Brief Reports
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 14, 2005; 11(30): 4727-4730
Published online Aug 14, 2005. doi: 10.3748/wjg.v11.i30.4727
Prevalence of porcine endogenous retrovirus in Chinese pig breeds and in patients treated with a porcine liver cell-based bioreactor
Qing Liu, Zheng Liu, Evangelos Dalakas
Qing Liu, Artificial Liver Treatment and Training Center, Beijing Youan Hospital, Capital University of Medical Sciences, Beijing 100054, China
Zheng Liu, Department of General Surgery, Shen Zheng Hospital, Peking University, Shenzheng 518036, Guangdong Province, China
Evangelos Dalakas, Department of Hepatology, Chancellor’s Building, University of Edinburgh, Edinburgh EH16 4SB, Scotland, UK
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Qing Liu, Artificial Liver Treatment and Training Center, Beijing Youan Hospital, Beijing 100054, China. liuqing7@yahoo.com
Telephone: +86-10-63295285 Fax: +86-10-63295285
Received: June 28, 2004
Revised: July 20, 2004
Accepted: July 22, 2004
Published online: August 14, 2005
Abstract

AIM: To determine the prevalence of porcine endogenous retrovirus (PERV) in various pig breeds raised in China including Chinese experimental mini-pigs by PERV-reverse transcriptase (PERV-RT enzyme). Moreover, the potential for infection of PERV was investigated in patients treated with a bioreactor based on porcine liver cells (n = 3).

METHODS: Pig serum, liver and muscle cell-free supernatants were collected from various Chinese pig breeds. Porcine hepatocytes were isolated with a two-step perfusion method. Three patients with acute or chronic liver failure were treated with a bioartificial liver support system (BALSS) for 8-12 h and serum samples were collected from the patients before, immediately after and 30 d after treatment.

RESULTS: The activities of PERV-RT enzyme in pig liver and muscle cell-free supernatants were higher than in normal human controls. PERV-TR enzyme activity did not increase in patients before and after 1 mo of treatment. PERV-RT activities were not significantly different when compared with pre-treatment group (1.544 ± 0.155576), the post-treatment groups (1.501 ± 0.053507, 1.461 ± 0.033808 and 1.6006667 ± 0.01963 for 0, 14 and 30 d post-treatment, respectively, P > 0.05), and normal control group (1.440 ± 1.0641, P > 0.05). RT enzyme activity in Chinese experimental mini-pigs was higher than in normal human control group (1.440 ± 1.0641 U/mL, P < 0.05), and not significantly different (P > 0.05) when compared with the pig breeds except in the muscle supernatants. All the samples including muscle and liver cell supernatants from the Chinese mini-experimental pigs and the four domestic Chinese pig breeds contained PERVs.

CONCLUSION: These results suggest that the risk of PERV infection through BALSS containing porcine liver cells without immunosuppressants may be quite low. Although there were PERVs in Chinese experimental mini-pigs and porcine liver cell culture suspensions, we did not find any evidence of persistent PERV infection in patients treated with this porcine hepatocyte-based bioartificial liver.

Keywords: Porcine endogenous retrovirus; Bioartificial liver support system; Porcine endogenous retrovirus-reverse transcriptase