Ivana Parker
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Ivana Parker has a total of 10 co-authors. Here are the top co-authors by number of shared publications:
- Amy Martin
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
1 shared publication - Andrew Hickey
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
1 shared publication - George M. Khalil
Quantitative Sciences and Data Management Branch, Division of HIV Prevention, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
1 shared publication - Janet M. McNicholl
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
1 shared publication - Jose Gerardo Garcia-Lerma
Laboratory Branch, Division of HIV Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
1 shared publication - Kachit Choopanya
Bangkok Tenofovir Study Group, Bangkok 10600, Thailand
1 shared publication
Latest Publications
- 1 March 2021
- Published by SAGE Publications in AIDS Research and Human Retroviruses
- Vol. 37 (3) , 189-195
Altered Antibody Responses in Persons Infected with HIV-1 While Using Preexposure Prophylaxis
Background: Pre-exposure prophylaxis (PrEP) is an effective HIV prevention tool, although effectiveness is dependent upon adherence. It is important to characterize the impact of PrEP on HIV antibody responses in people who experience breakthrough infections in order to understand the potential impact on timely diagnosis and treatment. Methods: Longitudinal HIV-1-specific antibody responses were evaluated in 42 people who inject drugs (PWID) from the Bangkok Tenofovir Study (placebo=28; PrEP=14) who acquired HIV while receiving PrEP. HIV-1 antibody levels and avidity to three envelope proteins (gp41, gp160, and gp120) were measured in the plasma using a customized Bio-Plex (Bio-Rad Laboratories) assay. A survival analysis was performed for each biomarker to compare the distribution of times at which study subjects exceeded the recent/long-term assay threshold, comparing PrEP and placebo treatment groups. We fit mixed-effects models to identify longitudinal differences in antibody levels and avidity between groups. Results: Overall, longitudinal antibody levels and avidity were notably lower in the PrEP breakthrough group compared to the placebo group. Survival analyses demonstrated a difference in time to antibody reactivity between treatment groups for all Bio-Plex biomarkers. Longitudinal gp120 antibody levels within the PrEP breakthrough group were decreased compared to the placebo group. When accounting for PrEP adherence, both gp120 and gp160 antibody levels were lower in the PrEP breakthrough group compared to the placebo group. Conclusion: We demonstrate hindered envelope antibody maturation in PWID who became infected while receiving PrEP in the Bangkok Tenofovir Study, which has significant implications for HIV diagnosis. Delayed maturation of the antibody response to HIV may increase the time to detection for antibody-based tests.
- 1 March 2021
- Published by SAGE Publications in AIDS Research and Human Retroviruses
- Vol. 37 (3) , 189-195
Altered Antibody Responses in Persons Infected with HIV-1 While Using Preexposure Prophylaxis
Background: Pre-exposure prophylaxis (PrEP) is an effective HIV prevention tool, although effectiveness is dependent upon adherence. It is important to characterize the impact of PrEP on HIV antibody responses in people who experience breakthrough infections in order to understand the potential impact on timely diagnosis and treatment. Methods: Longitudinal HIV-1-specific antibody responses were evaluated in 42 people who inject drugs (PWID) from the Bangkok Tenofovir Study (placebo=28; PrEP=14) who acquired HIV while receiving PrEP. HIV-1 antibody levels and avidity to three envelope proteins (gp41, gp160, and gp120) were measured in the plasma using a customized Bio-Plex (Bio-Rad Laboratories) assay. A survival analysis was performed for each biomarker to compare the distribution of times at which study subjects exceeded the recent/long-term assay threshold, comparing PrEP and placebo treatment groups. We fit mixed-effects models to identify longitudinal differences in antibody levels and avidity between groups. Results: Overall, longitudinal antibody levels and avidity were notably lower in the PrEP breakthrough group compared to the placebo group. Survival analyses demonstrated a difference in time to antibody reactivity between treatment groups for all Bio-Plex biomarkers. Longitudinal gp120 antibody levels within the PrEP breakthrough group were decreased compared to the placebo group. When accounting for PrEP adherence, both gp120 and gp160 antibody levels were lower in the PrEP breakthrough group compared to the placebo group. Conclusion: We demonstrate hindered envelope antibody maturation in PWID who became infected while receiving PrEP in the Bangkok Tenofovir Study, which has significant implications for HIV diagnosis. Delayed maturation of the antibody response to HIV may increase the time to detection for antibody-based tests.