Results of interferon-based treatments in Alaska Native and American Indian population with chronic hepatitis C

Figures & data

Table 1. Hepatitis C treatment sustained virologic response by regimen and genotype in a cohort of Alaska Native and American Indian people

Treatment regimen	Number treated	SVR (%)^a	Genotype 1 SVR	Genotype 2 SVR	Genotype 3 SVR
Interferon	18^b	3 (16.7)	1/10 (10%)	0/1 (0%)	1/6 (16.7%)
Interferon/ribavirin	37	11 (29.7)	2/12 (16.7%)	3/9 (33.3%)	6/16 (37.5%)
Pegylated interferon/ribavirin^c	119^d	61 (51.3)	10/46 (21.7%)	38/51 (74.5%)	13/22 (59.1%)
Pegylated interferon/ribavirin/telaprevir or boceprevir^e	15	7 (46.7)	7/15 (46.7%)	–	–

^aSVR=Sustained virologic response, defined as undetectable HCV RNA 24 weeks after the end of treatment and expressed as intention to treat results.

^bIncludes 1 person with genotype 2 whose treatment results were unknown. Genotype on 1 person who achieved SVR was unknown.

^cEight persons were treated twice with pegylated interferon/ribavirin and results from first treatment course are reported. Three achieved SVR with the second treatment course.

^dIncludes 2 persons who achieved an end-of-treatment response but were lost to follow-up.

^eFive of twelve persons treated with telaprevir (41.7%) and 2 of 3 treated with boceprevir (66.7%) achieved SVR.

Table 2. Baseline characteristics of Alaska Native and American Indian people treated with pegylated interferon and ribavirin

Characteristic	Overall (%)	Genotype 1 (%)	Genotype 2 (%)	Genotype 3 (%)
Number treated	119	46 (38.7)	51 (42.9)	22 (18.5)
Male gender	59 (49.6)	19 (41.3)	29 (56.9)	11 (50)
Female gender	60 (50.4)	27 (58.7)	22 (43.1)	11 (50)
Mean age, years^a	44.7	43.8	45.4	44.6
Mean BMI^a,b	29.4	30.0	28.4	30.4
Mean ALT^a,c	105.7	96.7	121.4	87.5
Mean HCV RNA^a,d	4,096,347	2,516,909	6,821,071	1,341,314
Liver biopsy	78	39	26	13
Advanced fibrosis^e	22 (28.2)	10 (25.6)	7 (26.9)	5 (38.5)

^aMean of characteristic at start of treatment.

^bBMI=body mass index.

^cALT=alanine aminotransferase; available for 117 of 119 patients.

^dHCV RNA, IU/mL, available for 107 of 119 patients.

^eAdvanced fibrosis on liver biopsy, defined as Ishak 3–6.

Table 3. Results of pegylated interferon–ribavirin treatment of Alaska Native and American Indian people

Genotype		Number	SVR^a (%)	Failure^b (%)	Relapse^c (%)	Discontinued^d (%)
1a		34	7 (20.6)	5 (14.7)	3 (8.8)	19 (55.9)
1b		8	3 (37.5)	2 (25)	0 (0)	3 (37.5)
Other^e		4	0 (0)	2 (50)	0 (0)	2 (50)
	Total	46	10 (21.7)	9 (19.5)	3 (6.5)	24 (52.2)
2		51^f	38 (74.5)	3 (5.9)	3 (6.1)	9^g (17.6)
3		22^f	13 (59.1)	1 (4.5)	2 (9.1)	6 (27.3)

^aSVR=Sustained Virologic Response, defined as undetectable HCV RNA 24 weeks after the end of treatment.

^bFailure=<2-log drop of HCV RNA at week 12 or detectable HCV RNA at end-of-treatment course.

^cRelapse=detectable HCV RNA within 6 months after undetectable at the end of treatment.

^dDiscontinued=treatment discontinued due to side effects.

^eOther=genotype 1a/1b (2) or no subtype identified (2).

^fIncludes 2 persons with genotype 2 who achieved end-of-treatment response and then were lost to follow-up.

^gIncludes 2 who achieved SVR despite discontinuation.

Table 4. Factors related to hepatitis C treatment sustained virologic response^a in Alaska Native and American Indian people treated with pegylated interferon and ribavirin

Factor	Level	Number	SVR (n)	P
Sex	Female	60	55% (33)	0.17
	Male	59	43% (25)
Age	<40 years	31	45% (14)	0.39
	40–49 years	40	43% (17)
	50+ years	48	56% (27)
HCV genotype	1	46	22% (10)	<0.01
	2	51	69% (35)
	3	22	59% (13)
Body mass index	<25	29	38% (11)	0.40
	25–29	40	53% (21)
	30+	50	52% (26)
Diabetes–pre-diabetes	Yes	41	54% (22)	0.29
	No	65	43% (28)
Estimated duration of HCV infection	<10 years	29	38% (11)	0.02
	10–20 years	31	35% (11)
	20–30 years	27	59% (16)
	30+ years	23	65% (15)
Baseline HCV RNA (IU/mL)	<500,000	33	55% (18)	0.14
	≥500,000–<3,000,000	36	44% (16)
	≥3,000,000	38	37% (14)
Advanced fibrosis (Ishak≥3)	Yes	22	45% (10)	0.43
	No	56	36% (20)
Baseline ALT level^b	<40	24	58% (14)	0.46
	40–<80	40	45% (18)
	80–<120	21	48% (10)
	120+	33	45% (15)
Baseline Hgb level^c	<14	30	60% (18)	0.03
	≥14	39	33% (13)
Baseline ANC level^d	<4	30	50% (15)	0.52
	≥4	22	41% (9)
Baseline platelet count^e	<200	36	42% (15)	0.35
	200–<300	45	51% (23)
	≥300	36	53% (19)
	≥1.5	28	32% (9)
TSH	<1.5	51	45% (23)	0.26
	>1.5	28	32% (9)

^aSustained virologic response was defined as undetectable HCV RNA 24 weeks after the end of treatment.

^bALT=alanine aminotransferase, expressed as units/litre.

^cHgb=haemoglobin, expressed in grams/decilitre.

^dANC=absolute neutrophil count, 10⁹ per litre.

^ePlatelet count, 10³ per microliter.

Table 5. Factors significantly related by multivariate analysis to hepatitis C treatment sustained virologic response in Alaska Native and American Indian people treated with pegylated interferon and ribavirin

Factor	Multivariate P-value	Comparison	Odds ratio of SVR (confidence interval)
Genotype	<0.0001	2 vs. 1	14.0 (4.6, 42.4)
		3 vs. 1	7.1 (2.0, 25.1)
Gender	0.03	Female vs. male	3.1 (1.2, 8.2)
Estimated duration of HCV infection	0.03	10-year increase	1.5 (1.0, 2.2)

^aSustained virologic response (SVR) was defined as undetectable HCV RNA 24 weeks after the end of treatment.