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Rapid, Sensitive, and Accurate Evaluation of Drug Resistant Mutant (NS5A-Y93H) Strain Frequency in Genotype 1b HCV by Invader Assay.

Yoshimi S, Ochi H, Murakami E, Uchida T, Kan H, Akamatsu S, Hayes CN, Abe H, Miki D, Hiraga N, Imamura M, Aikata H, Chayama K - PLoS ONE (2015)

Bottom Line: Even in serum samples with low HCV titers, more than half of the samples could be successfully assayed.Interestingly, patients with the Y93H mutant strain showed significantly lower ALT levels (p=8.8 x 10-4), higher serum HCV RNA levels (p=4.3 x 10-7), and lower HCC risk (p=6.9 x 10-3) than those with the wild type strain.Because the method is both sensitive and rapid, the NS5A-Y93H mutant strain detection system established in this study may provide important pre-treatment information valuable not only for treatment decisions but also for prediction of disease progression in HCV genotype 1b patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Liver Research Project Center, Hiroshima University, Hiroshima, Japan.

ABSTRACT
Daclatasvir and asunaprevir dual oral therapy is expected to achieve high sustained virological response (SVR) rates in patients with HCV genotype 1b infection. However, presence of the NS5A-Y93H substitution at baseline has been shown to be an independent predictor of treatment failure for this regimen. By using the Invader assay, we developed a system to rapidly and accurately detect the presence of mutant strains and evaluate the proportion of patients harboring a pre-treatment Y93H mutation. This assay system, consisting of nested PCR followed by Invader reaction with well-designed primers and probes, attained a high overall assay success rate of 98.9% among a total of 702 Japanese HCV genotype 1b patients. Even in serum samples with low HCV titers, more than half of the samples could be successfully assayed. Our assay system showed a better lower detection limit of Y93H proportion than using direct sequencing, and Y93H frequencies obtained by this method correlated well with those of deep-sequencing analysis (r = 0.85, P <0.001). The proportion of the patients with the mutant strain estimated by this assay was 23.6% (164/694). Interestingly, patients with the Y93H mutant strain showed significantly lower ALT levels (p=8.8 x 10-4), higher serum HCV RNA levels (p=4.3 x 10-7), and lower HCC risk (p=6.9 x 10-3) than those with the wild type strain. Because the method is both sensitive and rapid, the NS5A-Y93H mutant strain detection system established in this study may provide important pre-treatment information valuable not only for treatment decisions but also for prediction of disease progression in HCV genotype 1b patients.

No MeSH data available.


Related in: MedlinePlus

Histogram of HCV RNA levels according to the detectability of Y93H by the Invader assay.White and black bars represent successful and unsuccessful detection cases, respectively. Closed circles represent the success rate for each log level of viremia from 1 through 7.
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pone.0130022.g005: Histogram of HCV RNA levels according to the detectability of Y93H by the Invader assay.White and black bars represent successful and unsuccessful detection cases, respectively. Closed circles represent the success rate for each log level of viremia from 1 through 7.

Mentions: Next, the assay success rate and the lower detection limit in HCV RNA level were evaluated. Fig 5 shows histograms of successful samples and unsuccessful samples based on their HCV titer assayed by a quantitative commercial RT-PCR assay. The overall success rate was 98.9% (694/702). Even in serum samples with low HCV titers, more than half of samples could be successfully assayed. Thus, the lower detection limit of HCV RNA level could be estimated to be almost 1 log order. Among 694 patients successfully tested, the mutant strain (Y93H) was observed in 23.6% (164/694) patients.


Rapid, Sensitive, and Accurate Evaluation of Drug Resistant Mutant (NS5A-Y93H) Strain Frequency in Genotype 1b HCV by Invader Assay.

Yoshimi S, Ochi H, Murakami E, Uchida T, Kan H, Akamatsu S, Hayes CN, Abe H, Miki D, Hiraga N, Imamura M, Aikata H, Chayama K - PLoS ONE (2015)

Histogram of HCV RNA levels according to the detectability of Y93H by the Invader assay.White and black bars represent successful and unsuccessful detection cases, respectively. Closed circles represent the success rate for each log level of viremia from 1 through 7.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4470996&req=5

pone.0130022.g005: Histogram of HCV RNA levels according to the detectability of Y93H by the Invader assay.White and black bars represent successful and unsuccessful detection cases, respectively. Closed circles represent the success rate for each log level of viremia from 1 through 7.
Mentions: Next, the assay success rate and the lower detection limit in HCV RNA level were evaluated. Fig 5 shows histograms of successful samples and unsuccessful samples based on their HCV titer assayed by a quantitative commercial RT-PCR assay. The overall success rate was 98.9% (694/702). Even in serum samples with low HCV titers, more than half of samples could be successfully assayed. Thus, the lower detection limit of HCV RNA level could be estimated to be almost 1 log order. Among 694 patients successfully tested, the mutant strain (Y93H) was observed in 23.6% (164/694) patients.

Bottom Line: Even in serum samples with low HCV titers, more than half of the samples could be successfully assayed.Interestingly, patients with the Y93H mutant strain showed significantly lower ALT levels (p=8.8 x 10-4), higher serum HCV RNA levels (p=4.3 x 10-7), and lower HCC risk (p=6.9 x 10-3) than those with the wild type strain.Because the method is both sensitive and rapid, the NS5A-Y93H mutant strain detection system established in this study may provide important pre-treatment information valuable not only for treatment decisions but also for prediction of disease progression in HCV genotype 1b patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Liver Research Project Center, Hiroshima University, Hiroshima, Japan.

ABSTRACT
Daclatasvir and asunaprevir dual oral therapy is expected to achieve high sustained virological response (SVR) rates in patients with HCV genotype 1b infection. However, presence of the NS5A-Y93H substitution at baseline has been shown to be an independent predictor of treatment failure for this regimen. By using the Invader assay, we developed a system to rapidly and accurately detect the presence of mutant strains and evaluate the proportion of patients harboring a pre-treatment Y93H mutation. This assay system, consisting of nested PCR followed by Invader reaction with well-designed primers and probes, attained a high overall assay success rate of 98.9% among a total of 702 Japanese HCV genotype 1b patients. Even in serum samples with low HCV titers, more than half of the samples could be successfully assayed. Our assay system showed a better lower detection limit of Y93H proportion than using direct sequencing, and Y93H frequencies obtained by this method correlated well with those of deep-sequencing analysis (r = 0.85, P <0.001). The proportion of the patients with the mutant strain estimated by this assay was 23.6% (164/694). Interestingly, patients with the Y93H mutant strain showed significantly lower ALT levels (p=8.8 x 10-4), higher serum HCV RNA levels (p=4.3 x 10-7), and lower HCC risk (p=6.9 x 10-3) than those with the wild type strain. Because the method is both sensitive and rapid, the NS5A-Y93H mutant strain detection system established in this study may provide important pre-treatment information valuable not only for treatment decisions but also for prediction of disease progression in HCV genotype 1b patients.

No MeSH data available.


Related in: MedlinePlus