Survival after AIDS-defining events in patients with < 200 lymphocytes CD4+ x 10(6)/L who are toxoplasmosis antibody positive. ANRS 005/ACTG 154 Trial Group

Temporary restoration of immune response against Toxoplasma gondii in HIV-infected individuals after HAART, as studied in the hu-PBMC-SCID mouse model

We studied immune reconstitution against the parasite T. gondii in HIV-infected patients treated for 1 years with highly active antiretroviral therapy (HAART). We used SCID mice, humanized with peripheral blood mononuclear cells (PBMC) from patients, which were then infected with T. gondii cysts. Mice humanized with PBMC from patients before the start of HAART were highly susceptible to infection. In contrast, mice humanized with PBMC from patients who had received HAART for 6 months displayed higher survival rates, correlating with lower intracerebral parasite loads. However, this resistance was lost during follow up because mice humanized with PBMC from patients treated with HAART for 12 months survived for no longer than mice that had not been humanized. Specific lymphocyte proliferation assays showed that the increase in proliferative response depended on treatment duration and that HAART induced changes in IFN-gamma secretion in the presence of Toxoplasma antigens. Thus, our results indicate partial immune reconstitution against T. gondii in HIV-infected patients following HAART, possibly due to changes in the patterns of specific IFN-gamma production and redistribution of functional memory CD4+ cells.

[Contribution of clinical epidemiology to the management of HIV infections]

INTRODUCTION

The objective of this publication is to make clinicians more aware of clinical epidemiology through our experience in the field of human immunodefiency virus (HIV) infection.

CURRENT KNOWLEDGE AND KEY POINTS

Clinical epidemiology is aimed at studying diagnostic, therapeutic and prognostic aspects of diseases, and their consequences, with the objective of improving both scientific knowledge and patient's management. Examples, including longitudinal studies and clinical trials, illustrate the value of clinical epidemiology.

FUTURE PROSPECTS AND PROJECTS

Beyond HIV infection, the importance of both multidisciplinary collaboration and education of clinicians in regard to biostatistical and epidemiological methods is emphasized.