Artificial liver support

Table 1: Comparison of liver-assist devices made with primary hepatocytes versus an immortalized human liver cell line (C3A)
Aspects of liver-assist devices Primary hepatocytes Cell line
Ease of obtaining a large mass of cells Difficult: automated system for cell isolation not available Easy: clonal expansion of existing cell line
Current count per cartridge 6 × 10⁹ (estimated 6-12 g) 2 × 10¹¹ (estimated 200 g)
Cell survival during treatment Limited: cells vacuolated after 7 h Indefinite: viability up to 7 d
Immunogenicity of infused proteins Unknown, especially with repeated use No problem after several days of treatment (human proteins)
Risk of infectious agents Unknown: screening of each sample or gnotobiotic animal may be required Controlled culture conditions: master cell bank screened for human pathogens
Risk of tumour Negligible Unknown; probably low (requires follow-up)
Effectiveness in animal studies Improved blood pressure and levels of blood chemicals after 6 h Recovery from massive liver necrosis after 48 h
Goal of treatment Short-term treatment intended as a bridge to liver transplantation Metabolic support until liver regenerates; bridge to liver transplantation is secondary goal
Effectiveness in patients Suggestive evidence; effectiveness must be proven in randomized trial Suggestive evidence; effectiveness must be proven in randomized trial
Cost Labour intensive and therefore expensive Expected to be less than or equal to US$20 000 per patient

[Return to text]

Table 1: Comparison of liver-assist devices made with primary hepatocytes versus an immortalized human liver cell line (C3A)
Aspects of liver-assist devices	Primary hepatocytes	Cell line
Ease of obtaining a large mass of cells	Difficult: automated system for cell isolation not available	Easy: clonal expansion of existing cell line
Current count per cartridge	6 × 10⁹ (estimated 6-12 g)	2 × 10¹¹ (estimated 200 g)
Cell survival during treatment	Limited: cells vacuolated after 7 h	Indefinite: viability up to 7 d
Immunogenicity of infused proteins	Unknown, especially with repeated use	No problem after several days of treatment (human proteins)
Risk of infectious agents	Unknown: screening of each sample or gnotobiotic animal may be required	Controlled culture conditions: master cell bank screened for human pathogens
Risk of tumour	Negligible	Unknown; probably low (requires follow-up)
Effectiveness in animal studies	Improved blood pressure and levels of blood chemicals after 6 h	Recovery from massive liver necrosis after 48 h
Goal of treatment	Short-term treatment intended as a bridge to liver transplantation	Metabolic support until liver regenerates; bridge to liver transplantation is secondary goal
Effectiveness in patients	Suggestive evidence; effectiveness must be proven in randomized trial	Suggestive evidence; effectiveness must be proven in randomized trial
Cost	Labour intensive and therefore expensive	Expected to be less than or equal to US$20 000 per patient