To explore allergen-specific effector and regulatory T cell response in HIV-infected children before and after HAART initiation

Recently, US investigators have observed that HIV-infected (HIV+) children on highly active antiretroviral therapy (HAART) have a much greater cumulative incidence of asthma.Regulatory T cells may mitigate the pathogenicity of asthma through the suppression of Th2 responses. Since asthma is predominantly a TH2 mediated condition, we propose that new onset of asthma after HAART in HIV- infected children may be secondary to dysregulated immune reconstitution. The restoration of CD4+ T cell-mediated immunity in HIV+ patients treated with HAART may lead to airway inflammation, narrowing, hyperresponsiveness, and possibly remodeling.

The increased incidence of asthma in HIV-infected children treated with HAART is likely secondary to multiple factors that may include hypersensitivity to certain aeroallergens, dysregulation of effector and regulatory T cell response, as well as the imbalance of TH1 vs. TH2 cytokines. Therefore this study will identify the immunopathogenesis of increased airway hyperresponsiveness in HIV-positive patients.

Inclusion Criteria:

1. Children aged 2-18 years
2. Parent signed inform consent and children signed assent form
3. Children who are starting highly active antiretroviral therapy (HAART) due to clinical indication or switching HAART due to treatment failure within 45 days after screening visit

Exclusion Criteria:

1. Pregnancy
2. History of chronic lung disease including lymphoid interstitial pneumonitis (LIP), and bronchopulmonary dysplasia (BPD).
3. Active opportunistic infections i.e. pulmonary tuberculosis, PCP, pneumonia
4. Conditions limiting ability of subject to comprehend questionnaires (i.e. mental retardation).