Hepatitis C virus infection: Are there still specific problems with genotype 3?

Table 2 Factors associated with poor response to pegylated interferon α/RVB in hepatitis C virus GT-3- infected patients

Factors	Study design	Number of patients	Characteristics	Ref.	Comments
Viral factors
High baseline viral load (> 8 × 105 UI/mL)	Prospective	426 (all GT-3)	223 patients with viral load > 8 × 105 UI/mL	[56]	Combined with non-RVR
High baseline viral load (> 6 × 105 UI/mL)	Retrospective	107 (all GT-3)	45 non-SVR/62 SVR	[71]	Combined with advanced fibrosis
High baseline quasi- species complexity and diversity	Retrospective	10 (all GT-3)		[58]
Mutations in NS5A	Prospective	49 (all GT-3)	25 non-SVR/24 SVR	[62]	Significant mutations at positions 2309 (Ala to Ser) and 2326 (Gly to Ala)
Host factors
Fibrosis/Cirrhosis	Prospective	91 (all GT-3)	17 cirrhotic/74 non-cirrhotic	[63]	Also associated with increased risk of post-treatment relapse
	Retrospective	604 (all GT-3)	145 cirrhotic/459 non-cirrhotic	[64]	Response not affected by ethnicity
	Retrospective	180	108 GT-3/72 GT-2	[66]	Lack of SVR associated with fibrosis and GT-3
	Retrospective	107 (all GT-3)	45 non-SVR/62 SVR	[71]	Combined with high baseline viral load
Steatosis	Prospective	224	182 GT-3/42 GT-2	[69]	Lower SVR in GT-3
	Retrospective	932	505 GT-3/427 GT-2	[70]	Associated with higher relapse rates in GT-3 patients who had RVR
Ethnicity	Retrospective	103	66 Caucasians/38 Asians	[74]	Poor response could reflect more advanced liver disease at baseline in Asian patients
	Retrospective	604 (all GT-3)	305 non-Asians/299 South Asians	[64]	No correlation between ethnicity and treatment relapse
IFNL3 gene polymorphisms	Retrospective	107 (all GT-3)	45 non-SVR/62 SVR	[71]	No correlation between IFNL3 polymorphisms and SVR
	Prospective	293 HCV RNA- positive	65.87% GT-3/32.08% GT-1	[78]	CC and TT alleles strongly associated with SVR in GT-3 patients
Intrahepatic ISG15 expression/IFNL4 gene polymorphisms	Retrospective	92	36 GT-3/56 GT-1	[79]	In GT-3, low ISG15 expression and good-responder IFNL4 genotype associated with high SVR rates

GT: Genotype; SVR: Sustained virologic response; RVR: Rapid virologic response; NS5A: Non-structural 5A protein; IFNL: Interferon lambda; ISG: Interferon-stimulated gene; HCV: Hepatitis C virus.