Seropositivity and reactivations of HSV-1, but not of HSV-2 nor VZV, associate with altered blood-brain barrier, beta amyloid, and tau proteins in people living with HIV.

Among 128 adult people living with HIV and no neurological conditions confounding the cerebrospinal fluid results, the presence of HSV-1 chronic infection (detected either by serology or PCR), but not of HSV-2 and VZV, independently associated with higher odds of blood-brain barrier impairment, abnormally increased cerebrospinal fluid levels of tau and phosphorylated-181 tau, and decreased concentrations of fragments 1-42 of beta amyloid compared to the seronegative counterpart. These associations were even stronger for seropositive participants with a positive history of at least one symptomatic reactivation of HSV-1.

Brain 18 F-Florbetapir PET/CT Findings in an Early-onset Alzheimer Disease Patient Carrying Presenilin-1 G378E Mutation.

Positron emission tomography (PET) with 18 F-Fluorodeoxyglucose ( 18 F-FDG) plays an outstanding role in the diagnostic work-up of dementia. Amyloid PET imaging is a complementary imaging technique for the early detection of Alzheimer disease (AD). ß-amyloid precursor protein ( APP ), Presenilin-1 ( PSEN1 ) and Presenilin-2 ( PSEN2 ) are the 3 main causative genes responsible for autosomal dominant early-onset Alzheimer disease (EOAD). This is the first report of 18 F-Florbetapir amyloid imaging findings in a 35-year-old male patient with EOAD carrying the G378E mutation in PSEN1 gene. Brain computed tomography (CT) and magnetic resonance imaging scans showed remarkable cerebral atrophy with dilatation of the cerebrospinal fluid spaces; furthermore, a 18 F-Florbetapir PET/CT scan demonstrated also widespread remarkable accumulation of the amyloid tracer in the cerebral cortex, with reduction of the normal contrast between white and gray matter and flattening of the external cortical margins. Furthermore, PET/CT showed intense 18 F-florbetapir uptake in the striatum and in the thalamus bilaterally. Our case supports the usefulness of amyloid PET imaging in the diagnostic work-up of EOAD.

Screening Accuracy of Mini Addenbrooke's Cognitive Examination Test for HIV-Associated Neurocognitive Disorders in People Ageing with HIV.

Aging and increased cardiovascular risk are major drivers for HIV-associated neurocognitive disorders (HAND), for which accurate screenings are lacking. Mini-Addenbrooke's Cognitive Examination (MACE) reliably detects vascular and neurodegenerative cognitive decline among HIV-negative patients. We evaluated MACE diagnostic accuracy in detecting HAND in people living with HIV (PLWH) and we compared it with the International HIV Dementia Scale (IHDS). A single-centre double-blind study of diagnostic accuracy on adult outpatient PLWH without neurocognitive confounding was performed. MACE and IHDS were administered in 5 and 10 min by clinicians, followed by the reference standard battery (14 tests) by neuropsychologists. HAND diagnosis was based on the modified version of Frascati's criteria by Gisslén to reduce false positives. Exploratory cut-offs were evaluated for MACE. Diagnostic accuracy and clinical utility parameters were assessed. 231 patients were enrolled. 75.7% men with a median age, education, and length of infection of 54 (48-59), 10 (8-13) and 16 (5-25) years. HAND prevalence was 48.5% (38.9% asymptomatic impairment). Compared to IHDS, MACE sensitivity (89.3% vs 70.5%), specificity (94.1% vs 63.0%), correct classification rate (86.5% vs 66.7%), J index (0.83 vs 0.34), AUROC (0.97 vs 0.79), agreement with the gold standard (k 0.84 vs 0.33) and effect size in distinguishing HAND vs non-HAND (d 2.11 vs 1.15) were higher. Among PLWH aged 65 years and above (n = 37) MACE performance was consistently better than IHDS. The quick and easy-to-perform MACE could possess an accurate and useful screening performance for HAND in otherwise neurocognitively healthy cohorts of PLWH.

Prevalence and predictors of atrial fibrillation in patients with embolic stroke of undetermined source: a real-life single-center retrospective study.

INTRODUCTION: Up to one-third of ischemic strokes remained cryptogenic despite extensive investigations. Atrial fibrillation may be detected in a significant proportion of patients with embolic stroke of undetermined source, particularly after the introduction of implantable loop recorder in clinical practice. METHODS: We retrospectively included all the consecutive patients with embolic stroke of undetermined source referred to our units in the period November 2013 to December 2018 and in which an implantable loop recorder was positioned within 6 months from stroke event. Prevalence and predictors of atrial fibrillation were investigated. RESULTS: One hundred thirty-eight patients with embolic stroke of undetermined source fulfilling inclusion criteria were identified. The crude prevalence of atrial fibrillation at the end of observation period was of 45.7%. Incidence rates at 6, 12, 18, 24, and 36 months resulted, respectively, 31.8% (95% CI, 30.4-46.7), 38.0% (95% CI, 30.4-46.9), 42.6% (95% CI, 34.5-51.6), 46.6% (95% CI, 38.2-55.8), and 50.4% (95% CI, 41.6-59.9). On multivariate analysis, only excessive supraventricular electric activity and left atrial enlargement resulted to be significant predictors of atrial fibrillation (p = 0.037 and p < 0.0001, respectively). CONCLUSIONS: Atrial fibrillation may be detected in a relevant proportion (up to 50%) of patients with embolic stroke of undetermined source if a careful and extensive diagnostic work-up is employed. Excessive supraventricular electric activity and left atrial enlargement are significant predictors of the occurrence of atrial fibrillation in these patients.

Pilot prospective open, single-arm multicentre study on off-label use of tocilizumab in patients with severe COVID-19.

OBJECTIVES: No agent has yet been proven to be effective for the treatment of patients with severe COVID-19. METHODS: We conducted a pilot prospective open, single-arm multicentre study on off-label use of tocilizumab (TCZ) involving 63 hospitalised adult patients (56 males, age 62.6±12.5) with severe COVID-19. Clinical and laboratory parameters were prospectively collected at baseline, day 1, 2, 7 and 14. No moderate-to-severe adverse events attributable to TCZ were recorded. RESULTS: We observed a significant improvement in the levels of ferritin, C-reactive protein, D-dimer. The ratio of the partial pressure of oxygen (Pa02) to the fraction of inspired oxygen (Fi02) improved (mean±SD Pa02/Fi02 at admission: 152±53; at day 7: 283.73±115.9, at day 14: 302.2±126, p<0.05). The overall mortality was 11%; D-dimer level at baseline, but not IL-6 levels were predictors of mortality. TCZ administration within 6 days from admission in the hospital was associated with an increased likelihood of survival (HR 2.2 95%CI 1.3-6.7, p<0.05). CONCLUSIONS: In hospitalised adult patients with severe COVID-19, TCZ could be a safe option. An improvement in respiratory and laboratory parameters was observed. Future controlled trials in patients with severe illness are urgently needed to confirm the definite benefit with IL-6 target therapy.

Case series of six kidney transplanted patients with COVID-19 pneumonia treated with tocilizumab.

Few reports described the outcome of kidney transplanted patients (KTs) affected by COVID-19 treated with interleukin-6 receptor inhibitor tocilizumab (TCZ). We report our case series of 6 KTs with COVID-19 pneumonia who received TCZ: All were of male gender, with a mean age of 55.5 ± 8.4 years, a median time from transplantation of 3611 days (1465-5757); 5/6 had cardiovascular comorbidities, 1/6 had diabetes, and 3/6 have one or more previous KTs. Four out of six patients died, at an average time of 9.75 ± 2.4 days after tocilizumab administration, 3/6 due to a coexistent septic shock. Two patients improved after TCZ and were discharged at 20 and 21 days, respectively; in both patient, a significant increase of total lymphocyte count was observed. In conclusion, KTs, where the role of peculiar factors such as chronic immunosuppression is still undetermined, represent a high-risk group with significant COVID-19-associated mortality. The evaluation of the TCZ effect in COVID-19 pneumonia requires controlled studies (ideally RCTs) in this specific population.

Cerebrospinal fluid biomarkers in patients with central nervous system infections: a retrospective study.

BACKGROUND: Central nervous system (CNS) may be infected by several agents, resulting in different presentations and outcomes. Analysis of cerebrospinal fluid (CSF) markers could be helpful to differentiate specific conditions and setting an appropriate therapy. METHODS: Patients presenting with signs and symptoms were enrolled if, before receiving a diagnostic lumbar puncture, signed a written informed consent. We analyzed CSF indexes of blood-brain barrier permeability (CSF to serum albumin ratio or CSAR), inflammation (CSF to serum IgG ratio, neopterin), amyloid deposition (1-42 ß-amyloid), neuronal damage (Total tau (T-tau), Phosphorylated tau (P-tau), and 14.3.3 protein) and astrocyte damage (S-100ß). RESULTS: Two hundred and eighty-one patients were included: they were mainly affected by herpesvirus encephalitis, enterovirus meningoencephalitis, bacterial meningitis (Neisseria meningitidis and Streptococcus pneumoniae), and infection by other etiological agents or unknown pathogen. Their CSF features were compared with HIV-negative patients and native HIV-positive individuals without CNS involvement. 14.3.3 protein was found in bacterial and HSV infections while T-tau and neopterin were abnormally high in the herpesvirus group. P-tau, instead, was elevated in enterovirus meningitis. S-100ß was found to be high in patients with HSV-1 and HSV-2 infections but not in those with Varicella Zoster Virus (VZV). Thirty-day mortality was unexpectedly low (2.7%): patients who died had higher levels of T-tau and, significantly, lower levels of Aß1-42. CONCLUSION: This work demonstrates that CSF biomarkers of neuronal damage or inflammation may vary during CNS infections according to different causative agents. The prognostic value of these biomarkers needs to be assessed in prospective studies.

Not Just Homeless, Creutzfeldt-Jakob Disease: A Case Report.

Over a 3-month period, a homeless person was admitted several times to emergency departments after displaying severe behavioral changes and paranoia. No psychiatric tests were performed but all other tests were repeatedly normal; antianxiety treatments or painkillers were the common outcome. It may seem that any diagnosis rested on the patient's immediately apparent social circumstances. Indeed, the patient was admitted to our internal medicine department after a diagnosis of acute delirium within a context of social disadvantage. This social predicament, namely, the patient's evident homelessness, proved to be a false but significant and overarching influence on several misdiagnoses until that moment. Subsequently, actual psychological observations, assessments and tests indicated and confirmed the presence of Creutzfeldt-Jakob disease. Creutzfeldt-Jakob disease is an uncommon and fatal disease; however, early diagnosis can enable the implementation of an important palliative care program. The starkly impoverished social circumstances of a patient should never distract a medical practitioner from a comprehensive diagnosis. Homelessness, for example, may invite certain physical and mental considerations, but it must not overdetermine our response and must not obscure or detract from a wider diagnosis. Homelessness is not a medical condition.

The "milky way" galaxy of HIV-related central nervous system immune reaction syndromes.

The landscape of central nervous system HIV infection is rapidly changing, leading to the recognition of a new constellation of overlapping syndromes and to a better insight for the elder ones. Among these, progressive multifocal leukoencephalopathy (PML) still poses several diagnostic and therapeutic challenges; nevertheless, recent developments in understanding PML in patients with multiple sclerosis may have benefitted HIV-positive patients suffering from PML too. We describe a peculiar case of PML-immune reconstitution inflammatory syndrome (IRIS) presenting a punctate pattern with "milky way" appearance on magnetic resonance imaging. Despite the fact that brain imaging and histopathology remain the mainstays for extricating through the expanding galaxy of HIV-related central nervous system dysimmune syndromes and although punctate pattern has been already well acknowledged as a suggestive finding of PML among patients on natalizumab, this radiological presentation is still poorly recognised in AIDS-related PML cases, leading to possible life-threatening diagnostic delays. This is also the first report about intravenous immunoglobulin treatment in AIDS-related PML-IRIS; the favourable clinical and radiological outcome of our case and the preliminary administrations of intravenous immunoglobulins in natalizumab-associated PML-IRIS from literature support probable benefits also among HIV-positive patients.

Sporadic Fatal Insomnia in Europe: Phenotypic Features and Diagnostic Challenges.

OBJECTIVE: Comprehensively describe the phenotypic spectrum of sporadic fatal insomnia (sFI) to facilitate diagnosis and management of this rare and peculiar prion disorder. METHODS: A survey among major prion disease reference centers in Europe identified 13 patients diagnosed with sFI in the past 20 years. We undertook a detailed analysis of clinical and histopathological features and the results of diagnostic investigations. RESULTS: Mean age at onset was 43 years, and mean disease duration 30 months. Early clinical findings included psychiatric, sleep, and oculomotor disturbances, followed by cognitive decline and postural instability. In all tested patients, video-polysomnography demonstrated a severe reduction of total sleep time and/or a disorganized sleep. Cerebrospinal fluid (CSF) levels of proteins 14-3-3 and t-tau were unrevealing, the concentration of neurofilament light protein (NfL) was more consistently increased, and the real-time quaking-induced conversion assay (RT-QuIC) revealed a positive prion seeding activity in 60% of cases. Electroencephalography and magnetic resonance imaging showed nonspecific findings, whereas fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated a profound bilateral thalamic hypometabolism in 71% of cases. Molecular analyses revealed PrPSc type 2 and methionine homozygosity at PRNP codon 129 in all cases. INTERPRETATION: sFI is a disease of young or middle-aged adults, which is difficult to reconcile with the hypothesis of a spontaneous etiology related to stochastic, age-related PrP misfolding. The combination of psychiatric and/or sleep-related symptoms with oculomotor abnormalities represents an early peculiar clinical feature of sFI to be valued in the differential diagnosis. Video-polysomnography, FDG-PET, and especially CSF prion RT-QuIC and NfL constitute the most promising supportive diagnostic tests in vivo. Ann Neurol 2018;84:347-360.

Symptomatic cerebrospinal fluid HIV-1 escape with no resistance-associated mutations following low-level plasma viremia.

The majority of neurologically symptomatic cerebrospinal fluid HIV-1 escape cases are connected with resistance-associated mutations and potentially explained by low cerebrospinal fluid antiretroviral concentrations. However, there are still significant knowledge gaps regarding the physiopathology and long-term management of neurosymptomatic viral escape. We report a case of Parkinson-like syndrome following cerebrospinal fluid HIV-1 escape in a 40-year-old female patient with an history of persistent low-level plasma viremia under treatment. No resistance-associated mutations, high viral diversity (env deep sequencing), adequate pharmacokinetics, atypical CD3-CD14-CD4+CD5-CD2-/+CD7-/+ lymphocytes, low-level Epstein-Barr virus replication, and white matter autoimmune reactivity were observed in the cerebrospinal fluid. Antiretroviral regimen modification led to rapid clinical and radiological improvements. This case may increase the current uncertain knowledge on the origin of cerebrospinal fluid HIV-1 and illustrates the consequences of uncontrolled compartmental viral replication; it also highlights the relevance and persistence of immune activation and the possibility of various detrimental mechanisms underlying neurosymptomatic viral escape.

A large genomic deletion leads to enhancer adoption by the lamin B1 gene: a second path to autosomal dominant adult-onset demyelinating leukodystrophy (ADLD).

Chromosomal rearrangements with duplication of the lamin B1 (LMNB1) gene underlie autosomal dominant adult-onset demyelinating leukodystrophy (ADLD), a rare neurological disorder in which overexpression of LMNB1 causes progressive central nervous system demyelination. However, we previously reported an ADLD family (ADLD-1-TO) without evidence of duplication or other mutation in LMNB1 despite linkage to the LMNB1 locus and lamin B1 overexpression. By custom array-CGH, we further investigated this family and report here that patients carry a large (∼660 kb) heterozygous deletion that begins 66 kb upstream of the LMNB1 promoter. Lamin B1 overexpression was confirmed in further ADLD-1-TO tissues and in a postmortem brain sample, where lamin B1 was increased in the frontal lobe. Through parallel studies, we investigated both loss of genetic material and chromosomal rearrangement as possible causes of LMNB1 overexpression, and found that ADLD-1-TO plausibly results from an enhancer adoption mechanism. The deletion eliminates a genome topological domain boundary, allowing normally forbidden interactions between at least three forebrain-directed enhancers and the LMNB1 promoter, in line with the observed mainly cerebral localization of lamin B1 overexpression and myelin degeneration. This second route to LMNB1 overexpression and ADLD is a new example of the relevance of regulatory landscape modifications in determining Mendelian phenotypes.

Modulation of cell-cycle dynamics is required to regulate the number of cerebellar GABAergic interneurons and their rhythm of maturation.

The progenitors of cerebellar GABAergic interneurons proliferate up to postnatal development in the prospective white matter, where they give rise to different neuronal subtypes, in defined quantities and according to precise spatiotemporal sequences. To investigate the mechanisms that regulate the specification of distinct interneuron phenotypes, we examined mice lacking the G1 phase-active cyclin D2. It has been reported that these mice show severe reduction of stellate cells, the last generated interneuron subtype. We found that loss of cyclin D2 actually impairs the whole process of interneuron genesis. In the mutant cerebella, progenitors of the prospective white matter show reduced proliferation rates and enhanced tendency to leave the cycle, whereas young postmitotic interneurons undergo severe delay of their maturation and migration. As a consequence, the progenitor pool is precociously exhausted and the number of interneurons is significantly reduced, although molecular layer interneurons are more affected than those of granular layer or deep nuclei. The characteristic inside-out sequence of interneuron placement in the cortical layers is also reversed, so that later born cells occupy deeper positions than earlier generated ones. Transplantation experiments show that the abnormalities of cyclin D2(-/-) interneurons are largely caused by cell-autonomous mechanisms. Therefore, cyclin D2 is not required for the specification of particular interneuron subtypes. Loss of this protein, however, disrupts regulatory mechanisms of cell cycle dynamics that are required to determine the numbers of interneurons of different types and impairs their rhythm of maturation and integration in the cerebellar circuitry.

Intrathecal production of anti-Epstein-Barr virus viral capsid antigen IgG is associated with neurocognition and tau proteins in people with HIV.

OBJECTIVE: HIV and Epstein-Barr virus (EBV) co-infection has been linked to increased immune activation and larger HIV reservoir. We assessed whether anti-EBV humoral responses are associated with increased cerebrospinal fluid (CSF) inflammation and with neurocognitive impairment (NCI) in people with HIV (PWH). DESIGN: Cross-sectional analysis in 123 EBV-seropositive PWH either on antiretroviral therapy ( n  = 70) or not. METHODS: Serum and CSF anti-EBV viral capsid antigen immunoglobulin G (anti-EVI) and CSF EBV DNA were measured by commercial immunoassay and RT-PCR. Seventy-eight participants without neurological confounding factors underwent neurocognitive assessment (Global Deficit Score, GDS). CSF total tau and 181-phosphorylated-tau (ptau) were measured by immunoassays together with biomarkers of blood-brain barrier (BBB) integrity, immune activation, astrocytosis, and intrathecal synthesis. Logistic and linear regressions and moderation analysis were used to investigate the relationships between CSF anti-EVI, GDS, and biomarkers. RESULTS: Twenty-one (17.1%) and 22 participants (17.9%) had detectable CSF anti-EVI (10.5-416.0 U/ml) and CSF EBV DNA (25-971 copies/ml). After adjusting for BBB integrity, age, and clinical factors, the presence of CSF anti-EVI was only associated with serum levels of anti-EVI, and not with CSF EBV DNA. CSF anti-EVI, tau and ptau showed reciprocal interactions affecting their associations with GDS. After adjusting for demographics and clinical parameters, higher CSF anti-EVI levels were associated with worse GDS (aß 0.45, P  < 0.001), and CSF levels of tau and ptau had a moderation effect on the strength of this association (models' P  < 0.001). CONCLUSION: Humoral immune responses against EBV within the central nervous system may contribute to NCI in PWH through mechanisms that involve neuronal injury.

Cannabinoid levels description in a cohort of patients with chronic and neuropathic pain treated with Cannabis decoction: A possible role of TDM.

The phytocomplex of Cannabis is made up of approximately 500 substances: terpeno-phenols metabolites, including Δ-9-tetrahydrocannabinol and cannabidiol, exhibit pharmacological activity. Medical Cannabis has several pharmacological potential applications, in particular in the management of chronic and neuropathic pain. In the literature, a few data are available concerning cannabis pharmacokinetics, efficacy and safety. Thus, aim of the present study was the evaluation of cannabinoid pharmacokinetics in a cohort of patients, with chronic and neuropathic pain, treated with inhaled medical cannabis and decoction, as a galenic preparation. In this study, 67 patients were enrolled. Dried flower tops with different THC and CBD concentrations were used: Bedrocan® medical cannabis with THC level standardized at 19% and with a CBD level below 1%, Bediol® medical cannabis with THC and CBD level standardized at similar concentration of 6.5% and 8%, respectively. Cannabis was administered as a decoction in 47 patients and inhaled in 11 patients. The blood withdrawn was obtained before the new dose administration at the steady state and metabolites plasma concentrations were measured with an UHPLC-MS/MS method. Statistically significant differences were found in cannabinoids plasma exposure between inhaled and oral administration of medical cannabis, between male and female and cigarette smokers. For the first time, differences in cannabinoid metabolites exposures between different galenic formulations were suggested in patients. Therapeutic drug monitoring could be useful to allow for dose adjustment, but further studies in larger cohorts of patients are required in order to confirm these data.

Quantitative analysis of prion disease using an AI-powered digital pathology framework.

Prion disease is a fatal neurodegenerative disorder characterized by accumulation of an abnormal prion protein (PrPSc) in the central nervous system. To identify PrPSc aggregates for diagnostic purposes, pathologists use immunohistochemical staining of prion protein antibodies on tissue samples. With digital pathology, artificial intelligence can now analyze stained slides. In this study, we developed an automated pipeline for the identification of PrPSc aggregates in tissue samples from the cerebellar and occipital cortex. To the best of our knowledge, this is the first framework to evaluate PrPSc deposition in digital images. We used two strategies: a deep learning segmentation approach using a vision transformer, and a machine learning classification approach with traditional classifiers. Our method was developed and tested on 64 whole slide images from 41 patients definitively diagnosed with prion disease. The results of our study demonstrated that our proposed framework can accurately classify WSIs from a blind test set. Moreover, it can quantify PrPSc distribution and localization throughout the brain. This could potentially be extended to evaluate protein expression in other neurodegenerative diseases like Alzheimer's and Parkinson's. Overall, our pipeline highlights the potential of AI-assisted pathology to provide valuable insights, leading to improved diagnostic accuracy and efficiency.

A Novel PSEN1 Variant Leading to Posterior Cortical Atrophy: A Case Report.

We describe a 52-year-old patient with a progressive visuospatial disorder and apraxia. Neuropsychological assessment, neuroradiological findings, and Alzheimer's disease (AD) core biomarker assay on cerebrospinal fluid led to a diagnosis of posterior cortical atrophy due to AD. We performed a next generation sequencing dementia-gene panel and found the c.1301 C>T p.(Ala434Val) variant in the Presenilin1 (PSEN1) gene. The missense change affects the PAL (Pro433-Ala434-Leu435) motif critical for catalytic activity of the macromolecular γ-secretase complex. Evolutionary and integrated bioinformatic tools predicted a deleterious effect of the variant supporting its role in the AD pathogenesis.

A case report and literature review of cognitive malingering and psychopathology.

Malingering of cognitive difficulties constitutes a major issue in psychiatric forensic settings. Here, we present a selective literature review related to the topic of cognitive malingering, psychopathology and their possible connections. Furthermore, we report a single case study of a 60-year-old man with a long and ongoing judicial history who exhibits a suspicious multi-domain neurocognitive disorder with significant reduction of autonomy in daily living, alongside a longtime history of depressive symptoms. Building on this, we suggest the importance of evaluating malingering conditions through both psychiatric and neuropsychological assessment tools. More specifically, the use of Performance Validity Tests (PVTs)-commonly but not quite correctly considered as tests of "malingering"-alongside the collection of clinical history and the use of routine psychometric testing, seems to be crucial in order to detect discrepancies between self-reported patient's symptoms, embedded validity indicators and psychometric results.

Patterns of Cerebrospinal Fluid Alzheimer's Dementia Biomarkers in People Living with HIV: Cross-Sectional Study on Associated Factors According to Viral Control, Neurological Confounders and Neurocognition.

People living with HIV (PLWH) age with an excess burden of comorbidities that may increase the incidence of age-related complications. There is controversy surrounding the hypothesis that HIV can accelerate neurodegeneration and Alzheimer's dementia (AD). We performed a retrospective study to analyze the distribution of cerebrospinal fluid (CSF) AD biomarkers (beta amyloid 1-42 fragment, tau, and phosphorylated tau) in adult PLWH (on cART with undetectable viremia, n = 136, with detectable viremia, n = 121, and with central nervous system CNS disorders regardless of viremia, n = 72) who underwent a lumbar puncture between 2008 to 2018; HIV-negative controls with AD were included (n = 84). Five subjects (1.5%) presented CSF biomarkers that were compatible with AD: one was diagnosed with AD, whereas the others showed HIV encephalitis, multiple sclerosis, cryptococcal meningitis, and neurotoxoplasmosis. Regardless of confounders, 79.6% of study participants presented normal CSF AD biomarkers. Isolated abnormalities in CSF beta amyloid 1-42 (7.9%) and tau (10.9%) were associated with age, biomarkers of intrathecal injury, and inflammation, although no HIV-specific feature was associated with abnormal CSF patterns. CSF levels of AD biomarkers very poorly overlapped between HIV-positive clinical categories and AD controls. Despite the correlations with neurocognitive performance, the inter-relationship between amyloid and tau proteins in PLWH seem to differ from that observed in AD subjects; the main driver of the isolated increase in tau seems represented by non-specific CNS inflammation, whereas the mechanisms underlying isolated amyloid consumption remain unclear.

A new UHPLC-MS/MS method for cannabinoids determination in human plasma: A clinical tool for therapeutic drug monitoring.

Cannabinoid derivates have been largely used for different medical purpose. In the literature, several methods capable of separating THC and its principles metabolites are described, although Δ8- and Δ9-THC separation has not been completely achieved. THC metabolism has not been fully understood and metabolites plasma distribution in healthy and pathological patients remains to further deepen. The aim of this study was the validation of UHPLC-MS/MS method for the quantification of 10 cannabinoids in human plasma, as important tool for improving clinical efficacy of cannabis administration. Obtained results were in accordance with recommendations of ICH Harmonised Guideline for bioanalytical method validation, showing a good linearity, optimal accuracy as well as satisfactory results in terms of intra-day and inter-day precision and matrix effect. Furthermore, blood sampling study was performed to investigate the better collection method. Optimal separation of Δ-9-tetrahydrocannabinol (Δ9-THC), Δ8-tetrahydrocannabinol (Δ8-THC) was obtained. The present method showed optimal linearity and satisfactory results in terms of specificity and selectivity. Recovery was between 92.0% and 96.5% for all analytes. The matrix-effect showed good performance; no carry over was observed. Cannabinoid metabolites present in higher plasma concentrations were: 11-Hydroxy-Δ9-tetrahydrocannabinol, 11-Nor-9carboxy-Δ9-tetrahydrocannabinol and THC-COOH-glucuronide. Method performance makes it suitable for routine purposes and a potential tool for therapeutic ranges definition. The present work will be used to test several samples in a long-term clinical study, paving the way for further future works.