infection, but there is scarce information about the diet components and their role in this setting. OBJECTIVES This study aims to evaluate the dietary intake, metabolic profile, presence of metabolic syndrome (MetS) and cardiovascular risk in patients with chronic HCV infection according to the presence of fibrosis. METHODS Cross-sectional study which 58 patients with HCV infection without active antiviral therapy and non-cirrhotic were assessed. All patients were subjected to clinical, laboratorial and dietary evaluation, and classified according to the METAVIR score. Patients were divided as the presence of hepatic fibrosis. RESULTS In this sample, fifty-five percent of patients were females, the average age was 51.6 ± 9.7 years, and 79.3% were carriers of HCV genotype 1. Patients with HF presented higher energy, and fat intake as well as higher glycemic load of meals in comparison to those without HF. Patients with HF presented higher systolic and diastolic arterial pressure and higher levels of insulin. CONCLUSIONS In conclusion, patients with HF had higher total daily energy and total fat intakes, and worse metabolic profile, characterized by a higher insulin resistance and blood pressure.

Effect of Vitamin D Serum Levels and GC Gene Polymorphisms in Liver Fibrosis Due to Chronic Hepatitis C

INTRODUCTION AND AIM Vitamin D has been associated with chronic liver diseases and low vitamin levels may contribute to progression of chronic hepatitis C. The aim of this study was to evaluate the influence of vitamin D serum levels and GC gene polymorphisms in the severity of liver fibrosis in patients with chronic hepatitis C genotype 1. MATERIAL AND METHODS Cross-sectional study that enrolled 132 adult patients with chronic hepatitis C genotype 1 attended at the outpatient Clinic of Gastroenterology Division at Hospital de Clínicas de Porto Alegre. At the time of enrollment patients had a blood withdraw for serum 25(OH)D determination and genotypic analysis of rs7041 and rs4588 polymorphisms in GC gene. None/mild fibrosis was considered as METAVIR F0, F1 and F2 and severe fibrosis as METAVIR F3 and F4. RESULTS Median 25(OH)D levels in the sample were 19.9 ng/mL (P25-P75: 14.0-29.4). Fifty percent of patients presented vitamin D deficiency (< 20 ng/mL). In stepwise multiple linear regression the variables associated with 25(OH)D levels were blood withdrawn in Winter/spring season, the haplotypes AT/AT + AG/AT of rs7041 and rs4588 and female sex. For evaluation of severe fibrosis, variables associated in logistic regression were age, vitamin D severe deficiency (< 10 ng/mL), glucose levels, BMI and platelets count. CONCLUSIONS Vitamin D levels are associated with severity of liver fibrosis in chronic hepatitis C genotype 1 patients. Although the rs7041 and rs4588 GC polymorphisms are strong predictors of vitamin D levels, they do not play a direct role in liver fibrosis.INTRODUCTION AND AIM Vitamin D has been associated with chronic liver diseases and low vitamin levels may contribute to progression of chronic hepatitis C. The aim of this study was to evaluate the influence of vitamin D serum levels and GC gene polymorphisms in the severity of liver fibrosis in patients with chronic hepatitis C genotype 1. MATERIAL AND METHODS Cross-sectional study that enrolled 132 adult patients with chronic hepatitis C genotype 1 attended at the outpatient Clinic of Gastroenterology Division at Hospital de Clínicas de Porto Alegre. At the time of enrollment patients had a blood withdraw for serum 25(OH)D determination and genotypic analysis of rs7041 and rs4588 polymorphisms in GC gene. None/mild fibrosis was considered as METAVIR F0, F1 and F2 and severe fibrosis as METAVIR F3 and F4. RESULTS Median 25(OH)D levels in the sample were 19.9 ng/mL (P25-P75: 14.0-29.4). Fifty percent of patients presented vitamin D deficiency (< 20 ng/mL). In stepwise multiple linear regression the variables associated with 25(OH)D levels were blood withdrawn in Winter/spring season, the haplotypes AT/AT + AG/AT of rs7041 and rs4588 and female sex. For evaluation of severe fibrosis, variables associated in logistic regression were age, vitamin D severe deficiency (< 10 ng/mL), glucose levels, BMI and platelets count. CONCLUSIONS Vitamin D levels are associated with severity of liver fibrosis in chronic hepatitis C genotype 1 patients. Although the rs7041 and rs4588 GC polymorphisms are strong predictors of vitamin D levels, they do not play a direct role in liver fibrosis.

High Frequency of Hb E-Saskatoon (HBB: c.67G > A) in Brazilians: A New Genetic Origin?

Abstract Hb E-Saskatoon [β22(B4)Glu→Lys, HBB: c.67G > A] is a rare, nonpathological β-globin variant that was first described in a Canadian woman of Scottish and Dutch ancestry and has since then been detected in several populations. The aim of the present study was to identify the origin of Hb E-Saskatoon in Brazil using β-globin haplotypes and genetic ancestry in carriers of this hemoglobin (Hb) variant. Blood samples were investigated by isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) using commercial kits. Hb E-Saskatoon was confirmed by amplification of the HBB gene, followed by sequence analysis. Haplotypes of the β-globin gene were determined by polymerase chain reaction (PCR), followed by digestion with specific restriction enzymes. Individual ancestry was estimated with 48 biallelic insertion/deletions using three 16-plex PCR amplifications. The IEF pattern was similar to Hbs C (HBB: c.19G > A) and Hb E (HBB: c.79G > A) [isoelectric point (pI): 7.59-7.65], and HPLC results showed an elution in the Hb S (HBB: c.20A > T) window [retention time (RT): 4.26-4.38]. DNA sequencing of the amplified β-globin gene showed a mutation at codon 22 (GAA>AAA) corresponding to Hb E-Saskatoon. A total of 11 cases of this variant were identified. In nine unrelated individuals, Hb E-Saskatoon was in linkage disequilibrium with haplotype 2 [+ – – – –]. All subjects showed a high degree of European contribution (mean = 0.85). Hb E-Saskatoon occurred on the β-globin gene of haplotype 2 in all Brazilian carriers. These findings suggest a different genetic origin for this Hb variant from that previously described.