Persistence of Human Immunodeficiency Virus–Associated Cerebral Toxoplasmosis Lesions in Successfully Treated Patients Receiving Combination Antiretroviral Therapy

Abstract

Background Toxoplasmic encephalitis (TE) is a life-threatening complication of people with HIV (PWH) with severe immunodeficiency, especially those with a CD4+ T cell count under 100 cells/mm3. Following a clinical response to anti-Toxoplasma therapy, and immune reconstitution after initiation of combination anti-retroviral therapy (ART), anti-Toxoplasma therapy can be discontinued with a low risk of relapse. Methods To better understand the evolution of MRI-defined TE lesions in PWH receiving ART, we undertook a retrospective study of PWH initially seen at the NIH between 2001 and 2012, who had at least 2 serial MRI scans. Lesion size and change over time were calculated and correlated with clinical parameters. Results Among 24 PWH with TE and serial MRI scans, only 4 had complete clearance of lesions at the last MRI (follow-up, 0.09 to 5.8 years). Of 10 PWH off all anti-Toxoplasma therapy (median, 3.2 years after TE diagnosis), 6 had persistent MRI enhancement. In contrast, all 5 PWH seen in a pre-ART era study who were followed for >6 months had complete clearance of lesions. TE lesion area at diagnosis was associated with the absolute change in area (p < 0.0001). Conclusions Thus, contrast enhancement can persist even when TE has been successfully treated and anti-Toxoplasma therapy has been stopped, highlighting the need to consider diagnostic alternatives in successfully treated patients with immune reconstitution presenting with new neurologic symptoms.