AEGiS-15IAC: Neutralization Activity in Plasma From HAART: Comparison of "Successfully" and "Unsuccessfully" Treated Patients.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Neutralization Activity in Plasma From HAART: Comparison of "Successfully" and "Unsuccessfully" Treated Patients.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. A10195)

Ouverney EP, Grinsztejn B, Pilotto JH, Morgado MG, Bongertz V
AIDS and Molecular Lab, IOC, FIOCRUZ, Rio de Janeiro, Brazil

BACKGROUND: The development and implementation, in 1995, of the Highly Active Antiretroviral Therapy (HAART), has revolutionized the treatment against Human Immunodeficiency Virus (HIV) infection, and is associated with dramatic decreases in HIV related mortality. Due to the numerous mutations of the virus and the lack of treatment adherence, viral resistance is observed, i.e., cases in which HAART cannot reduce the viral load to undetectable levels or reestablish the CD4 T-cell count and consequently the normal immune response, but where an antigenic stimulation occurs continuously at low levels. One question is if this continuous low antigenic stimulation can activate the immune response.

METHODS: The neutralizing capability of plasma from 13 patients successfully undergoing HAART (undetectable viral load), 9 patients that had a previous occasion of therapy failure, and 12 treatment-naïve patients (viral loads below 30.000 copies/mm³), is being analyzed. Infection of PBMC by the T-cell line adapted HIV-1 virus MN was evaluated in presence or absence of serum samples.

RESULTS: The 100% neutralization level at low plasma dilutions was observed in 23% of the individuals without failure, 33% of the individuals in therapeutic failure, and 33% of the individuals without treatment. According to the statistical analyses, these numbers are very similar.

CONCLUSIONS: These preliminary results indicate that the capacity of plasma from individuals who had never had undergone anti-retroviral therapy and from individuals with a case history of one or more "therapy failures" neutralized the HIV-1 MN isolate to a similar extent, while plasma from individuals undergoing "successful therapy" showed not only a lower frequency but also lower neutralization titers of this reference viral isolate. These results, although preliminary, indicate that the presence of viral antigens may be indeed needed to induce a sustained humoral immune response against HIV-1.

Keywords: AEGIS, Antiretroviral Therapy, Highly Active, Viral Load, CD4 Lymphocyte Count, HIV-1, HIV-1 Reverse Transcriptase, Humans

040711
A10195