1. ¹School of Public Health, National Defense Medical Center, School of Public Health, No. 161, Section 6, Min-Chuan East Road, Taipei 114, Taiwan, Republic of China
2. ²Institute of Aboriginal Health, Tzu Chi University, Hualien County 970, Taiwan, Republic of China
3. ³Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei 100, Taiwan, Republic of China
4. ⁴Division of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA

Correspondence: C-A Sun, E-mail: sunca@ndmctsgh.edu.tw

Received 27 May 2002; Revised 31 July 2002; Accepted 7 August 2002.

Abstract

Dietary exposure to aflatoxins is one of the major risk factors for hepatocellular carcinoma. Individual susceptibility to aflatoxin-induced hepatocarcinogenesis may be modulated by both genetic and environmental factors affecting metabolism. A cross-sectional study was performed to evaluate determinants of the formation of aflatoxin covalently bound to albumin (AFB₁-albumin adducts). A total of 474 subjects who were free of liver cancer and cirrhosis and were initially selected as controls for previous case–control studies of aflatoxin-induced hepatocarcinogenesis in Taiwan, were employed in this study. Aflatoxin-albumin adducts were determined by competitive enzyme-linked immunosorbent assay, hepatitis B surface antigen and antibodies to hepatitis C virus by enzyme immunoassay, as well as genotypes of glutathione S-transferase M1-1 and T1-1 by polymerase chain reaction. The detection rate of AFB₁-albumin adducts was significantly higher in males (42.5%) than in females (21.6%) (multivariate-adjusted odds ratio=2.6, 95% confidence interval=1.4–5.0). The formation of detectable albumin adducts was moderately higher in hepatitis B surface antigen carriers (42.8%) than in non-carriers (36.6%) (multivariate-adjusted odds ratio=1.4, 95% confidence interval=1.0–2.1). In addition, the detection rate of AFB₁-albumin adducts tended to increase with the increasing number of null genotypes of glutathione S-transferase M1-1 and glutathione S-transferase T1-1. In conclusion, this cross-sectional study has assessed the relative contributions of environmental exposure and host susceptibility factors in the formation of AFB₁-albumin adducts in a well characterised Chinese adult population. This study further emphasises the necessity to reduce aflatoxin exposure in people living in an area endemic for chronic hepatitis B virus infection.