Cerebrospinal Fluid Viral Load Research Articles

Practical approach to method verification in plasma and validation in cerebrospinal fluid under accreditation using a flexible scope in molecular virology: setting up the HIV, HBV and HCV Aptima™ Quant Dx assays.

Background Our laboratory obtained the ISO 15189 accreditation for the plasmatic HIV-1, HBV and HCV viral load (VL) using the m2000 RealTime™ system, which was recently changed for the platform Panther®. Here, we discuss a strategy for performing method validation/verification very quickly. Methods We performed the mandatory (repeatability, internal quality assessment [IQA], measurement uncertainty [MU]) and optional technical verifications for CE/IVD assays using the flexible scope range A. We also performed the mandatory assays for the validation of HIV-1 VL in the cerebrospinal fluid (CSF) using the flexible scope range B. The change was checked by following up on the turnaround time (TAT). Results The coefficient of variation (CV%) for repeatability and IQA complied with the limit of 0.25 log. The MU results ranged from 0.04 to 0.25 log copies or IU/mL. The comparisons of methods showed excellent correlations (R2 = 0.96 for the three parameters) but a delayed centrifugation on HCV VL showed variations of up to 2 log IU/mL. An excellent linearity for HIV-1 in the CSF was obtained from 1.5 to 5 log copies/mL with R2 = 0.99. The TAT increased (84%-98%) in routine usage. Conclusions The three Aptima assays are well suited for routine laboratory use and can be integrated within less than 2 weeks in accordance with flexible scope range A. Our data allows us to confidently perform HIV-1 VL in CSF following flexible scope range B. Finally, we provide an organizational guide for flexible scope management in molecular virology within a short time frame.

Neuroinflammatory Changes in Relation to Cerebrospinal Fluid Viral Load in Simian Immunodeficiency Virus Encephalitis.

The exact cause of neurocognitive dysfunction in HIV-positive patients despite successful control of the infection in the periphery is not completely understood. One suggested mechanism is a vicious cycle of microglial activation and release of proinflammatory chemokines/cytokines that eventually leads to neuronal loss and dysfunction. However, the exact role of microglial activation in the earliest stages of the infection with high cerebrospinal fluid (CSF) viral loads (VL) is unclear. In this study, we imaged the translocator protein (TSPO), a mitochondrial membrane receptor known to be upregulated in activated microglia and macrophages, in rhesus macaques before and multiple times after inoculation with a neurotropic simian immunodeficiency virus (SIV) strain (SIVsm804E), using 18F-DPA714 positron emission tomography (PET). The whole-brain standardized uptake values of TSPO at equilibrium reflecting total binding (SUVT) and binding potentials (BPND) were calculated and correlated with CSF and serum markers of disease, and a corresponding postmortem immunostaining analysis was also performed. SUVT was found to be inversely correlated with both CSF VL and monocyte chemoattractant protein 1 (MCP-1) levels. In SIV-infected macaques with very high CSF VL at necropsy (>106 copies/ml), we found decreased TSPO binding by PET, and this was supported by immunostaining which showed glial and neuronal apoptosis rather than microglial activation. On the other hand, with only moderately elevated CSF VL (∼104 copies/ml), we found increased TSPO binding as well as focal and diffuse microglial activation on immunostaining. Our results in the SIV-infected macaque model provide insights into the relationship between HIV neuropathology and CSF VL at various stages of the disease.IMPORTANCE Neurological and cognitive problems are a common complication of HIV infection and are prevalent even in treated individuals. Although the molecular processes underlying brain involvement with HIV are not completely understood, inflammation is suspected to play a significant role. Our work presents an in vivo assessment of neuroinflammation in an animal model of HIV, the simian immunodeficiency virus (SIV)-infected rhesus macaque. Using positron emission tomography (PET) imaging, we identified changes in brain inflammation after inoculation with SIV over time. Interestingly, we found decreased binding of the PET ligand in the presence of very high cerebrospinal fluid (CSF) viral loads. These findings were supported by immunostaining which showed marked glial loss instead of inflammation. This study provides insight into glial and neuronal changes associated with very high CSF viral load and could reflect similar changes occurring in HIV-infected patients.

CNS HIV virus persistence irrespective of CD4 T cell trafficking

Abstract Incomplete HIV virologic suppression in the central nervous system (CNS) can cause persisting neurologic disorders even with suppressed plasma viremia. To better understand immune properties that support CNS virus persistence we characterized T cells and virus genotypes from cerebrospinal fluid (CSF) of HIV-infected participants to understand local cell trafficking behavior and the influence of combination antiretroviral therapy (ART). Compared to blood, CSF T cells expressed higher frequencies of CCR5****, CD69****, CX3CR1****, CD39**, and HLADR**(P values:*≤0.05, **≤0.01, ***≤0.001,****≤0.0001). Among CSF T cells, CD4 T cells were more likely to express CCR7****, CX3CR1****, and CD39**, and less likely to express CCR5*. CX3CR1 expression on CSF CD4 T cells correlated with CSF viral load (VL)*, whereas, CD39 expression mirrored CSF** and plasma VL*. In the absence of ART, CSF HIV (VL>900 copies/mL) shared majority sequence similarity to plasma virus demonstrating a migratory influence of susceptible cells into the CNS. However, CSF CD4 T cells from persons on ART expressed decreased CCR5**, CX3CR1****, HLADR****, and CD39***, regardless of viral suppression, while matched-PBMC CD4 T cells did not exhibit these trends. CSF CD4 T cells expressed features consistent with immune-restricted localization but with a migratory profile indicative of immune surveillance function and lymphoid trafficking. ART use associated with reduced migratory properties regardless of CNS viremia, suggesting ongoing CNS HIV replication under therapy involves local susceptible cells distinct from circulation. This CSF cellular profile could serve as a reference to target biomedical interventions that improve HIV suppression in the CNS.

Detection of varicella-zoster virus from cerebrospinal fluid using advanced fragment analysis in a child with encephalitis: a case report

BackgroundVaricella zoster virus (VZV) encephalitis is an infectious inflammatory disease of brain that can cause irreversible mental damage without timely treatment. In fact, many viruses can cause encephalitis, and the viral loads in cerebrospinal fluid (CSF) in the early stage of the disease are usually too low to be detected. Here we report a case of VZV encephalitis diagnosed by advanced fragment analysis (AFA), which could potentially to contribute to early diagnosis of VZV central nervous system (CNS) infections with a small volume of CSF samples.Case presentationA 10-year-old boy was admitted to the hospital with obvious neurological symptoms of headache, dizziness and vomiting for one day. Physical examination showed left facial paralysis. Complete blood count (CBC) test only showed an unspecific inflammation, and the culture of cerebrospinal fluid and microscopic staining examination were all negative. AFA was performed to screen the common 18 encephalitis related pathogens in CSF. Obvious VZV DNA fragments were observed by capillary electrophoresis at 160 nt, suggesting the existence of VZV CNS infection in children. The results were consistence with real-time quantitative PCR and concomitant symptoms in the acute stage of the disease.ConclusionsWe report a case of acute VZV encephalitis in a child without obvious skin manifestations, which was rapidly diagnosed by AFA. Overall, we would recommend the use of AFA analysis as the rapid screening system for the identification and differentiation of encephalitis pathogens in children.

P59 Acute varicella zoster encephalitis? Don’t forget the treatment!

ObjectivesEducate physicians on the need for monitoring of Aciclivir levels in renal failure.DesignRetrospective case report.Subjects59 year old woman presented with acute psychosis following recent herpes zoster treated with oral Aciclovir.MethodsData collection from; original casenotes, electronic laboratory records, electronic picture archiving and communication system (PACS).ResultsLumbar puncture showed raised protein (0.92 g/L), CSF:serum glucose ratio(0.9), 36 WBCs/cmm(72% polymorphs) and detection of VZV DNA. MRI brain only revealed intracranial-hypotension secondary to lumbar puncture. Despite absence of VZV DNA on surveillance lumbar puncture, she remained minimally responsive. Aciclovir levels were significantly elevated post-dose at 32.7 mg/L (cutoff 10.8 mg/L) and a sedation hold revealed temporal correlation of pre-dose levels (6.4 mg/L) with improvement of GCS, strongly implicating Aciclovir as causative agent. Rapid resolution of encephalopathy occurred upon cessation with no residual neurological compromise.ConclusionsAciclovir neurotoxicity mimics zoster-related encephalitis and VZV DNA is commonly detected in cerebrospinal fluid of patient’s with herpes zoster (Rudzek et al. 2007). Our case highlights the need for vigilance of Aciclovir-neurotoxicity in renal failure patients.ReferenceRudzek D, Piskunova N, Zampachova E. High variability in viral load in cerebrospinal fluid from patients with herpes simplex and varicella-zoster infections of the central nervous system. Clinical Microbiology and Infection2007;13(12):1217–1219.

Bilateral Peripheral Facial Paralysis Combined with HIV Meningitis During Acute HIV-1 Infection: A Case Report

Here we reported a Chinese case of bilateral peripheral facial paralysis (PFP) in human immunodeficiency virusc (HIV) infected population. A 38-year-old homosexual male patient was referred to our hospital for bilateral facial paralysis. 21 days prior to admission he had developed high fever, chills, headache, fatigue, general malaise, nausea and vomiting. Neurological examination revealed bilateral ptosis of lower lip and cheeks, as well as failure of bilateral eyes closure. Analysis of cerebrospinal fluid (CSF) revealed pleocytosis, a marked rise of micro total protein and a marked rise of intrathecal lgG synthesis. The result of HIV-1 serology was positive by ELISA and that was confirmed by western blot. His CD4 + cell count was 180 cells/mm 3. HIV-1 viral load in CSF was almost 10 times higher than that in plasma. The patient's condition improved steadily and experienced complete resolution of bilateral PFP after 2 months.

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

Aim of this study was to estimate the prevalence of cerebrospinal fluid (CSF)/Plasma HIV-1 RNA discordance in virologically suppressed individuals presenting with incident neurologic symptoms.In this retrospective cohort study conducted between March 1, 2009, and March 1, 2017, HIV-1 infected adults exposed to atleast 12 months of antiretroviral therapy (ART) and having plasma viral load (VL) <1000 copies/mL (virologically suppressed) were included. Among these, individuals presenting with neurologic symptoms during follow-up were assessed for CSF/Plasma HIV-1 RNA discordance by measuring HIV-1 RNA in collected plasma and CSF samples. CSF/plasma HIV-1 RNA discordance was defined as either detectable CSF HIV-1 RNA (VL > 20 copies/mL) with an undetectable plasma RNA (complete viral suppression, VL ≤20 copies/mL) or CSF HIV-1 RNA ≥ 0.5 log10 higher than plasma RNA when plasma VL was between 20 and 1000 copies/mL (low-level viremia, LLV).Out of 1584 virologically suppressed patients, 71 (4.4%) presented with incident neurologic symptoms. Twenty out of 71 (28.2%) patients were diagnosed with CSF/Plasma HIV-1 discordance. Median plasma and CSF VL in patients with discordance was 120 [interquartile range (IQR): <20 to 332.5] and 4250 (IQR: 2550.0– 9615.0) copies/mL, respectively. All 9 individuals in which CSF HIV-1 genotypic resistance testing was done showed mutations that would compromise efficacy of prescribed ART regimen. Prevalence of CSF/plasma HIV-1 RNA discordance was higher among neurologically symptomatic patients with plasma LLV as compared with those with complete viral suppression (70% vs 11.8%, P < .001). The risk of discordance was also greater in patients who received protease inhibitor (PI) containing ART (P < .001) and those on ART regimens with central nervous system (CNS) penetration effectiveness (CPE) value <6 (P = .006).CSF/plasma HIV-1 RNA discordance indicates replication of HIV-1 that has adapted to the CNS or has developed antiretroviral drug resistance. Larger studies should be performed to study incidence of discordance in India. This will help in managing patients presenting with neurologic symptoms on suppressive ART with appropriate neuroeffective therapy.

Cerebrospinal fluid (CSF) biomarkers of iron status are associated with CSF viral load, antiretroviral therapy, and demographic factors in HIV-infected adults

BackgroundHIV-associated neurocognitive disorder (HAND) remains common, despite antiretroviral therapy (ART). HIV dysregulates iron metabolism, but cerebrospinal fluid (CSF) levels of iron and iron-transport proteins in HIV-infected (HIV+) persons are largely unknown. The objectives of this study were to characterize CSF iron-related biomarkers in HIV+ adults and explore their relationships to known predictors of HAND.MethodsWe quantified total iron, transferrin and heavy-chain (H)-ferritin by immunoassay in CSF sampled by lumbar puncture in 403 HIV+ participants in a multi-center, observational study and evaluated biomarker associations with demographic and HIV-related correlates of HAND [e.g., age, sex, self-reported race/ethnicity, ART, and detectable plasma virus and CSF viral load (VL)] by multivariable regression. In a subset (N = 110) with existing CSF: serum albumin (QAlb) measurements, QAlb and comorbidity severity were also included as covariates to account for variability in the blood–CSF-barrier.ResultsAmong 403 individuals (median age 43 years, 19% women, 56% non-Whites, median nadir CD4+ T cell count 180 cells/µL, 46% with undetectable plasma virus), men had 25% higher CSF transferrin (median 18.1 vs. 14.5 µg/mL), and 71% higher H-ferritin (median 2.9 vs. 1.7 ng/mL) than women (both p-values ≤0.01). CSF iron was 41% higher in self-reported Hispanics and 27% higher in (non-Hispanic) Whites than in (non-Hispanic) Blacks (median 5.2 and 4.7 µg/dL in Hispanics and Whites, respectively, vs. 3.7 µg/dL in Blacks, both p ≤ 0.01); these findings persisted after adjustment for age, sex, and HIV-specific factors. Median H-ferritin was 25% higher (p < 0.05), and transferrin 14% higher (p = 0.06), in Whites than Blacks. Transferrin and H-ferritin were 33 and 50% higher, respectively, in older (age > 50 years) than in younger persons (age ≤ 35 years; both p < 0.01), but these findings lost statistical significance in subset analyses that adjusted for QAlb and comorbidity. After these additional adjustments, associations were observed for CSF iron and transferrin with race/ethnicity as well as CSF VL, for transferrin with sex and ART, and for H-ferritin with plasma virus detectability and significant comorbidity (all p < 0.05).ConclusionsCSF iron biomarkers are associated with demographic factors, ART, and CSF VL in HIV+ adults. Future studies should investigate a role for CNS iron dysregulation, to which an altered blood-CSF barrier may contribute, in HAND.

Cerebrospinal fluid cell-free mitochondrial DNA is associated with HIV replication, iron transport, and mild HIV-associated neurocognitive impairment

BackgroundMitochondria are abundant organelles critical for energy metabolism and brain function. Mitochondrial DNA (mtDNA), released during cellular injury and as part of the innate immune response to viral pathogens, contains CpG motifs that act as TLR-9 ligands. We investigated relationships between cerebrospinal fluid (CSF) cell-free mtDNA levels and HIV viral load (VL), biomarkers of inflammation and iron transport, and neurocognitive (NC) function in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort.MethodsWe quantified cell-free mtDNA in CSF by droplet digital PCR in 332 CHARTER participants who underwent comprehensive neuropsychiatric evaluation. NC performance was assessed using the global deficit score (GDS) as either a continuous or a binary measure (GDS ≥ 0.5, impaired vs. GDS < 0.5, unimpaired). CSF, clinical, and biomarker data from the earliest available time point were analyzed. Cell-free mtDNA associations with CSF inflammation and iron-related biomarkers [CXCL10, IL-6, IL-8, TNF-a, transferrin (TF), ceruloplasmin (CP), and vascular endothelial growth factor (VEGF)], VL, and GDS were evaluated by multivariable regression.ResultsCSF cell-free mtDNA levels were significantly lower in participants with undetectable (vs. detectable) VL in either plasma (p < 0.001) or CSF (p < 0.001) and in those on antiretroviral therapy (ART; p < 0.001). Participants on ART with undetectable VL in both CSF and plasma had lower mtDNA levels than those with detectable VL in both compartments (p = 0.001). Higher mtDNA levels were observed in participants in the highest vs. lowest tertile (T3 vs. T1) of CSF CXCL10 (T3 vs. T1, p < 0.001) and TNF-a (T3 vs. T1, p < 0.05) in unadjusted analyses. MtDNA levels also correlated with CSF leukocyte count. After adjusting for CSF leukocyte count and VL, mtDNA levels were also associated with other inflammation- and iron-related biomarkers in CSF, including TF (T3 vs. T1, p < 0.05) and CP (T3 vs. T1, p < 0.05). With additional correction for ART use, mtDNA was also negatively associated with CSF VEGF (p < 0.05) and IL-6 (p = 0.05). We observed no associations of CSF mtDNA levels with age or GDS-defined NC impairment.ConclusionsCSF cell-free mtDNA levels were associated with HIV RNA and ART status, as well as with biomarkers of iron transport and VEGF, a growth factor with known effects on mitochondrial integrity and autophagy. CSF mtDNA may be a biomarker of iron dysregulation and/or neuroinflammation during HIV infection.

Relationship of Human Immunodeficiency Virus Viral Load in Cerebrospinal Fluid and Plasma in Patients Co-infected With Cryptococcal Meningitis.

We measured human immunodeficiency virus (HIV) ribonucleic acid (RNA) in paired cerebrospinal fluid (CSF) and plasma samples in a prospective study of 91 HIV-infected, antiretroviral therapy-naive patients with cryptococcal meningitis. Cerebrospinal fluid HIV RNA was lower than in plasma (median 4.7 vs 5.2 log10 copies/mL, P < .0001) and positively correlated with plasma HIV RNA, peripheral CD4+ T-cell percentage, and CSF CXCL10. Plasma/CSF ratio of HIV RNA ranged widely from 0.2 to 265.5 with a median of 2.6. Cerebrospinal fluid quantitative cryptococcal culture positively correlated with CSF CCL2 and CCL3. CSF-plasma viral discordance was not associated with cryptococcal-associated immune reconstitution inflammatory syndrome.

Reactivation of simian immunodeficiency virus reservoirs in the brain of virally suppressed macaques.

Objective:Resting CD4+ T cells have been recognized as the major cell reservoir of latent HIV-1 during antiretroviral therapy (ART). Using an simian immunodeficiency virus (SIV)/macaque model for AIDS and HIV-related neurocognitive disorders we assessed the contribution of the brain to viral latency and reactivation.Design:Pigtailed macaques were dual inoculated with SIVDeltaB670 and SIV17E-Fr and treated with an efficacious central nervous system-penetrant ART. After 500 days of viral suppression animals were treated with two cycles of latency reversing agents and increases in viral transcripts were examined.Methods:Longitudinal plasma and cerebrospinal fluid (CSF) viral loads were analyzed by quantitative and digital droplet PCR. After necropsy, viral transcripts in organs were analyzed by PCR, in-situ hybridization, and phylogenetic genotyping based on env V1 loop sequences. Markers for neuronal damage and CSF activation were measured by ELISA.Results:Increases in activation markers and plasma and CSF viral loads were observed in one animal treated with latency reversing agents, despite ongoing ART. SIV transcripts were identified in occipital cortex macrophages by in-situ hybridization and CD68+ staining. The most abundant SIV genotype in CSF was unique and expanded independent from viruses found in the periphery.Conclusion:The central nervous system harbors latent SIV genomes after long-term viral suppression by ART, indicating that the brain represents a potential viral reservoir and should be seriously considered during AIDS cure strategies.

Cytomegalovirus Polyradiculopathy in the Modern Age of Human Immunodeficiency Virus Therapies

Abstract Cytomegalovirus (CMV) polyradiculopathy in human immunodeficiency virus–infected patients is an increasingly rare disease given the widespread availability of effective antiretroviral therapy. Here, we describe a case of CMV polyradiculopathy in a man following the initiation of antiretrovirals. The patient presented with a 2-week history of rapidly progressing bilateral lower extremity weakness resulting in paraplegia; he was diagnosed with CMV polyradiculopathy based on cerebrospinal fluid and magnetic resonance imaging findings. Treatment with ganciclovir, foscarnet, and antiretroviral therapy resulted in rapid reduction of CMV viral load in cerebrospinal fluid and halting of disease progression. Six months after presentation, the patient continues to show improvement in lower extremity strength and has regained the ability to ambulate without assistance for short distances.

Cerebrospinal fluid viral load and biomarkers of neuronal and glial cells in Ramsay Hunt syndrome.

Reactivation of varicella zoster virus (VZV) can manifest with facial palsy diagnosed as Ramsay Hunt Syndrome (RHS) or Ramsay Hunt Syndrome zoster sine herpete (RHS-ZSH). These syndromes are associated with poor prognosis despite treatment with antivirals and corticosteroids. Concentrations of biomarkers such as neurofilament protein (NFL), S-100β protein and glial fibrillary acidic protein (GFAp) have previously been measured in cerebrospinal fluid (CSF) to assess neuronal damage and glial pathology. We employed immunochemical methods to measure concentrations of NFL, S-100β protein and GFAp in CSF from patients with RHS (n=15) and RHS-ZSH (n=13) diagnosed by detection of VZV DNA in the CSF by quantitative PCR, and compared with a control group (n=52). The biomarker concentrations were correlated with CSF viral load and outcome measured by House-Brackmann score. NFL and GFAp concentrations were increased compared with controls (P=0.008 and P=0.04), while S-100β levels were decreased. This pattern was more pronounced in patients with RHS compared to the patients with RHS-ZSH (NS and P=0.028). The amount of viral DNA in CSF correlated with increased GFAp (P=0.003) and NFL (P=0.006). No correlations were found between biomarker concentrations and patient outcome. Patients with facial palsy caused by VZV had biochemical signs of neuronal damage and astrogliosis. High amounts of viral DNA may be associated with the degree of damage on neuronal and astroglial cells. Prospective studies are warranted to elucidate the association of elevated biomarkers in the CSF and outcome assessed by more sensitive tests.

Putamen volume and its clinical and neurological correlates in primary HIV infection.

Little is known about the extent of cortical and subcortical volumetric alterations that may occur within the first year of HIV infection [primary HIV infection (PHI)]. We used structural MRI in this prospective cross-sectional neuroimaging study to determine the extent of volumetric changes in early HIV infection. Cerebrospinal fluid, blood, neuropsychological testing, and structural T1 MRI scans were acquired from 18 HIV and 47 PHI age-matched antiretroviral-naïve male participants. Using FreeSurfer 5.1, volumetric measurements were obtained from the caudate, amygdala, corpus callosum, ventricles, putamen, thalamus, cortical white matter, and total gray matter. Regional volumes were compared groupwise and related to biomarkers in cerebrospinal fluid (viral load, neopterin, and neurofilament light chain), blood (viral load, CD4, and CD8 T-cell count), and neuropsychometric tests (digit-symbol, grooved pegboard, finger-tapping, and timed gait). A trend-level moderate reduction of putamen volume (P = 0.076, adjusted Cohen's d = 0.5 after controlling for age) was observed for PHI compared with HIV-uninfected individuals. Within the PHI group, putamen volume associated with CD4 cell count (P = 0.03), CD4/CD8 ratio (P = 0.045), infection duration (P = 0.009), and worsening psychomotor performance on the digit-symbol (P = 0.028), finger-tapping (P = 0.039), and timed gait (P = 0.009) tests. Our volumetric results suggest that the putamen is preferentially susceptible to early HIV-associated processes. Examining the natural course of early HIV infection longitudinally will allow for mapping of the trajectory of HIV-associated central nervous system changes, enabling creation of improved interventional strategies to potentially stabilize or reverse these observed structural changes.

Enhanced antagonism of BST-2 by a neurovirulent SIV envelope.

Current antiretroviral therapy (ART) is not sufficient to completely suppress disease progression in the CNS, as indicated by the rising incidence of HIV-1-associated neurocognitive disorders (HAND) among infected individuals on ART. It is not clear why some HIV-1-infected patients develop HAND, despite effective repression of viral replication in the circulation. SIV-infected nonhuman primate models are widely used to dissect the mechanisms of viral pathogenesis in the CNS. Here, we identified 4 amino acid substitutions in the cytoplasmic tail of viral envelope glycoprotein gp41 of the neurovirulent virus SIVsm804E that enhance replication in macrophages and associate with enhanced antagonism of the host restriction factor BM stromal cell antigen 2 (BST-2). Rhesus macaques were inoculated with a variant of the parental virus SIVsmE543-3 that had been engineered to contain the 4 amino acid substitutions present in gp41 of SIVsm804E. Compared with WT virus-infected controls, animals infected with mutant virus exhibited higher viral load in cerebrospinal fluid. Together, these results are consistent with a potential role for BST-2 in the CNS microenvironment and suggest that BST-2 antagonists may serve as a possible target for countermeasures against HAND.

Cerebrospinal Fluid Biomarkers of Simian Immunodeficiency Virus Encephalitis : CSF Biomarkers of SIV Encephalitis.

Antiretroviral therapy has led to increased survival of HIV-infected patients but also increased prevalence of HIV-associated neurocognitive disorders. We previously identified YKL40 as a potential cerebrospinal fluid (CSF) biomarker of lentiviral central nervous system (CNS) disease in HIV-infected patients and in the macaque model of HIV encephalitis. The aim of this study was to define the specificity and sensitivity along with the predictive value of YKL40 as a biomarker of encephalitis and to assess its relationship to CSF viral load. CSF YKL40 and SIV RNA concentrations were analyzed over the course of infection in 19 SIV-infected pigtailed macaques and statistical analyses were performed to evaluate the relationship to encephalitis. Using these relationships, CSF alterations of 31 neuroimmune markers were studied pre-infection, during acute and asymptomatic infection, at the onset of encephalitis, and at necropsy. YKL40 CSF concentrations above 1122ng/ml were found to be a specific and sensitive biomarker for the presence of encephalitis and were highly correlated with CSF viral load. Macaques that developed encephalitis had evidence of chronic CNS immune activation during early, asymptomatic, and end stages of infection. At the onset of encephalitis, CSF demonstrated a rise of neuroimmune markers associated with macrophage recruitment, activation and interferon response. CSF YKL40 concentration and viral load are valuable biomarkers to define the onset of encephalitis. Chronic CNS immune activation precedes the development of encephalitis while some responses suggest protection from CNS lentiviral disease.

Immune Activation and HIV-Specific CD8(+) T Cells in Cerebrospinal Fluid of HIV Controllers and Noncontrollers.

The central nervous system (CNS) is an important target of HIV, and cerebrospinal fluid (CSF) can provide a window into host-virus interactions within the CNS. The goal of this study was to determine whether HIV-specific CD8(+) T cells are present in CSF of HIV controllers (HC), who maintain low to undetectable plasma viremia without antiretroviral therapy (ART). CSF and blood were sampled from 11 HC, defined based on plasma viral load (VL) consistently below 2,000 copies/ml without ART. These included nine elite controllers (EC, plasma VL <40 copies/ml) and two viremic controllers (VC, VL 40-2,000 copies/ml). All controllers had CSF VL <40 copies/ml. Three comparison groups were also sampled: six HIV noncontrollers (NC, VL >10,000 copies/ml, no ART); seven individuals with viremia suppressed due to ART (Tx, VL <40 copies/ml); and nine HIV-negative controls. CD4(+) and CD8(+) T cells in CSF and blood were analyzed by flow cytometry to assess expression of CCR5, activation markers CD38 and HLA-DR, and memory/effector markers CD45RA and CCR7. HIV-specific CD8(+) T cells were quantified by major histocompatibility complex class I multimer staining. HIV-specific CD8(+) T cells were detected ex vivo at similar frequencies in CSF of HC and noncontrollers; the highest frequencies were in individuals with CD4 counts below 500 cells/μl. The majority of HIV-specific CD8(+) T cells in CSF were effector memory cells expressing CCR5. Detection of these cells in CSF suggests active surveillance of the CNS compartment by HIV-specific T cells, including in individuals with long-term control of HIV infection in the absence of therapy.

Enterovirus meningitis in Tunisia (Monastir, Mahdia, 2011–2013): identification of virus variants cocirculating in France

Acute enterovirus (EV) meningitis is a frequent cause of hospitalisation, and over 100 EV serotypes may be involved. A total of 215 patients of all ages with meningitis signs were investigated in 2 Tunisian hospitals. Their cerebrospinal fluid (CSF) was analysed retrospectively for EVs with a TaqMan real-time RT-qPCR. The virus strains were typed, and their evolutionary relationships were determined by Bayesian phylogenetic methods. An EV genome was detected in 21/215 patients (9.8%). The CSF viral loads ranged from 3.27 to 5.63 log10 genome copies/mL. The strains were identified in 13/21 patients and assigned to EV-B types. Viruses identified in Tunisian patients were genetically related to variants detected in France. The viral loads were similar in Tunisian and French patients for most EV types. The phylogenetic data and viral loads determined in Tunisian and French patients suggest that close EV variants were involved in aseptic meningitis in the 2 countries over a same period.

Relevance of retrovirus quantification in cerebrospinal fluid for neurologic diagnosis.

Different human retroviruses, such as Human Immunodeficiency Virus (HIV) and Human T-cell Lymphotropic Virus (HTLV), can cause neurologic infection. However, a definitive diagnosis may be hampered by several factors. Quantification of the viral or proviral load in cerebrospinal fluid (CSF) may be helpful in the diagnosis of nervous system disorders due to retroviral infection and may influence the treatment approach. The present work discusses retrovirus infection and neurologic impairment, as well as the usefulness of the determination of the HIV and HTLV proviral or viral load in cerebrospinal fluid in cases of neurologic disorder, in light of recent advances in this field. This study also discusses the different molecular techniques for quantifying the proviral load (real-time quantitative PCR, droplet digital PCR, and semi-nested real-time reverse transcription PCR) that are currently available.

Cerebrospinal fluid and plasma lopinavir concentrations and viral response in virologically suppressed patients switching to lopinavir/ritonavir monotherapy once daily.

Lopinavir/ritonavir (LPV/r) monotherapy is used in selected virologically suppressed HIV-infected patients. Some would prefer a once-daily (OD) dose instead of the usual twice-daily dose to favour adherence. However, trough concentrations of the drug in blood and particularly in cerebrospinal fluid (CSF) may not be adequate to maintain viral suppression. Prospective, open-label pilot study to evaluate the efficacy and safety of LPV/r monotherapy OD. HIV-1-infected patients, virologically suppressed for at least 6 months were enrolled. HIV viral load (VL) was determined at baseline and at weeks 4, 8, 12, 16, 24, 36 and 48. Lumbar puncture was performed in a subgroup of patients to evaluate CSF VL and CSF LPV concentrations. A total of 21 patients were included. At week 48, 85.7% (n=18) showed viral suppression (VL<40 copies/ml). Two patients had viral failure (9.5%) and a third was withdrawn from the study because of gastrointestinal symptoms. Nine patients were enrolled in the substudy. CSF VL was <40 copies/ml in all cases. Median (range) LPV concentration was 9.78 ng/ml (1.93-78.3) in CSF and 1,970 (154-16,700) ng/ml in plasma; the CSF/plasma ratio was 0.004 (0.001-0.186). In this small pilot study, LPV/r monotherapy OD maintained plasma HIV RNA suppression at 48 weeks in most patients, with no cases of CSF viral escape. However, CSF LPV concentrations were close to the 50% inhibitory concentration threshold in several patients; hence, this intervention should be avoided in patients with advanced immune suppression and/or those individuals presenting with significant comorbidities such as hepatitis C coinfection.