Hepatitis C virus (HCV) RNA level determined by second-generation branched-DNA probe assay as predictor of response to interferon treatment in patients with chronic HCV viremia.
Using first- and second-generation branched-DNA probe assays (1st- and 2nd-bDNA), we investigated the predictors of favorable clinical response to interferon (IFN) treatment in patients with chronic HCV viremia. A total of 122 patients (85 genotype lb and 37 genotype 2a) with chronic HCV viremia received 24-week IFN-alpha treatment. Patients with sustained clearance of serum HCV RNA by polymerase chain reaction at six months after IFN treatment were defined as having a sustained response (SR). HCV RNA level was determined by 1st- and 2nd-bDNA assays prior to treatment. Mean HCV RNA level by 1st-bDNA was significantly higher in genotype lb patients [5.4 x 10(6) HCV genome equivalent (Meq)/ ml] than in genotype 2a patients (0.9 Meq/ml) (P < 0.05). There was no significant difference between patients with these genotypes in the level by 2nd-bDNA (1b: 5.2 Meq/ml and 2a: 3.1 Meq/ml). SR was achieved by 43 (35.2%) of 122 patients. Mean HCV RNA levels by both the 1st- and 2nd-bDNA of SR patients (1.0 and 1.9 Meq/ml) were significantly lower than those of non-SR patients (5.3 and 6.0 Meq/ml) (both P < 0.05). The SR rate in genotype 2a patients (59.5%) was significant higher than in genotype lb patients (24.7%) (P < 0.05). Stepwise logistic regression analysis showed that HCV RNA level < or = 1.0 Meq/ml by 2nd-bDNA (odds ratio = 7.6, compared to level > 1.0 Meq/ml, P < 0.05) was a significant predictive cutoff for SR. Using 2nd-bDNA, a significantly higher rate of SR was found in genotype lb patients with level < or = 1.0 Meq/ml (57.6%) than in those with level > 1.0 Meq/ml (3.8%) (P < 0.05). The SR rate of genotype 2a patients with level >1.0 Meq/ml (68.6%) was somewhat higher than for those with level < or = 1.0 Meq/ml (52.4%). These findings suggested that, using 2nd-bDNA, a low HCV RNA level of < or = 1.0 Meq/ml was the most favorable marker of successful IFN treatment and that patients with genotype 2a, even those with level >1.0 Meq/ml, had a high rate of SR to IFN treatment.
Furusyo
Norihiro
N
Department of General Medicine, Kyushu University Hospital, Fukuoka, Japan.
Hayashi
Jun
J
Kashiwagi
Kenichiro
K
Nakashima
Hisashi
H
Nabeshima
Shigeki
S
Sawayama
Yasunori
Y
Kinukawa
Naoko
N
Kashiwagi
Seizaburo
S
D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D021121:Branched DNA Signal Amplification Assay; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics* / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood*; D014766:Viremia / Q000188:drug therapy / Q000821:virology
D000998:Antiviral Agents; D016898:Interferon-alpha; D012367:RNA, Viral