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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.

BackgroundPlasma C-X-C-motif chemokine ligand-13 (CXCL13) has been linked to disease progression and mortality in people living with HIV (PLWH) and is a candidate target for immune-based strategies for HIV cure. Its role in central nervous system (CNS) of PLWH has not been detailed. We described CSF CXCL13 levels and its potential associations with neurological outcomes.MethodsCross-sectional study enrolling PLWH without confounding for CXCL13 production. Subjects were divided according to CSF HIV-RNA in controllers (Results175 subjects were included. Prevalence of detectable CSF CXCL13 was higher in viremics (31.4%) compared to controllers (13.5%; OR 2.9 [1.4-6.3], p=0.006), but median CSF levels did not change (15.8 [8.2-91.0] vs 10.0 [8.1-14.2] pg/mL). In viremics (n=86), CXCL13 associated with higher CSF HIV-RNA, proteins, neopterin, Tourtelotte index, and CSF-to-serum albumin ratio. In controllers (n=89), CXCL13 associated with higher CD4+T-cells count, CD4/CD8 ratio, CSF proteins, neopterin, and several intrathecal synthesis markers. Detection of CSF CXCL13 in controllers increased the likelihood of HIV-associated neurocognitive disorders (58.3% vs 28.6%, p=0.041) and HIV-related CNS disorders (8.3% vs 0%, p=0.011). Sensitivity analyses confirmed all these findings.ConclusionsCSF CXCL13 identified a subgroup of PLWH presenting increased CNS IgG synthesis, and immune activation. In controllers, CSF CXCL13 associated with increased likelihood of neurocognitive impairment and HIV-related CNS disorders.Graphical abstract

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). β-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.

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.

Despite the substantial changes resulting from the introduction of combination antiretroviral therapy (cART), the prevalence of HIV-associated neurocognitive disorders (HAND) remains substantial. Blood–brain barrier impairment (BBBi) is a frequent feature in people living with HIV (PLWH) and it may persist despite effective antiretroviral treatment. A cross-sectional study was performed in PLWH who underwent lumbar puncture for clinical reasons or research protocols and several cerebrospinal fluid biomarkers were studied. BBBi was defined as cerebrospinal fluid-to-serum albumin ratio (CSAR) &gt, 6.5 (&lt, 40 years) or &gt, 8 (&gt, 40 years). We included 464 participants: 147 cART-naïve and 317 on cART. Male sex was prevalent in both groups (72.1% and 72.2% respectively), median age was 44 (38–52) years in naïve and 49 (43–57) years in treated subjects. BBBi was observed in 35.4% naïve and in 22.7% treated participants, the use of integrase inhibitors was associated with a lower prevalence (18.3 vs. 30.9%, p = 0.050). At multivariate binary logistic regression (including age and sex) nadir CD4 cell count (p = 0.034), presence of central nervous system (CNS) opportunistic infections (p = 0.024) and cerebrospinal fluid (CSF) HIV RNA (p = 0.002) in naïve participants and male sex (p = 0.021), a history of CNS opportunistic infections (p = 0.001) and CSF HIV RNA (p = 0.034) in treated patients were independently associated with BBBi. CSF cells and neopterin were significantly higher in participants with BBBi. BBBi was prevalent in naïve and treated PLWH and it was associated with CSF HIV RNA and neopterin. Systemic control of viral replication seems to be essential for BBB integrity while sex and treatment influence need further studies.

BackgroundTuberculous meningitis (TBM) is an important disease leading to morbidity, disability and mortality that primarily affects children and immune-depressed patients. Specific neuromarkers predicting outcomes, severity and inflammatory response are still lacking. In recent years an increasing number of evidences show a possible role for infective agents in developing neurodegenerative diseases. MethodsWe retrospectively included 13 HIV-negative patients presenting with meningeal tuberculosis. Lumbar punctures were performed for clinical reasons and CSF biomarkers were routinely available: we analyzed blood brain barrier permeability (CSF to serum albumin ratio, “CSAR”), intrathecal IgG synthesis, (CSF to serum IgG ratio), inflammation (neopterin), amyloid deposition (Aβ1-42), neuronal damage (T-tau, P-tau, 14.3.3) and astrocytosis (S-100 β). ResultsPatients were 83% male and 67 % Caucasian with a median age of 51 years (24.5-63.5 IQR). Apart from altered CSAR (median value 18.4, 17.1-30.9 IQR), neopterin (14.3 ng/ml, 9.7-18.8) and IgG ratios (15.4, 7.9-24.9), patients showed very low levels of Aβ1-42 in their CSF (348.5 pg/mL,125-532.2). Protein 14.3.3. tested altered in 38.5% cases. T-tau, ptau and S100Beta were in the range of normality. Altered low level of Aβ1-42 correlated over time with classical TBm findings and altered neuromarkers.ConclusionsCSF Biomarkers from patients with TBM were compatible with inflammation, blood brain barrier damage and impairment in amyloid-beta metabolism. Amyloid-beta could be tested as a prognostic markers, backing the routine use of available neuromarkers. To our knowledge this is the first case showing such low levels of Aβ1-42 in TBM; its accumulation, drove by neuroinflammation related to infections, can be central in understanding neurodegenerative diseases.

ObjectiveGiven the aging of people living with HIV (PLWH) and the high prevalence of HIV-associated neurocognitive disorders, we aimed at describing the clinical, instrumental, and CSF features of PLWH diagnosed with Alzheimer dementia (AD).MethodsThe databases of 3 large Italian outpatient clinics taking care of more than 9,000 PLWH were searched for the diagnosis of AD. After obtaining patients' or their next of kin's consent for publication, anonymous data were collected in an excel spreadsheet and described. Routinely collected CSF biomarkers and radiologic imaging results were recorded whether available.ResultsFour patients were included in this case series who were diagnosed with AD aged between 60 and 74 years. All participants were on highly active antiretroviral therapy and showed nondetectable serum HIV RNA. Memory impairment was the most prominent cognitive feature. The diagnosis was obtained considering the exclusion of other potential causes, MRI and fluorodeoxyglucose-PET features, and, in (in 2/4), CSF AD biomarkers levels. In 1 patient, longitudinal CSF tau/p-tau increased, and beta-amyloid1–42 decreased over time despite antiretroviral therapy containing nucleotide reverse transcriptase inhibitors.ConclusionsIn older PLWH cognitive symptoms may represent the onset of AD: a multidisciplinary team may be needed for reaching a likely in vivo diagnosis.

Introduction Tubercolous meningitis (TBM) is an important disease leading to morbidity, disability and mortality that primarily affects children and immune-depressed patients. Specific neuromarkers predicting outcomes, severity and inflammatory response are still lacking. In recent years an increasing number of evidences show a possible role for infective agents in developing neurodegenerative diseases. Methods We retrospectively included 13 HIV-negative patients presenting with meningeal tuberculosis. Lumbar punctures were performed for clinical reasons and CSF biomarkers were routinely available: we analyzed blood brain barrier permeability (CSF to serum albumin ratio, “CSAR”), intrathecal IgG synthesis, (CSF to serum IgG ratio), inflammation (neopterin), amyloid deposition (1-42 β-amyloid), neuronal damage (T-tau, P-tau, 14.3.3) and astrocytosis (S-100 β). Results Patients were 83% male and 67 % Caucasian with a median age of 51 years(24.5-63.5 IQR). Apart from altered CSAR (median value 18.4, 17.1-30.9 IQR), neopterin (14.3 ng/ml, 9.7-18.8) and IgG ratios (15.4, 7.9-24.9) patients showed very low levels of 1-42 β-amyloid in their CSF (348.5 pg/mL,125-532.2). Protein 14.3.3. tested altered in 38.5% cases. T-tau, ptau and S100Beta were in the range of normality. Altered low level of beta amyloid correlated over time with classical TBm findings and altered neuromarkers.Conclusion CSF Biomarkers from patients with TBM were compatible with inflammation, blood brain barrier damage and impairment in beta amyloid metabolism. Aβ1-42 could be tested as a prognostic markers, backing the routine use of available neuromarkers. To our knowledge this is the first case showing such low levels of Aβ1-42 in TBM; its accumulation, drove by neuroinflammation related to infections, can be central in understanding neurodegenerative diseases.

OBJECTIVE Aim of this study was to compare cerebrospinal fluid (CSF) virological control, biomarkers and neurocognition of neurologically symptomatic patients on dual antiretroviral therapies (dual therapy) vs. 2 nucleoside reverse transcriptase inhibitors-based three-drug regimens (triple therapy). DESIGN Retrospective monocentric cross-sectional study. METHODS We analysed data from people living with HIV undergoing lumbar puncture for clinical/research reasons with plasma HIV-RNA less than 200 copies/ml and neurological/neurocognitive symptoms without significant contributing comorbidities. We measured CSF HIV-RNA, inflammation, blood-brain barrier integrity, neuronal damage and astrocytosis biomarkers (five biomarkers by ELISA and five indices by immunoturbidimetry) and recorded the neurocognitive performance (14 tests). CSF escape was defined as any case of CSF HIV-RNA 0.5 Log10 higher than viraemia or any case of detectable CSF HIV-RNA coupled with undetectable viraemia. RESULTS A total of 78 patients on triple therapy and 19 on dual therapy were included. Overall, 75.3% male, median age 51 years (46-58), current CD4 count 545 cells/μl (349-735), time on current regimens 18 months (8-29), but length of plasma suppression 32 months (14-94). The two groups did not differ in terms of HIV-associated neurological diagnoses, demographic and viro-immunological features. Undetectable CSF HIV-RNA (73.7% in dual therapy vs. 78.2% in triple therapy, p.67) and CSF escape (21.1% in dual therapy vs. 19.2% in triple therapy, p.86) did not differ. No difference was observed in depression, anxiety, neurocognition (in 63 participants) nor in any tested biomarker. CONCLUSION In people living with HIV with neurological/neurocognitive symptoms, peripherally effective dual therapy can show CSF virosuppression, inflammation, neuronal and astrocyte integrity and neurocognition comparable to triple therapy.

OBJECTIVE The current study aimed to investigate whether cerebrospinal fluid (CSF) Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA was associated with viral, inflammatory and neuronal damage biomarkers in people living with HIV (PLWH). DESIGN A cross-sectional diagnostic study on CSF fluid samples in patients undergoing lumbar punctures for clinical reasons, to better understand the role of EBV and CMV in the CNS on HIV RNA replication, blood-brain-barrier (BBB) damage and biomarkers of neuronal damage/inflammation. METHODS EBV, CMV DNA and HIV RNA were measured on CSF, through real time (RT)-PCR, from PLWHs undergoing lumbar punctures for clinical reasons (excluding oncho-haematological comorbidities). Immune-enzymatic assays evaluated blood-brain barrier inflammation and damage. Patients were stratified according to plasma HIV RNA levels in viremic (≥50 copies/ml) and aviremic (

BackgroundCentral 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.MethodsPatients 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 β-amyloid), neuronal damage (Total tau (T-tau), Phosphorylated tau (P-tau), and 14.3.3 protein) and astrocyte damage (S-100β).ResultsTwo 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-100β 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 Aβ1–42.ConclusionThis 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.

Prion diseases are neurodegenerative disorders which are caused by an accumulation of the abnormal, misfolded prion protein known as scrapie prion protein (PrPSc). These disorders are unique as they occur as sporadic, genetic and acquired forms. Sporadic Creutzfeldt-Jakob Disease (CJD) is the most common human prion disease, accounting for approximately 85–90% of cases, whereas autosomal dominant genetic forms, due to mutations in the prion protein gene (PRNP), account for 10–15% of cases. Genetic forms show a striking variability in their clinical and neuropathological picture and can sometimes mimic other neurodegenerative diseases. We report a novel PRNP mutation (V189I) in four CJD patients from three unrelated pedigrees. In three patients, the clinical features were typical for CJD and the diagnosis was pathologically confirmed, while the fourth patient presented with a complex phenotype including rapidly progressive dementia, behavioral abnormalities, ataxia and extrapyramidal features, and the diagnosis was probable CJD by current criteria, on the basis of PrPSc detection in CSF by Real Time Quaking-Induced Conversion assay. In all the three patients with autopsy findings, the neuropathological analysis revealed diffuse synaptic type deposition of proteinase K-resistant prion protein (PrPres), and type 1 PrPres was identified in the brain by western blot analysis. So, the histopathological and biochemical profile associated with the V189I mutation was indistinguishable from the MM1/MV1 subtype of sporadic CJD. Our findings support a pathogenic role for the V189I PRNP variant, confirm the heterogeneity of the clinical phenotypes associated to PRNP mutations and highlight the importance of PrPSc detection assays as diagnostic tools to unveil prion diseases presenting with atypical phenotypes. Electronic supplementary material The online version of this article (10.1186/s40478-018-0656-4) contains supplementary material, which is available to authorized users.

Background During the twentieth century, frontotemporal dementia (FTD) was often misdiagnosed, confused with Alzheimer's disease or psychiatric disorders, jeopardizing care and research. Objective To analyze the FTD genes in the DNA samples of patients belonging to families clinically classified as probable Alzheimer's disease (FAD) in the early 1990s and not carrying mutation in the three main genes linked to FAD (Presenilin 1, Presenilin 2, and Amyloid precursor protein). Methods The genetic screening was performed on 63 probands diagnosed as FAD before the early 2000s. Results Four patients out of the 63 studied (4/63, 6.3%) resulted as carrying four different GRN genetic variations: p.T272SfsX10, p.R110X, p.C149LfsX10, and p.W304C. The first two mutations (p.T272SfsX10, p.R110X) are the most frequent ones in Italy in FTD patients; the latter two (p.C149LfsX10 and p.W304C) are not described in the scientific literature. Conclusion Our data suggest that it can be important to re-examine FAD patients diagnosed when the FTD spectrum was not well recognized and the causative FTD genes had not yet been identified. Moreover, we propose initially analyzing genes associated with the first form of suspected dementia and, if the results are negative, studying genes implicated in the other form of dementia.

Blood brain barrier impairment occurs early in the course of infection by HIV and it may persist in a subset of patients despite effective antiretroviral treatment. We tested the hypothesis that HIV-positive patients with dysfunctional blood brain barrier may have altered biomarkers of neuronal damage. In adult HIV-positive highly active antiretroviral treatment (HAART)-treated patients (without central nervous system infections and undergoing lumbar punctures for clinical reasons) cerebrospinal fluid albumin to serum ratios (CSAR), total tau, phosphorylated tau, 1–42 beta amyloid, and neopterin were measured. In 101 adult patients, cerebrospinal fluid-to-serum albumin ratios were 4.8 (3.7–6.1) with 12 patients (11.9 %) presenting age-defined impaired blood brain barrier. A significant correlation was observed between CSAR and total tau (p = 0.005), phosphorylated tau (p = 0.008), and 1–42 beta amyloid (p = 0.040). Patients with impaired blood brain barrier showed significantly higher total tau (201.6 vs. 87.3 pg/mL, p = 0.010), phosphorylated tau (35.3 vs. 32.1 ng/mL, p = 0.035), and 1–42 beta amyloid (1134 vs. 830 pg/mL, p = 0.045). Despite effective antiretroviral treatment, blood brain barrier impairment persists in some HIV-positive patients: it is associated with markers of neuronal damage and it was not associated with CSF neopterin concentrations.

Progressive multifocal leukoencephalopathy (PML) is a severe encephalic demyelinating disease associated with JC virus (JCV) reactivation that occurs mostly in patients with immune disorders. Patients affected by sarcoidosis are at risk for developing PML both for leukocyte dysfunction and for receiving immunosuppressive medications: delayed diagnosis and high-dose corticosteroids are associated with a reduced survival. Although no specific treatment for PML exists, several therapeutic possibilities have been assessed with uncertain benefits (5HT2a receptor inhibitors are active in vitro against JCV): the cornerstone of sarcoidosis-associated PML is immunosuppressants withdrawal.We report the case of a female patient affected by systemic sarcoidosis for 30 years receiving low-dose corticosteroids (5 mg every other day). Due to memory impairment an MRI was performed showing three T2 hyperintense lesions involving white matter. Cerebrospinal fluid JCV PCR (845 copies/ml), neuropathological examination and immunohistochemistry (SV40 protein and JCV DNA positivity) on brain biopsy confirmed PML. Mirtazapine 15 mg was started while prednisone treatment was continued. 3 and 6 months later cognitive performances improved and brain MRIs were stable while cerebrospinal fluid JCV DNA was undetectable (6 months later). In conclusion the diagnosis of PML in patients with sarcoidosis is challenging given the overlapping presentation; the use of 5HT2a receptor antagonists deserves further studying in patients needing immunosuppressant drugs to control their dysimmune disease.

Blood brain barrier (BBB) damage is a common feature in central nervous system infections by HIV and it may persist despite effective antiretroviral therapy. Astrocyte involvement has not been studied in this setting. Patients were enrolled in an ongoing prospective study and subjects with central nervous system-affecting disorders were excluded. Patients were divided into two groups: treated subjects with cerebrospinal fluid (CSF) HIV RNA

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 ( approximately 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.

denced a decerebrate coma with preserved brainstem reflexes. Diffuse PSWC were evident upon EEG recording ( fig. 1 ). In spite of sodium correction, valproate administration and supportive therapy, no clinical or EEG improvement was observed. The CSF 14-3-3 protein test was positive, and tau concentration was raised (5,080 pg/ml). Brain MRI showed mildly high DWI signals involving the left parietal cortex (not shown). PRNP gene analysis disclosed a 129 VV genotype with no mutations. A diagnosis of clinically probable sporadic CJD was made. Tau concentration had risen to 10,480 pg/ml when a second CSF sample was drawn 4 weeks later. The patient died after 2 months from multiple organ failure. Because of suspected CJD, postmortem analysis was limited to the intracranial content. On eosin-hematoxylinstained sections, typical lesions of prion diseases (spongiosis, gliosis, and neuron loss) were absent. Furthermore, Western blot and immunohistochemistry studies failed to detect the pathologic prion protein. Therefore, a CJD diagnosis was ruled out. Instead, disseminated foci of vacuolation were evident in the transverse tracts of the basis pontis and were associated with scattered axonal swellings and activated macrophages ( fig. 2 ). Rare foci of vacuolation were present also at the supratentorial level (not shown). A pathological diagnosis of MNL was made. Dear Sir, Creutzfeldt-Jakob disease (CJD) is a prion encephalopathy characterized by rapidly progressive dementia, myoclonus and various neurological symptoms. The diagnosis is supported by a typical EEG pattern with periodic spike-wave complexes (PSWC) and/or a positive CSF 14-33 protein test [1] . Additionally, raised CSF tau levels ( 1 1,300 pg/ml) and certain MRI aspects – i.e. high diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery signals involving deep nuclei and the cerebral cortex – have been shown to be useful in the diagnostic work-up of prion diseases [2, 3] . Multifocal necrotizing leukoencephalopathy (MNL) is an uncommon clinicopathological entity usually diagnosed in immune-suppressed patients and characterized by multiple foci of vacuolation at the basis pontis and, less frequently, at the supratentorial level [4] . Here we describe an MNL patient mimicking sporadic CJD in its whole clinical, EEG, MRI and CSF aspects.

Ataxia is a frequently reported symptom in prion diseases (PD) and it is characteristic of Gerstmann-Straussler-Scheinker syndrome (GSS), a genetic PD mainly related to the P102L mutation in the PRNP gene. Our aim was to screen for the P102L and other six known PRNP gene mutations (P105L, A117V, Y145X, E200K, D202N, and V210I) a group of 206 consecutive patients diagnosed with adult-onset cerebellar ataxia of unknown origin. The patients, negative for the most common acquired and genetic forms, were analyzed using a combination of restriction endonuclease digestion and pyrosequencing; eight, affected by ataxia and cognitive dysfunction, were also sequenced for the PRNP gene. One patient resulted to be heterozygous for the P102L mutation. Retrospectively, the clinical picture was consistent with a "classical" GSS phenotype. In conclusion, the screening for the P102L mutation, or even the sequencing of the PRNP gene should be taken in consideration in patients with late-onset ataxia (>50 years).

Cytoskeletal abnormalities with accumulation of ubiquilated inclusions in the anterior horn cells are a pathological hallmark of both familial and sporadic amyotrophic lateral sclerosis (ALS) and of mouse models for ALS. Phosphorylated neurofilaments besides ubiquitin and dorfin have been identified as one of the major components of the abnormal intracellular perikaryal aggregates. As we recently found that p38 mitogen-activated protein kinase (p38MAPK) colocalized with phosphorylated neurofilaments in spinal motor neurons of SOD1 mutant mice, a model of familial ALS, we investigated whether this kinase also contributed to the inclusions found in ALS patients and SOD1 mutant mice. Intense immunoreactivity for activated p38MAPK was observed in degenerating motor neurons and reactive astrocytes in ALS cases. The intracellular immunostaining for activated p38MAPK appeared in some neurons as filamentous skein-like and ball-like inclusions, with an immunohistochemical pattern identical to that of ubiquitin. Intracellular p38MAPK-positive aggregates containing ubiquitin and neurofilaments were also found in the spinal motor neurons of SOD1 mutant mice. Our observations indicate that activation of p38MAPK might contribute significantly to the pathology of motor neurons in ALS.

The identification of mutations in the Tau gene in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) has made it possible to express human tau protein with pathogenic mutations in transgenic animals. Here we report on the production and characterization of a line of mice transgenic for the 383 aa isoform of human tau with the P301S mutation. At 5-6 months of age, homozygous animals from this line developed a neurological phenotype dominated by a severe paraparesis. According to light microscopy, many nerve cells in brain and spinal cord were strongly immunoreactive for hyperphosphorylated tau. According to electron microscopy, abundant filaments made of hyperphosphorylated tau protein were present. The majority of filaments resembled the half-twisted ribbons described previously in cases of FTDP-17, with a minority of filaments resembling the paired helical filaments of Alzheimer's disease. Sarkosyl-insoluble tau from brains and spinal cords of transgenic mice ran as a hyperphosphorylated 64 kDa band, the same apparent molecular mass as that of the 383 aa tau isoform in the human tauopathies. Perchloric acid-soluble tau was also phosphorylated at many sites, with the notable exception of serine 214. In the spinal cord, neurodegeneration was present, as indicated by a 49% reduction in the number of motor neurons. No evidence for apoptosis was obtained, despite the extensive colocalization of hyperphosphorylated tau protein with activated MAP kinase family members. The latter may be involved in the hyperphosphorylation of tau.

Introduction : Low level HIV-1 CSF replication (CsfLLV) is often found even in patients with controlled plasma viraemia. The clinical consequences of such finding are uncertain; however, both symptomatic neurological disturbances and neurocognitive disorders may arise in the context of CSF-escape. Two reports suggested that low level replication in the CSF may be associated with increased CSF neopterine although the impact on other markers of neuroinflammation/damage is currently unknown. Materials and Methods : Patients with neurocognitive disorders, new neurological symptoms or followed in longitudinal studies were included provided that they were on HAART, with last available viral load below 20 copies/mL and without central nervous system (CNS)-involving infections/neoplasms. After brain Magnetic Resonance (MR) CSF HIV RNA (CAP/CTM HIV-1 v2.0) and biomarkers [total tau (t-tau), phosphorylated tau (p-tau), 1–42 Beta amyloid (Beta42), neopterine and S100beta] were measured through validated methods. Data are presented as medians (IQR); non-parametric tests are used for all analysis. Results : 70 patients [66.7% male, median age 47.8 years (40–56), median BMI 22.2 kg/m2 (20–24)] were enrolled. Current and nadir CD4+ cell count were 379 (219–656) and 116 cell/mm3 (46–225); HIV RNA was undetectable since 19.7 months (9–53). CSF HIV RNA was undetectable in 24 (34.3%), below 20 copies/mL in 26 (37.1%), above 20 copies/mL in 25 patients [35.7%, median 69 copies/mL (41–134]). Median (IQR) CSF biomarkers values were as follows: t-tau 109 pg/mL (

JNK and p38, two members of the MAP kinase family, are strongly induced by various stresses including oxidative stress and have been involved in regulation of apoptosis. As both kinases phosphorylate tau protein in vitro, we have investigated their immunohistochemical localization in a group of neurodegenerative diseases characterized by intracellular deposits of hyperphosphorylated tau. Cases included Alzheimer disease, Pick disease, progressive supranuclear palsy, corticobasal degeneration, Gerstmann-Straussler-Scheinker disease-Indiana kindred, and frontotemporal dementia with parkinsonism linked to chromosome 17. In all tissue samples, strong immunoreactivity for both MAP kinases was found in the same neuronal or glial cells that contained tau-positive deposits. By double immunohistochemistry, JNK and p38 colocalized with tau in the inclusions. Analysis of apoptosis-related changes (DNA fragmentation, activated caspase-3) showed that the expression of JNK and p38 was unrelated to activation of an apoptotic cascade. Our data indicate that phospho-JNK and phospho-p38 are associated with hyperphosphorylated tau in a variety of abnormal tau inclusions, suggesting that these kinases may play a role in the development of degenerative diseases with tau pathology.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss and astrogliosis. We studied the immunohistochemical expression of S-100beta, a calcium-binding protein with both neurotrophic and neurotoxic activities, in the spinal cord of patients with ALS. Adjacent sections were processed with an in situ end-labeling technique for the demonstration of apoptosis-related DNA fragmentation. In controls, low expression of S-100beta was found in astrocytes but not motor neurons. Compared to controls, S-100beta was overexpressed in ALS. Most stained cells were reactive astrocytes, but a minority of motor neurons was also labeled. Neuronal labeling was unrelated to the presence of signs of atrophy/degeneration. S-100beta expression was also unrelated to neuronal or glial apoptosis. S-100beta upregulation in ALS spinal cord suggests that the protein might be involved in cellular defense mechanisms against oxidative stress.

A missense mutation in the gene coding for the G-protein-activated inwardly rectifying potassium (GIRK) channel, GIRK2, is responsible for apoptosis in the external germinal layer (EGL) of the cerebellum and a nonapoptotic death of midbrain dopaminergic neurons in the weaver (wv) mouse. Failure of axonogenesis and migration are considered to be the primary consequences of GIRK2 channel malfunction in the cerebellum. We investigated whether a disruption of the cell cycle precedes the failure of migration and axonogenesis and leads to massive apoptosis. To this end, immunohistochemistry and immunoblotting for PCNA, Cdk4, cyclin D, cyclin A, and the Cdk inhibitor p27/kip1, as well as in situ end-labeling for apoptotic DNA fragmentation, were applied to cerebella of P7-P21+/+, wv/+, and wv/wv mice. In +/+ and wv/+ mice, the expression of cell cycle proteins was limited to the outer, premigratory zone of the EGL. Antibodies to p27, a marker of cell differentiation, gave a reverse staining pattern. Due to migration delay, patches of p27-positive cells persisted in the outer EGL in P21 wv/+ mice. On the contrary, marked cell cycle up-regulation and absence of p27 occurred throughout the EGL at all ages in wv/wv mice, indicating an inability to switch off the cell cycle. Mitotic index evaluation showed that cell cycle activation was unrelated to proliferative events. Cell cycle proteins were not expressed in the substantia nigra, suggesting that nonapoptotic death of mature dopaminergic neurons is not preceded by abortive cell cycle re-entry. Our data show that abnormalities of the cell cycle in wv/wv cerebellum represent a major and early consequence of GIRK2 channel malfunction and may strongly influence the susceptibility of EGL cells to apoptosis. These observations may help in understanding the pathogenesis of human neurological channelopathies.