Performance attributes of the LCx HCV RNA quantitative assay.
The LCx HCV RNA quantitative assay (Abbott Laboratories, North Chicago, IL) is designed to use competitive reverse transcriptase-polymerase chain reaction (RT-PCR) and microparticle enzyme immunoassay (MEIA), in combination with a modified Qiagen sample preparation method, to measure the level of hepatitis C virus (HCV) in human plasma and serum. The assay provides quantitative results in international units (IU) of HCV RNA/ml, in copies of HCV RNA/ml, or their log (base 10) equivalents. A conversion study determined that 1IU equals 4.3 copies. The LCx HCV assay detected HCV RNA transcripts representative of genotypes 1-6 with near equal efficiency. The assay did not cross-react with high concentrations of 21 potentially cross-reactive microorganisms or with 100 HCV-negative specimens. The lower limit of detection was demonstrated to be 23IU/ml. The LCx assay had similar sensitivity to the Roche Amplicor HCV (version 2.0) qualitative assay when used to test panels containing 6, 12, 23, and 47IU/ml. The assay linear range was shown to extend from 23 to 2.3millionIU/ml. The intra-assay standard deviation (S.D.) was < or =0.066 logIU/ml for the four HCV positive samples tested, while for the same samples the observed inter-assay S.D. was < or =0.075 logIU/ml. The overall mean assay quantitation value for seven HCV-positive WHO-standardized Acrometrix NAP linearity panel members was within 0.06 logIU/ml of the mean assigned value. The assay was demonstrated to correlate acceptably against the Roche Amplicor HCV monitor test (version 2.0). These data suggest that the assay is standardized appropriately against the WHO standard across its linear range and can be used for quantitation of HCV. In addition, with a sensitivity of 23IU/ml, the assay can be used to determine if post-therapy viral clearance has occurred.
Leckie
Gregor
G
Abbott Laboratories, Molecular Diagnostics, D99G AP20, 100 Abbott Park Road, Abbott Park, IL 60064-6015, USA. gregor.leckie@abbott.com
Schneider
George
G
Abravaya
Klara
K
Hoenle
Robert
R
Johanson
Julie
J
Lampinen
John
J
Ofsaiof
Reuben
R
Rundle
Lisa
L
Shah
Shruti
S
Frank
Andrea
A
Toolsie
Dan
D
Vijesurier
Roy
R
Wang
Hong
H
Robinson
John
J
D003429:Cross Reactions; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D006526:Hepatitis C / Q000188:drug therapy / Q000821:virology; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D012367:RNA, Viral / Q000097:blood* / Q000235:genetics*; D012015:Reference Standards; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity; D014766:Viremia / Q000188:drug therapy / Q000821:virology; D014773:Virology / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data
D012367:RNA, Viral