Discordant CSF/plasma HIV-1 RNA in individuals on virologically suppressive antiretroviral therapy in Western India

Changes in Cerebrospinal Fluid Proteins across the Spectrum of Untreated and Treated Chronic HIV-1 Infection

Using the Olink Explore 1536 platform, we measured 1,463 unique proteins in 303 cerebrospinal fluid (CSF) specimens from four clinical centers that included uninfected controls and 12 groups of people living with HIV-1 infection representing the spectrum of progressive untreated and treated chronic infection. We present three initial analyses of these measurements: an overview of the CSF protein features of the sample; correlations of the CSF proteins with CSF HIV-1 RNA and neurofilament light chain protein (NfL) concentrations; and comparison of the CSF proteins in HIV-associated dementia ( HAD ) and neurosymptomatic CSF escape ( NSE ). These reveal a complex but coherent picture of CSF protein changes that includes highest concentrations of many proteins during CNS injury in the HAD and NSE groups and variable protein changes across the course of neuroasymptomatic systemic HIV-1 progression, including two common patterns, designated as lymphoid and myeloid patterns, related to the principal involvement of their underlying inflammatory cell lineages. Antiretroviral therapy reduced CSF protein perturbations, though not always to control levels. The dataset of these CSF protein measurements, along with background clinical information, is posted online. Extended studies of this unique dataset will provide more detailed characterization of the dynamic impact of HIV-1 infection on the CSF proteome across the spectrum of HIV-1 infection, and further the mechanistic understanding of HIV-1-related CNS pathobiology.

Cerebrospinal fluid viral escape in HIV patients on antiretroviral therapy: A systematic review of reported cases

Cerebrospinal fluid (CSF) viral escape rarely occurs when HIV is detected in the CSF, while it is undetectable in the blood plasma or detectable in CSF at levels that exceed those in the blood plasma. We conducted this review to comprehensively synthesise its clinical presentation, diagnosis, management strategies and treatment outcomes. A review registered with PROSPERO (CRD42023475311) searched evidence across PubMed/MEDLINE, Embase, Web of Science, Scopus, and Google Scholar to gather articles (case reports/series) that report on CSF viral escape in people living with HIV (PLHIV) on antiretroviral therapy (ART). The quality of studies was assessed based on the domains of selection, ascertainment, causality, and reporting. A systematic search identified 493 articles and 27 studies that include 21 case reports, and six case series were involved in the review. The studies reported 62 cases of CSF viral escape in PLHIV. The majority were men (66.67%), with a median age of 43 (range: 28-73) years. Approximately, 31 distinct symptoms were documented, mostly being cognitive dysfunction, gait abnormalities, and tremors (12.51%). Diagnosis involved blood and CSF analysis, magnetic resonance imaging, and neuropsychological assessments. Over 36 ART regimens were employed, with a focus on ART intensification; almost one-third of the regimens contained Raltegravir (integrase strand transfer inhibitor). The outcomes showed 64.49% full recovery, 30.16% partial recovery, and 4.76% died. When neuropsychological symptoms manifest in PLHIV, monitoring for CSF viral escape is essential, regardless of plasma viral suppression. Personalised treatment strategies, particularly ART intensification, are strongly advised for optimising treatment outcomes in PLHIV diagnosed with CSF HIV escape.

Cerebrospinal Fluid Viral Escape on Highly Active Antiretroviral Therapy: Analysis from Single Tertiary Care Centre

HIV-infected individuals receiving regular antiretroviral therapy (ART) can present with a high viral load in cerebrospinal fluid (CSF) at times when it is suppressed in blood. This study presents data of HIV-infected patients who had undetectable or low plasma viral load in blood but presented with neurological signs and symptoms and were diagnosed to have CSF HIV viral escape. Records were reviewed for clinical manifestations, details of opportunistic or coinfection, and HIV viral copies in plasma and CSF at time of diagnosis of CSF escape. A total of 10,200 HIV-infected individuals were registered in HIV care till December 31, 2021. Nineteen individuals (14 virologically confirmed and 5 clinically) were diagnosed with high viral copies in CSF from June 2014 to December 2021. Mean age was 41.5 ± 9.2 (median, 39.5; range, 30-62) years. Average duration of antiretroviral treatment received at the time of diagnosis of CSF escape was 10.1 years. Median plasma HIV-viral copies were 2,469.8 (undetectable to 29,418) and in CSF were 12,773.7 (n = 14, range, 1,340-48,530) copies/mL. HIV viral copies in CSF were significantly higher than in plasma at the time of presentation (p = .003). ART regimen switch was done after identification of HIV CSF escape. Seventeen patients were alive with a regular follow-up of average 35 (range 7-66) months. All had documented clinical improvement with reversal of neurological impairment after ART switch. There was one death and one lost to follow-up. Early identification and timely intervention in CSF viral escape could revert severe neurological impairment and improves treatment outcome.

Is the Central Nervous System Reservoir a Hurdle for an HIV Cure?

There is currently no cure for HIV infection although adherence to effective antiretroviral therapy (ART) suppresses replication of the virus in blood, increases CD4+ T-cell counts, reverses immunodeficiency, and increases life expectancy. Despite these substantial advances, ART is a lifelong treatment for people with HIV (PWH) and upon cessation or interruption, the virus quickly rebounds in plasma and anatomic sites, including the central nervous system (CNS), resulting in disease progression. With recent advances in quantifying viral burden, detection of genetically intact viral genomes, and isolation of replication-competent virus from brain tissues of PWH receiving ART, it has become apparent that the CNS viral reservoir (largely comprised of macrophage type cells) poses a substantial challenge for HIV cure strategies. Other obstacles impacting the curing of HIV include ageing populations, substance use, comorbidities, limited antiretroviral drug efficacy in CNS cells, and ART-associated neurotoxicity. Herein, we review recent findings, including studies of the proviral integration sites, reservoir decay rates, and new treatment/prevention strategies in the context of the CNS, together with highlighting the next steps for investigations of the CNS as a viral reservoir.

The presence of resistance‐associated mutations in reverse transcriptase gene is associated with cerebrospinal fluid HIV‐1 escape: A multicentric retrospective analysis

Higher risk of cerebrospinal fluid escape (CVE) has been associated with the use of specific antiretroviral (ARV) classes, such as protease inhibitors. We assessed whether archived resistance-associated mutations (RAMs) can mediate this relationship by identifying patients treated with incompletely active antiretroviral regimens. A retrospective multicentric study on 282 adult people with HIV on antiretroviral therapy (ART) and available historical plasma genotype resistance testing (HGRT) for reverse transcriptase (RT) and protease genes between 2001 and 2021. The odds ratio for demographic, clinic-, and ART-related variables and CVE was estimated by multivariable modeling. HGRT-adjusted central nervous system effectiveness penetration (CPE) score was computed in modeling the risk. Median age, plasma VL, and CD4 count were 49 years, <50 copies/mL, and 310 cells/μL. CVE was detected in 51 participants (17.0%). No difference in CVE prevalence was observed according to ART type, number of ARVs or ARV classes. Participants with CVE had more frequently plasma (52.9% vs. 32.1%, p = 0.005) and CSF RAMs in RT (n = 63, 57.1% vs. 28.6%, p = 0.029), but not in protease gene. The presence of plasma RAMs in RT associated with increased odds of CVE in adjusted analyses (aOR 3.9, p < 0.001) and in models restricted to plasma viral load ≤50 copies/mL (n = 202; aOR 4.3, p = 0.003). CVE risk decreased by 40% per each point increase in HGRT-adjusted CPE score in multivariable models (p < 0.001). Rather than the type of ARV classes or of ART regimens, functional mono or dual regimens caused by the presence of RAMs affecting ART components may explain the majority of cases of CVE.

Clinical Reasoning: Rapidly Progressive Dementia in a Man With HIV Infection and Undetectable Plasma Viral Load

Neurocognitive decline associated with HIV infection remains prevalent even in the antiretroviral therapy (ART) era, albeit usually in less severe forms. The differential diagnosis of cognitive impairment in this population is quite broad, including infectious causes such as CNS opportunistic infections, causes directly related to HIV such as HIV-associated neurocognitive disorders, and causes entirely unrelated to HIV infection such as primary dementia syndromes. In this case report, a 47-year-old man with HIV on ART with an undetectable plasma viral load presented with rapidly progressive dementia to a clinic in Zambia. He had been functioning independently and fully employed before symptom onset but had to stop working within 2 months of symptom onset because of the severity and rapidity of his cognitive decline. Initial workup led to an empiric diagnosis and initiation of an empiric treatment regimen, which was ultimately ineffective. This prompted re-evaluation, additional workup, and, ultimately, discovering the correct diagnosis. This case highlights the stepwise approach to developing a diagnosis in a resource-limited setting where there exists a high burden of HIV infection, including the necessity of empiric diagnoses of treatment plans when investigations are limited and the importance of reconsidering these diagnoses in the face of additional clinical information. In addition, it highlights both infectious and noninfectious causes of cognitive decline in people with HIV.

Risk Factors for CSF/Plasma HIV-1 RNA Discordance in HIV-Infected Patients

BACKGROUND

Few large investigations have evaluated the association of cerebrospinal fluid/plasma (CSF/plasma) discordance with opportunistic neurological infections. We aimed to determine risk factors for CSF/plasma discordance to further assess whether CSF/plasma discordance is associated with antiretroviral therapy (ART) and opportunistic neurological infections.

METHODS

A retrospective study was conducted based on HIV RNA viral load and associated risk factors in plasma and CSF samples from 491 HIV-infected patients. HIV RNA levels higher in CSF compared with plasma was defined as CSF/plasma discordance.

RESULTS

In this study, the rate of CSF/plasma discordance was 18.3%. We observed that headache, cryptococcal antigen, CSF cell count, Treponema pallidum particle assay positivity, and ART use were significantly associated with CSF/plasma discordance in the multivariate logistic regression model. The CSF RNA/plasma RNA ratio was significantly higher in HIV-infected patients with neurological infections than in HIV-infected cases without neurological infections (P < 0.001). CSF/plasma discordance was significantly different between HIV-infected patients without central nervous system (CNS) infection and those with CNS infection, tuberculous meningitis, cryptococcal meningitis, and neurosyphilis (P < 0.05).

CONCLUSIONS

ART and CNS inflammation may influence CSF/plasma discordance.

Association of High Ratio of CSF/Plasma HIV-1 RNA with Central Nervous System Co-Infection in HIV-1-Positive Treatment-Naive Patients

Cerebrospinal fluid (CSF) human immunodeficiency virus-1 (HIV-1) ribonucleic acid (RNA) at higher levels than in plasma has been observed in HIV-1-positive patients and defined as CSF/plasma discordance or CSF escape. Discordance is particularly seen in untreated patients with antiretroviral agents. Quantitative data regarding its association with blood−brain barrier (BBB) damage and intracranial co-infection with other pathogens are limited. Therefore, we used the CSF to plasma HIV-1 RNA ratio (HRR) to determine its relation to central nervous system (CNS) co-infection in HIV-1-positive treatment-naïve individuals. We retrospectively recruited the subjects with HIV-1-positive and potential neurological deficits. A lumbar puncture was performed before the antiretroviral therapy. The paired CSF/plasma HIV-1 RNA samples were analyzed. Univariate and multivariate logistic regression models and multiple spine regression analyses were performed to assess the association between the HRR and CNS co-infection. A total of 195 patients with 78% males (median age: 49 years) were included in this study, of whom 98 (50.2%) had CNS co-infection with other pathogens. The receiver-operating characteristic curve analysis showed that the optimal cutoff value for the HRR to predict the CNS co-infection was 1.00. Higher HRR (≥1) was significantly associated with tuberculous meningitis (OR 6.50, 95% CI 2.08−20.25, p = 0.001), cryptococcus meningitis (OR 7.58, 95% CI 2.10−27.32, p = 0.001), and multiple co-infection (OR 4.04, 95% CI 1.02−16.04, p = 0.047). Higher HRR (≥1) (OR 3.01, 95% CI 1.09−8.73, p = 0.032) was independently associated with the CNS co-infection after adjusting for covariates. No significant nonlinear association was found between the HRR and CNS co-infection in the multivariate spline regression (p > 0.05) and a positive relationship was found between the HRR and CNS co-infection when the HRR was ≥0.78. Higher HRR was associated with an increased risk of CNS co-infection in HIV-1-positive patients. The relationship between the HRR and CNS co-infection may be related to the BBB disturbance and warrants further investigation with a large, longitudinal cohort.

Reversal of CSF HIV-1 Escape during Treatment of HIV-Associated Cryptococcal Meningitis in Botswana

Cerebrospinal fluid (CSF) viral escape has been poorly described among people with HIV-associated cryptococcal meningitis. We determined the prevalence of CSF viral escape and HIV-1 viral load (VL) trajectories in individuals treated for HIV-associated cryptococcal meningitis. A retrospective longitudinal study was performed using paired CSF and plasma collected prior to and during the antifungal treatment of 83 participants recruited at the Botswana site of the phase-3 AMBITION-cm trial (2018−2021). HIV-1 RNA levels were quantified then CSF viral escape (CSF HIV-1 RNA ≥ 0.5 log10 higher than plasma) and HIV-1 VL trajectories were assessed. CSF viral escape occurred in 20/62 (32.3%; 95% confidence interval [CI]: 21.9−44.6%), 13/52 (25.0%; 95% CI: 15.2−38.2%) and 1/33 (3.0%; 95% CI: 0.16−15.3%) participants at days 1, 7 and 14 respectively. CSF viral escape was significantly lower on day 14 compared to days 1 and 7, p = 0.003 and p = 0.02, respectively. HIV-1 VL decreased significantly from day 1 to day 14 post antifungal therapy in the CSF but not in the plasma (β = −0.47; 95% CI: −0.69 to −0.25; p < 0.001). CSF viral escape is high among individuals presenting with HIV-associated cryptococcal meningitis; however, antifungal therapy may reverse this, highlighting the importance of rapid initiation of antifungal therapy in these patients.

T cell derived HIV-1 is present in the CSF in the face of suppressive antiretroviral therapy

HIV cerebrospinal fluid (CSF) escape, where HIV is suppressed in blood but detectable in CSF, occurs when HIV persists in the CNS despite antiretroviral therapy (ART). To determine the virus producing cell type and whether lowered CSF ART levels are responsible for CSF escape, we collected blood and CSF from 156 neurosymptomatic participants from Durban, South Africa. We observed that 28% of participants with an undetectable HIV blood viral load showed CSF escape. We detected host cell surface markers on the HIV envelope to determine the cellular source of HIV in participants on the first line regimen of efavirenz, emtricitabine, and tenofovir. We confirmed CD26 as a marker which could differentiate between T cells and macrophages and microglia, and quantified CD26 levels on the virion surface, comparing the result to virus from in vitro infected T cells or macrophages. The measured CD26 level was consistent with the presence of T cell produced virus. We found no significant differences in ART concentrations between CSF escape and fully suppressed individuals in CSF or blood, and did not observe a clear association with drug resistance mutations in CSF virus which would allow HIV to replicate. Hence, CSF HIV in the face of ART may at least partly originate in CD4+ T cell populations.

CNS infections in HIV

PURPOSE OF REVIEW

Central nervous system (CNS) infections associated with HIV remain significant contributors to morbidity and mortality, particularly among people living with HIV (PLWH) in resource-limited settings worldwide. In this review, we discuss several recent important scientific discoveries in the prevention, diagnosis, and management around two of the major causes of CNS opportunistic infections-tuberculous meningitis (TBM) and cryptococcal meningitis including immune reconstitution syndrome (IRIS) associated with cryptococcal meningitis. We also discuss the CNS as a possible viral reservoir, highlighting Cerebrospinal fluid viral escape.

RECENT FINDINGS

CNS infections in HIV-positive people in sub-Saharan Africa contribute to 15-25% of AIDS-related deaths. Morbidity and mortality in those is associated with delays in HIV diagnosis, lack of availability for antimicrobial treatment, and risk of CNS IRIS. The CNS may serve as a reservoir for replication, though it is unclear whether this can impact peripheral immunosuppression.

SUMMARY

Significant diagnostic and treatment advances for TBM and cryptococcal meningitis have yet to impact overall morbidity and mortality according to recent data. Lack of early diagnosis and treatment initiation, and also maintenance on combined antiretroviral treatment are the main drivers of the ongoing burden of CNS opportunistic infections. The CNS as a viral reservoir has major potential implications for HIV eradication strategies, and also control of CNS opportunistic infections.

Relapse of Symptomatic Cerebrospinal Fluid HIV Escape

PURPOSE OF REVIEW

Symptomatic cerebrospinal fluid (CSF) HIV escape defines the presence of neurological disease in combination antiretroviral therapy (cART)-treated persons due to HIV replication in CSF despite systemic suppression or to higher viral replication in CSF than in plasma. The aim was to search for cases of recurrent symptomatic CSF escape and to define their characteristics.

RECENT FINDINGS

By review of the literature, we identified symptomatic CSF escape relapses in three patients who had shown clinical remission of a first escape episode following cART optimization. By examination of our cohort of 21 patients with symptomatic CSF escape, we identified five additional patients. In the latter, viral escape relapsed over a median follow-up of 108 months because of low adherence or upon treatment simplification of a previously optimized regimen. cART reoptimization based on resistance profile and potential drug neuropenetration and efficacy led to relapse resolution with no further episodes after a median follow-up of 50 months from relapse. The observation that CSF escape may relapse highlights the importance of long-term neuro-suppressive regimens after a first episode and supports the role of the brain as a reservoir for HIV.

Differences in human immunodeficiency virus-1C viral load and drug resistance mutation between plasma and cerebrospinal fluid in patients with human immunodeficiency virus-associated cryptococcal meningitis in Botswana

To determine effects of cryptococcal meningitis (CM) on human immunodeficiency virus (HIV)-1C cerebrospinal fluid (CSF) viral escape, CSF/plasma viral discordance, and drug resistance mutation (DRM) discordance between CSF and plasma compartments, we compared CSF and plasma viral load (VL) and DRMs in individuals with HIV-associated CM in Botswana.This cross-sectional study utilized 45 paired CSF/plasma samples from participants in a CM treatment trial (2014-2016). HIV-1 VL was determined and HIV-1 protease and reverse transcriptase genotyping performed. DRMs were determined using the Stanford HIV database. CSF viral escape was defined as HIV-1 ribonucleic acid ≥0.5 log10 higher in CSF than plasma and VL discordance as CSF VL > plasma VL.HIV-1 VL was successfully measured in 39/45 pairs, with insufficient sample volume in 6; 34/39 (87.2%) participants had detectable HIV-1 in plasma and CSF, median 5.1 (interquartile range: 4.7-5.7) and 4.6 (interquartile range:3.7-4.9) log10 copies/mL, respectively (P≤.001). CSF viral escape was present in 1/34 (2.9%) and VL discordance in 6/34 (17.6%). Discordance was not associated with CD4 count, antiretroviral status, fungal burden, CSF lymphocyte percentage nor mental status. Twenty-six of 45 (57.8%) CSF/plasma pairs were successfully sequenced. HIV-1 DRM discordance was found in 3/26 (11.5%); 1 had I84IT and another had M46MI in CSF only. The third had K101E in plasma and V106 M in CSF.Our findings suggest that HIV-1 escape and DRM discordance may occur at lower rates in participants with advanced HIV-disease and CM compared to those with HIV associated neurocognitive impairment.

HIV and cardiovascular disease

HIV-related cardiovascular disease research is predominantly from Europe and North America. Of the estimated 37·9 million people living with HIV worldwide, 25·6 million live in sub-Saharan Africa. Although mechanisms for HIV-related cardiovascular disease might be the same in all people with HIV, the distribution of cardiovascular disease risk factors varies by geographical location. Sub-Saharan Africa has a younger population, higher prevalence of elevated blood pressure, lower smoking rates, and lower prevalence of elevated cholesterol than western Europe and North America. These variations mean that the profile of cardiovascular disease differs between low-income and high-income countries. Research in, implementation of, and advocacy for risk reduction of cardiovascular disease in the global context of HIV should account for differences in the distribution of traditional cardiovascular disease risk factors (eg, hypertension, smoking), consider non-traditional cardiovascular disease risk factors (eg, access to antiretroviral therapy with more benign cardiovascular disease side effect profiles, indoor air pollution), and encourage the inclusion of relevant risk reduction approaches for cardiovascular disease in HIV-care guidelines. Future research priorities include implementation science to scale up and expand integrated HIV and cardiovascular disease care models, which have shown promise in sub-Saharan Africa; HIV and cardiovascular disease epidemiology and mechanisms in women; and tobacco cessation for people living with HIV.

Herpes zoster in HIV-1 infection: The role of CSF pleocytosis in secondary CSF escape and discordance

HIV cerebrospinal fluid (CSF) escape is defined by a concentration of HIV-1 RNA in CSF above the lower limit of quantification of the employed assay and equal to or greater than the plasma HIV-1 RNA level in the presence of treatment-related plasma viral suppression, while CSF discordance is similarly defined by equal or higher CSF than plasma HIV-1 RNA in untreated individuals. During secondary CSF escape or discordance, disproportionate CSF HIV-1 RNA develops in relation to another infection in addition to HIV-1. We performed a retrospective review of people living with HIV receiving clinical care at Sahlgrenska Infectious Diseases Clinic in Gothenburg, Sweden who developed uncomplicated herpes zoster (HZ) and underwent a research lumbar puncture (LP) within the ensuing 150 days. Based on treatment status and the relationship between CSF and plasma HIV-1 RNA concentrations, they were divided into 4 groups: i) antiretroviral treated with CSF escape (N = 4), ii) treated without CSF escape (N = 5), iii) untreated with CSF discordance (N = 8), and iv) untreated without CSF discordance (N = 8). We augmented these with two additional cases of secondary CSF escape related to neuroborreliosis and HSV-2 encephalitis and analyzed these two non-HZ cases for factors contributing to CSF HIV-1 RNA concentrations. HIV-1 CSF escape and discordance were associated with higher CSF white blood cell (WBC) counts than their non-escape (P = 0.0087) and non-discordant (P = 0.0017) counterparts, and the CSF WBC counts correlated with the CSF HIV-1 RNA levels in both the treated (P = 0.0047) and untreated (P = 0.002) group pairs. Moreover, the CSF WBC counts correlated with the CSF:plasma HIV-1 RNA ratios of the entire group of 27 subjects (P = <0.0001) indicating a strong effect of the CSF WBC count on the relation of the CSF to plasma HIV-1 RNA concentrations across the entire sample set. The inflammatory response to HZ and its augmenting effect on CSF HIV-1 RNA was found up to 5 months after the HZ outbreak in the cross-sectional sample and, was present for one year after HZ in one individual followed longitudinally. We suggest that HZ provides a ‘model’ of secondary CSF escape and discordance. Likely, the inflammatory response to HZ pathology provoked local HIV-1 production by enhanced trafficking or activation of HIV-1-infected CD4+ T lymphocytes. Whereas treatment and other systemic factors determined the plasma HIV-1 RNA concentrations, in this setting the CSF WBC counts established the relation of the CSF HIV-1 RNA levels to this plasma set-point.

Two treatment strategies for management of Neurosymptomatic cerebrospinal fluid HIV escape in Pune, India

Symptomatic cerebrospinal fluid (CSF) viral escape (sCVE) is reported in people with HIV, who are on ritonavir-boosted protease inhibitor (PI/r) containing antiretroviral therapy (ART). Management of sCVE includes performing genotypic HIV-1 resistance testing (GRT) on CSF and plasma HIV and changing ART accordingly. Neither GRT nor newer drugs (Dolutegravir and Darunavir/ritonavir) are routinely available in India. As a result, management of sCVE includes 2 modalities: a) ART intensification by adding drugs that reach therapeutic concentrations in CSF, like Zidovudine, to existing ART or b) Changing to a regimen containing newer boosted PI/r and integrase strand transfer inhibitor (INSTI) as per GRT or expert opinion. In this retrospective study, we report the outcomes of above 2 modalities in treatment of sCVE in Pune, India.Fifty-seven episodes of sCVE in 54 people with HIV taking PI/r-containing ART were identified. Clinical, demographic, laboratory and ART data were recorded. Forty-seven cases had follow-up data available after ART change including measurement of plasma and CSF viral load (VL).Of the 47 cases, 23 received zidovudine intensification (Group A, median VL: plasma- 290, CSF- 5200 copies/mL) and 24 received PI/INSTI intensification (Group B, median VL: plasma- 265, CSF-4750 copies/mL). CSF GRT was performed in 16 participants: 8 had triple class resistance. After ART change, complete resolution of neurologic symptoms occurred in most participants (Group A: 18, Group B: 17). In Group A, follow-up plasma and CSF VL were available for 21 participants, most of whom achieved virologic suppression (VL < 20 copies/mL) in plasma (17) and CSF (15). Four participants were shifted to the PI/INSTI intensification group due to virologic failure (plasma or CSF VL > 200 copies/mL). In Group B, follow-up plasma and CSF VL were available for 23 participants, most of whom also achieved virologic suppression in plasma (21) and CSF (18). Four deaths were noted, 2 of which were in individuals who interrupted ART.This is a unique sCVE cohort that was managed with 1 of 2 approaches based on treatment history and the availability of GRT. At least 75% of participants responded to either approach with virologic suppression and improvement in symptoms.

The far-reaching HAND of cART: cART effects on astrocytes

Following the introduction of combination antiretroviral therapy (cART), the morbidity and mortality from human immunodeficiency virus (HIV) infection has been drastically curtailed and HIV has now become a chronic manageable disease. Persons living with HIV (PLWH) are living longer and experiencing significant co-morbidities and conditions of aging. NeuroHIV, clinically defined as HIV-Associated Neurocognitive Disorders (HAND) and pathologically manifested by persistent inflammation in the CNS despite cART, is a significant co-morbid condition for PLWH. In the pre-cART era, HIV mediated much of the pathogenesis in the Central Nervous System (CNS); in the cART era, with low to undetectable viremia, other mechanisms may be contributing to persistent neuroinflammation. Emerging data point to the adverse effects at the cellular level of cART, independent of HIV. Astrocytes are the most abundant cells in the CNS, playing vital roles in maintaining CNS homeostasis (e.g. metabolic support to neurons, clearance of neurotransmitters, ion balance, modulation of synaptic functions and maintaining the structural integrity of the blood brain barrier (BBB). Therefore, any disruption of their function will have wide repercussions in the CNS. In this review, we will address current knowledge and gaps on the impact of antiretrovirals (ARVs) on astrocytes and physiologic consequences in the CNS. Understanding the status of this field, will provide a practical framework to elucidate the potential role of cART-mediated dysregulation of astrocytes in neuroHIV pathogenesis and inform therapeutic strategies that are "neuro-friendly". Graphical abstract CNS-penetrating cART have the potential to cause resting astrocytes to become activated into an A1 or neurotoxic phenotype. These cells can in turn secrete inflammatory cytokines that affect surrounding microglia macrophages, as well as neurotoxic factors that impact nearby neurons. In addition, impairment in the physiologic functions of astrocytes will result in altered BBB permeability and disrupted metabolic homeostasis. CNS=Central Nervous System; cART=combined antiretroviral therapy; BBB=blood brain barrier.

Factors associated with high-risk low-level viremia leading to virologic failure: 16-year retrospective study of a Chinese antiretroviral therapy cohort

BACKGROUND

Low level viremia (LLV) often occurs during antiretroviral therapy (ART) against HIV-1. However, whether LLV increases the risk of virologic failure (VF) is controversial because of the non-uniform definitions of LLV and VF.

METHODS

A long-term first line regimen ART cohort from 2002 to 2018 from Shenyang, northeast China, was retrospectively studied. All participants were followed up every 3 to 6 months to evaluate the treatment effect. The high-risk LLV subgroups leading to VF (with strict standards) were explored with Cox proportional hazards model and linear mixed-effect model. The association factors of high-risk LLV were further explored using multivariate logistic regression analyses.

RESULTS

A total of 2155 HIV-1 infected participants were included; of these, 38.7% showed LLV. Both high level LLV (HLLV) and any other level LLV coupled with high level blip (HLB) showed higher risk of VF (hazards ratios, HR_HLLV = 5.93, and HR_HLB = 2.84, p <  0.05 respectively). Moreover, HR increased with prolonged duration of LLV. Independent factors associated with high-risk LLV included the zenith baseline viral load (VL) above 6 log copies/ml (aOR = 3.49, p = 0.002), nadir baseline CD4 + T cell counts below 200 cells/mm³ (aOR = 1.78, p = 0.011), Manchu (aOR = 2.03, p = 0.003), ART over 60 months (aOR = 1.81, p = 0.004), AZT + 3TC + NVP (aOR = 2.26, p <  0.001) or DDI-based regimen (aOR = 9.96, p = 0.002), and subtype B' infection (aOR = 8.22, p = 0.001).

CONCLUSIONS

In case of VF with strict standards, high-risk LLV leading to VF includes VL above 400 copies/ml, occurring at least once. Serious laboratory indicators or advanced stage of infection, long term ART and subtype B' infection might also predict the occurrence of high-risk LLV.

Clinical Treatment Options and Randomized Clinical Trials for Neurocognitive Complications of HIV Infection: Combination Antiretroviral Therapy, Central Nervous System Penetration Effectiveness, and Adjuvants

The etiology and pathogenesis of human immunodeficiency virus type-I (HIV)-associated neurocognitive disorders (HAND) remain undetermined and are likely the produce of multiple mechanisms. This can mainly include neuronal injury from HIV, inflammatory processes, and mental health issues. As a result, a variety of treatment options have been tested including NeuroHIV-targeted regimens based on the central nervous system (CNS) penetration effectiveness (CPE) of antiretroviral therapy (ART) and adjuvant therapies for HAND. NeuroHIV-targeted ART regimens have produced consistent and statistically significant HIV suppression in the CNS, but this is not the case for cognitive and functional domains. Most adjuvant therapies such as minocycline, memantine, and selegiline have negligible benefit in the improvement of cognitive function of people living with HIV (PLWH) with mild to moderate neurocognitive impairment. Newer experimental treatments have been proposed to target cognitive and functional symptoms of HAND as well as potential underlying pathogenesis. This review aims to provide an analytical overview of the clinical treatment options and clinical trials for HAND by focusing on NeuroHIV-targeted ART regimen development, CPE, and adjuvant therapies.

Symptomatic cerebrospinal fluid escape

: Cerebrospinal fluid (CSF) viral escape is defined by detectable HIV-RNA in CSF despite undetectable or lower-than-CSF level in plasma of patients receiving combination antiretroviral therapy (cART). This condition may occasionally be associated with neurological problems, consisting of new and progressive cognitive decline and/or focal symptoms and signs, defining the 'symptomatic CSF escape'. Brain MRI usually shows diffuse white matter hyperintensities that recall the presentation of HIV encephalopathy in the precART era. However, patients develop symptomatic CSF escape with relatively high CD4 cell counts and suppressed or low systemic virus replication. In addition, the frequent CSF pleocytosis and the pathological demonstration of CD8 T-cell brain infiltrates in some cases of symptomatic escape indicate that inflammation is an important component in the pathogenesis of this condition. Low nadir CD4 cells are common, likely reflecting the establishment of a HIV reservoir in the central nervous system (CNS). CSF escape seems to result from reactivation of CNS infection when cART potency is lowered, because of low patient's adherence, drug resistance, or use of drug combinations that are poorly effective in the CNS and cART optimization is key to revert escape and neurological disease in the great majority of cases.

CROI 2019: neurologic complications of HIV disease

Investigators reported many new neuroHIV research findings at the 2019 Conference on Retroviruses and Opportunistic Infections (CROI). These findings included confirmation that HIV-associated neurocognitive disorder (HAND) remains common with an increasingly recognized role for comorbidities (eg, obesity) and neurodegenerative conditions (eg, Alzheimer's disease), especially as persons living with HIV (PLWH) advance into their seventh decade of life and beyond. HAND is increasingly recognized as a heterogeneous disorder that differs between individuals (eg, by sex) in the trajectory of specific neurocognitive abilities (eg, executive functioning). A more recent focus at this year's conference was toxicity of combination antiretroviral therapy: neurocognitive performance and neuroimaging data from several studies were presented but did not consistently support that integrase strand transfer inhibitors are associated with worse neurologic outcomes. Neuroimaging studies found that white matter changes reflect a combination of the effects of HIV and comorbidities (including cerebrovascular small vessel disease) and best correlate with blood markers of inflammation. The pathogenesis of HIV in the central nervous system (CNS) was the focus of a plenary lecture and numerous presentations on HIV compartmentalization in the CNS and cerebrospinal fluid viral escape. Novel findings were also presented on associations between HIV-associated neurologic complications and glycomics, neuron-derived exosomes, and DNA methylation in monocytes. This summary will review findings from CROI and identify new research and clinical opportunities.

Cerebrospinal fluid HIV-1 escape according to different thresholds and underlying comorbidities: is it time to assess the definitions?

: No consensus has been reached on how to define cerebrospinal fluid HIV-1 escape (CSF-E). We describe its prevalence in 1095 paired CSF-plasma HIV-RNA measurements from antiretroviral-treated patients according to several definitions and neurological affections. CSF-E prevalence varied substantially (9.0-38.9%) and was higher in patients with cerebrovascular disorders, HIV-associated dementia and white matter abnormalities. Considering the variability in HIV-RNA quantification assays, the biological relevance of viral escape at different thresholds needs to be accurately assessed.

Symptomatic cerebrospinal fluid HIV-1 escape in two patients on second-line antiretroviral therapy in Uganda

Two HIV-infected individuals on second-line atazanavir-based antiretroviral therapy presented with neuropsychiatric symptoms. Cerebrospinal fluid HIV RNA was higher than plasma HIV RNA and antiretroviral regimens’ optimization led to prompt resolution of symptoms in one. Patients on second-line atazanavir-based antiretroviral therapy with documented previous treatment failure may be at risk of symptomatic cerebrospinal fluid escape.

Cerebrospinal fluid compartmentalization of HIV-1 and correlation with plasma viral load and blood-brain barrier damage

PURPOSE

We aimed to evaluate HIV-1 compartmentalization between the cerebrospinal fluid (CSF) and plasma and investigate as to which extent HIV-1 strains in CSF differ from those in blood and whether a correlation with either plasma viral load (pVL) or an altered blood-brain barrier (BBB) does exist.

STUDY DESIGN

We retrospectively evaluated paired CSF/blood samples collected from 86 HIV+ patients. HIV-RNA quantification, pol (PR/RT), and V3 sequencing were performed. HIV coreceptor tropism (CRT) was inferred (g2p, false-positive rate 10%, FPR). Data of standard CSF analysis were also reviewed; an altered CSF/plasma albumin ratio signified BBB damage. Neurological abnormalities (NA) were recorded.

RESULTS

Overall, 32% of patients had a CSF/plasma HIV-RNA ratio > 1 (discordance); 3% of patients had detectable CSF HIV-RNA despite suppressed pVL (escape). Discordance was more frequent in ART-treated patients (p < 0.001) and in patients with NA (p = 0.016), but was independent of BBB damage (p = 0.65) and AIDS diagnosis (p = 0.96). Finally, CSF/plasma discordance was significantly more frequent (p < 0.0001) in patients with lower pVL values (< 10.000 copies/ml). Env divergence > 10% was found in 44% of sequences and was associated with ART (p = 0.008) and NA (p = 0.037). Overall, 24% of patients had a discordant CSF/blood CRT. A 100% nucleotide identity was observed in only 7.3% of pol sequences; notably, 10% of patients had resistance-associated mutations in CSF, but not in blood.

CONCLUSIONS

Our data confirm an independent replication and evolution of HIV within the CSF. A number of factors either hinder or contribute to the compartmentalization of HIV.