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Interindividual variation of human immunodeficiency virus (HIV) RNA setpoint in cerebrospinal fluid (CSF) and its determinants are poorly understood, but relevant for HIV neuropathology, brain reservoirs, viral escape, and reseeding after antiretroviral interruptions. Longitudinal multicentric study on demographic, clinical, and laboratory correlates of CSF HIV RNA in 2000 follow-up visits from 597 people with HIV (PWH) off antiretroviral therapy (ART) and with plasma HIV RNA > the lower limit of quantification (LLQ). Factors associated with CSF control (CSFC; CSF HIV RNA < LLQ while plasma HIV RNA > LLQ) and with CSF/plasma discordance (CSF > plasma HIV RNA > LLQ) were also assessed through mixed-effects models. Posthoc and sensitivity analyses were performed for persistent CSFC and ART-naïve participants, respectively. Over a median follow-up of 2.1 years, CSF HIV RNA was associated with CD4+ and CD8+ T cells, CSF leukocytes, blood-brain barrier (BBB) integrity, biomarkers of iron and lipid metabolism, serum globulins, past exposure to lamivudine, and plasma HIV RNA (model p < 0.0001). CSFC (persistent in 7.7% over 3 years) and CSF/plasma discordance (persistent in <0.01% over 1 year) were variably associated with the same parameters (model p < 0.001). Sensitivity analyses confirmed most of the previous associations in participants never exposed to ART. Persistent CSFC was associated with higher CD4 + T-cell count nadir (p < 0.001), lower serum globulins (p = 0.003), and lower CSF leukocytes (p < 0.001). Without ART, one in 13 PWH had persistently undetectable CSF HIV RNA, while persistent CSF/plasma discordance was extremely rare over years. Immune responses, inflammation, BBB permeability, and iron and lipid metabolism were all associated with HIV replication in CSF., (© 2024 Wiley Periodicals LLC.)

HIV reservoirs persist in anatomic compartments despite antiretroviral therapy (ART). Characterizing archival HIV DNA in the central nervous system (CNS) and other tissues is crucial to inform cure strategies. We evaluated paired autopsy brain-frontal cortex (FC), occipital cortex (OCC), and basal ganglia (BG)-and peripheral lymphoid tissues from 63 people with HIV. Participants passed away while virally suppressed on ART at the last visit and without evidence of CNS opportunistic disease. We quantified total HIV DNA in all participants and obtained full-length HIV-envelope (FL HIV- env ) sequences from a subset of 14 participants. We detected HIV DNA ( gag ) in most brain (65.1%) and all lymphoid tissues. Lymphoid tissues had higher HIV DNA levels than the brain ( P  < 0.01). Levels of HIV gag between BG and FC were similar ( P  > 0.2), while OCC had the lowest levels ( P  = 0.01). Females had higher HIV DNA levels in tissues than males ( gag , P  = 0.03; 2-LTR, P  = 0.05), suggesting possible sex-associated mechanisms for HIV reservoir persistence. Most FL HIV- env sequences ( n  = 143) were intact, while 42 were defective. Clonal sequences were found in 8 out of 14 participants, and 1 participant had clonal defective sequences in the brain and spleen, suggestive of cell migration. From 10 donors with paired brain and lymphoid sequences, we observed evidence of compartmentalized sequences in 2 donors. Our data further the idea that the brain is a site for archival HIV DNA during ART where compartmentalized provirus may occur in a subset of people. Future studies assessing FL HIV-provirus and replication competence are needed to further evaluate the HIV reservoirs in tissues. IMPORTANCE HIV infection of the brain is associated with adverse neuropsychiatric outcomes, despite efficient antiretroviral treatment. HIV may persist in reservoirs in the brain and other tissues, which can seed virus replication if treatment is interrupted, representing a major challenge to cure HIV. We evaluated reservoirs and genetic features in postmortem brain and lymphoid tissues from people with HIV who passed away during suppressed HIV replication. We found a differential distribution of HIV reservoirs across brain regions which was lower than that in lymphoid tissues. We observed that most HIV reservoirs in tissues had intact envelope sequences, suggesting they could potentially generate replicative viruses. We found that women had higher HIV reservoir levels in brain and lymphoid tissues than men, suggesting possible sex-based mechanisms of maintenance of HIV reservoirs in tissues, warranting further investigation. Characterizing the archival HIV DNA in tissues is important to inform future HIV cure strategies., Competing Interests: The authors declare no conflict of interest.

CD14 ++ CD16 + monocytes are susceptible to HIV-1 infection, and cross the blood-brain barrier. HIV-1 subtype C (HIV-1C) shows reduced Tat protein chemoattractant activity compared to HIV-1B, which might influence monocyte trafficking into the CNS. We hypothesized that the proportion of monocytes in CSF in HIV-1C is lower than HIV-1B group. We sought to assess differences in monocyte proportions in cerebrospinal fluid (CSF) and peripheral blood (PB) between people with HIV (PWH) and without HIV (PWoH), and by HIV-1B and -C subtypes. Immunophenotyping was performed by flow cytometry, monocytes were analyzed within CD45 + and CD64 + gated regions and classified in classical (CD14 ++ CD16 - ), intermediate (CD14 ++ CD16 + ), and non-classical (CD14 low CD16 + ). Among PWH, the median [IQR] CD4 nadir was 219 [32-531] cell/mm 3 ; plasma HIV RNA (log 10 ) was 1.60 [1.60-3.21], and 68% were on antiretroviral therapy (ART). Participants with HIV-1C and -B were comparable in terms of age, duration of infection, CD4 nadir, plasma HIV RNA, and ART. The proportion of CSF CD14 ++ CD16 + monocytes was higher in participants with HIV-1C than those with HIV-1B [2.00(0.00-2.80) vs. 0.00(0.00-0.60) respectively, p = 0.03 after BH correction p = 0.10]. Despite viral suppression, the proportion of total monocytes in PB increased in PWH, due to the increase in CD14 ++ CD16 + and CD14 low CD16 + monocytes. The HIV-1C Tat substitution (C30S31) did not interfere with the migration of CD14 ++ CD16 + monocytes to the CNS. This is the first study to evaluate these monocytes in the CSF and PB and compare their proportions according to HIV subtype., (© 2023. The Author(s) under exclusive licence to The Journal of NeuroVirology, Inc.)

The transactivator of transcription (Tat) is a HIV regulatory protein which promotes viral replication and chemotaxis. HIV-1 shows extensive genetic diversity, HIV-1 subtype C being the most dominant subtype in the world. Our hypothesis is the frequency of CSF CD3 + CD56 + and CD3 - CD56 dim is reduced in HIV-1C compared to HIV-1B due to the Tat C30S31 substitution in HIV-1C. 34 CSF and paired blood samples (PWH, n = 20; PWoH, n = 14) were studied. In PWH, the percentage of CD3 + CD56 + was higher in CSF than in blood (p < 0.001), comparable in both compartments in PWoH (p = 0.20). The proportion of CD3 - CD56 dim in CSF in PWH was higher than PWoH (p = 0.008). There was no subtype differences. These results showed CNS compartmentalization of NKT cell response in PWH., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare regarding the publication of this article., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The accumulation of soluble proteins and metabolites during wakefulness and their clearance during sleep via the glymphatic system occurs in healthy adults and is disturbed in some neurological conditions. Such diurnal variations in the cerebrospinal fluid (CSF) proteins produced outside the central nervous system and entering via the blood-brain barrier (BBB) have not been evaluated in people with HIV (PWH). CSF and blood were collected in 165 PWH at six US centers between 2003 and 2007. The time of collection was compared to CSF albumin, globulin, and total protein concentrations using bivariate and multivariate regression. Participants all took antiretroviral therapy (ART) and were mostly middle-aged (median age 44.0 years) men (78.8%), with AIDS (77.0%), plasma HIV RNA ≤ 200 copies/mL (75.8%), and immune recovery (median CD4+ T-cell count 414/µL). CSF was collected at median 1:10 p.m. (range 9:00 a.m. to 5:20 p.m.) and within a median of 15 min of blood collection. A later time of CSF collection was associated with higher total protein ( p = 0.0077) and albumin ( p = 0.057) in CSF but not in serum, and was additionally associated with higher CSF globulin ( p = 0.013). The glymphatic clearance of albumin, globulin, and total protein is preserved in PWH. The analyses of soluble biomarkers in CSF should account for the time of collection.

Monocytes and macrophages activation are crucial in human immunodeficiency virus (HIV) central nervous system (CNS) infection and HIV associated neurocognitive disorders (HAND) pathogenesis. The soluble form of CD14 (sCD14) is a marker of monocyte activation. We hypothesized that sCD14 levels would be lower in people with HIV-1 subtype C (HIV-1C) than in HIV-1B owing to a variant Tat cysteine dimotif (C30S31) with reduced chemotactic activity. A total of 68 paired cerebrospinal fluid (CSF) and blood samples from people with HIV (PWH); 27 samples of the HIV-1B subtype and 40 of the non-B HIV-1 subtypes (including 26,HIV-1C), and 18 HIV-negative controls were included. sCD14 levels were quantified using a high-sensitivity enzyme-linked immunosorbent assay. sCD14 increase in serum, but not in CSF, was higher in samples from HIV-1B than HIV-1C (p = 0.002; Cohen's d, 0.7). CSF or serum sCD14 values were not correlated with global deficit score or specific cognitive domains. The impact of HIV-1 on monocyte stimulation biomarkers evaluated by sCD14 in serum was subtype-dependent, higher in HIV-1B than HIV-1C, consistent with reduced chemotactic activity as hypothesized., (Copyright © 2022 Elsevier B.V. All rights reserved.)

HIV-1 subtype C (HIV-1C) shows reduced Tat protein chemoattractant activity compared with HIV-1B. The impact of HIV-1C Tat on the chemotaxis of the main lymphocyte subpopulations in the cerebrospinal fluid (CSF) and the peripheral blood (PB) is unclear. We hypothesized that there would be a lower frequency of specific lymphocyte subpopulations CD3 + or CD19 + in CSF in HIV-1C than in HIV-1B. The objectives were to detect the differences in the proportions of main lymphocyte subpopulations in CSF and PB, between people with HIV (PWH) and HIV-1-uninfected volunteers (PWoH) and in HIV-1B and HIV-1C. Lymphocyte immunophenotyping was studied in CSF and paired PB samples of PWH (n = 22) and PWoH (n = 14). Lymphocytes were analyzed within the CD45 + gated region. The proportions of CSF CD3 + CD4 + , CD3 + CD8 + , and CD3 - CD19 + lymphocytes in CSF were comparable in HIV-1B and C. There was an increase in the proportion of CD3 + CD8 + cells and a decrease in CD3 + CD4 + T cells (ps = 0.016) in the CSF samples of the PWH compared with the PWoH group. In the PWH group, both CD3 + CD4 + and CD3 + CD8 + lymphocytes were significantly higher in the CSF than in the PB (p = 0.047 and 0.005). The proportion of CD3 + CD4 + was lower and that of CD3 + CD8 + was higher in the CSF samples of the aviremic group than that of HIV-negative control (p = 0.0008 and < 0.0001, respectively). HIV-1C Tat substitution (C30S) did not interfere with the CNS migration of the main lymphocyte subpopulations. This is the first study to evaluate these lymphocytes in CSF and PB of HIV-1C compared with HIV-1B., (© 2022. Journal of NeuroVirology, Inc.)

We hypothesized that humoral immunity stimulation in the CNS in HIV-1C patients would be lower than that in HIV-1B due to a defective Tat chemokine dimotif (C30C31) that might influence cellular trafficking and CNS inflammation. Sixty-eight paired CSF and blood samples from people with HIV (PWH), free of CNS opportunistic infections, were included, HIV-1B (n = 27), HIV-1C (n = 26), and HIV negative (n = 25). IgG intrathecal synthesis was assayed using quantitative and qualitative methods. IgG oligoclonal bands (OCB) in CSF were observed in 51% of PWH, comparable between HIV-1B and HIV-1C, as well as the medians of IgG intrathecal synthesis formulas. The group with HIV infection aviremic in CSF and blood showed 75% of OCB. There was a poor positive correlation between the IgG quotient and GDS. The impact of HIV-1 on IgG intrathecal production was not subtype dependent. Low-grade CNS intrathecal IgG production persists in HIV CNS infection even in PWH with CSF and blood HIV RNA controlled., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The transactivator of transcription (Tat) is a key HIV regulatory protein. We aimed to identify the frequency of key polymorphisms in HIV-1C compared with HIV-1B Tat protein, chiefly in the cysteine-, arginine-, and glutamine-rich domains and identify novel point mutations in HIV-1B and C sequences from Southern Brazil. This study was the first to investigate the genetic diversity and point mutations within HIV-1 Tat C in a Brazilian cohort. This was an observational, cross-sectional study, which included sequences of HIV-1B (n = 20) and HIV-1C (n = 21) from Southern Brazil. Additionally, 344 HIV-1C sequences were obtained from the Los Alamos database: 29 from Brazil and 315 from Africa, Asia, and Europe. The frequency of C31S substitution on HIV-1 Tat C in Brazil was 82% vs. 10% in the HIV-1B group (p < 0.0001). The frequency of the R57S substitution among the HIV-1C sequences from Brazil was 74% vs. 20% in HIV-1B (p = 0.004), and that of substitution Q63E in HIV-1C was 80% and 20% in HIV-1B (p < 0.0001). The mutation P60Q was more frequent in HIV-1B than in HIV-1C (55% and 6.12%, respectively, p < 0.0001)). Novel point mutations in the HIV-1C and B Tat functional domains were described. The frequency of C31S and other key point mutations in HIV-1 Tat C in Brazil were similar to those described in Africa, although lower than those in India. The Tat-B and C sequences found in Southern Brazil are consistent with biological differences and have potential implications for HIV-1 subtype pathogenesis.

Background: The objective was to compare the effect of HIV-1C and HIV-1B subtypes on neurofilament light (NfL) cerebrospinal fluid (CSF) levels and ratios of NfL to tau proteins. Additional comparisons were performed between people with HIV (PWH), participants with Alzheimer disease (AD), and HIV-negative controls (HIV-). We also calculated the diagnostic characteristics of CSF NfL and its ratios in HIV-associated neurocognitive disorder (HAND) diagnosis., Methods: CSF NfL, T-tau, and P-tau181 concentrations were measured using immunoassays in a total of 108 CSF samples, including PWH (n = 68), HIV- (n = 16), and participants with AD (n = 24). These proteins were compared between HIV-1B (n = 27) and HIV-1C (n = 26) using multiple linear regression adjusted for nadir CD4 and plasma viral load suppression. Comparisons between PWH, HIV-, and participants with AD were adjusted for gender and age., Results: CSF neurocytoskeleton proteins and their ratios were comparable in HIV-1B and HIV-1C. However, the HIV-1C group had a higher proportion of samples of CSF NfL above the reference value (n = 14, 53.85%) than the HIV-1B group (n = 8, 29.63%), P = 0.098. The values of CSF NfL were higher in the AD group [2578 (1864; 3500) pg/mL] than those in PWH [683 (500; 1197) pg/mL, P < 0.001] and control [660 (539; 802) pg/mL, P = 0.012] groups. The value of CSF NfL and its ratios for HAND diagnosis were poor., Conclusion: The effects of HIV-1B and HIV-1C on CSF NfL and tau ratios were comparable. The differences in CSF neurocytoskeleton proteins between PWH and individuals with AD suggested they might not share the same mechanisms of impairment. Further research is necessary to evaluate CSF NfL on the differential diagnoses of HAND with AD.

If strategies currently in development succeed in eradicating HIV reservoirs in peripheral blood and lymphoid tissues, residual sources of virus may remain in anatomic compartments. Paired blood and semen samples were collected from 12 individuals enrolled in a randomized, double-blind, placebo-controlled therapeutic vaccine clinical trial in people with HIV (PWH) who began antiretroviral therapy (ART) during acute or early infection (ClinicalTrials registration no. NCT01859325). After the week 56 visit (postintervention), all participants interrupted ART. At the first available time points after viral rebound, we sequenced HIV-1 env (C2-V3), gag (p24), and pol (reverse transcriptase) regions amplified from cell-free HIV RNA in blood and seminal plasma using the MiSeq Illumina platform. Comprehensive sequence and phylogenetic analyses were performed to evaluate viral population structure, compartmentalization, and viral diversity in blood and seminal plasma. Compared to that in blood, HIV RNA rebound in semen occurred significantly later (median of 66 versus 42 days post-ART interruption, P < 0.01) and reached lower levels (median 164 versus 16,090 copies/ml, P < 0.01). Three of five participants with available sequencing data presented compartmentalized viral rebound between blood and semen in one HIV coding region. Despite early ART initiation, HIV RNA molecular diversity was higher in semen than in blood in all three coding regions for most participants. Higher HIV RNA molecular diversity in the genital tract (compared to that in blood plasma) and evidence of compartmentalization illustrate the distinct evolutionary dynamics between these two compartments after ART interruption. Future research should evaluate whether the genital compartment might contribute to viral rebound in some PWH interrupting ART. IMPORTANCE To cure HIV, we likely need to target the reservoirs in all anatomic compartments. Here, we used sophisticated statistical and phylogenetic methods to analyze blood and semen samples collected from 12 persons with HIV who began antiretroviral therapy (ART) during very early HIV infection and who interrupted their ART as part of a clinical trial. First, we found that HIV RNA rebound in semen occurred significantly later and reached lower levels than in blood. Second, we found that the virus in semen was genetically different in some participants compared to that in blood. Finally, we found increased HIV RNA molecular diversity in semen compared to that in blood in almost all study participants. These data suggest that the HIV RNA populations emerging from the genital compartment after ART interruption might not be the same as those emerging from blood plasma. Future research should evaluate whether the genital compartment might contribute to viral rebound in some people with HIV (PWH) interrupting ART., (Copyright © 2020 American Society for Microbiology.)

Background: Few large projects have evaluated the factors that influence the HIV RNA concentrations (viral load) in cerebrospinal fluid (CSF) during antiretroviral therapy (ART) over time. We aimed to determine the correlates of HIV RNA in CSF in a large cohort., Methods: We analysed longitudinal data from adults living with HIV in the US CHARTER cohort. Participants in the CHARTER study were recruited from six US academic medical centres-in Baltimore (MD), Galveston (TX), New York (NY), St Louis (MO), San Diego (C92A), and Seattle (WA). Participants in this study had been assessed at least three times between Sept 4, 2003, and Sept 14, 2010, and were taking ART and underwent venous and lumbar puncture with measurement of HIV RNA concentration at all assessments. The lower limit of quantification of the HIV RNA assays was 50 copies per mL. Data were analysed with longitudinal mixed effects logistic regression to identify correlates of HIV RNA concentration (as a binary [detectable or not] and as a continuous variable) in CSF over time. We tested demographic characteristics, plasma HIV RNA, nadir and current CD4 cell count in blood, current CD8 cell count in blood, estimated duration of HIV infection, AIDS diagnosis, duration of ART, adherence to ART, ART characteristics, and CSF characteristics as potential correlates., Findings: At the time of analysis, 2207 assessments from 401 participants met the criteria for inclusion in this study. Mean duration of observation was 33·7 months (range 12-84). HIV RNA concentrations in 710 (32·2%) plasma specimens and in 255 (11·6%) CSF specimens were greater than the lower limit of quantification. The best multivariate model of HIV RNA concentration in CSF greater than the lower limit of quantification over time included increased plasma HIV RNA concentration (odds ratio 18·0 per 1 log 10 copy per mL, 95% CI 11·3 to 28·8; p<0·0001), increased CSF leucocyte count (2·01 per 5 cells per μL, 1·61 to 2·39; p<0·0001), decreased CD4 cell count (0·53 per 5 square-root cells per μL, 0·35 to 0·79; p=0·0025), decreased CNS penetration-effectiveness value (0·71 per unit, 0·56 to 0·92; p=0·0078), increased CD8 cell count (1·51 per 5 square-root cells, 1·11 to 2·06; p=0·0089), and protease inhibitor use (3·26, 1·04 to 10·23; p=0·039; model R 2 =0·22, p<0·0001). Analyses of continuous HIV RNA concentration in CSF that accounted for censoring below the lower limit of quantification had similar findings, although increased HIV RNA concentrations in CSF were also associated with black ethnicity (change in log 10 HIV RNA concentration in CSF 0·205, 0·0367 to 0·3733; p=0·017), increased total protein in CSF (0·0025, -0·0002 to 0·0052; p=0·069), and the presence of addictive-drug metabolites in urine (0·103, -0·013 to 0·219; p=0·081)., Interpretation: The identified correlates of HIV RNA concentration in CSF during ART could strengthen clinical prediction of risk for failure to achieve or maintain HIV RNA suppression in CSF. Because most participants in this analysis were ART-experienced and were taking a three-drug regimen that did not include an integrase inhibitor, future research should focus on participants who are taking their first ART regimens or regimens that include integrase inhibitors or two drugs., Funding: The work was supported by the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Human immunodeficiency virus (HIV) genetic compartmentalization is defined as genetic differences in HIV in different tissue compartments or subcompartments that characterize viral quasispecies. This descriptive, longitudinal study assessed the dynamics of inflammation, humoral immune response, blood-brain barrier, blood-cerebrospinal fluid (CSF) barrier, as well as neuronal injury biomarkers in serially obtained CSF and serum samples from an antiretroviral (ARV) therapy-naïve patient with HIV-1 subtype C with CSF HIV genetic compartmentalization that resolved spontaneously without ARV treatment. The first CSF sample showed an increase in white blood cell (WBC) count (382 cells/mm 3 ) and a marked increase in the levels of inflammatory cytokines and chemokines, including tumor necrosis factor (TNF)α, interleukin (IL)-10, IP-10, and regulated on activation, normal T cell expressed and secreted (RANTES), which raise the suspicion of dual infection. Serum sample analysis showed all cytokine levels to be normal, with only IP-10 slightly increased. These results corroborate the hypothesis that the CNS immunologic response in a patient with HIV infection was independent of the systemic immunologic response. The patient also had persistently elevated levels of sCD14, neopterin, and β 2 M, which were strongly suggestive of persistent CNS immunologic stimulation. This report describes a patient with HIV subtype C who developed a transient episode of asymptomatic HIV meningitis with compartmentalization of HIV in the CSF that resolved independently of ARV therapy. Extensive CSF studies were performed as part of an ongoing longitudinal study, which revealed CNS immune abnormalities. This case presents evidence of HIV-1 subtype C neurotropism and compartmentalization.

The Human Immunodeficiency Virus (HIV) infects cells in the Central Nervous System (CNS), where the access of antiretrovirals and antibodies that can kill the virus may be challenging. As a result of the early HIV entry in the brain, infected individuals develop inflammation and neurological deficits at various levels, which are aggravated by drugs of abuse. In the non-human primate model of HIV, we have previously shown that drugs of abuse such as Methamphetamine (Meth) increase brain viral load in correlation with a higher number of CCR5-expressing myeloid cells. CCR5 is a chemokine receptor that may be involved in increasing inflammation, but also, it is a co-receptor for viral entry into target cells. CCR5-expressing myeloid cells are the main targets of HIV in the CNS. Thus, the identification of factors and mechanisms that impact the expression of CCR5 in the brain is critical, as changes in CCR5 levels may affect the infection in the brain. Using a well-characterized in vitro system, with the THP1 human macrophage cell line, we have investigated the hypothesis that the expression of CCR5 is acutely affected by Meth, and examined pathways by which this effect could happen. We found that Meth plays a direct role by regulating the abundance and nuclear translocation of transcription factors with binding sites in the CCR5 promoter. However, we found that the main factor that modifies the CCR5 gene promoter at the epigenetic level towards transcription is Dopamine (DA), a neurotransmitter that is produced primarily in brain regions that are rich in dopaminergic neurons. In THP1 cells, the effect of DA on innate immune CCR5 transcription was mediated by DA receptors (DRDs), mainly DRD4. We also identified a role for DRD1 in suppressing CCR5 expression in this myeloid cell system, with potential implications for therapy. The effect of DA on innate immune CCR5 expression was also detectable on the cell surface during acute time-points, using low doses. In addition, HIV Tat acted by enhancing the surface expression of CCR5, in spite of its poor effect on transcription. Overall, our data suggests that the exposure of myeloid cells to Meth in the context of presence of HIV peptides such as Tat, may affect the number of HIV targets by modulating CCR5 expression, through a combination of DA-dependent and-independent mechanisms. Other drugs that increase DA may affect similar mechanisms. The implications of these epigenetic and translational mechanisms in enhancing HIV infection in the brain and elsewhere are demonstrated., Competing Interests: The authors have declared that no competing interests exist.

Based on prior reports that the HIV-1 Tat protein modulates amyloid-beta (Aβ) metabolism, this study aimed to compare CSF neural injury biomarkers between 27 patients with HIV subtype B, 26 patients with HIV subtype C, 18 healthy HIV-negative controls, and 24 patients with Alzheimer's disease (AD). Immunoassays were used to measure soluble amyloid precursor protein α and β (sAPPα, sAPPβ), Aβ oligomers 38, 40, 42, and Aβ-total; phosphorylated tau (P-tau 181 ), and total tau (T-tau). Comparisons between HIV(+) and HIV(-) (including AD) were adjusted by linear regression for gender and age; HIV subtype comparisons were adjusted for nadir CD4 and plasma viral load suppression. The p values were corrected for multiple testing with the Benjamini-Hochberg procedure. CSF Aβ-42 and Hulstaert (P-tau 181 ) index were lower in HIV1-C than B (p = 0.03, and 0.049 respectively); subtypes did not differ on other CSF biomarkers or ratios. Compared to AD, HIV(+) had lower CSF levels of T-tau, P-tau 181 (p < 0.001), and sAPPα (p = 0.041); HIV(+) had higher CSF Aβ-42 (p = 0.002) and higher CSF indexes: [Aß-42/(240 + 1.18 T-tau)], P-tau 181 /Aβ-42, T-tau/Aβ-42, P-tau 181 /T-tau, sAPPα/β (all p ≤ 0.01) than AD. Compared to HIV(-), HIV(+) had lower CSF Aβ-42, and T-tau (all p ≤ 0.004). As conclusion, amyloid metabolism was influenced by HIV infection in a subtype-dependent manner. Aß-42 levels were lower in HIV1-C than B, suggesting that there may be greater deposition of Aß-42 in HIV1-C. These findings are supported by CSF Hulstaert (P-tau 181 ) index. Differences between HIV and AD in the patterns of Aß and Tau biomarkers suggest that CNS HIV infection and AD may not share some of same mechanisms of neuronal injury.

The search for a cure for HIV infection has highlighted the need for increasingly sensitive and precise assays to measure viral burden in various tissues and body fluids. We describe the application of a standardized assay for HIV-1 RNA in multiple specimen types. The fully automated Aptima HIV-1 Quant Dx assay (Aptima assay) is FDA cleared for blood plasma HIV-1 RNA quantitation. In this study, the Aptima assay was applied for the quantitation of HIV RNA in peripheral blood mononuclear cells (PBMCs; n = 72), seminal plasma ( n = 20), cerebrospinal fluid (CSF; n = 36), dried blood spots (DBS; n = 104), and dried plasma spots (DPS; n = 104). The Aptima assay was equivalent to or better than commercial assays or validated in-house assays for the quantitation of HIV RNA in CSF and seminal plasma. For PBMC specimens, the sensitivity of the Aptima assay in the detection of HIV RNA decayed as background uninfected PBMC counts increased; proteinase K treatment demonstrated some benefit in restoring signal at higher levels of background PBMCs. Finally, the Aptima assay yielded 100% detection rates of DBS in participants with plasma HIV RNA levels of ≥35 copies/ml and 100% detection rates of DPS in participants with plasma HIV RNA levels of ≥394 copies/ml. The Aptima assay can be applied to a variety of specimens from HIV-infected subjects to measure HIV RNA for studies of viral persistence and cure strategies. It can also detect HIV in dried blood and plasma specimens, which may be of benefit in resource-limited settings.

Despite the effective suppression of viremia with antiretroviral therapy, HIV can still replicate in the central nervous system (CNS). This was a longitudinal study of the cerebrospinal fluid (CSF) and serum dynamics of several biomarkers related to inflammation, the blood-brain barrier, neuronal injury, and IgG intrathecal synthesis in serial samples of CSF and serum from a patient infected with HIV-1 subtype C with CNS compartmentalization.The phylogenetic analyses of plasma and CSF samples in an acute phase using next-generation sequencing and F-statistics analysis of C2-V3 haplotypes revealed distinct compartmentalized CSF viruses in paired CSF and peripheral blood mononuclear cell samples. The CSF biomarker analysis in this patient showed that symptomatic CSF escape is accompanied by CNS inflammation, high levels of cell and humoral immune biomarkers, CNS barrier dysfunction, and an increase in neuronal injury biomarkers with demyelization. Independent and isolated HIV replication can occur in the CNS, even in HIV-1 subtype C, leading to compartmentalization and development of quasispecies distinct from the peripheral plasma. These immunological aspects of the HIV CNS escape have not been described previously. To our knowledge, this is the first report of CNS HIV escape and compartmentalization in HIV-1 subtype C.

Even when antiretroviral therapy (ART) is started early after infection, HIV DNA might persist in the central nervous system (CNS), possibly contributing to inflammation, brain damage and neurocognitive impairment. Paired blood and cerebrospinal fluid (CSF) were collected from 16 HIV-infected individuals on suppressive ART: 9 participants started ART <4 months of the estimated date of infection (EDI) ("early ART"), and 7 participants started ART >14 months after EDI ("late ART"). For each participant, neurocognitive functioning was measured by Global Deficit Score (GDS). HIV DNA levels were measured in peripheral blood mononuclear cells (PBMCs) and CSF cell pellets by droplet digital (dd)PCR. Soluble markers of inflammation (sCD163, IL-6, MCP-1, TNF-α) and neuronal damage (neurofilament light [NFL]) were measured in blood and CSF supernatant by immunoassays. HIV-1 partial C2V3 env deep sequencing data (Roche 454) were obtained for 8 paired PBMC and CSF specimens and used for phylogenetic and compartmentalization analysis. Median exposure to ART at the time of sampling was 2.6 years (IQR: 2.2-3.7) and did not differ between groups. We observed that early ART was significantly associated with lower molecular diversity of HIV DNA in CSF (p<0.05), and lower IL-6 levels in CSF (p = 0.02), but no difference for GDS, NFL, or HIV DNA detectability compared to late ART. Compartmentalization of HIV DNA populations between CSF and blood was detected in 6 out of 8 participants with available paired HIV DNA sequences (2 from early and 4 from late ART group). Phylogenetic analysis confirmed the presence of monophyletic HIV DNA populations within the CSF in 7 participants, and the same population was repeatedly sampled over a 5 months period in one participant with longitudinal sampling. Such compartmentalized provirus in the CNS needs to be considered for the design of future eradication strategies and might contribute to the neuropathogenesis of HIV., Competing Interests: The authors have declared that no competing interests exist.

Background:  Neurocognitive disorders remain common among human immunodeficiency virus (HIV)-positive adults, perhaps owing to persistent HIV-1 RNA in cerebrospinal fluid (CSF) during antiretroviral therapy (ART)., Methods:  Using a single-copy assay, we measured HIV-1 RNA levels in CSF and plasma specimens from 220 HIV-positive adults who were taking suppressive ART. Fifty-five participants were tested twice., Results:  HIV-1 RNA was detected in 42.3% of CSF and 65.2% of plasma samples. Correlates of higher CSF HIV-1 RNA levels included higher nadir and current CD4 + T-cell counts, a plasma HIV-1 RNA level of ≥ 1 copy/mL, and a lower central nervous system penetration-effectiveness score (model P < .001). Worse neurocognitive performance was associated with discordance in HIV-1 RNA detection between plasma and CSF, lower overall CSF HIV-1 RNA level, and longer ART duration, among others (model P < .001). In the longitudinal subgroup, CSF HIV-1 RNA persisted in most participants (69%) over 7 months., Conclusions:  Low-level HIV-1 RNA in CSF is common during suppressive ART and is associated with low-level HIV-1 RNA in blood, better immune status, and lower ART drug distribution into CSF. The association between HIV-1 RNA discordance and HIV-associated neurocognitive disorder (HAND) may reflect compartmentalization. The relationship between HAND, lower HIV-1 RNA levels in CSF, and lower CD4 + T-cell counts may reflect disturbances in the immune response to HIV-1 in the CNS., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.)

Major depressive disorder (MDD) is among the most prevalent neuropsychiatric disorders associated with HIV infection; however, its risks and neurobiologic correlates in diverse cultures are poorly understood. This study aimed to examine the frequency of MDD among HIV+ participants in southern Brazil. We hypothesized that the frequency and severity of MDD would be higher among individuals with HIV+ compared with HIV- and higher in HIV subtype B compared with C. Individuals with HIV (n = 39) as well as seronegative controls (n = 22) were enrolled in a cross-sectional, prospective, observational study. Current and lifetime history of MDD was diagnosed by MINI-Plus; symptom severity was assessed by Beck Depression Inventory-II (BDI-II). Current and past episodes of MDD were significantly more frequent in the HIV+ versus HIV- group: current MDD, 15 (38.5 %) vs. 0 (0 %), p = 0.0004; past MDD, 24 (61.5 %) vs. 3 (13.6 %), p = 0.0004. The median BDI-II score in the HIV+ group was significantly higher than that in the HIV- (13 (8-27.5) vs. 2.5 (1-5.5); p < 0.0001). Current suicide risk, defined as during the last month, was found in 18 % of participants in the HIV-positive and none in the HIV-negative group. Neither current MDD frequency (8 (57.1 %) vs. 6 (40 %), p = 0.47) nor BDI-II score differed across subtypes B and C. HIV+ group may be more likely to experience current MDD than HIV-. This was the first study to compare the frequency and severity of MDD in HIV subtypes B and C; we found no difference between HIV subtypes B and C., Competing Interests: SERGIO M. DE ALMEIDA, the author declare that have no conflict of interest. FRANCISCO JAIME BARBOSA, the author declare that have no conflict of interest. RUJVI KAMAT, the author declare that have no conflict of interest. ANA PAULA DE PEREIRA, the author declare that have no conflict of interest. SONIA M. RABONI, the author declare that have no conflict of interest. INDIANARA ROTTA, the author declare that have no conflict of interest. CLEA E. RIBEIRO, the author declare that have no conflict of interest. MARIANA CHERNER, the author declare that have no conflict of interest. RONALD J. ELLIS, the author declare that have no conflict of interest. JOSEPH HAMPTON ATKINSON, the author declare that have no conflict of interest.

Older HIV-infected adults have a higher risk of neurocognitive impairment, but the underlying mechanisms are poorly understood. Here, we investigated the associations between levels of HIV DNA in peripheral blood, soluble markers of inflammation and cellular trafficking in blood and cerebrospinal fluid (CSF) and neurocognitive functioning among 18 younger (22-40 years) and 26 older (50-71 years) HIV-infected subjects, who were administered a comprehensive neurocognitive battery. Older HIV-infected individuals presented higher levels of inflammation in CSF and blood compared to younger individuals, but no difference was observed in HIV DNA levels. Among older participants, higher HIV DNA levels were significantly associated with more severe neurocognitive impairment (p = 0.005), particularly in the Executive Functions domain (p = 0.004). No association was observed between HIV DNA and neurocognition among younger individuals. Despite significantly increased inflammation observed in the older group, none of the inflammatory markers were associated with neurocognitive impairment among older HIV+ individuals (p > 0.05). Our study supports the involvement of peripheral HIV DNA reservoir in the pathogenesis of neurocognitive disorder during suppressive ART. Correlates of neurocognitive impairment might differ between younger and older adults, suggesting that future treatment and prevention strategies for HIV-associated neurocognitive disorders likely need to be tailored based on age.

Background: Measurement of HIV DNA-bearing cells in cerebrospinal fluid (CSF) is challenging because few cells are present. We present a novel application of the sensitive droplet digital (dd)PCR in this context., Methods: We analyzed CSF cell pellets and paired peripheral blood mononuclear cells (PBMC) from 28 subjects, 19 of whom had undetectable HIV RNA (<48 copies/mL) in both compartments. We extracted DNA from PBMC using silica-based columns and used direct lysis on CSF cells. HIV DNA and the host housekeeping gene (RPP30) were measured in CSF and PBMC by (dd)PCR. We compared HIV DNA levels in virally-suppressed and-unsuppressed subgroups and calculated correlations between HIV DNA and RNA levels in both compartments using non-parametric tests., Results: HIV DNA was detected in 18/28 (64%) CSF cell pellets, including 10/19 (53%) samples with undetectable HIV RNA. HIV DNA levels in CSF cell pellets were not correlated with RPP30 (p = 0.3), but correlated positively with HIV RNA in CSF (p = 0.04) and HIV DNA in PBMC (p = 0.03). Cellular HIV DNA in CSF was detected in comparable levels in HIV RNA-suppressed and unsuppressed subjects (p = 0.14). In contrast, HIV DNA levels in PBMC were significantly lower in HIV RNA-suppressed than in unsuppressed subjects (p = 0.014). Among subjects with detectable HIV DNA in both compartments, HIV DNA levels in CSF were significantly higher than in PBMC (p<0.001)., Conclusions: Despite low mononuclear cell numbers in CSF, HIV DNA was detected in most virally suppressed individuals. In contrast to PBMC, suppressive ART was not associated with lower HIV DNA levels in CSF cells, compared to no ART, perhaps due to poorer ART penetration, slower decay of HIV DNA, or enrichment of HIV DNA-bearing mononuclear cells into the CSF, compared to blood. Future studies should determine what fraction of HIV DNA is replication-competent in CSF leukocytes, compared to PBMC.

Blood plasma specimens are the clinical standard for HIV-1 pol gene genotyping from viral populations; however, it is not always successful, often from low viral loads or the presence of polymerase chain reaction (PCR) inhibitors. Objective To describe the successful of HIV-1 genotyping in two samples of cerebrospinal fluid (CSF), after genotype procedures failed from blood. Method Two HIV-infected patients enrolled in a neurocognitive research study were evaluated when standard HIV-1 genotyping failed from blood plasma samples. Genotyping was performed using the commercial system TRUGENE HIV-1 Genotyping Kit and the OpenGene DNA Sequencing System (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Results CSF genotyping was performed via the same commercial platform and was successful in both cases. Conclusion This report demonstrates that CSF could be used as an alternate clinical specimen for HIV-1 genotyping when it fails from blood.

Peripheral neuropathy (PN) is a common neurological complication of HIV infection that has debilitating effects on quality of life. While there has been a comprehensive evaluation of the prevalence of neuropathic signs/symptoms and risk factors (RFs) for PN or symptomatic PN (SPN) with initiation of combination antiretroviral therapy (cART) in ART-naïve patients, similar evaluation in ART-experienced patients is limited. This study investigated the prevalence and RFs for PN/SPN in ART-experienced patients enrolled in clinical salvage therapy studies. Between February 2000 and June 2007, 522 ART-experienced participants who experienced virologic failure with a prior regimen and started new regimens were followed longitudinally and annually screened for signs and symptoms of PN. Rates of PN/SPN at 3 years since parent study entry were 52.8 and 24.0 %, respectively. Aging, taller height, protease inhibitor use, and female sex were significant RFs for PN/SPN. The use of statin drugs was significantly associated with lower odds of SPN, and it may prevent progression from no SPN to SPN.

HIV-1 clade C isolates show reduced Tat protein chemoattractant activity compared with clade B. This might influence neuropathogenesis by altering trafficking of monocytes into the CNS. A previous study suggested low rates of HIV-associated dementia in clade C-infected individuals. The present study evaluated neurocognitive impairment rates in clade B- and C-infected individuals from the same local population. HIV+ and HIV- participants were recruited from the same geographic region in Southern Brazil. We evaluated neuropsychological (NP) impairment using a screening instrument (the International HIV Dementia Scale (IHDS)), as well as a Brazilian Portuguese adaptation of a comprehensive battery that has demonstrated sensitivity to HIV-associated neurocognitive disorders (HAND) internationally. NP performance in controls was used to generate T scores and impairment ratings by the global deficit score (GDS) method. Clade assignments were ascertained by sequencing pol and env. Blood and cerebrospinal fluid were collected from all HIV+ participants. HIV+ and HIV- participants were comparable on demographic characteristics. HIV+ participants overall were more likely to be impaired than HIV- by the IHDS and the GDS. Clade B- and C-infected individuals were demographically similar and did not differ significantly in rates of impairment. The prevalence of pleocytosis, a marker of intrathecal cellular chemotaxis, also did not differ between clade B and C infections. Clade B and C HIV-infected individuals from the same geographic region, when ascertained using comparable methods, did not differ in their rates of neurocognitive impairment, and there was no evidence of differences in CNS chemotaxis.

HIV-associated sensory neuropathy remains an important complication of combination antiretroviral therapy and HIV infection. Mitochondrial DNA haplogroups and single nucleotide polymorphisms (SNPs) have previously been associated with symptomatic neuropathy in clinical trial participants. We examined associations between mitochondrial DNA variation and HIV-associated sensory neuropathy in CNS HIV Antiretroviral Therapy Effects Research (CHARTER). CHARTER is a USA-based longitudinal observational study of HIV-infected adults who underwent a structured interview and standardized examination. HIV-associated sensory neuropathy was determined by trained examiners as ≥1 sign (diminished vibratory and sharp-dull discrimination or ankle reflexes) bilaterally. Mitochondrial DNA sequencing was performed and haplogroups were assigned by published algorithms. Multivariable logistic regression of associations between mitochondrial DNA SNPs, haplogroups, and HIV-associated sensory neuropathy were performed. In analyses of associations of each mitochondrial DNA SNP with HIV-associated sensory neuropathy, the two most significant SNPs were at positions A12810G [odds ratio (95 % confidence interval) = 0.27 (0.11-0.65); p = 0.004] and T489C [odds ratio (95 % confidence interval) = 0.41 (0.21-0.80); p = 0.009]. These synonymous changes are known to define African haplogroup L1c and European haplogroup J, respectively. Both haplogroups were associated with decreased prevalence of HIV-associated sensory neuropathy compared with all other haplogroups [odds ratio (95 % confidence interval) = 0.29 (0.12-0.71); p = 0.007 and odds ratio (95 % confidence interval) = 0.42 (0.18-1.0); p = 0.05, respectively]. In conclusion, in this cohort of mostly combination antiretroviral therapy-treated subjects, two common mitochondrial DNA SNPs and their corresponding haplogroups were associated with a markedly decreased prevalence of HIV-associated sensory neuropathy.

Standard methods used to estimate HIV-1 population diversity are often resource intensive (e.g., single genome amplification, clonal amplification and pyrosequencing) and not well suited for large study cohorts. Additional approaches are needed to address the relationships between intraindividual HIV-1 genetic diversity and 2 disease. With a small cohort of individuals, we validated three methods for measuring diversity: Shannon entropy and average pairwise distance (APD) using single genome sequences, and counts of mixed bases (i.e. ambiguous nucleotides) from population based sequences. In a large cohort, we then used the mixed base approach to determine associations between measure HIV-1 diversity and HIV associated disease. Normalized counts of mixed bases correlated with Shannon Entropy at both the nucleotide (rho=0.72, p=0.002) and amino acid level (rho=0.59, p=0.015), and APD (rho=0.75, p=0.001). Among participants who underwent neuropsychological and clinical assessments (n=187), increased HIV-1 population diversity was associated with both a diagnosis of AIDS and neuropsychological impairment., (Published by Elsevier Inc.)

The purpose of this study is to evaluate risk factors for progression from asymptomatic peripheral neuropathy (APN) to symptomatic peripheral neuropathy (SPN). Antiretroviral therapy (ART)-naïve patients initiating combination ART were followed longitudinally and screened for signs/symptoms of PN. Having APN was associated with higher odds of future SPN (odds ratio (OR) = 1.58, 95 % confidence interval (CI) = (1.08, 2.29), p = 0.027). Neurotoxic ART use was associated with increased odds of progression to SPN (OR = 2.16, 95 % CI = (1.21, 3.85), p = 0.009) while use of glucose-lowering drugs (non-insulin) was protective (OR = 0.12, 95 % CI = (0.02, 0.83), p = 0.031). Use of glucose-lowering drugs (non-insulin) may prevent progression from APN to SPN.

To measure maraviroc total cerebrospinal fluid (CSF) concentrations and compare them with total and unbound plasma concentrations. Total maraviroc was measured by reverse-phase high-performance liquid chromatography with tandem mass spectrometry, whereas ultrafiltration was used for unbound maraviroc. Maraviroc was detected in all nine CSF/plasma pairs with a median CSF total concentration of 2.4 ng/ml. CSF concentrations exceeded the 50% inhibitory concentration of wild-type CC chemokine receptor 5-tropic HIV-1 in all specimens. CSF concentrations are lower than expected based on plasma concentrations and physicochemical characteristics. Unbound maraviroc plasma concentrations may be informative in estimating concentrations in CSF.

Since HIV-1 Tat has been associated with neurocognitive dysfunction, we investigated 60 HIV-1 subtype B-infected individuals who were characterized for neurocognitive functioning and had paired CSF and blood plasma samples available. To avoid issues with repeated sampling, we generated population-based HIV-1 tat sequences from each compartment and evaluated these data using a battery of phylogenetic, statistical, and machine learning tools. These analyses identified position HXB2 5905 within the cysteine-rich domain of tat as a signature of CSF-derived HIV-1, and a higher number of mixed bases in CSF, as measure of diversity, was associated with HIV-associated neurocognitive disorder. Since identified mutations were synonymous, we evaluated the predicted secondary RNA structures, which showed that this mutation altered secondary structure. As a measure of divergence, the genetic distance between the blood and CSF-derived tat was inversely correlated with current and nadir CD4+ T cell counts. These data suggest that specific HIV-1 features of tat influence neurotropism and neurocognitive impairment.

Objective: We conducted a study of minocycline to assess its safety, tolerability, and efficacy for the treatment of HIV-associated cognitive impairment., Methods: HIV-1-infected individuals with progressive neurocognitive decline were enrolled in a double-blind, placebo-controlled study of minocycline. Participants were randomized to receive minocycline 100 mg or matching placebo orally every 12 hours. The primary efficacy measure was change in a neuropsychological test composite z score (NPZ-8) from baseline to week 24. Measures of safety included the frequency of adverse events and changes over time in laboratory tests. After 50% of participants completed the double-blind phase, an interim analysis of futility for the primary outcome measure was performed, and our Data and Safety Monitoring Board recommended early study termination., Results: A total of 107 HIV-1-infected individuals with cognitive impairment were enrolled. The minocycline group did not show improvement in the primary outcome measure (NPZ-8) (mean 24-week change = 0.12) compared to placebo (mean 24-week change = 0.17) (95% confidence interval = [-0.26, 0.39], p = 0.70). There were few severe adverse events or laboratory abnormalities in either treatment group., Conclusion: Minocycline was safe and well-tolerated in individuals with HIV-associated cognitive impairment, but cognitive improvement was not observed. Classification of evidence. This interventional study provides Class II evidence for the safety, tolerability, and efficacy of minocycline for the treatment of HIV-associated cognitive impairment.

Objectives: To estimate neuropathic sign/symptom rates with initiation of combination antiretroviral therapy (cART) in HIV-infected ART-naive patients, and to investigate risk factors for: peripheral neuropathy and symptomatic peripheral neuropathy (SPN), recovery from peripheral neuropathy/SPN after neurotoxic ART (nART) discontinuation, and the absence of peripheral neuropathy/SPN while on nART., Design: AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trial participants who initiated cART in randomized trials for ART-naive patients were annually screened for symptoms/signs of peripheral neuropathy. ART use and disease characteristics were collected longitudinally., Methods: Peripheral neuropathy was defined as at least mild loss of vibration sensation in both great toes or absent/hypoactive ankle reflexes bilaterally. SPN was defined as peripheral neuropathy and bilateral symptoms. Generalized estimating equation logistic regression was used to estimate associations., Results: Two thousand, one hundred and forty-one participants were followed from January 2000 to June 2007. Rates of peripheral neuropathy/SPN at 3 years were 32.1/8.6% despite 87.1% with HIV-1RNA 400 copies/ml or less and 70.3% with CD4 greater than 350 cells/μl. Associations with higher odds of peripheral neuropathy included older patient age and current nART use. Associations with higher odds of SPN included older patient age, nART use, and history of diabetes mellitus. Associations with lower odds of recovery after nART discontinuation included older patient age. Associations with higher odds of peripheral neuropathy while on nART included older patient age and current protease inhibitor use. Associations with higher odds of SPN while on nART included older patient age, history of diabetes, taller height, and protease inhibitor use., Conclusion: Signs of peripheral neuropathy remain despite virologic/immunologic control but frequently occurs without symptoms. Aging is a risk factor for peripheral neuropathy/SPN.

Objective: To evaluate the long-term safety and efficacy of memantine use as treatment of HIV-associated cognitive impairment., Background: The results of a 20-week, randomized, double-blind, placebo-controlled trial of memantine in HIV-infected participants with cognitive impairment (ACTG 301) were previously reported. We report the results of the up-to-60-week open-label phase following the double-blind phase., Method: Participants received open-label memantine and were escalated to a 40 mg/day dose or their maximum tolerated dose in the double- blind phase. Adverse experiences were used to evaluate safety, and changes in the mean of eight neuropsychological test scores (NPZ-8) were used to evaluate efficacy., Results: Ninety-nine participants entered the initial 12-week open-label phase and 45 in the additional 48-week extension. Twenty-seven participants reported severe adverse experiences. During the initial 12-week open-label phase, participants randomized to memantine in the double-blind phase had a statistically significant higher improvement in NPZ-8 compared to those randomized to placebo in the double-blind phase. No statistically significant NPZ-8 changes were detected during the 48-week extension., Conclusion: Long-term use of memantine appears safe and tolerable. Future randomized studies with longer follow-up are necessary to establish efficacy of memantine for the treatment of HIV-associated cognitive impairment.

Objectives: To characterize HIV-1 env compartmentalization between cerebrospinal fluid (CSF) and peripheral blood plasma over all stages of the HIV-1 disease course, and to determine the relationship between the extent of CSF HIV-1 env compartmentalization and clinical neurologic disease status., Design: Paired blood plasma and CSF specimens were collected from 66 HIV-infected patients cross-sectionally representing all major clinical stages relating to HIV-associated neurologic disease, including primary infection, asymptomatic chronic infection, chronic infection with minor global impairment, and immune deficiency with HIV-associated dementia., Methods: Heteroduplex tracking assays and bulk sequence analysis targeting the V1/V2, C2-V3, and V4/V5 regions of env were performed to characterize the genetic makeup of complex HIV-1 populations in the cross-sectional blood plasma and CSF specimens. The levels of blood plasma/CSF env compartmentalization were quantified and compared across the different clinical stages of HIV-1 neurologic disease., Results: Blood plasma/CSF env compartmentalization levels varied considerably by disease stage and were generally consistent across all three regions of env characterized. Little or no compartmentalization was observed in non-impaired individuals with primary HIV-1 infection. Compartmentalization levels were elevated in chronically infected patients, but were not significantly different between mildly impaired and non-impaired patients. Patients with HIV-associated dementia showed significantly greater blood plasma/CSF env compartmentalization relative to other groups., Conclusion: : Increased CSF compartmentalization of the HIV-1 env gene, which may reflect independent HIV-1 replication and evolution within the central nervous system, is specifically associated with HIV-associated dementia and not the less severe forms of HIV-1 neurologic disease.

Introduction: We hypothesized that pleocytosis, which is a marker of central nervous system (CNS) inflammation, would result in viral genetic equilibration or de-compartmentalization between HIV populations in the blood and cerebrospinal fluid (CSF), suggesting viral trafficking., Methods: Study subjects, who started or interrupted their antiretroviral treatment, had viral loads measured and clonal viral env sequences generated from HIV RNA extracted from paired blood and CSF samples. White blood counts in CSF were also measured at each timepoint. Degree of inter-compartment segregation was calculated by posterior probability using linear discriminant analysis and multidimensional scaling. Co-receptor usage was determined using a trained support vector machine., Results: Pleocytosis was strongly associated with disruption of viral compartmentalization., Conclusions: Inflammation in the CNS, marked by pleocytosis, allows HIV populations to mix between blood and CSF, which may increase the overall viral genetic diversity within the CSF.

Asymptomatic human immunodeficiency virus (HIV) infection is associated with impaired cognitive functioning in both clade B and C infections. The nature of cognitive change longitudinally has not been studied in asymptomatic clade C infection. The present study evaluated changes in neuropsychological functioning over a 2(1/2)-year period in a cohort of HIV-1 clade C-infected asymptomatic individuals from South India. Participants with CD4 counts below 250 were started on highly active antiretroviral therapy (HAART) as per National AIDS Control Organisation NACO guidelines and hence excluded. The sample consisted of 68 patients (30 men and 38 women), with a mean age of 29.4 years (SD=5.6 years) and a mean education of 10.0 years (SD=2.7 years). A comprehensive neuropsychological assessment with 12 tests yielding 21 variables was used to examine cognitive functioning at baseline and subsequently at 6-monthly intervals for five follow-ups. Shift in CD4 and viral load categories measured by the McNemar's test indicated disease progression. Latent growth curve (LGC) modeling assessed the nature of change in cognition over the 2(1/2)-year study period. Ten variables representing attention, executive functions, and long-term memory fit the LGC model. Excepting visual working memory, the slope was nonsignificant for nine variables, indicating absence of deterioration in cognition over a 2(1/2)-year period. However, CD4 and viral load levels worsened, indicating disease progression. Asymptomatic individuals with HIV-1 clade C infection do not show any significant decline on individual neuropsychological functions over 2(1/2) years despite disease progression, as evidenced by immune suppression and viral loads.

Although no longer considered therapeutically beneficial, antiretroviral treatment interruptions (TIs) still occur frequently among patients with human immunodeficiency virus (HIV) infection for a variety of reasons. TIs typically result in viral rebound and worsening immunosuppression, which in turn are risk factors for neurocognitive decline and dementia. We sought to determine the extent of neurocognitive risk with TIs and subsequent reintroduction of highly active antiretroviral therapy (HAART) by using a comprehensive, sensitive neuropsychological assessment and by concurrently determining changes in plasma and cerebrospinal fluid (CSF) viral load and CD4 counts. Prospective, serial, clinical evaluations including neuropsychological (NP) testing and measurement of plasma HIV RNA and CD4 count and mood state were performed on HIV-1-infected individuals (N=11) at three time points: (1) prior to a TI, while on HAART; (2) after TIs averaging 6 months; and (3) after reinitiating HAART therapy. During TI, plasma HIV RNA increased and CD4 counts declined significantly, but NP performance did not change. Following reinitiation of HAART, viral loads fell below pre-TI levels, and CD4 counts rose. Improved viral suppression and immune restoration with reinitiation of HAART resulted in significant improvement in neurocognitive performance. No changes on comprehensive questionnaires of mood state were observed in relation to TI.NP performance and mood state remained stable during TIs despite worsened viral loads and CD4 counts. Because "practice effects" are generally greatest between the first and second NP testing sessions, improvement at the third, post-TI time point was unlikely to be accounted for by practice. TIs of up to 6 months appear to be neurocognitively and psychiatrically safe for most patients.

Human immunodeficiency virus (HIV-1) can rapidly evolve due to selection pressures exerted by HIV-specific immune responses, antiviral agents, and to allow the virus to establish infection in different compartments in the body. Statistical models applied to HIV-1 sequence data can help to elucidate the nature of these selection pressures through comparisons of non-synonymous (or amino acid changing) and synonymous (or amino acid preserving) substitution rates. These models also need to take into account the non-independence of sequences due to their shared evolutionary history. We review how we have developed these methods and have applied them to characterize the evolution of HIV-1 in vivo. To illustrate our methods, we present an analysis of compartment-specific evolution of HIV-1 env in blood and cerebrospinal fluid and of site-to-site variation in the gag gene of subtype C HIV-1.

Objectives: A minority of HIV-infected patients taking an antiretroviral (ARV) regimen containing dideoxynucleosides (d-drugs) such as stavudine (d4T) and didanosine (DDI) experiences dose-limiting neuropathic pain and paraesthesias, usually within weeks of starting these drugs. Because d-drugs are among the few affordable options available in developing countries, continuing d-drug therapy would be a desirable strategy for many HIV-infected individuals. Therefore, we evaluated the safety of continuing d-drug therapy., Methods: In a US cohort, we compared the rates of worsening neuropathic symptoms and signs in HIV-infected individuals on stable ARV regimens that did (n=252) or did not (n=250) include d-drugs. Rates of worsening were compared using proportional hazards model and the log-rank test., Results: The risk ratios (RR) were not significantly larger for worsening neuropathy signs [0.94; 95% confidence interval (CI) 0.84-1.07] or symptoms (0.99; 95% CI 0.88-1.14) in patients taking d-drugs continuously compared to those not taking d-drugs., Conclusions: Continued d-drug exposure among patients tolerating an initial trial did not increase the risk of worsening neuropathy compared to non-d-drug-containing regimens. If applicable in developing countries, these findings suggest that in most patients d-drugs can be continued safely in the long term without increasing the risk of worsening neuropathy.

Brazil has the largest number of HIV cases of any single country in Latin America - over 600,000. Recently, investigators have begun to characterize the extent of neurological morbidity due to HIV in this country. During 2005 and 2006, the U.S. National Institute of Mental Health cosponsored two meetings of experts aimed at summarizing existing knowledge of HIV and its neurological complications in Brazil. Topics addressed ranged from clinical neurobehavioral aspects to molecular biology. Experts attending the meeting considered fruitful directions for future research.

Objective: To determine the effects of low-dose oral lithium on the neuropsychological performance of individuals diagnosed with HIV-associated neurocognitive impairment., Design and Methods: The project was a single-arm, open-label, 12-week pilot study at a university-based tertiary care center. The participants were adults who had been diagnosed with HIV-associated neurocognitive impairment and had been on stable antiretroviral therapy for at least 12 weeks. Conditions that could affect cognition, worsen adherence to study procedures, or increase the risk of lithium adverse reactions were excluded. Twenty-one individuals were screened and eight were enrolled, all of whom completed the study. Oral lithium was initiated at 300 mg daily and was titrated to maintain 12-h trough concentrations between 0.4 and 0.8 mEq/l. Global neuropsychological performance was assessed by the global deficit score., Results: At baseline, all participants had impaired neuropsychological performance and most had reduced CD4 cell counts (median 292 cells/microl), and HIV RNA levels in plasma below 400 copies/mL (seven of eight). Titrated lithium doses ranged between 600 and 1200 mg/day. Performance improved in all eight individuals after 12 weeks, and became unimpaired in six. The study treatment was well tolerated with no grade 3 or 4 adverse events and no premature discontinuations., Conclusions: Lithium resulted in improved neuropsychological performance in antiretroviral-treated, impaired individuals in this small, open-label study. Based on published in vitro data, lithium may exert this effect by inhibiting neuronal glycogen synthase kinase-3beta.

HIV-1 often invades the CNS during primary infection, eventually resulting in neurological disorders in up to 50% of untreated patients. The CNS is a distinct viral reservoir, differing from peripheral tissues in immunological surveillance, target cell characteristics and antiretroviral penetration. Neurotropic HIV-1 likely develops distinct genotypic characteristics in response to this unique selective environment. We sought to catalogue the genetic features of CNS-derived HIV-1 by analysing 456 clonal RNA sequences of the C2-V3 env subregion generated from CSF and plasma of 18 chronically infected individuals. Neuropsychological performance of all subjects was evaluated and summarized as a global deficit score. A battery of phylogenetic, statistical and machine learning tools was applied to these data to identify genetic features associated with HIV-1 neurotropism and neurovirulence. Eleven of 18 individuals exhibited significant viral compartmentalization between blood and CSF (P < 0.01, Slatkin-Maddison test). A CSF-specific genetic signature was identified, comprising positions 9, 13 and 19 of the V3 loop. The residue at position 5 of the V3 loop was highly correlated with neurocognitive deficit (P < 0.0025, Fisher's exact test). Antibody-mediated HIV-1 neutralizing activity was significantly reduced in CSF with respect to autologous blood plasma (P < 0.042, Student's t-test). Accordingly, CSF-derived sequences exhibited constrained diversity and contained fewer glycosylated and positively selected sites. Our results suggest that there are several genetic features that distinguish CSF- and plasma-derived HIV-1 populations, probably reflecting altered cellular entry requirements and decreased immune pressure in the CNS. Furthermore, neurological impairment may be influenced by mutations within the viral V3 loop sequence.

Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) is a significant cause of morbidity. The requirements for HIV adaptation to the CNS for neuropathogenesis and the value of CSF virus as a surrogate for virus activity in brain parenchyma are not well established. We studied 18 HIV-infected subjects, most with advanced immunodeficiency and some neurocognitive impairment but none with evidence of opportunistic infection or malignancy of the CNS. Clonal sequences of C2-V3 env and population sequences of pol from HIV RNA in cerebrospinal fluid (CSF) and plasma were correlated with clinical and virologic variables. Most (14 of 18) subjects had partitioning of C2-V3 sequences according to compartment, and 9 of 13 subjects with drug resistance exhibited discordant resistance patterns between the two compartments. Regression analyses identified three to seven positions in C2-V3 that discriminated CSF from plasma HIV. The presence of compartmental differences at one or more of the identified positions in C2-V3 was highly associated with the presence of discordant resistance (P = 0.007), reflecting the autonomous replication of HIV and the independent evolution of drug resistance in the CNS. Discordance of resistance was associated with severity of neurocognitive deficits (P = 0.07), while low nadir CD4 counts were linked both to the severity of neurocognitive deficits and to discordant resistance patterns (P = 0.05 and 0.09, respectively). These observations support the study of CSF HIV as an accessible surrogate for HIV virions in the brain, confirm the high frequency of discordant resistance in subjects with advanced disease in the absence of opportunistic infection or malignancy of the CNS, and begin to identify genetic patterns in HIV env associated with adaptation to the CNS.

The benefits of combination antiretroviral therapy (ART) for HIV cognitive disorders vary substantially between individuals. This study evaluated whether cerebrospinal fluid (CSF) drug penetration and CSF virological suppression influence the extent of neuropsychological (NP) improvement during ART. Overall performance on a battery of NP tests administered at baseline and follow-up (median 15 weeks) was computed by using the global deficit score (GDS) methods in 31 cognitively impaired, HIV-infected individuals who began new ART regimens. Virological suppression (attaining undetectable viral load by RT-PCR at follow-up) was assessed separately for plasma and CSF. Subjects on regimens containing greater numbers of CSF-penetrating drugs showed significantly greater reduction in CSF viral load. Subjects attaining CSF virological suppression demonstrated greater GDS improvement than those who did not (median GDS change, 0.62 vs 0.23; p = 0.01). A similar trend for plasma did not reach statistical significance (p = 0.053). NP improvement was greater in ART-naive versus treatment-experienced subjects. In a multivariate model (overall p = 0.0008), significant, independent predictors of GDS reduction were CSF HIV RNA suppression, baseline antiretroviral history, and their interaction. Including CSF-penetrating drugs in the ART regimen and monitoring CSF viral load may be indicated for individuals with HIV-associated cognitive impairment.

Objective: The effects of aging on the presentation of HIV-associated neurocognitive disorders are largely unknown. In a cross-sectional observational study, we compared the neuropsychological profiles of 67 HIV-positive patients aged at least 50 years with those of 52 participants aged 35 years or less., Methods: Participants received neuropsychological, psychiatric and neuromedical evaluations. Raw neuropsychological test scores were converted to demographically corrected T-scores; all were corrected for the effects of normal aging. Clinical ratings of impairment were assigned to the neuropsychological results., Results: The two groups did not differ statistically with respect to demographic variables, percentage with AIDS, or CD4 cell counts. The 'younger' group had higher viral burdens in plasma and cerebrospinal fluid (CSF), and fewer were receiving antiretroviral treatment. The proportion of neuropsychologically impaired subjects in the 'older' group was slightly greater than in the younger group, and the older group tended to have higher rates of impairment across most ability domains. When group differences in CSF viral load were modeled statistically, both viral burden and age were significant predictors of neuropsychological impairment, together with a significant interaction between viral burden and age. Older individuals with detectable virus in CSF had twice the prevalence of neuropsychological impairment of those with undetectable levels. Among younger individuals, this proportion was not affected by viral load. Lifetime major depression, substance use disorder, and current depression symptoms were not associated with neuropsychological impairment., Conclusion: Although further studies with larger and older samples are needed, this investigation suggests that older adults may be at greater risk of HIV-related neurocognitive dysfunction.

Abuse of methamphetamine (METH) is a frequent comorbidity among individuals infected with human immunodeficiency virus (HIV) type 1. In cell cultures and animal models, METH accelerates retroviral replication. To determine whether METH increases HIV replication in humans, we evaluated HIV loads in HIV-positive METH users and nonusers. We studied 3 groups: Tox+, active METH use and positive urine toxicology results; METH(+)Tox-, previous METH dependence/abuse and negative urine toxicology results; METH(-)Tox-, no METH dependence/abuse and negative urine toxicology results. Tox+ subjects' plasma virus loads were significantly higher than METH(+)Tox- and METH(-)Tox- subjects'; cerebrospinal fluid virus loads showed a similar but nonsignificant trend. Stratification by use of highly active antiretroviral therapy (HAART) revealed that virus loads were higher only in those Tox+ subjects who reported receiving HAART. In contrast, abstinent former METH abusers (METH(+)Tox-) receiving HAART effectively suppressed viral replication. These data suggest that abstinence programs are a key component of effective treatment of HIV in METH-abusing populations.

To characterize, over time, cerebrospinal fluid (CSF) virus-load change in clinically stable patients, human immunodeficiency virus (HIV)-1 RNA levels were measured in serial CSF samples and in plasma samples obtained, during periods of 20 days-6 years, from 17 HIV-infected individuals not receiving antiretroviral treatment. Longitudinal trends were analyzed by linear regression and restricted maximum-likelihood techniques. CSF HIV-1 RNA levels varied within a restricted range (+/-0.5 log(10) copies/mL) around each subject-specific mean. Although 16 of the 17 subjects had CSF slopes not significantly different from zero, slopes that were more positive were associated with lower CD4 counts. In an individual patient, a CSF virus-load change >0.5 log(10) copies/mL may be clinically significant. Furthermore, our data suggest that, if the CSF virus load reflects the size of the reservoir of infected cells in the central nervous system, this reservoir may increase in those individuals with advanced immunosuppression but is stable, over several years, in patients without AIDS.

Chronic hyperactivation of excitatory amino acid pathways in the CNS of patients infected with HIV-1 may contribute to the pathogenesis of HIV-1-associated dementia complex. However, no correlation between the concentration of glutamate in CSF (mean 3.3 micromol/L) and either HIV-1 infection or HIV-1-associated dementia complex was observed. The results clarify several important issues regarding analysis of glutamate in the CSF and the role of excitotoxins in HIV-1-associated dementia complex.

To determine whether cerebrospinal fluid (CSF) viral burden measurements can assist in the evaluation of human immunodeficiency virus (HIV)-associated neurocognitive disorders, we quantified HIV type 1 (HIV-1) RNA in CSF. Because previous findings suggested that disease stage, lymphocytic pleocytosis, and HIV-1 RNA levels in plasma may influence CSF viral burden, these variables were examined as potential modifying factors. HIV-1 RNA levels were quantified by using a reverse transcriptase-polymerase chain reaction assay. Performance on a comprehensive neuropsychological (NP) battery was noted in 97 prospectively enrolled, HIV-infected subjects. Among subjects with acquired immunodeficiency syndrome (AIDS) (<200 CD4+ lymphocytes), NP impairment was associated with significantly higher CSF RNA levels (3.1 vs 1.8 log10 copies/ml; p = 0.02); most impaired subjects met criteria for HIV-associated dementia or minor cognitive-motor disorder. In subjects without AIDS, CSF RNA and NP impairment were unrelated. Before AIDS, CSF RNA was strongly correlated to plasma RNA and to pleocytosis, but in AIDS, CSF and plasma RNA were independent. In conclusion, we found elevated CSF HIV-1 RNA levels in NP impaired subjects with AIDS. Before AIDS, systemic viral replication, possibly through CD4+ mononuclear cell trafficking, may govern virus levels in CSF, whereas in AIDS, CD4 cell depletion may unmask a correlation between increased productive central nervous system HIV infection and clinical neurocognitive disorders.

Objective: To determine if mortality is increased in individuals with human immunodeficiency virus type 1 (HIV-1)-associated neurocognitive disorders less severe than frank dementia., Design: A prospective cohort study; median duration of follow-up was 2.4 years. Kaplan-Meier analysis and Cox proportional hazards models were used to compare survival times according to neurocognitive classification., Setting: University-based research unit., Participants: A volunteer sample of 414 individuals seropositive for HIV-1. Subjects were classified at their baseline evaluation as neuropsychologically (NP) normal or abnormal (impaired in > or = 2 NP test domains). A subgroup of NP abnormal subjects met operational criteria for HIV-associated minor cognitive motor disorder; the remaining subjects were designated NP impaired. Subjects with frank dementia were excluded., Main Outcome Measure: Mortality., Results: At the baseline evaluation, 256 (62%) of 414 subjects were designated normal; 109 (26%). NP impaired; and 49 (12%), minor cognitive motor disorder. One hundred six participants (26%) died during follow-up. Compared with the NP normal group, the unadjusted relative risk (RR) of death for all NP abnormal subjects (minor cognitive motor disorder and NP impaired) was significantly increased (RR, 1.7; 95% confidence interval [CI], 1.2-2.6; P < .005). After adjusting for concurrently measured predictors of survival (CD4 lymphocyte counts, Centers for Disease Control and Prevention HIV disease classification, hemoglobin concentration, and serum beta 2-microglobulin) in proportional hazards models, mortality for all NP abnormal subjects remained elevated (RR, 1.8; 95% CI, 1.2-2.8; P < .01). The elevation in mortality risk for subjects with minor cognitive motor disorder was statistically significant (RR, 2.2; 95% CI, 1.2-3.8; P < .01); for NP impaired subjects it was marginally significant (RR, 1.6; 95% CI, 1.0-2.8; P = .06)., Conclusions: The HIV-infected individuals with NP impairment had a higher risk of dying than those without impairment. This was particularly true for those meeting syndromic diagnostic criteria.