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Modification of AxSYM Human Immunodeficiency Virus Assay to Identify Recent Human Immunodeficiency Virus Infections in Korean Human Immunodeficiency Virus-Positive Individuals.

Wang JS, Kee MK, Choi BS, Kim SS - Osong Public Health Res Perspect (2015)

Bottom Line: We determined that the concentration of Guanidine to be used in the avidity assay was 1.5M.The cutoff value of the avidity index (AI) was 0.8, and the sensitivity and specificity were 90.2% and 83.8%, respectively, under this condition.The mean of coefficient of variation was low, at 5.43%.

View Article: PubMed Central - PubMed

Affiliation: Division of AIDS, Korea National Institute of Health, Cheongju, Korea ; Division of Biobank for Health Sciences, Korea National Institute of Health, Cheongju, Korea.

ABSTRACT

Objectives: To estimate human immunodeficiency virus (HIV) incidence using HIV avidity assays in Korea, we established a serological testing method to differentiate recent HIV infections from long-standing ones.

Methods: We adopted two incidence assays, the BED HIV-1 incidence test (Calypte Biomedical) and an HIV avidity assay (using Abbott AxSYM HIV Antigen/Antibody Combo), and performed them on Korean HIV samples obtained from 81 HIV seroconverters (n = 193), 135 HIV-positive samples, and three HIV commercial incidence panels (PRB965, PRB933, and PRB601 from SeaCare). To determine the most optimal concentration of the chaotropic agent (Guanidine) and the cutoff value for the avidity assay, we evaluated the sensitivity and specificity of the assay at different concentration levels.

Results: We determined that the concentration of Guanidine to be used in the avidity assay was 1.5M. The cutoff value of the avidity index (AI) was 0.8, and the sensitivity and specificity were 90.2% and 83.8%, respectively, under this condition. The gray zone for the avidity assay was 0.75-0.85 AI. The mean of coefficient of variation was low, at 5.43%.

Conclusion: An optimized avidity assay for the diagnosis of recent HIV infections using Korean samples was established. This assay will be applied to investigate the level of recent infection and will provide basic data to the HIV prevention policy in Korea.

No MeSH data available.


Related in: MedlinePlus

Distribution of the avidity index for the three human immunodeficiency virus (HIV)-positive groups. Dotted line = avidity cutoff (0.8). Early = the early stage of incidence samples (n = 9) under 30 days since seroconversion; nine samples in the early stage of incidence belong to PRB933 and PRB965 seroconversion panels. Among them, negative incidence results were regarded as zero avidity index in this plot, which had very low titers of HIV antibodies. Inc = incidence samples (n = 21) between 30 days and 200 days since seroconversion; Est = established samples (n = 24) more than 200 days since seroconversion.
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fig1: Distribution of the avidity index for the three human immunodeficiency virus (HIV)-positive groups. Dotted line = avidity cutoff (0.8). Early = the early stage of incidence samples (n = 9) under 30 days since seroconversion; nine samples in the early stage of incidence belong to PRB933 and PRB965 seroconversion panels. Among them, negative incidence results were regarded as zero avidity index in this plot, which had very low titers of HIV antibodies. Inc = incidence samples (n = 21) between 30 days and 200 days since seroconversion; Est = established samples (n = 24) more than 200 days since seroconversion.

Mentions: To construct a gray zone, we applied the formula—{cutoff value ± [coefficient of variation (CV) × cutoff value]}—of Suligoi et al [20]. The precision of the repeat test results was expressed as the CV. The AI distributions of three sample groups—early stage of incidence, incidence, and established—were compared using a nonparametric method (Figure 1).


Modification of AxSYM Human Immunodeficiency Virus Assay to Identify Recent Human Immunodeficiency Virus Infections in Korean Human Immunodeficiency Virus-Positive Individuals.

Wang JS, Kee MK, Choi BS, Kim SS - Osong Public Health Res Perspect (2015)

Distribution of the avidity index for the three human immunodeficiency virus (HIV)-positive groups. Dotted line = avidity cutoff (0.8). Early = the early stage of incidence samples (n = 9) under 30 days since seroconversion; nine samples in the early stage of incidence belong to PRB933 and PRB965 seroconversion panels. Among them, negative incidence results were regarded as zero avidity index in this plot, which had very low titers of HIV antibodies. Inc = incidence samples (n = 21) between 30 days and 200 days since seroconversion; Est = established samples (n = 24) more than 200 days since seroconversion.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4551139&req=5

fig1: Distribution of the avidity index for the three human immunodeficiency virus (HIV)-positive groups. Dotted line = avidity cutoff (0.8). Early = the early stage of incidence samples (n = 9) under 30 days since seroconversion; nine samples in the early stage of incidence belong to PRB933 and PRB965 seroconversion panels. Among them, negative incidence results were regarded as zero avidity index in this plot, which had very low titers of HIV antibodies. Inc = incidence samples (n = 21) between 30 days and 200 days since seroconversion; Est = established samples (n = 24) more than 200 days since seroconversion.
Mentions: To construct a gray zone, we applied the formula—{cutoff value ± [coefficient of variation (CV) × cutoff value]}—of Suligoi et al [20]. The precision of the repeat test results was expressed as the CV. The AI distributions of three sample groups—early stage of incidence, incidence, and established—were compared using a nonparametric method (Figure 1).

Bottom Line: We determined that the concentration of Guanidine to be used in the avidity assay was 1.5M.The cutoff value of the avidity index (AI) was 0.8, and the sensitivity and specificity were 90.2% and 83.8%, respectively, under this condition.The mean of coefficient of variation was low, at 5.43%.

View Article: PubMed Central - PubMed

Affiliation: Division of AIDS, Korea National Institute of Health, Cheongju, Korea ; Division of Biobank for Health Sciences, Korea National Institute of Health, Cheongju, Korea.

ABSTRACT

Objectives: To estimate human immunodeficiency virus (HIV) incidence using HIV avidity assays in Korea, we established a serological testing method to differentiate recent HIV infections from long-standing ones.

Methods: We adopted two incidence assays, the BED HIV-1 incidence test (Calypte Biomedical) and an HIV avidity assay (using Abbott AxSYM HIV Antigen/Antibody Combo), and performed them on Korean HIV samples obtained from 81 HIV seroconverters (n = 193), 135 HIV-positive samples, and three HIV commercial incidence panels (PRB965, PRB933, and PRB601 from SeaCare). To determine the most optimal concentration of the chaotropic agent (Guanidine) and the cutoff value for the avidity assay, we evaluated the sensitivity and specificity of the assay at different concentration levels.

Results: We determined that the concentration of Guanidine to be used in the avidity assay was 1.5M. The cutoff value of the avidity index (AI) was 0.8, and the sensitivity and specificity were 90.2% and 83.8%, respectively, under this condition. The gray zone for the avidity assay was 0.75-0.85 AI. The mean of coefficient of variation was low, at 5.43%.

Conclusion: An optimized avidity assay for the diagnosis of recent HIV infections using Korean samples was established. This assay will be applied to investigate the level of recent infection and will provide basic data to the HIV prevention policy in Korea.

No MeSH data available.


Related in: MedlinePlus