Clinical evaluation of Detect-HIV™ (v.4)

Price : $5500 each (we have 4 in stock)
Call : Martin 514-585-0531

Assay characteristics

• Adaltis Detect-HIV™ (v.4) (Adaltis Inc.)
• Lot: 5160022
• Expiry date: 2005 SE The Adaltis Detect-HIV™ (v.4) kit is a solid-phase enzyme immunoassay for the simultaneous detection of antibodies to

HIV-1 and HIV-2 envelope proteins as well as the p24 antigen of HIV-1 in human serum and plasma.

Evaluation panel

To evaluate Adaltis Detect-HIV™ (v.4), we tested a panel that consists of 75 HIV-1-positive samples (subtype unknown), 40 HIV-1-positive samples (non-B subtypes) and 90 HIV-2positive samples. The panel contained 88 serum samples and 117 plasma samples. The evaluation panel was stored at –20°C until use.

90 HIV-2-positive samples

To determine the HIV serological status, each serum specimen was first screened with at least one of the following enzyme-linked immunosorbent assays (ELISAs): Vironostika HIV Mixt (Organon Teknika), Vironostika HIV Uniform (Organon Teknika), HIV1/HIV2 Elisa Kit (Cambridge Biotech.), Vironostika HIV Uniform II Plus O (Biomérieux) or Enzygnost anti-HIV-1/2 Plus (Dade Behring). All samples were further characterized by HIV Blot 1.2 (Genelabs Diagnostics), Georges Dayan, New Lav Blot II (Sanofi Pasteur Diagnostics/Bio-Rad) or Innolia HIV confirmation/Innolia HIV I/II Score (Innogenetics). To differentiate HIV-1 from HIV-2 infections, PEPTI-LAV 1-2 (Sanofi Pasteur Diagnostics) was performed on some samples.

All reference assays were interpreted according to the instructions given by the manufacturer.

The two plasma samples were selected retrospectively on the basis of the HIV status of people attending the clinic of the Institute of Tropical Medicine in Antwerp.

115 HIV-1-positive samples (40 non-B subtypes and 75 unknown subtypes)

All samples were selected retrospectively on the basis of the HIV status of people attending the clinic of the Institute of Tropical Medicine in Antwerp. The isolates from the 40 HIV-1 non-B subtype samples were classified by gag/env heteroduplex mobility assay (HMA) and/or by sequencing.

Equipment used that was not supplied

All equipment used in this evaluation had belonged to an accredited laboratory (ISO17025) since 1999 and was treated accordingly

• refrigerator (storage test kit; 4°C)
• freezer (storage evaluation panel; –20°C)
• dynamic incubator (Abbott)
• Bio-Tek ELx50 Microplate Washer (B.R.S.)
• Bio-Tek ELx800 Microplate Reader (B.R.S.)
• micropipettes and multichannels
• pipette tips.

Procedure

On the day of testing, the panel and test kit were brought to room temperature. After testing, the samples were refrozen immediately. The washing solution was prepared according to the instructions of the manufacturer and kept at room temperature during the testing days. All the tests were performed in 1 week.

The following reagents were added:

• 100 �l of sample diluent
• 100 �l of samples, negative control (3 wells), HIV-1 calibrator (3 wells), and HIV-2-positive control (2 wells)
• 200 �l of conjugate 1 solution
• 200 �l of conjugate 2 solution
• 200 �l of substrate solution
• 100 �l of stop solution.

A further procedure was carried out according to the instructions of the manufacturer. The absorbance of the samples was read on a microplate reader at 450 nm, with a reference wavelength of 630 nm. The last 15 HIV-1-positive samples were read at 450 nm and at 405 nm, with a reference wavelength of 630 nm.

Results

Validation

• Negative control signal mean <0.310
• HIV-1 calibrator signal mean ≥0.500
• HIV-2-positive control signal mean ≥0.500 All test plates satisfied these validation criteria.

Samples

All samples came out as strong HIV-positive. Results obtained by measuring at 450 nm for 15 samples corresponded to the results obtained at 405 nm.

Conclusion

In this evaluation, we used a panel of 205 samples (115 HIV-1, 90 HIV-2). They all resulted as HIV-positive. Our conclusion is that the Adaltis Detect-HIV™ (v.4) performed well in identifying the HIV-positive samples belonging to all known subtypes