IL28B polymorphism genotyping as predictor of rapid virologic response during interferon plus ribavirin treatment in hepatitis C virus genotype 1 patients

Table 1 Demographic and clinical features of 118 hepatitis C virus genotype 1 infected patients n (%)

Variables	Patients
Age, yr	49 (16)
Male gender	52.5%
BMI, kg/m2	23.5 (3.6)
AST, IU/mL	82 (71)
ALT, IU/mL	55 (48)
gGT, IU/mL	46 (57)
Platelets, 109 L	182 (90)
APRI index	0.4 (0.6)
Basal HCV RNA, log IU/mL	6 (1.1)
Fibrosis (stiffness)	6.7 (19)
Fibrosis Metavir
F0-F1-F2	20 (25)
F3-F4	59 (75)
IL28B SNP rs8099917
TT	59 (50)
TG	56 (47)
GG	3 (3)
IL28B SNP rs12979860
CC	30 (25)
CT	73 (62)
TT	15 (13)
HCV RNA decline < 1 log10 IU/mL w4	26 (22)
rs8099917_G*/rs12979860_**	21 (81)
rs8099917_TT/rs12979860_T*	3 (11)
rs8099917_TT/rs12979860_CC	2 (8)
Therapy outcome
R	53 (55)
NR	65 (45)

Data are reported as median (interquartile range) and frequencies (%). IL: Interleukin; BMI: Body mass index; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; gGT: Gamma-glutamyl transpeptidase; IL28B: Interleukin-28B; SNP: Single nucleotide polymorphism; w4: Treatment week 4; R: Responder; NR: Non-responder.

Table 2 Univariate and multivariate analysis of baseline factors associated with hepatitis C virus RNA reduction < 1 log₁₀ IU/mL at week 4 on treatment n (%)

Baseline factors	Univariate			Multivariate
	HCV RNA drop <1 log10: w4	HCV RNA drop≥log10: w4	P value	OR	95%CI	P value
	(n = 26)	(n = 92)
Age, yr	49 (14)	49 (18)	NS	-	-	NS
Male gender	15 (26)	47 (74)	NS	-	-	NS
BMI, kg/m2	23 (2)	24 (4)	NS	-	-	-
AST, IU/mL	90 (46)	67 (74)	0.032	1.01	0.99-1.02	NS
ALT, IU/mL	73 (60)	49 (44)	0.002	0.97	0.95-0.99	0.018
gGT, IU/mL	68 (71)	39 (43)	0.001	0.99	0.98-0.99	0.009
Platelets, 109 L	151 (93)	196 (83)	0.019	-	-	NS
APRI index	0.6 (1.2)	0.4 (0.6)	0.033	-	-	NS
Basal HCV RNA, log IU/mL	6.1 (0.8)	6 (1.1)	NS	-	-	-
Fibrosis F3/F4	11 (58)	48 (80)	NS	-	-	NS
IL28B rs8099917_TG/GG	21 (81)	38 (41)	< 0.001	7.90	1.99-31.18	0.003
IL28B rs12979860_CT/TT	23 (88)	65 (71)	NS	-	-	NS

Data are reported as median (interquartile range) and frequencies (%). IL: Interleukin; BMI: Body mass index; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; gGT: Gamma-glutamyl transpeptidase; Null-R: Null-responders; NS: Not significant.

Table 3 Sensitivity, specificity, positive and negative predictive value of single and combined IL28B polymorphisms for achieving hepatitis C virus RNA drop ≥ 1 log at treatment week 4

IL28B polymorphisms	Sn	Sp	PPV	NPV	LR
rs8099917_TT	59%	81%	91%	36%	3.05
rs12979860_CC	29%	88%	90%	26%	2.54
rs8099917_TT or rs12979860_CC	29%	92%	93%	27%	3.82

IL: Interleukin; Sn: Sensitivity; Sp: Specificity; PPV: Positive predictive value; NPV: Negative predictive value; LR: Likelihood ratio.