Efficacy of Neuro-HAART in Patients With HIV

St Vincent's Hospital, Sydney19 enrolled

Overview

Patients infected with Human Immunodeficiency Virus (HIV) are at risk of brain related complications despite the use of highly active antiretroviral therapy (HAART). Such complications are termed HIV neurocognitive disorders (HAND) and comprise a spectrum from asymptomatic neurocognitive impairment (ANI), through mild cognitive impairment (MCI) to severe HIV dementia (HAD). Prior to HAART approximately 30% of patients with advanced HIV disease had cognitive impairment; with HAART the incidence of HAND has decreased but its prevalence increased. The reasons for the ongoing development of cognitive impairment in HAART treated patients are not clear. They might relate to virus induced brain injury prior to starting HAART, the onset of a separate neurological process, toxicity related to HAART, or ongoing viral infection in the brain. It is clear that the ability of different antiretroviral drugs to penetrate the brain varies but what is not established is whether these differences between drugs lead to different neurological outcomes. The investigators propose to study HIV infected patients stable on HAART for 12 months; subdividing the groups according to the brain penetrance of their drug combination. Patients would undergo neuropsychological assessment and MRI brain scan at the start of the study and after 12 months. Differences in neuropsychological tests and MRI would be sought between treatment groups to establish whether HAART with better CNS penetration is associated with better outcome and fewer MRI changes.

Study Type

OBSERVATIONAL

Enrollment

Conditions

HIV

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * HIV positive with nadir cluster of differentiation 4 (CD4) count \<350 /microlitre (uL) * Taking HAART with CNS Penetration Effectiveness (CPE) score of either ≤7.0 or ≥7.5 for 1 year or more. Changes in antiretrovirals (ARVs) within the last 12 months are allowed so long as the CPE score does not lead to a change groups * Plasma HIV viral load \<50 copies / mL for preceding 12 months or longer * Informed consent given by participant or legally appointed guardian Exclusion Criteria: * Non-HIV related neurological disorders and active CNS opportunistic infection as assessed by full blood count, electrolytes, creatinine, glucose, liver function tests, cryptococcal antigen, venereal disease reaction level (VDRL), MRI brain scan and cerebrospinal fluid analyses for cell count, protein, glucose, culture, VDRL and cryptococcal antigen. * Psychiatric disorders on the psychotic axis, current major depression, and current substance use disorder as assessed by the Study Enrolment Questionnaire for Eligibility * Severe substance use disorders (within 12 months of study entry) * Active Hepatitis C virus (HCV) (detectable HCV RNA because HCV per se can cause cognitive impairment) * History of loss of consciousness \>1 hour * Non-proficient in English as assessed by the "English as a second language questionnaire" * Medications known pharmacologically to interact with ARVs * Pregnancy as assessed by the urinary pregnancy test

Outcomes

Primary Outcomes

Change in Neurocognitive Functioning

Change in overall neurocognitive performance, defined as a global neurocognitive z-score, after a 12-month period of observation, between HIV positive patients taking antiretroviral regimens categorized as being either of high or low CNS penetration. To derive this score, 1) raw scores obtained from a 5-domain brief neurocognitive battery were converted to age-corrected z-scores (M=0, Standard Deviation=1) and 2) the set of individual subtest z-scores were averaged to generate a single composite (global) z-score for each subject. Lower (negative) scores therefore indicate greater levels of cognitive impairment.

Time frame: Change from baseline Neuropsychological testing at 6 and 12 months

Secondary Outcomes

Change in MRS Cerebral Metabolite Ratios in Basal Ganglia

Change in major cerebral metabolites in the basal ganglia, as measured by 1H-Magnetic Resonance Spectroscopy (MRS), after a 12 month period of observation. Spectra were acquired on a Phillips Achieva 3T MRI scanner using point-resolved spectroscopy (PRESS) sequence with short echo time (TE). jMRUI/AMARES algorithm was used to process spectra. Metabolite ratios were calculated for the following metabolites: N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mIo), in relation to internal water (H20) as standard.

Time frame: Baseline and 12 months

Change in MRS Cerebral Metabolite Ratios in Frontal White Matter

Change in major cerebral metabolites in the frontal white matter, as measured by 1H-Magnetic Resonance Spectroscopy (MRS), between baseline and 12-months. Spectra were acquired on a Phillips Achieva 3T MRI scanner using point-resolved spectroscopy (PRESS) sequence with short TE. jMRUI/AMARES algorithm was used to process spectra. Metabolite ratios were calculated for the following metabolites: N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mIo), glutamate/glutamine complex (Glx), in relation to internal H20 as standard.

Time frame: Baseline and 12 months

Cerebrospinal Fluid

To measure plateaux CSF ARV concentrations. This will identify the proportion of patients achieving levels of specific ARVs capable of inhibiting 95% of in vitro viral replication (IC95).

Time frame: Baseline to 12 Months