RealTime HIV-1

1105_20348
RealTime HIV-1

Description


The Abbott RealTime HIV-1 assay is an in vitro reverse transcription-polymerase chain reaction (RT-PCR) assay for the quantitation of Human Immunodeficiency Virus type 1 (HIV-1) on the automated m2000 System in human plasma from HIV-1 infected individuals over the range of 40 to 10,000,000 copies/mL. The Abbott RealTime HIV-1 assay is intended for use in conjunction with clinical presentation and other laboratory markers for disease prognosis and for use as an aid in assessing viral response to antiretroviral treatment as measured by changes in plasma HIV-1 RNA levels.

Abbott RealTime HIV-1 Performance
Sensitivity   40 copies/mL for 1.0 mL input, 75 copies/mL for 0.5 mL input, 150 copies/mL for 0.2 mL input
Linear Range   40 copies/mL (1.6 log copies/mL) to 10 million copies/mL (7.0 log copies/mL)
Precision   Inter-assay standard deviation (SD) of < than or = to 0.25 log copies/mL
Specificity   100%†
Specimen Type   Plasma (ACD-A and EDTA)
HIV-1 Subtype Detection   Group M subtypes A—H, Group O and Group N
Standardization   Virology Quality Assurance (VQA) Laboratory of the AIDS Clinical Trial Group and against World Health
Organization (WHO) 1st International Standard for HIV-1 RNA (97/656)
Internal Control   Added to lysis buffer during extraction and detected at all levels

This assay is not intended to be used as a donor screening test for HIV-1 or as a diagnostic test to confirm the presence of HIV-1 infection.

† The specificity of the RealTime HIV-1 assay was evaluated at three external sites by testing 514 HIV-1 seronegative plasma specimens from volunteer blood donors. HIV-1 RNA was not detected for all 514 specimens and the RealTime HIV-1 assay specificity was estimated to be 100% (514/514), (95% CI 99.28 to 100%). 

Detection of HIV-1 Subtypes and Groups
Group/
Subtypes		     n     RealTime
Detected		     Comparator 1
Detected		     Comparator 2 
Detected
M/Subtype A     10     10     10 (1)     10 (1)
M/Subtype B     10     10     10 (0)     10 (0)
M/Subtype C     10     10     10 (0)     10 (0)
M/Subtype D     10     10     10 (0)     10 (0)
M/Subtype AE     10     10     10 (0)     10 (0)
M/Subtype F     10     10     10 (0)     10 (0)
M/Subtype AG     10     10     10 (3)     10 (1)
M/Subtype G     10     10     10 (2)     10 (1)
Group O     10     10     0 (NA)     7 (7)

A total of 90 clinical specimens, ten of each Group M subtype (A, B, C, D, CRF01-AE, F, CRF02-AG, G) and of Group O, were tested with the RealTime HIV-1 assay and by two other approved HIV-1 quantitative assays referred to as Comparator 1 (FDA-approved version used)  and Comparator 2
(CE-Marked version used). The numbers in parentheses are the number of specimens that had lower quantitation values by more than 1.00 log copies/mL when compared to RealTime HIV-1 assay.



Correlation to Comparator Assay
A total of 301 specimens collected from HIV-1 infected patients were tested with the RealTime HIV-1 assay at three external sites and with the comparator method at a central laboratory site. The results from a total of 259 specimens that fell within the common assay dynamic range were analyzed by the Passing-Bablok linear regression method.

Design

Development Philosophy
Today's clinical molecular diagnostics laboratory must have confidence in the quality of the HIV-1 patient results. As a result of our real-time PCR development philosophy, Abbott RealTime HIV-1 is engineered to tolerate the genetic diversity of HIV-1 Subtypes.

HIV-1 diversity can be attributed to:

  • Error-prone reverse transcriptase enzyme
  • Recombination of subtypes
  • Cross-species transmission

Accurate quantitation is dependent upon a combination of:

  • Primer Design
  • Probe Design
  • Cycling Conditions
Primers and Probe are Targeted to the Integrase Region of the Polymerase Gene


The integrase region of the polymerase gene is a conserved region of the HIV-1 genome.
Partially Double Stranded Probe Design

In the absence of target, the probe hybridizes to the quencher digoneucleotide, preventing fluorescent signal generation.


In the presence of target, the probe prefers to hybridize with the target sequence, disassociating from the quencher oligonucleotide and allowing fluorescent detection.

Cycling Conditions: Low Temperature Read Cycles
The cycling conditions for Abbott RealTime HIV-1 encompass a low temperature read cycle. This read cycle allows the probe to tolerate mismatches more effectively than a probe required to bind during the extension phase.

Order Information

Product Name Package Size Vysis® Order Number Abbott Order Number
RealTime HIV-1 Abbott RealTime HIV-1 Calibrator Kit 12 Cal A, 12 Cal B, 4 Complete Calibration Sets 02G31-70 02G31-70
RealTime HIV-1 Abbott RealTime HIV-1 Control Kit 8 Low Positive, 8 High Positive, 8 Negative 02G31-80 02G31-80
RealTime HIV-1 Abbott RealTime HIV-1 Amplification Reagent Kit 96 Assays (4 packs x 24 assays) 02G31-90 02G31-90
RealTime HIV-1 Abbott RealTime HIV-1 Application CD-ROM 01L68 01L68
In Vitro Diagnostic Available in the United States.
 
CE Marked