Prevalence of aflatoxin B1 in liver biopsies of proven hepatocellular carcinoma in India determined by an in-house immunoperoxidase test

1 Department of Microbiology, Faculty of Medicine, Dr ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, India 2 Medical Gastroenterology Unit of the Government General Hospital, Chennai 600 001, India 3 Medical and Surgical Gastroenterology Unit of the Government Stanley Medical College and Hospital, Chennai 600 001, India 4 Government Kilpauk Medical College and Hospital, Chennai 600 029, India Correspondence K. G. Murugavel murugavel{at}yrgcare.org Received 4 January 2007 Accepted 29 June 2007 Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death in the world. The incidence of HCC in India is reportedly low and varies from 0.2 to 1.9 %. Aflatoxins, secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus , are potent human carcinogens implicated in HCC. The prevalence of aflatoxin B1 (AFB1) as co-carcinogen was analysed using an in-house immunoperoxidase test in 31 liver biopsies and 7 liver-resection specimens from histopathologically proven HCC, and in 15 liver biopsies from cirrhosis patients (control group). Serum was tested for hepatitis B and C serological markers using commercial assays, and for AFB1 using an in-house ELISA with a sensitivity of 1 ng ml –1 for AFB1. In spite of positive AFB1 immunostaining in HCC cases, all serum specimens, from both HCC and the control groups, were AFB1-negative. There were 18 (58.1 %) HCC cases that revealed AFB1 in liver biopsies; 68.8 % ( n =11) of non-B non-C hepatitis cases with HCC and 46.1 % ( n =6) of the hepatitis B surface-antigen-positive subjects were positive for AFB1. Out of the two hepatitis B/hepatitis C virus co-infected cases, one was positive for AFB1. Of seven tumour-resection samples, six were positive for AFB1. Only one case revealed AFB1 in the non-tumour area of the resected material. Thus AFB1 staining was significantly associated with tumour tissue ( P =0.03). Aflatoxins proved to have a significant association with HCC in this peninsular part of the subcontinent. The impact seems to be a cumulative process, as revealed by the AFB1 deposits in HCC liver tissue, even though the serum levels were undetectable. Abbreviations: AFB1, aflatoxin B1; DAB, 3'3'-diaminobenzidine tetrahydrochloride; HBsAg, hepatitis B surface antigen; HCC, hepatocellular carcinoma.