[Genotypic resistance in HIV-1-infected patients with persistent low-level viremia].

Introduction: Highly active antiretroviral therapy (HAART) in HIV patients is considered successful when plasma viral load (VL) reaches < 50 copies/ml. However, many patients have a persistent VL of 50 to 1000 copies/ml, and treatment guidelines do not recommend genotypic resistance testing at these levels because of poor performance. The aim of this study was to evaluate the usefulness of a concentration technique for HIV-1 sequencing in samples with < 1000 copies/ml, and determine the virological consequences of HAART treatment changes guided by resistance testing in this scenario.

Detection of IgA and low-avidity IgG antibodies for the diagnosis of recent active toxoplasmosis.

OBJECTIVE: To determine the clinical value of testing IgA and the avidity of IgG (by two commercial systems) for the detection of recent active toxoplasmosis (RAT), and to study the IgG avidity during the course of infection. METHODS: The IgA was tested by a capture ELISA (Pasteur, France) and the avidity of IgG was determined by two modified commercial indirect ELISA methods (Sorin, Italy; Behringwerke, Germany) in 12 patients who were not immunosuppressed (group I) and 57 healthy subjects with a past infection by Toxoplasma gondii (group II). RESULTS: IgA was present in 75% of patients from group I and 21% of subjects from group II.