A team led by Dr. A Behzad-Behbahani from Shiraz University of Medical Sciences has determined that HBV genotype D is the dominant genotype in different clinical forms of either acute or chronic hepatitis. It has been determined that there is a significant association between the presence of anti-HBe antibody and increasing ALT levels among either HBeAg-negative or HBeAg-positive individuals. These results suggest that anti-HBe may play a role in the progression of the disease.
Genotype D is found to be the only detected type in different clinical forms of HBV infections, including cirrhosis, among residents of southwestern Iran. A significant association between the presence of anti-HBe antibody and increasing ALT levels among either HBeAg-negative or HBeAg-positive individuals was also determined.
The heterogeneity in the global distribution of HBV genotypes may account for differences in the clinical outcomes of HBV infections and in the responses to antiviral treatment. The clinical and serological statuses of the patients infected with a specific genotype of HBV in this geographic region (southwestern Iran) need to be further investigated.
Serum samples were collected from HBsAg-positive subjects attending the Gastroenterology and Hepatology Clinic at the Department of Internal Medicine, Shiraz University of Medical Sciences, Shiraz, in southwestern Iran. The definition and diagnostic criteria for clinical terms were adopted from the American Association for the Study of Liver Disease (AASLD) practice guidelines. All sera were then investigated to determine HBV DNA and serological markers. For all the positive quantitative PCR samples, biochemical and histopathological assays and genotyping were also performed. Quantitative real-time PCR assays were carried out using SYBER-Green signal detection. Abdominal ultrasounds were also performed to determine if there were features of cirrhosis. Liver biopsies were performed based on clinical indications.
Genotype D was the only type detected in different clinical forms of acute and chronic infections. There was an increased prevalence of HBeAg-negative status among HBV-infected patients with chronic hepatitis. Cirrhosis was diagnosed among patients with chronic hepatitis. A significant association between the presence of anti-HBe antibody and the increase in ALT levels among either HBeAg-negative or HBeAg-positive individuals was demonstrated. No significant differences were observed between the clinical outcomes of HBeAg-positive and ¨Cnegative patients.
In the view of the authors, this report shows the prevalence of this specific genotype of HBV and its clinical relevance in a part of the Middle East. This isolated genotype is associated with active disease, cirrhosis and hepatocellular carcinoma. A significant number of patients infected with genotype D were HBeAg-negative. Another interesting finding was that a large number of patients with positive anti-HBe had elevated ALT levels.
Using a prospective cohort study in a group of patients infected with HBV genotype D would be helpful to assess the clinical outcomes of different management strategies for the patients. An in vitro study needs to be established in order to clarify the molecular biology of different HBV genotypes.
Further research should explain the mechanism of pathogenesis of different HBV genotypes in specific geographical regions.
Reference: Mojiri A, Behzad-Behbahani A, Saberifirozi M, Ardabili M, Beheshti M, Rahsaz M, Banihashemi M, Azarpira N, Geramizadeh B, Khadang B, Moaddeb A, Ghaedi M, Heidari T, Torab A, Salah AR, Amirzadeh S, Jowkar Z, Mehrabani D, Amini-Bavil-Olyaee S, Dehyadegari MA. Hepatitis B virus genotypes in southwest Iran: Molecular, serological and clinical outcomes. World J Gastroenterol 2008; 14(10): 1510-1513
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