Preparation and Characterization of RNA Standards for Use in Quantitative Branched DNA Hybridization Assays

Collins, Mark L.; Zayati, C; Detmer, Jill; Daly, Barbara; Kolberg, Janice A.; Cha, Tai-An; Irvine, Bruce; Tucker, James H. R.; Urdea, M. S.

doi:10.1006/abio.1995.1199

Cited by 120 publications

(79 citation statements)

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“…43 In contrast to earlier reports to threefold for genotypes 2 and 3. 22,42 This probably occurs from Japan, this study showed that loss of HCV RNA by 4 to some extent in all currently used polymerase chain reacweeks was not an accurate predictor of response. Further tion-based methods.…”

Section: Prediction Of Treatment Response By Cirrhosismentioning

confidence: 78%

“…22 Although the difference in response rates to a short course of interferon Mean response rates according to the presence or absence of the pretreatment factors were determined by pooling pa-was marked between those with low or high levels of viremia, the predictive value of a low HCV RNA level for either ETR tient data rather than averaging rates from different studies. Although this provides a better sense of the influence of the or SR was low (48% and 71%, respectively) ( Table 3).…”

Section: Published Reports Of Predictive Factorsmentioning

confidence: 99%

“…4,8,[13][14][15][16][17][18][20][21][22][23][24][25][26][27] Patients with HCV genotypes 1a and 1b respond poorly to treatment compared with those However, the usefulness of this analysis may be limited bequasispecies and ISDR mutation measurements to predict cause these data were derived from studies that used biotreatment outcome has not yet been confirmed prospectively chemical end points (normal ALT levels alone), whereas or in large series. 31 most investigators currently define response by decrease of…”

Section: Prediction Of Treatment Responsementioning

confidence: 99%

“…A recent nucleic acid extraction, hybridization efficiency, technician report suggests that loss of HCV RNA and normalization experience, and viral genotype. 22,37,42 The latter can result in ALT may be similar in their ability to predict treatment reunderestimation of the HCV RNA level by as much as twofold sponse early in the course. 43 In contrast to earlier reports to threefold for genotypes 2 and 3.…”

Section: Prediction Of Treatment Response By Cirrhosismentioning

confidence: 99%

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Factors predictive of a beneficial response to therapy of hepatitis C

1997

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disease. 2 Many of these studies identified pretreatment paAlpha interferon is the only drug that has been shown to tient characteristics that are associated with a greater or lesser be effective in the treatment of chronic hepatitis C, but only likelihood of response to interferon ( Table 1). The most clinihalf of patients respond, either transiently or permanently.cally important of these factors were the level of serum HCV Pretreatment features that are associated with a greater likeli-RNA, viral genotype, and the histology of the pretreatment hood of response to short courses of interferon include low liver biopsy specimen. [3][4][5] Indeed, each of these factors has hepatitis C virus (HCV) RNA levels, viral genotypes 2 or 3, been shown by multivariate analysis to be independently and the absence of fibrosis or cirrhosis on liver biopsy. Each associated with response by the end of the course of interof these features is more predictive of sustained response feron treatment, known as end-of-treatment response (ETR; (SR) than the end-of-treatment response (ETR). However, the previously termed complete response), and sustained reaccuracy of these features in predicting response in individual sponse (SR; response persisting for at least 6 months after patients is poor. Furthermore, there are several limitations to the discontinuation of treatment). The clinical application of using these factors in the clinical management of patients.these predictive factors has taken several forms. First, and Most importantly, they were identified in 6-month treatment most importantly, it has allowed clinical investigators to detrials. Longer treatment or combination of interferon with sign better studies by stratifying for these factors that influribavirin reduces relapses and will therefore lessen the associence response. It has also allowed investigators to understand ation of these factors with long-term response. In addition, differences in response rates in studies conducted in different changes in the definition of treatment end points and the populations. However, it has also led to changes in treatment technology used to measure HCV RNA might change the assopatterns. In an attempt to improve response rates and reduce ciation between these predictive factors and response. The the cost of interferon treatment, some have suggested exclubest predictor of a treatment response is the early normalizasion of patients from treatment if they have one or more of tion of the serum alanine aminotransferase (ALT) level during the pretreatment markers that have been associated with a interferon treatment. HCV RNA loss during treatment may reduced likelihood of response. Some physicians routinely also be helpful in predicting response, but it is probably no exclude patients with cirrhosis from treatment and some clinbetter than serum ALT levels and is expensive. In summary, ical trials have excluded them to increase response rates. 6 several clinical and virological features are associated with Furthermore, commercial advertisements ...

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Section: Prediction Of Treatment Response By Cirrhosismentioning

confidence: 78%

Section: Published Reports Of Predictive Factorsmentioning

confidence: 99%

Section: Prediction Of Treatment Responsementioning

confidence: 99%

Section: Prediction Of Treatment Response By Cirrhosismentioning

confidence: 99%

See 2 more Smart Citations

Factors predictive of a beneficial response to therapy of hepatitis C

1997

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“…These data suggest that questioned. Collins et al 57 have experimentally proved that the bDNA assay (ver. 1.0) underestimates geno-the HCV virus does not cause liver injury by simply expanding the viral load and thus resulting in a cytotypes 2 and 3 by factors of 3 and 2, respectively, because of the lack of nucleotide homology between the bDNA pathic process.…”

Section: Correlation Between Hepatic Hcv-rna Levels Withmentioning

confidence: 99%

Intrahepatic hepatitis C RNA levels do not correlate with degree of liver injury in patients with chronic hepatitis C

et al. 1996

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jury. Intrahepatic viral load appears to be significantly The balance between a direct cytopathic effect by hepincreased in patients with genotype 1b. IFN-a treatment atitis C virus (HCV) and immune-mediated injury redoes significantly lower intrahepatic HCV load. (HEPAmains unclear. This report aims to test the following TOLOGY 1996;23:676-687.) hypotheses: (1) that intrahepatic HCV load would correlate with the degree of liver injury; (2) that interferon alfa (IFN-a) would decrease intrahepatic HCV-RNA levPersistent hepatitis C infection results in varying deels. Liver tissues (n Å 56) were obtained from 47 patients grees of chronic liver injury. [1][2][3][4][5][6] Healthy carriers of the with chronic HCV (9 before and after IFN-a therapy). hepatitis C virus (HCV) have been described but seem Total RNA was isolated and quantitated for specific HCV uncommon. 7 The pathogenesis of HCV-induced hepatic RNA by dot-blot polymerase chain reaction (DB-PCR) injury remains unclear and could be attributable to either using a standard curve created from synthetic HCV RNA direct cytopathic damage by HCV 8-10 or immune-mediof known titer to calculate actual RNA levels. A multivar-ated hepatic injury induced by HCV. 1,[11][12][13][14][15] It is possible iate analysis was undertaken to determine the relationthat both may act simultaneously. 16,17ship of intrahepatic HCV-RNA levels with risk factors,One way to identify whether liver damage is attributlength of HCV exposure, and histological injury scores.The confounding effect of HCV genotype was examined able to direct cytopathic damage is to examine whether by direct sequencing of the NS5b region. Liver HCV RNA the degree of viral load correlates with the degree of ranged from 10 2 to 3.1 1 10 7 molecules per microgram liver injury. Most studies addressing this question have total liver RNA. The multiple regression analysis showed measured the amount of HCV in serum. 9,10,12,16,[18][19][20][21] Ideno effect of length of HCV exposure, risk factors, degree ally, HCV-RNA viral load should be estimated directly of bile duct damage, steatosis, or total Scheuer or Kno-from liver tissue itself, because serum levels of virus dell score on RNA levels. No significant confounding ef-may be contributed to and influenced by extrahepatic fect of HCV genotype on the degree of liver injury was sources. Also, the presence of serum immune complexes observed. However, genotype 1b had a significantly may introduce further variables. Doubt has also been higher mean intrahepatic HCV-RNA load compared raised as to the validity of HCV-RNA quantitation in with the other genotypes detected. In the 9 patients who received IFN-a, treatment, 7 had no detectable HCV serum compared with plasma. after treatment. This was associated with a significantAs well as the sample type, the method of HCV quandecrease in intrahepatic HCV-RNA levels (7.57 { 2.53 titation itself is important. A number of techniques 1 10 5 to 1.82 { 1.80 1 10 3 molecules per microgram total have been reported for quantitation of HCV by...

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Hepatitis C plasma viral load is associated with HCV genotype but not with HIV coinfection

Berger

Prondzinski²,

et al. 1996

J. Med. Virol.

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The influence of human immunodeficiency virus (HIV) coinfection and hepatitis C virus (HCV) genotype distribution on HCV viral load and alanine amino transferase (ALT) levels in chronically infected patients remains unclear. In the present study, serum samples from a group of haemophiliac patients were investigated retrospectively. HCV geno- and subtyping was carried out using the Inno line probe assay (Inno LIPA, Innogenetics, Zwijnaarde, Belgium) in 87 patients positive by HCV RT PCR. Of these patients, 31 (35.6%) were HIV coinfected. HCV RNA was quantified with the HCV Monitor kit (Roche, Basel, Switzerland) in 43 patients (22 HIV-negatives, 21 HIV-positives). The most prevalent genotypes were 1 (n = 52) and 3a (n = 16) followed by genotype 2 (n = 9) and 4 (n = 3). Mixed infections were detected in 7 patients. Of genotype 1 positive samples, 24 and 23 were classified as subtype a and b, respectively. Five samples could not be subtyped. Although higher mean values of ALT were observed in genotype 1 infected patients, there was no statistically significant association between HCV genotype or subtype and liver enzymes (P > 0.05). On the other hand, statistically significant higher HCV RNA titres were observed in haemophiliacs infected with HCV genotype 1 in comparison to those infected with other genotypes (P < 0.01). No relationship was found between the presence of HIV coinfection and viral load of HCV RNA. There was no evidence that HCV infection had a more severe outcome in HIV-positive patients who had been infected with HIV and HCV more than ten years ago, even in those with very low CD4+ cell counts. No clear association between high ALT levels and large amounts of viral RNA was observed. In conclusion, a large viral load is associated with HCV genotype 1 infection; HIV coinfection has no clear effect on the intensity of HCV replication. An ongoing prospective study will evaluate the respective role of viral load, genotype, HIV coinfection and ALT level in the response to interferon therapy.

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Preparation and Characterization of RNA Standards for Use in Quantitative Branched DNA Hybridization Assays

Cited by 120 publications

References 0 publications

Factors predictive of a beneficial response to therapy of hepatitis C

Factors predictive of a beneficial response to therapy of hepatitis C

Intrahepatic hepatitis C RNA levels do not correlate with degree of liver injury in patients with chronic hepatitis C

Hepatitis C plasma viral load is associated with HCV genotype but not with HIV coinfection

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