The Particle Size Of Hepatitis C Virus Estimated By Filtration Through Microporous Regenerated Cellulose Fibre

Yuasa, Tazuko; Ishikawa, Gen; Manabe, Sei-ichi; Sekiguchi, Sadayoshi; Takeuchi, Kenji; Miyamura, Tatsuo

doi:10.1099/0022-1317-72-8-2021

Cited by 78 publications

(25 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1,000 core subunits on the average. This is very unlikely because the particles are believed to be 50 nm in diameter (6) or less (19), and this size would not accommodate so many subunits.…”

Section: Resultsmentioning

confidence: 99%

Variable Ratio of Hepatitis C Virus RNA to Viral Core Antigen in Patient Sera

et al. 2004

View full text Add to dashboard Cite

Quantification of hepatitis C virus (HCV) core antigen and RNA in serum samples leads to a highly variable ratio of both. It is not clear whether this is due to the inaccuracy of RNA quantification or whether both are independent parameters in a certain range. We established a real-time reverse transcription (RT)-PCR for HCV RNA that combines very high sensitivity with a large dynamic range and minimal standard deviations. The assay was calibrated with the first international standard, 96/790, and the international genotype panel for HCV from the National Institute of Biological Standardisation and Control. A linear readout was obtained between 200 and 5 ؋ 10 7 IU/ml. The detection limit was 80 IU/ml, the reproducibility was <0.05 log, and the standard error within one run was <0.01. Comparison of the method with the Roche Monitor competitive RT-PCR revealed its high accuracy. The core protein concentration was determined within a range from 1.5 to 400 pg/ml by using the preliminary trak-C assay from Ortho Clinical Diagnostics. Correlating the HCV RNA levels with core antigen concentrations in 197 serum samples from 23 interferon-treated patients, a average ratio of 7,900 IU of HCV RNA per pg of core antigen was estimated, but the variability of this ratio exceeded largely the variability of the two assays, ranging from 50 to 20,000 IU/pg. Theoretically, HCV should contain ca. 43,000 IU of RNA/pg core. In conclusion, the core antigen assay seems to detect, in addition to complete virions, RNA-free core protein structures, which enhances its sensitivity (98% in this group). The variable ratio of RNA and core protein is not mainly due to standard deviations of quantification but could be an additional parameter for treatment follow-up and state of viral replication.The accurate quantification of virus particles in the plasma of persons infected with hepatitis C virus (HCV), the so-called viral load, is essential for decisions on the therapy with interferon and ribavirin and the monitoring of this therapy (1,5,13). For this purpose, several tests for the detection of HCV RNA genomes are commercially available, which lead to sometimes conflicting results for HCV RNA copies per milliliter or international units per milliliter. It appears that some divergences are caused by saturation phenomena in competitive nucleic acid amplification tests (4). Different reactivities of the assays with various HCV genotypes other than genotype 1 may also contribute to the problem (3, 11). With the real-time technology for in situ signal generation during DNA amplification (e.g., using the TaqMan or LightCycler system), saturation phenomena can be overcome.Some efforts have been made to establish real-time protocols for HCV quantification by using the SYBR Green format on LightCycler (17) or the TaqMan technology (8, 10). These published real-time-based techniques are two-step procedures with separate reverse transcription (RT), or they use only the nonspecific SYBR Green for generation of the signal.One aim of our study was to estab...

show abstract

Section: Resultsmentioning

confidence: 99%

Variable Ratio of Hepatitis C Virus RNA to Viral Core Antigen in Patient Sera

et al. 2004

View full text Add to dashboard Cite

show abstract

“…HCV has an approximate diameter of 30–40 nm [14]. Although it largely exceeds the size of the membrane pore, at least two possible conditions might account for this passage: microscopic breaks, increased by succeeding reuses, or passage of viral fragments instead of total virions [10, 15].…”

Section: Discussionmentioning

confidence: 99%

Evidence of Hepatitis C Virus Passage Across Dialysis Membrane

Valtuille¹,

Fernández²,

Berridi³

et al. 1998

Nephron

View full text Add to dashboard Cite

The passage of hepatitis C virus (HCV) across the dialysis membrane is a controversial issue. We performed a study applying extreme conditions of permeability to the dialysis membrane and avoiding the use of heparin and dialysis bath that might interfere with polymerase chain reaction (PCR) results. We obtained samples from the ultrafiltrate at the beginning of 18 hemodialysis sessions carried out in 6 HCV RNA-positive patients. HCV RNA was detected by PCR in 3 (16.7%) ultrafiltrate samples belonging to 1 of the patients. HCV genotype was the same as that found in positive ultrafiltrate samples and in the serum corresponding to this patient. The viral load of this patient was under the levels detectable by the assay employed. Therefore, contamination of the ultrafiltrate may constitute a potential risk for HCV transmission in hemodialysis units.

show abstract

“…Several investigators have noted that the viral load is reduced after a standard hemodialysis session [1,2]. Since the pore size of the dialysis membrane is too small to allow passage of the virion from the blood compartment into the dialysate [3,4], the virus may be adsorbed in the protein layer coating the membrane surface. Alternatively, the nonspecific activation of the immune system (complement, cytokine production, etc.)…”

mentioning

confidence: 99%