Sandro da Costa Ferreira1, Silvana Gama Florêncio Chachá2, Fernanda Fernandes Souza3, Andreza Corrêa Teixeira3, Rodrigo de Carvalho Santana4, Neifi Hassan Saloun Deghaide5, Sandra Rodrigues3, Leonardo A Marano6, Celso Teixeira Mendes-Junior7, Leandra Naira Zambelli Ramalho8, Sérgio Zucoloto8, Eduardo Antônio Donadi5, Ana de Lourdes Candolo Martinelli3. 1. Division of Gastroenterology, Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil. Electronic address: sandrocferreira@terra.com.br. 2. Division of Gastroenterology, Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil; Department of Medicine, University Federal of São Carlos (UFSCAR), Brazil. 3. Division of Gastroenterology, Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil. 4. Division of Infectious Diseases, Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil. 5. Division of Clinical Immunology, Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil. 6. Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil. 7. Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP - USP), Brazil. 8. Department of Pathology, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Brazil.
Abstract
BACKGROUND AND AIMS: HLA-G has well-recognized immunomodulatory properties, and this molecule is frequently expressed in the livers of hepatitis B virus (HBV)-infected patients. Because the HLA-G 14 bp-insertion/deletion polymorphism (rs371194629) has been associated with the magnitude of HLA-G expression, we evaluated this polymorphism in the recognized evolutionary forms of chronic HBV infection. METHODS: We studied 196 chronic HBV-infected patients (118 HBeAg-negative chronic hepatitis, 53 HBeAg-positive chronic hepatitis and 25 inactive carriers exhibiting low levels of serum HBVDNA and persistently normal ALT levels), and 202 healthy individuals. Chronic hepatitis HLA-G typing was performed using PCR-amplified DNA hybridized with specific primers. RESULTS: The frequencies of the insertion/deletion alleles and genotypes were very similar in patients and controls. After patient stratification according to the evolutionary form of the chronic HBV infection, the frequencies of the deletion allele (P=0.0460; OR=1.26; 95%CI=1.01-1.45) and of the deletion/deletion genotype (P=0.0356; OR=2.08; 95%CI=1.05-4.09) were overrepresented in HBeAg-positive patients when compared to HBeAg-negative patients. No differences were observed when HBV inactive carriers were compared to HBeAg-negative chronic hepatitis patients. CONCLUSIONS: Because the 14-bp deletion allele has been associated with increased HLA-G production and because HLA-G may down regulate the cytotoxic activity of TCD8 and NK cells, patients exhibiting the 14-bp deletion allele at single or double doses are at increased risk for developing chronic forms of HBV associated with persistent viremia and worse prognoses.
BACKGROUND AND AIMS: HLA-G has well-recognized immunomodulatory properties, and this molecule is frequently expressed in the livers of hepatitis B virus (HBV)-infectedpatients. Because the HLA-G 14 bp-insertion/deletion polymorphism (rs371194629) has been associated with the magnitude of HLA-G expression, we evaluated this polymorphism in the recognized evolutionary forms of chronic HBV infection. METHODS: We studied 196 chronic HBV-infectedpatients (118 HBeAg-negative chronic hepatitis, 53 HBeAg-positive chronic hepatitis and 25 inactive carriers exhibiting low levels of serum HBVDNA and persistently normal ALT levels), and 202 healthy individuals. Chronic hepatitisHLA-G typing was performed using PCR-amplified DNA hybridized with specific primers. RESULTS: The frequencies of the insertion/deletion alleles and genotypes were very similar in patients and controls. After patient stratification according to the evolutionary form of the chronic HBV infection, the frequencies of the deletion allele (P=0.0460; OR=1.26; 95%CI=1.01-1.45) and of the deletion/deletion genotype (P=0.0356; OR=2.08; 95%CI=1.05-4.09) were overrepresented in HBeAg-positive patients when compared to HBeAg-negative patients. No differences were observed when HBV inactive carriers were compared to HBeAg-negative chronic hepatitispatients. CONCLUSIONS: Because the 14-bp deletion allele has been associated with increased HLA-G production and because HLA-G may down regulate the cytotoxic activity of TCD8 and NK cells, patients exhibiting the 14-bp deletion allele at single or double doses are at increased risk for developing chronic forms of HBV associated with persistent viremia and worse prognoses.