Differential maturation of avidity of IgG antibodies to gp41, p24 and p17 following infection with HIV-1

Thomas, H. I. J.; Wilson, Stephen E.; O’Toole, Carol; Lister, C. M.; Saeed, A. Mahdi; Watkins, Robert P.; Morgan‐Capner, P.

doi:10.1046/j.1365-2249.1996.951642.x

Cited by 53 publications

(45 citation statements)

References 24 publications

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“…Alternatively, this sheep may present some failure in the mechanisms that underly the ability to maintain the production of high affinity antibodies. A failure of T helper function may be responsible for the loss of high affinity antibodies as well as the associated decay of the antibody titer, that have been reported in individuals who later developed AIDS ( Chargelegue et al, 1993, Chargelegue et al, 1995and Thomas et al, 1996. SRLV infection, however, does not involve the lymphocyte compartment, and sheep 1 antibody titer does not decrease, therefore a different mechanism may be responsible.…”

Section: Discussionmentioning

confidence: 97%

Seroconversion against SU5 derived synthetic peptides in sheep experimentally infected with different SRLV genotypes

Carrozza¹,

Mazzei²,

Lacerenza³

et al. 2009

Veterinary Microbiology

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Synthetic peptides were generated, corresponding to SU5 domain of envelope glycoprotein of Italian SRLV isolates It--561 and It--Pi1, belonging respectively to MVV--and CAEV--like genotypes. The peptides, encompassing an N--terminal variable and a C--terminal conserved antibody--binding site, were used in an ELISA assay to analyse the sera of two groups of sheep experimentally infected with these isolates. The kinetics and specificity of the humoral response to the homologous and heterologous antigen and the affinity maturation of the sera were evaluated. Seroconversion occurred between week 3 and 8. The response to SU5 antigen was mostly type--specific. The few broadly reacting sera may reflect the production of antibodies directed to the SU5 constant antibody--binding site. All sera underwent with time avidity maturation, resulting in the appearance of high affinity antibodies. This study suggests constant monitoring of the circulating viral variants to develop a panel of diagnostic peptides representative of local genotypes.

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Section: Discussionmentioning

confidence: 97%

Seroconversion against SU5 derived synthetic peptides in sheep experimentally infected with different SRLV genotypes

Carrozza¹,

Mazzei²,

Lacerenza³

et al. 2009

Veterinary Microbiology

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“…For HIV infection, early studies evaluated antibody maturation and avidity to specific antigens (i.e., p24 and gp41) (16) as indicators of clinical progression of HIV disease. The first instance of the broad-range epidemiological application of HIV antibody maturation was the study of Janssen et al (4), who used two tests in order to detect recent infections (i.e., a on May 10, 2018 by guest http://jcm.asm.org/ standard HIV-1 antibody assay approved by the Food and Drug Administration and a "detuned" version of the same assay in which both sample dilution and incubation times were modified).…”

Section: Discussionmentioning

confidence: 99%

Precision and Accuracy of a Procedure for Detecting Recent Human Immunodeficiency Virus Infections by Calculating the Antibody Avidity Index by an Automated Immunoassay-Based Method

Suligoi

Galli

Massi³

et al. 2002

J Clin Microbiol

108

102

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We evaluated the precision and accuracy of a procedure for detecting recent human immunodeficiency virus (HIV) infections, specifically, the avidity index (AI) calculated using a method based on an automated AxSYM HIV 1/2gO assay (Abbott). To evaluate precision, we performed multiple replicates on eight HIV-positive serum samples. To evaluate the accuracy in identifying recent infections (i.e., within 6 months of seroconversion), we used 216 serum samples from 47 persons whose dates of seroconversion were known. To evaluate the sensitivity and specificity of the procedure for different AI cutoff values, we performed receiver operating characteristic (ROC) analysis. To determine the effects of antiretroviral treatment, advanced stage of the disease (i.e., low CD4-cell count), and low HIV viral load on the AI, we analyzed 15 serum samples from 15 persons whose dates of seroconversion were unknown. The precision study showed that the procedure was robust (i.e., the total variance of the AI was lower than 10%). Regarding accuracy, the mean AI was significantly lower for samples collected within 6 months of seroconversion, compared to those collected afterwards (0.68 ؎ 0.16 versus 0.99 ؎ 0.10; P < 0.0001), with no overlap of the 95% confidence intervals. The ROC analysis revealed that an AI lower than 0.6 had a sensitivity of 33.3% and a specificity of 98.4%, compared to 87.9 and 86.3%, respectively, for an AI lower than 0.9. Antiretroviral treatment, low CD4-cell count, and low viral load had no apparent effect on the AI. In conclusion, this procedure is reproducible and accurate in identifying recent infections; it is automated, inexpensive, and easy to perform, and it provides a quantitative result with different levels of sensitivity and specificity depending on the selected cutoff.For persons infected with the human immunodeficiency virus (HIV), knowing at what point in time infection occurred would be useful for a variety of purposes, including surveillance, the planning of vaccine trials, making decisions with regard to treatment, tailoring and evaluating preventive measures, and partner notification. Although for other infections the time of infection can be approximated based on the dynamics of the antibody response, these procedures have not been standardized for HIV infection. Moreover, although the classic sequence of the antibody response, in which a primary immunoglobulin M (IgM) response is followed by an increase in IgG and the IgG response increases with repeated exposures (20), is generally applicable to HIV infection, current screening assays are not able to discriminate among the immunoglobulin classes of anti-HIV antibodies.In the attempt to discover a means of distinguishing recent HIV infections from established infections in single sampling, researchers have studied various antibody assays and testing strategies (4, 12). However, some of these assays have a number of drawbacks, specifically, high costs, difficulties in performing the assay, low reproducibility, qualitative rather than quantita...

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“…Most cross-sectional HIV incidence assays measure characteristics of anti-HIV antibodies. 5,6 The 1 BED capture enzyme immunoassay (BED-CEIA) 7 is currently used in the United States 8,9 and other countries 10 to estimate HIV incidence and identify high-incidence populations. A modified version of the Bio-Rad 1/2 + O ELISA (Bio-Rad Avidity assay) 11 has also been used for cross-sectional incidence estimation.…”

Section: Introductionmentioning

confidence: 99%

Impact of HIV Subtype on Performance of the Limiting Antigen-Avidity Enzyme Immunoassay, the Bio-Rad Avidity Assay, and the BED Capture Immunoassay in Rakai, Uganda

Longosz

Serwadda

Nalugoda

et al. 2014

AIDS Research and Human Retroviruses

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Previous studies demonstrated that individuals with subtype D HIV infection who had been infected for 2 or more years were frequently misclassified as assay positive using cross-sectional incidence assays. Samples from 510 subjects (212 subtype A, 298 subtype D) who were infected for 2.2 to 14.5 years (median 5.4 years) and were not virally suppressed were tested using an LAg-Avidity enzyme immunoassay (LAg-Avidity EIA), Bio-Rad Avidity assay, and BED capture enzyme immunoassay (BED-CEIA). The performance of these three assays was evaluated using various assay cutoff values [LAg-Avidity EIA: < 1.0 OD-n and < 2.0 OD-n; Bio-Rad Avidity assay: < 40% avidity index (AI) and < 80% AI; BED-CEIA: < 0.8 OD-n]. The mean LAg-Avidity EIA result was higher for subtype A than D (4.54 -0.95 vs. 3.86 -1.26, p < 0.001); the mean Bio-Rad Avidity assay result was higher for subtype A than D (88.9% -12.5% vs. 75.1 -30.5, p < 0.001); and the mean BED-CEIA result was similar for the two subtypes (2.2 -1.2 OD-n for subtype A, 2.2 -1.3 OD-n for subtype D, p < 0.9). The frequency of misclassification was higher for individuals with subtype D infection compared to those with subtype A infection, using either the LAg-Avidity EIA with a cutoff of < 2.0 OD-n or the Bio-Rad Avidity assay with cutoffs of < 40% or < 80% AI. No subtype-specific differences in assay performance were observed using the BED-CEIA. Sex and age were not significantly associated with misclassification by any assay. The LAg-Avidity EIA with a cutoff < 1.0 OD-n had the lowest frequency of misclassification in this Ugandan population.

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Differential maturation of avidity of IgG antibodies to gp41, p24 and p17 following infection with HIV-1

Cited by 53 publications

References 24 publications

Seroconversion against SU5 derived synthetic peptides in sheep experimentally infected with different SRLV genotypes

Seroconversion against SU5 derived synthetic peptides in sheep experimentally infected with different SRLV genotypes

Precision and Accuracy of a Procedure for Detecting Recent Human Immunodeficiency Virus Infections by Calculating the Antibody Avidity Index by an Automated Immunoassay-Based Method

Impact of HIV Subtype on Performance of the Limiting Antigen-Avidity Enzyme Immunoassay, the Bio-Rad Avidity Assay, and the BED Capture Immunoassay in Rakai, Uganda

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