Aflatoxin B1 is a
carcinogen produced by Aspergillus flavus and a few related fungi that are often present in many food substances. It interacts synergistically with
Hepatitis B or C virus (HBV, HBC)
infection, thereby increasing the risk of
hepatocellular carcinoma (HCC). The G to T transversion at the third position of
codon 249 (AGG) of the TP53 gene, substituting
arginine to
serine, is the most common
aflatoxin-induced mutation linked to HCC. This study examined mutations in TP53 by PCR-RFLP analysis and by measurement of an
aflatoxin-albumin adduct as a
biomarker for human exposure of
aflatoxin B1 by indirect-competitive ELISA, in samples collected from healthy controls as well as patients with
hepatitis in Hyderabad, Andhra Pradesh, India. A total of 238 blood samples were analyzed the presence of the G to T mutation. Eighteen of these samples were from HBV-positive subjects, 112 of these were from subjects who had HBV-induced
liver cirrhosis, and 108 samples were taken from subjects without HBV
infection or
liver cirrhosis (control group). The G to T mutation was detected in 10 samples, 8 of which were from subjects positive to both HBV and
aflatoxin-albumin adduct in blood (p=0.07); whilst two were from individuals who were HBV-negative, but positive for the
aflatoxin-albumin adduct (p=0.14). The
aflatoxin-albumin adduct was detected in 37 of 238 samples, 29 samples were from HBV-positive subjects and eight were from individuals who were positive for both HBV and the TP53 mutation (p=0.07). The concentration of
aflatoxin-albumin adduct ranged from 2.5 to 667pg/mg
albumin. Despite low incidence of the G to T mutation, its detection in subjects positive to
aflatoxin-adducts is indicative of a strong association between the mutation and
aflatoxin exposure in India.