Background: Hepatitis B virus (HBV) is classified into eight genotypes with distinct geographic distributions. Studies have shown that genotypic differences affect clinical outcomes. Although genotypes B and C are the frequently reported genotypes in Asia, a local study has shown Genotype A as the predominant type among Filipinos. Objectives: To determine the predominant genotype in Filipino patients and to determine association of HBV genotypes and viral load, E antigen status, alanine aminotransferase level (ALT), cirrhosis and treatment response. Methodology: Prospective, observational study on patients with chronic HBV infection enrolled from April to September 2005 at St. Luke's Medical Center. Hepatitis profile, quantitative viral load, genotyping, liver function test and ultrasound were done. Patients were followed up to determine initiation and response to treatment. One-way ANOVA, Fisher exact and Spearman were done when appropriate at 95 percent confidence level (two-tailed). Results: There are 37 patients included in the study. Genotype A is the predominant genotype (37.8 percent) followed by genotypes B, D and C. Majority of these patients (81.8 percent) are HBeAg positive. Eighty-six percent of patients with genotypes A, C and D have chronic hepatitis while 62.5 percent of patients with genotype B have cirrhosis. Although there were no significant differences in mean viral load and ALT levels across the four genotypes, a statistically significant inverse relationship was seen with HBV DNA levels and stage of illness (p 0.041). There was a statistically significant difference in treatment response with genotype A compared to D (p 0.0242); however, no significant difference is seen comparing genotypes B and C. Conclusion; Genotype A is the predominant genotype among the subjects in the study. Patients with genotype A HBV infection appear to have a better treatment response rate compared to genotype D. However, no significant association is seen between genotype and viral load, ALT levels and HBeAg positivity.
1. To determine the predominant genotype among Filipino patients with hepatitis B infection at St. Luke's Medical Center. 2. To determine the association between hepatitis B virus genotypes and mean viral load (HBV DNA), hepatitis B e antigen status (HBeAg), mean alanine aminotransferase level (ALT) and cirrhosis.