B-088 Estimation of Antibodies to Hbsag and Liver Function Markers From a Large Laboratory Database in São Paulo, Brazil
Authors: Fernandes G S , Carvalho G C , Ramadan D R , Tufik S , Feres M C 
Published: September 2023

Abstract

Background
The Hepatitis B virus (HBV) infection can lead to chronic hepatitis B and severe hepatic disease. The Gamma Glutamyl Transferase (GGT), Aspartate Aminotransferase (AST), and Alanine Aminotransferase (ALT) tests are commonly used to assess liver function. Despite having an effective vaccine schedule, many people in Brazil are still susceptible to HBV. Vaccines use the surface protein (AgHBs) of the virus to induce immunity, and patients with antibody levels above 10 mUL/mL to this protein are considered to have vaccine-induced immunity. The study aims to analyze the pattern of hepatitis B markers and liver function in HBV-positive populations.

Methods
A retrospective analysis from 2020 to 2022 was conducted from a large laboratory database in São Paulo, Brazil selecting all individuals from whom the following serological diagnostic markers for Hepatitis B were requested: HBsAg, total Anti-HBc, IgM Anti-HBc, and Anti-HBs. HBV groups were classified based upon results for the following serological diagnostic markers: HBsAg, total Anti-HBc, IgM Anti-HBc, and Anti-HBs. The HBV susceptible group was identified as negative for all markers, the naturally immune group with Anti-HBc and Anti-HBs markers, and the vaccinated group with Anti-HBs only. Liver function was evaluated in two conditions: naturally immune and vaccinated, using liver cell injury markers: GGT, AST, and ALT. The Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis with P &lt; 0.05 considered significant.

Results
Results from a total of 57 311 (32%) men and 121 404 (68%) women were evaluated. The study observed a lower frequency of individuals in the male vaccinated group (36%) compared to the susceptible group (56%). Conversely, the female group showed a higher frequency of individuals immunized by vaccination (51%) in relation to the susceptible group (45%). The rate of individuals exposed to natural infection was higher in the male group (9%) compared to the female group (4%). Regarding Anti-Hbs antibody levels, higher levels were observed in the population with natural infection markers compared to those immunized by HBV vaccination (527.5 ± 4.0 SEM vs 332.3 ± 1.1 mUI/mL, P &lt; 0.001). Analyzing the age ranges with the greatest susceptibility (31–40 and 41–50 years), a gradual decrease in antibodies was observed over the years when compared: Naturally, P = 0.03, and immunized, P &lt; 0.001). Indicator exams of liver function in both conditions showed average GGT levels above the reference value for the naturally infected groups: female 62.4 ± 5.34 SEM U/L; male 86.7 ± 5.4 SEM U/L, P &lt; 0.001. No significant values of ALT and AST activity levels were seen.

Conclusion
The study results showed that this specific male population was more susceptible to HBV infection, while the female population has higher concentrations of Anti-HBs antibodies. Individuals who had a natural Hepatitis B infection exhibit GGT values above the standard.