Browsing by Author "Bouzas, María Belén"

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    Safe Treatment Interruptions in Patients With Nadir CD4 Counts of More Than 350 Cells/μL
    (2006-04-01) Krolewiecki, Alejandro J.; Zala, Carlos; Vanzulli, Claudia; Pérez, Héctor; Iannella, María del Carmen; Bouzas, María Belén; Gun, Ana; Valiente, José; Cassetti, Isabel; Cahn, Pedro
    Objective: To evaluate clinical, immunologic, and virologic performance of patients with nadir CD4 counts of >350cells/μL upon treatment interruption. Design: Randomized, open-label clinical trial of 48 weeks' duration. Methods: Patients on effective highly active antiretroviral therapy, with nadir CD4 counts of >350 cells/μL and peak viral loads of <50,000 copies/mL were randomized to continue therapy or to interrupt antiretroviral medication. End points for patients with treatment interruption were CD4 counts of <350 cells/μL, viral loads of >1 log above the pretherapy values, or clinical symptoms attributable to HIV, at which point treatment was restarted. In the continuation group, the end points were virologic failure, opportunistic infections, and treatment discontinuation due to toxicities. Results: Twenty patients were randomized to stop therapy and 16 patients to continue. Median CD4 counts at baseline were 643 cells/μL for the interruption group and 633 cells/μL for the continuation group. No end points were reached in the interruption group. By week 8, viral load returned to values comparable to those of pretherapy in all patients in the interruption group and remained stable until week 48. CD4 counts dropped in the interruption group (median loss of 156 cells/μL) at week 48. Significant decreases in venous lactate were observed in the interruption group. Conclusions: Treatment interruptions in patients with nadir CD4 counts of >350 cells/μL seem safe for at least 48 weeks. Pretherapy viral load appears as a valuable tool to predict its level at week 48.
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    Serologic evaluation of human immunodeficiency virus type 1-infected individuals from Argentina and the United States indicates a similar distribution of subgroup B isolates
    (1995-02) Warren, Ronald; Wong, Michael; Melcher, Gregory; Blatt, Stephen; Cahn, Pedro; Perez, Héctor; Zapiola, Inés; Bouzas, María Belén; Muchinik, Guillermo; Anderson, Stephanie; Kennedy, Ronald
    This study examined serum specimens from HIV-1 infected individuals from Argentina (n = 50) and the United States (n = 38) for antibody reactivity to a panel of V3-based synthetic peptides. Serum specimens were further analyzed for the ability to neutralize laboratory and clinical isolates of HIV-1 in vitro. Patterns of antibody reactivity to these V3 peptides, together with neutralizing activity, indicated that infected individuals from both Argentina and the US have been exposed to HIV-1 isolates belonging to subgroup B. Serum specimens from the United States (37 males and 1 female) were obtained from military personnel and their dependents. Of these patients, 35 were asymptomatic and 3 were symptomatic. Specimens from Argentina were obtained from HIV-1-infected individuals examined in Buenos Aires, Argentina (37 males and 13 females). Half of the infected individuals from Argentina were symptomatic. Serum specimens were screened for antibody reactivity to HIV-1 gp160 synthetic peptides by an enzyme-linked immunosorbent assay. Examination of V3 peptide recognition indicated that a higher percentage of Argentinean serum specimens reacted with peptide RP189 than serum specimens from the United States (34% and 5%, respectively). A higher percentage of serum specimens from the United States reacted with peptide RP135 (LAI) than was observed with serum specimens from Argentina (47% vs. 16%, respectively). Neutralization assays again indicated a similar pattern of antibody reactivity with serum specimens from infected individuals from Argentina and the United States. Nucleotide sequence analysis of clinical isolates has demonstrated that the HIV-1 subgroup B is predominant in the United States. Serologic reactivity to V3-based peptides in this study suggests that isolates commonly found in the US (i.e., MN, SF2, and NY-5) are also frequently observed in Argentina. These results suggest that there is similar distribution of HIV-1 subgroup B isolates among infected individuals from Argentina and the United States.