Does antiretroviral therapy alter the course of Parkinson's disease in people living with HIV?

South Africa has the world's largest antiretroviral programme which has resulted in an increase in life expectancy in persons living with HIV. Parkinson's disease (PD) is an age-related neurodegenerative disorder. No data has been published in this setting with regards to the interaction between PD and people infected with HIV. This was a retrospective study which matched two HIV non-infected PD patients to one HIV-infected patient with PD. Patients with secondary causes of Parkinsonism were excluded. Demographic, clinical and laboratory data were extracted from the charts. Hoehn and Yahr scale was used to assess PD severity. Twenty PD patients were recruited from 1 January 2008 to 31 October 2020 and were diagnosed with HIV for a median of 72 months. The median age at onset of PD was 52 years. All patients were on antiretroviral therapy. There were no statistically significant differences in the levodopa equivalent daily dose, clinical phenotype, impulse control disorders (ICDs) and frequency of a positive family history between the two groups. HIV-infected patients had a higher frequency of dopamine dysregulation syndrome. At the end of follow-up, 3 (15%) PLH-PD had moderate to severe PD compared to 16 (40%) of PD controls. The OR of having moderate to severe PD in HIV non-infected PD patients was 4. Persons living with HIV and Parkinson's disease present with PD symptoms at a younger age, progress slower to a severe stage and respond well to dopaminergic replacement therapy.