Comparison of the Performance of Commercially Available Quantitative Viral Load Assays Using Clinical Samples from Patients from Regions Where Distinct HIV-1 Subtypes Co-Circulate: Potential Implications for Patient Management.

HIV RNA plasma viral load (VL) is the standard surrogate marker to monitor response to antiretroviral treatment (ART). We compared the linearity, repeatability, and concordance of six commercially available HIV RNA VL platforms using clinical samples from patients from Brazilian sites where different HIV-1 subtypes co-circulate. A total of 150 plasma samples from each city were collected in Curitiba, Southern Brazil (subtype C), São Paulo (subtype B), and Santos (BF recombinants), Southeast Brazil.

Establishing the reference range for T lymphocytes subpopulations in adults and children from Brazil.

In Brazil, the existing reference values for T-lymphocytes subsets are based on data originated in other countries. There is no local information on normal variation for these parameters in Brazilian adults and children. We evaluated the normal variation found in blood donors from five large Brazilian cities, in different regions, and in children living in Salvador, and Rio de Janeiro.

HIV type 1 antiretroviral resistance mutations in subtypes B, C, and F in the City of São Paulo, Brazil.

In Brazil, where three distinct HIV-1 subtypes (B, F, and C) cocirculate, a significant portion of the HIV-infected population has been exposed to antiretroviral drugs. This study analyzes the antiretroviral resistance profiles of HIV-1-infected individuals failing antiretroviral therapy. Genotypic resistance profiles of 2474 patients presenting virologic failure to antiretroviral therapy in the city of São Paulo, Brazil, were generated and analyzed.