Related Experiment Videos
Early viremia and immune responses in vertical human immunodeficiency virus type 1 infection
K Luzuriaga1, P McQuilken, A Alimenti
1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester 01605.
Insights
Five infants born to HIV-1-positive mothers were studied. Two showed in utero infection, while three had later transmission, with viral loads declining naturally in most cases.
Area of Science:
- Virology
- Immunology
- Pediatrics
Background:
- Vertical transmission of Human Immunodeficiency Virus Type 1 (HIV-1) remains a significant concern.
- Understanding the timing and mechanisms of early HIV-1 infection in infants is crucial for intervention.
Purpose of the Study:
- To evaluate the virologic and immunologic characteristics of HIV-1 infection in infants born to seropositive mothers.
- To investigate the timing of HIV-1 acquisition (in utero, intrapartum, or early neonatal).
Main Methods:
- Evaluation of 33 infants from birth using plasma and peripheral blood mononuclear cell (PBMC) cultures.
- Application of polymerase chain reaction (PCR) and serum p24 antigen assays for HIV-1 detection.
- Longitudinal monitoring of viral load and immune responses.
Main Results:
- Five of 33 infants were identified as HIV-1 infected.
- Two infants showed evidence of in utero transmission (positive cord blood samples).
- Three infants had negative initial virologic studies, becoming positive by 8 weeks, suggesting intrapartum or later transmission; viral titers declined spontaneously in most.
Conclusions:
- Early HIV-1 infection in infants can occur via in utero or intrapartum/neonatal routes.
- Spontaneous decline in viral load was observed in some infants without antiretroviral therapy or specific immune responses.
- Further research in larger cohorts is needed to inform strategies for preventing vertical HIV-1 transmission.
Abstract:
Thirty-three infants born to human immunodeficiency virus type 1 (HIV-1)-seropositive women were evaluated from birth using plasma and peripheral blood mononuclear cell (PBMC) cultures, polymerase chain reaction, and serum p24 antigen assays. Five children were identified as infected. Evidence of infection was found in cord blood and subsequent samples from 2 infected children, suggesting in utero infection. Virologic studies on cord blood and early neonatal specimens from the 3 other infected children were negative but became positive by 8 weeks of age, suggesting either intrapartum transmission or sequestration of virus with subsequent detection. An increase in blood (plasma and PBMC) virus titers consistent with primary viremia was observed in 4 infants between 3 and 16 weeks of age. Blood virus titers subsequently declined in the absence of antiretroviral therapy and in the absence of activated HIV-1-specific cytotoxic T lymphocyte responses or broadly neutralizing antibodies. Confirmation of these results in larger studies may be helpful in the design of clinical trials to interrupt vertical transmission or to modify the course of infection.