Virologic, immunologic, and clinical evaluation of human immunodeficiency virus antibody status of symptom-free children born to infected mothers

Incomplete HIV type 1 antibody evolution and seroreversion in acutely infected individuals treated with early antiretroviral therapy

BACKGROUND

The diagnosis of human immunodeficiency virus type 1 (HIV-1) infection by standard tests relies on the formation of HIV-1-specific antibodies. Early treatment of acute HIV-1 infection may have unique immunologic effects on host cellular and humoral responses. Rare cases of HIV-1 seroreversion have been reported for patients with advanced or rapidly progressive disease. Here, we report seroreversion that occurred in subjects with acute HIV-1 infection who initiated early antiretroviral therapy.

METHODS

A total of 150 patients with symptomatic acute or early onset HIV-1 infection that was treated with antiretroviral therapy were observed prospectively by means of monthly clinical and laboratory evaluation, which included serial HIV enzyme-linked immunosorbent assay and Western blots, until a fully evolved HIV-1 antibody response was documented.

RESULTS

Three patients who initiated antiretroviral therapy a mean interval of 8 days (range, 1-16 days) after presentation and were observed for a mean duration of 50.2 months (range, 40.2-55.7 months) did not develop a fully evolved HIV-1 antibody response or demonstrated complete or partial HIV-1 seroreversion, despite maintenance of cytomegalovirus-specific humoral responses. Virologic suppression and seroreversion (complete or partial) occurred a mean duration of 4.1 months (range, 2.3-5.7 months) and 15.5 months (range, 6.7-26.3 months), respectively, after the initiation of therapy. All patients maintained complete virologic suppression while receiving therapy and had an undetectable HIV-1 RNA load at the time of seroreversion.

CONCLUSIONS

Early antiretroviral therapy associated with durable virologic suppression in acute HIV-1 infection may abrogate the formation or detection of HIV-1-specific antibodies. Ongoing antigenic stimulation may be required to maintain HIV-1-specific humoral responses. Incomplete evolution of the HIV-1 antibody response and/or presence of seroreversion (although infrequently observed) underscore the potential unique immunologic effect of early antiretroviral therapy in patients with primary HIV-1 infection.

Vertical transmission of HIV in New York State: a basis for statewide testing of newborns

Infants (n = 313) of HIV-infected mothers were enrolled (mean age 1.9 weeks, range 0-8 weeks) in a 3-year prospective study of vertical transmission. Fifty-six infants (17.9%) had laboratory and clinical evidence of HIV infection. Polymerase chain reaction (PCR) provided early and reliable identification of infected infants. Thirty-one of the 56 infected infants had specimens submitted when the infants were 4 weeks of age or less and 30 (97%) tested PCR positive. This percentage increased to 100% by 8 weeks of age when 51 of the 56 infected infants had specimens tested for that time period. Immune complex dissociation (ICD) antigen testing was a sensitive method for diagnosis of infection but only in infants older than 1 month. p24 antigen testing, although free of false positives, is less sensitive than either of the other methods. Among surrogate markers of HIV infection, elevation of soluble CD8 levels precedes an increase in immunoglobulin levels or a decline in CD4 T lymphocytes. Vertical transmission is significantly lower in Central and Western New York State than other regions. Transmission is significantly higher in low birthweight babies and in infants whose mothers have CD4 counts < 500. This study provided the basis for establishing a Pediatric HIV PCR Testing Service for the early diagnosis of HIV infection in neonates.

Pediatric HIV infection

Developments in the prevention and treatment of HIV infection in pregnant women and their children are encouraging. Perinatal ZDV therapy can reduce the maternal-infant transmission rate by two thirds in select populations. New therapies and the development of diagnostic assays to monitor HIV viral burden have renewed hope that, by aggressively controlling viremia, the progressive immunodeficiency can be delayed or even prevented. The general pediatric approach of preventing illnesses through aggressive vaccination and education policies must be actively incorporated into an approach to this epidemic. Success in controlling the pediatric HIV epidemic requires a concerted, coordinated effort by public policy makers, health care providers, basic science researchers, and those who are HIV-infected.

Use of polymerase chain reaction and quantitative antibody tests in children born to human immunodeficiency virus-1-infected mothers

The diagnosis of human immunodeficiency virus (HIV) infection in children born to HIV-infected mothers is complicated by the presence of passively acquired maternal antibodies, and exclusion of infection in these infants remains problematic. The use of genome detection by polymerase chain reaction (PCR) amplification and the quantification of anti-HIV-1 antibodies were examined as methods for early diagnosis. Blood samples were taken from 84 non-breast-fed infants of HIV-infected mothers in five Italian and Spanish centres, a subgroup of children enrolled in the European Collaborative Study (ECS) for whom clinical and immunological information has been documented from birth. Whole blood was added to glycigel cryopreservative, stored, and tested in the United Kingdom by a nested PCR method. Antibody to HIV-1 was detected and quantified by titration using a gelatin particle agglutination test. PCR sensitivity and specificity were assessed. Twenty-one of the 84 children tested were infected. The estimated PCR sensitivity ranged from 0% (95% CI 0-26%) on day 1, 57% (19-85) on day 7, to 63% (33-92) on day 30. The negative predictive value of PCR ranged from 85% (83-88) on day 0 to 98% (94-100) at 3 months of age. On average, the level of maternal antibody halved every 33 days (31-36.5) in uninfected children. Between 6 and 9 months of age, increases in antibody titres in infected children were not more informative than absolute levels. These findings suggest that antibody measurement may supplement genomic diagnosis and that this collection method provides an alternative to the use of dried blood spots.