Reduced value of thallium-201 single-photon emission computed tomography in the management of HIV-related focal brain lesions in the era of highly active antiretroviral therapy.

To evaluate the diagnostic value of thallium-201 single-photon emission computed tomography (201Tl SPECT) in the management of focal brain disorders in the era of highly active antiretroviral therapy (HAART), a validation study of diagnostic procedure was performed in a tertiary clinical care center in Italy. Thirty-eight consecutive HIV-infected patients with neurological impairment and focal brain lesions (FBL) were enrolled in a prospective evaluation and underwent diagnostic procedures according to a standardized protocol based on modified previously released guidelines. Six out of seven PCNSL presented high uptake at 201Tl SPECT [sensitivity 86% (95% CI 42-99); specificity 77% (95% CI 58-90); positive predictive value (PPV) 46% (95% CI 20-74); negative predictive value (NPV) 96% (95% CI 78-100)]. Among toxoplasmic encephalitis (TE) cases 14 showed no uptake and 5 showed an increased uptake [sensitivity 74% (95% CI 49-90); specificity 42% (95% CI 21-66); PPV 56% (95% CI 35-75); NPV 61% (95% CI 32-85)]. Patients taking HAART were more likely to display an increased uptake of 201Tl in the cerebral lesions than patients without HAART (OR 5.07; 95% CI 1.19-21.5). Considering only the patients with diagnosis of TE, 60% of patients who showed high radionuclide uptake were taking HAART, while 79% of patients without relevant uptake were not taking HAART. As a result of the impact of HAART, the diagnostic value of 201Tl SPECT in the management of HIV-associated FBL could be substantially reduced. This observation suggests that in HAART-treated patients, this diagnostic tool be used only when combined with other more specific diagnostic markers.

Clinical epidemiology and survival of progressive multifocal leukoencephalopathy in the era of highly active antiretroviral therapy: data from the Italian Registry Investigative Neuro AIDS (IRINA).

Human immunodeficiency virus (HIV)-associated progressive multifocal leukoencephalopathy (PML) remains a relevant clinical problem even in the era of highly active antiretroviral therapy (HAART). Aims of the study were to analyze clinical and treatment-related features and the survival probability of PML patients observed within the Italian Registry Investigative Neuro AIDS (IRINA) during a 29-month period of HAART. Intravenous drug use, the presence of focal signs, and the involvement of white matter at neuroradiology increased the risk of having PML. A reduced probability of PML was observed when meningeal signs were reported. Patients starting HAART at PML diagnosis and previously naïve for antiretrovirals showed significantly higher 1-year probability of survival (.58), compared to those continuing HAART (.24), or never receiving HAART (.00). Higher CD4 cell count were associated with a higher survival probability (.45). At multivariate analysis, a younger age, higher CD4, starting HAART at PML diagnosis, the absence of previous acquired immunodeficiency syndrome (AIDS)-defining events, and the absence of a severe neurologic impairment were all associated with a reduced hazard of death. The use of cidofovir showed a trend towards a reduced risk of death.