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Introduction Besides distinctive respiratory and digestive hallmarks, COVID-19 has been recently associated with a high prevalence of pro-inflammatory and hypercoagulable states known as “COVID-19 Associated Coagulopathy” (CAC), corresponding to a worsening in patients’ conditions, whose causes are still to be elucidated. A link between anti-phospholipid antibodies (aPLs) and viral infections has long been suggested. APLs are assessed for anti-phospholipid syndrome (APS) diagnosis, characterized by thrombocytopenia, thrombosis, and coagulopathy. Furthermore, circulating immune complexes (CICs), arisen upon inflammatory responses and related immune dysregulation, can lead to endothelial cell damage and thrombotic complications. Method We performed an extended panel including IgG/IgM anti-cardiolipin, IgG/IgM anti-β2-glycoprotein-1, coupled with IgG/IgM anti-prothrombin, IgG/IgM anti-annexin-V on two COVID-19 patient groups (early and late infection time), and a negative control group. IgG CIC analysis followed to evaluate inflammatory status, through a possible complement system activation. Results Our results showed low positive case percentage in IgG/IgM anti-cardiolipin and IgG/IgM anti-β2-glycoprotein-1 assays (4.54%, 6.25%, and 4.55%; in early infection group, late infection group, and control group, respectively); few positive cases in IgG/IgM anti-prothrombin and IgG/IgM anti-annexin-V immunoassays; and no IgG CIC positivity in any patient. Conclusions In conclusion, our data show a low aPL prevalence, likely excluding an involvement in the pathogenesis of CAC. Interestingly, IgG/IgM anti-prothrombin and anti-annexin-V positive cases, detected in late infection group, suggest that aPLs could temporarily increase or could trigger a “COVID-19-induced-APS-like-syndrome” in predisposed patients. Key Points•To our knowledge, anti-prothrombin (aPT) antibodies, anti-annexin-V antibodies and CICs in COVID-19 patients have not been reported in the scientific literature.•Lack of uniformity and the low percentage of aCL/aβ2GP1 positivity preclude a putative role in CAC pathogenesis.•IgG/IgM anti-prothrombin and IgG/IgM anti-annexin-V data show that distribution of positive case number increases in late infection patients, significantly in anti-annexin-V results, suggesting a possible role for these anti-phospholipid antibodies in disease course.•aPLs can arise transiently in some patients with critical illness and SARS-CoV-2 infection (disappearing in a few weeks), as well as in other genetically predisposed patients; they could trigger a “COVID-19-induced-APS-like-syndrome”.

The outbreak of 2019 novel coronavirus disease (Covid-19) caused by SARS-CoV-2 has spread rapidly, inducing a progressive growth in infected patients number. Social isolation (lockdown) has been assessed to prevent and control virus diffusion, leading to a worldwide financial and political crisis. Currently, SARS-CoV-2 RNA detection in nasopharyngeal swab takes place by real-time PCR (RT-qPCR). However, molecular tests can give some false-negative results. In this context, serological assays can be useful to detect IgG/IgM antibodies, to assess the degree of immunization, to trace the contacts, and to support the decision to re-admit people at work. A lot of serological diagnostic kits have been proposed on the market but validation studies have not been published for many of them. The aim of our work was to compare and to evaluate different assays analytical performances (two different immunochromatographic cards, an immunofluorescence chromatographic card, and a chemiluminescence-automated immunoassay) on 43 positive samples with RT-qPCR-confirmed SARS-CoV-2 infection and 40 negative control subjects. Our data display excellent IgG/IgM specificities for all the immunocromatographic card tests (100% IgG and 100% IgM) and for the chemiluminescence-automated assay (100% IgG and 94% IgM); IgG/IgM sensitivities are moderately lower for all methods, probably due to the assay viral antigen’s nature and/or to the detection time of nasopharyngeal swab RT-qPCR, with respect to symptoms onset. Given that sensitivities (around 94% and 84% for IgG and IgM, respectively) implicate false-negative cases and given the lack of effective vaccines or treatments, the only currently available procedure to reduce SARS-CoV-2 transmission is to identify and isolate persons who are contagious. For this reason, we would like to submit a flowchart in which serological tests, integrated with nasopharyngeal swab RT-qPCR, are included to help social and work activities implementation after the pandemic acute phase and to overcome lockdown.

Introduction Dysregulation of cerebral glucose consumption, alterations in cerebrospinal fluid (CSF) biomarkers, and cognitive impairment have been reported in patients with obstructive sleep apnoea (OSA). On these bases, OSA has been considered a risk factor for Alzheimer’s disease (AD). This study aimed to measure cognitive performance, CSF biomarkers, and cerebral glucose consumption in OSA patients and to evaluate the effects of continuous positive airway pressure (CPAP) treatment on these biomarkers over a 12-month period. Methods Thirty-four OSA patients and 34 controls underwent 18F-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET), cognitive evaluation, and CSF analysis. A subgroup of 12 OSA patients treated with beneficial CPAP and performing the 12-month follow-up was included in the longitudinal analysis, and cognitive evaluation and 18F-FDG PET were repeated. Results Significantly reduced glucose consumption was observed in the bilateral praecuneus, posterior cingulate cortex, and frontal areas in OSA patients than controls. At baseline, OSA patients also showed lower β-amyloid42 and higher phosphorylated-tau CSF levels than controls. Increased total tau and phosphorylated tau levels correlated with a reduction in brain glucose consumption in a cluster of different brain areas. In the longitudinal analysis, OSA patients showed an improvement in cognition and a global increase in cerebral 18F-FDG uptake. Conclusions Cognitive impairment, reduced cerebral glucose consumption, and alterations in CSF biomarkers were observed in OSA patients, which may reinforce the hypothesis of AD neurodegenerative processes triggered by OSA. Notably, cognition and brain glucose consumption improved after beneficial CPAP treatment. Further studies are needed to evaluate the long-term effects of CPAP treatment on these AD biomarkers.

With the widespread use of coronavirus disease 2019 (COVID-19) vaccines, a rapid and reliable method to detect SARS-CoV-2 neutralizing antibodies (NAbs) is extremely important for monitoring vaccine effectiveness and immunity in the population. The purpose of this study was to evaluate the performance of the RapiRead™ reader and the TestNOW™ COVID-19 NAb rapid point-of-care (POC) test for quantitative measurement of antibodies against the spike protein receptor-binding domain of severe respiratory syndrome coronavirus 2 (SARS-CoV-2) in different biological matrices compared to chemiluminescence immunoassay (CLIA) methods. Ninety-four samples were collected and analyzed using a RapiRead™ reader and TestNOW™ COVID-19 NAb kits for detecting neutralizing antibodies, and then using two CLIAs. The data were compared statistically using the Kruskal-Wallis test for more than two groups or the Mann-Whitney test for two groups. Specificity and sensitivity were evaluated using a receiver operating characteristic (ROC) curve. Good correlation was observed between the rapid lateral flow immunoassay (LFIA) test system and both CLIA methods. RapiRead™ reader/TestNOW™ COVID-19 NAb vs. Maglumi: correlation coefficient (r) = 0.728 for all patients; r = 0.841 for vaccinated patients. RapiRead™ reader/TestNOW™ COVID-19 NAb vs. Mindray: r = 0.6394 in all patients; r = 0.8724 in vaccinated patients. The time stability of the POC serological test was also assessed considering two times of reading, 12 and 14 minutes. The data revealed no significant differences. The use of a RapiRead™ reader and TestNOW™ COVID-19 NAb assay is a quantitative, rapid, and valid method for detecting SARS-CoV-2 neutralizing antibodies and could be a useful tool for screening studies of SARS-CoV-2 infection and assessing the efficacy of vaccines in a non-laboratory context.

Background and aims SARS-CoV-2 antibody assays are relevant in managing the COVID-19 pandemic, providing valuable data on the immunization status of the population. However, current serology tests are highly variable, due to their different characteristics and to the lack of reference materials. The aim of the World Health Organization (WHO) first International Standard (IS) for anti-SARS-CoV-2 immunoglobulin is to harmonize humoral immune response assessment after natural infection or vaccination, and recommend reporting the results for binding activity in Binding Antibody Units (BAU). Materials and methods This study analyzed six commercial quantitative anti-SARS-CoV-2 S-protein assays in a head-to-head comparison, using the manufacturers' conversion factors for the WHO IS to obtain BAU/mL values. Results Our data showed good alignment up to 1000 BAU/mL, then began to disperse, exhibiting some discrepancies. Moreover, correlations among methods varied with Cohen’s Kappa ranging from 0.580 to 1.00, with the lowest agreement values for kits using different target antigens or different antibody isotypes, making it clear that the laboratory report should include this information. Values expressed as BAU/ml showed a reduced between-assays variability compared to AU/ml (median coefficients of variation 0.38 and 0.68, respectively; p Conclusion On the basis of these data at present anti-SARS CoV-2 serological assays’ results are not interchangeable, and, more importantly, individual immune monitoring should be performed with the same method.

Objective Preliminary findings suggest a relationship between lower serum 25-hydroxyvitamin D [25(OH)D] levels and incidence and severity of COVID-19. The aim of this study was to evaluate the relationship between vitamin D status at admission and different markers of inflammation, coagulation, and sepsis in hospitalized patients with COVID-19. Method We conducted a retrospective study on 137 consecutive patients with SARS-CoV-2 infection and available data on serum 25(OH)D levels, who were admitted to our Institution between March 1 and April 30, 2020. Patients were divided into two groups: survivors (n = 78; 57%) and non-survivors (n = 59; 43%). Results At admission, all patients showed hypovitaminosis D. Median total serum 25(OH)D levels at admission were significantly higher in survivors than non-survivors (12 ng/mL vs 8 ng/mL; p

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection has proven to be extremely contagious and has spread rapidly all over the world. A key aspect in limiting the virus diffusion is to ensure early and accurate diagnosis. Serological assays could be an alternative in increasing testing capabilities, particularly when used as part of an algorithmic approach combined with molecular analysis. The aim of this study was to evaluate the diagnostic accuracy of a second generation chemiluminescent automated immunoassay able to detect anti‐SARS‐CoV‐2 immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies. Data are carried out on healthy subjects and other infectious diseases pre‐pandemic sera, as controls, and on two different coronavirus disease 2019 hospitalized patient groups (early and late infection time). Data obtained have been analyzed in terms of precision, linearity, sensitivity and specificity. Specificities are: 100% for anti‐SARS‐CoV‐2 IgG and 98% for anti‐SARS‐CoV‐2 IgM, in all patient groups. Sensitivities are: 97%, 100%, and 98% for anti‐SARS‐CoV‐2 IgG and 87%, 83%, and 86% for anti‐SARS‐CoV‐2 IgM in the early infection, in the late infection and in the total patient group, respectively. The Mindray anti‐SARS‐CoV‐2 IgG and IgM assays demonstrated higher sensitivity and specificity, indicating that IgG and IgM simultaneous detection is useful even in the early phases of infection.

The antibody response to SARS-CoV-2 has not yet fully defined, but the availability of sensitive and specific serological assays is crucial to observe the presence of specific antibodies against the human receptor binding domain (S-RBD) and high specificity ACE-2-binding antibodies or neutralizing antibodies (NT) in response to vaccines. Indeed, these peculiar antibodies should prevent viral interaction between RBD and Angiotensin-Converting Enzyme 2 (ACE2) receptor, located on surface of host cells. In this study, 72 samples from 37 hospitalized COVID-19 patients and 35 not-hospitalized patients were analyzed longitudinally. The detection of S-RBD and NT antibodies was carried out using CLIA tests. Hospitalized patients showed elevated serum levels of S-RBD (97.22%) and NT (77.78%) antibodies, differently, not-hospitalized, who were paucisymptomatic or asymptomatic patients, showed lower serum levels of S-RBD (65.71%) and NT (38.14%) antibodies. The results suggest that the NT serum level is strongly related to disease severity (p

Lactoferrin (Lf), a multifunctional cationic glycoprotein synthesized by exocrine glands and neutrophils, possesses an in vitro antiviral activity against SARS-CoV-2. Thus, we conducted an in vivo preliminary study to investigate the antiviral effect of oral and intranasal liposomal bovine Lf (bLf) in asymptomatic and mild-to-moderate COVID-19 patients. From April 2020 to June 2020, a total of 92 mild-to-moderate (67/92) and asymptomatic (25/92) COVID-19 patients were recruited and divided into three groups. Thirty-two patients (14 hospitalized and 18 in home-based isolation) received only oral and intranasal liposomal bLf, 32 hospitalized patients were treated only with standard of care (SOC) treatment, and 28, in home-based isolation, did not take any medication. Furthermore, 32 COVID-19 negative, untreated, healthy subjects were added for ancillary analysis. Liposomal bLf-treated COVID-19 patients obtained an earlier and significant (p &lt, 0.0001) SARS-CoV-2 RNA negative conversion compared to the SOC-treated and untreated COVID-19 patients (14.25 vs. 27.13 vs. 32.61 days, respectively). Liposomal bLf-treated COVID-19 patients showed fast clinical symptoms recovery compared to the SOC-treated COVID-19 patients. In bLf-treated patients, a significant decrease in serum ferritin, IL-6, and D-dimers levels was observed. No adverse events were reported. These observations led us to speculate a potential role of bLf in the management of mild-to-moderate and asymptomatic COVID-19 patients.

Coronavirus disease (COVID-19) is challenging many health, economic, and social systems. RT-PCR assays are diagnosis gold standard; however, they can lead to false-negative results. Therefore, anti-SARS-CoV-2 IgG, IgM, and IgA investigation can play a complementary role in assessing the individuals immune status. Majority of serological tests focus on IgM and IgG although IgA are the main immunoglobulins involved in mucosal immunity. It has been reported that digestive symptoms may occur in the absence of any typical respiratory symptom. Thus, a complete screening, comprising IgA, IgM, and IgG detection could be more consistent and useful in patients with atypical symptoms or in paucisymptomatic cases. Current literature describes over 200 immunoassays available worldwide, pointing out a great results variability, depending on methodology or antigens’ nature. In our study we evaluated anti-SARS-CoV-2 IgA, IgM, and IgG trend on a control group and on two COVID-19 patient groups (early and late infection time) with a lateral-flow combined immunoassay (LFIA) and an enzyme-linked immunosorbent assay (ELISA). Dissimilar antibodies time kinetics have been described in COVID-19 (decreasing IgM concentration with IgA/IgG persistence for a longer time; as well as persistent IgA, IgG, and IgM concentration); our results confirmed both of them depending on the methodology; therefore, it is difficult to compare different studies outcomes, suggesting the importance of a serological tests international standardization. Nevertheless, we propose a flowchart with combined anti-SARS-CoV-2 IgG/IgM/IgA detection as a screening on general population, where serological positivity should be considered as an “alert,” to avoid and contain possible new outbreaks.

Background : Endocannabinoids (ECs) modulate both excitatory and inhibitory components in the CNS. There is a growing body of evidence that shows ECs influence both hypothalamic orexinergic and histaminergic neurons involved in narcolepsy physiopathology. Therefore, ECs may influence sleep and sleep-wake cycle. Objective : To evaluate EC levels in the CSF of untreated narcoleptic patients to test whether ECs are dysregulated in Narcolepsy Type 1 (NT1) and Type 2 (NT2). Methods : We compared CSF Anandamide (AEA), 2-Arachidonoylglycerol (2-AG) and orexin in narcoleptic drug-naïve patients and in a sample of healthy subjects. Results : We compared NT1 (n=6), NT2 (n=6), and healthy controls (n=6). We found significantly reduced AEA levels in NT1 patients compared to both NT2 and controls. No differences were found between AEA levels in NT2 versus controls and between 2-AG levels in all groups, although a trend toward a decrease in NT1 was evident. Finally, the CSF AEA level was related to CSF orexin levels in all subjects. Conclusion : We demonstrated that the EC system is dysregulated in NT1.

In addition to molecular testing, there is evolving interest for anti-SARS-CoV-2 antibodies serologic assays. Majority of them focus on IgM/IgG despite IgA important role in mucosal immunity. A simultaneous anti-SARS-CoV-2 IgA/IgG/IgM immunoassay, performed on an automated instrument by ELISA kit coated with native inactivated SARS-CoV-2, was detected on two control groups (negative swab healthcare workers; pre-pandemic healthy or with other viral infections individuals) and on two COVID-19 patient groups (early and late infection). Specificities were 100% in all groups, indicating no cross-reactivity with other infectious or pre-pandemic sera. Sensitivities were 94% in early infection group and 97% in total positive patient group, reaching 100% in late infection group. To our knowledge, this is the first technique based on native SARS-CoV-2. It is able to identify more positive samples than kits using recombinant antigens, therefore virus native epitopes as well as simultaneous anti-SARS-CoV-2 IgA/IgM/IgG detection could help to contain COVID-19 spreading.

Background: Therapeutic approaches targeting amyloid β42 (Aβ42) oligomers may represent a promising neuroprotective strategy for the prevention and treatment of Alzheimer's disease (AD). Objective: In this study we evaluated the ability of bromelain, a plant cysteine protease derived from pineapple stems, to interact with synthetic Aβ42 monomers and oligomers. We also examined the ability of bromelain to interfere in vitro with synthetic Aβ42 aggregates in the cerebrospinal fluid (CSF) of Alzheimer's disease as well as of control patients affected by other neurological diseases. Method: Both synthetic monomers and aggregates of Aβ42 were incubated in CSF with varying concentrations of bromelain. The effects of digestion were evaluated by Western Blot analysis using the specific monoclonal antibody 4G8 to identify the patterns of residual content of Aβ42. We further used rat primary cortical culture neurons (CN) to examine the cytotoxic action of this natural compound. Results: We found that bromelain successfully degraded Aβ42 monomers and low and high molecular weight oligomers. Indeed, when bromelain preparations of 3 and 6 mU were added to the CSF, the residual amount of Aβ42 monomers and oligomers were significantly reduced when compared to the same standard Aβ42 preparations incubated in CSF without bromelain. Moreover, bromelain incubations of 0.1, 0.5, and 1 mU/ml were not toxic to CN, as compared to vehicle treated cells. Conclusion: Overall, these results represent an important insight into the action of bromelain on Aβ42 oligomers, suggesting its potential use in the therapy of AD.

Complement system dysregulation has been hypothesized as a possible pathogenetic factor triggering epileptogenesis in both animal models and human studies. The aim of the present study is to evaluate the complement system in adult patients affected by idiopathic generalized epilepsy (IGE), either untreated or treated by antiepileptic drugs (AEDs). Thirty-seven IGE patients were compared to a population of 20 matched healthy controls. IGE patients underwent neurological investigation, epilepsy diary, 24-h EEG recording, and blood sample for the assessment of the complement factors C3 and C4, fibrinogen, and C-reactive protein (CRP) serum levels. We excluded patients with clinical and subclinical seizures in the 24h before obtaining the blood sample. We observed decreased C3 and C4 serum levels in IGE patients with respect to controls (p

The aim od this study is to test whether metabolism of beta-amyloid and tau proteins changes in narcolepsy along with the disease course.We analyzed a population of narcoleptic drug-naïve patients compared to a sample of healthy controls. Patients and controls underwent lumbar puncture for assessment of cerebrospinal fluid (CSF) beta-amyloid1-42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) levels. Moreover, based on the median disease duration of the whole narcolepsy group, the patients were divided into two subgroups: patients with a short disease duration (SdN,5 years) and patients with a long disease duration (LdN,5 years).We found significantly lower CSF Aβ42 levels in the whole narcolepsy group with respect to controls. Taking into account the patient subgroups, we documented reduced CSF Aβ42 levels in SdN compared to both LdN and controls. Even LdN patients showed lower CSF Aβ42 levels with respect to controls. Moreover, we documented higher CSF p-tau levels in LdN patients compared to both SdN and controls. Finally, a significant positive correlation between CSF Aβ42 levels and disease duration was evident.We hypothesize that beta-amyloid metabolism and cascade may be impaired in narcolepsy not only at the onset but also along with the disease course, although they show a compensatory profile over time. Concurrently, also CSF biomarkers indicative of neural structure (p-tau) appear to be altered in narcolepsy patients with a long disease duration. However, the mechanism underlying beta-amyloid and tau metabolism impairment in narcolepsy remains still unclear and deserves to be better elucidated.

Nocturnal sleep disruption develops in Alzheimer disease (AD) owing to the derangement of the sleep-wake cycle regulation pathways. Orexin contributes to the regulation of the sleep-wake cycle by increasing arousal levels and maintaining wakefulness.To study cerebrospinal fluid levels of orexin in patients with AD, to evaluate the relationship of orexin cerebrospinal fluid levels with the degree of dementia and the cerebrospinal fluid AD biomarkers (tau proteins and β-amyloid 1-42), and to analyze potentially related sleep architecture changes measured by polysomnography.We conducted a case-control study from August 1, 2012, through May 31, 2013. We included 48 drug-naive AD patients referred to the Neurological Clinic of the University Hospital of Rome Tor Vergata. Based on the Mini-Mental State Examination score, 21 patients were included in mild AD group (score, ≥21), whereas 27 were included in the moderate to severe AD group (score,21). The control group consisted of 29 nondemented participants of similar age and sex.Laboratory assessment of cerebrospinal fluid levels of orexin, tau proteins, and β-amyloid 1-42 and polysomnographic assessment of sleep variables.Levels of orexin, tau proteins, and β-amyloid 1-42; macrostructural variables of nocturnal sleep (total sleep time, sleep efficiency, sleep onset and rapid eye movement [REM] sleep latencies, non-REM and REM sleep stages, and wakefulness after sleep onset); and Mini-Mental State Examination scores.Patients with moderate to severe AD presented with higher mean (SD) orexin levels compared with controls (154.36 [28.16] vs 131.03 [26.55]; P.01) and with more impaired nocturnal sleep with respect to controls and patients with mild AD. On the other hand, in the global AD group, orexin levels were positively correlated with total tau protein levels (r = 0.32; P = .03) and strictly related to sleep impairment. Finally, cognitive impairment, as measured by the Mini-Mental State Examination, was correlated with sleep structure deterioration.Our results demonstrate that, in AD, increased cerebrospinal fluid orexin levels are related to a parallel sleep deterioration, which appears to be associated with cognitive decline. Therefore, the orexinergic system seems to be dysregulated in AD, and its output and function appear to be overexpressed along the progression of the neurodegenerative process. This overexpression may result from an imbalance of the neurotransmitter networks regulating the wake-sleep cycle toward the orexinergic system promoting wakefulness.

Narcolepsy is characterized by hypocretin deficiency due to the loss of hypothalamic orexinergic neurons, and is associated with both the human leucocyte antigen DQB1*06:02 and the T cell receptor polymorphism. The above relationship suggests autoimmune/inflammatory processes underlying the loss of orexinergic neurons in narcolepsy. To test the autoimmune/inflammatory hypothesis by means of cerebrospinal fluid (CSF) levels of beta-amyloid1-42 and/or total tau proteins in a sample of narcoleptic patients, we analysed 16 narcoleptic patients and 16 healthy controls. Beta-amyloid1-42 CSF levels were significantly lower in narcoleptic patients compared with healthy controls. We also documented pathologically low levels of CSF beta-amyloid1-42 (

The diuretic drug ethacrynic acid (EA), both an inhibitor and substrate of pi class glutathione S-transferase (GST P1-1), has been tested in clinical trials as an adjuvant in chemotherapy. We recently studied the role of the active site residue Tyr-108 in binding EA to the enzyme and found that the analysis was complicated by covalent binding of this drug to the highly reactive Cys-47. Previous attempts to eliminate this binding by chemical modification yielded ambiguous results and therefore we decided here to produce a double mutant C47S/Y108V by site directed mutagenesis and further expression in Escherichia coli and the interaction of EA and its GSH conjugate (EASG) examined by calorimetric studies and X-ray diffraction. Surprisingly, in the absence of Cys-47, Cys-101 (located at the dimer interface) becomes a target for modification by EA, albeit at a lower conjugation rate than Cys-47. The Cys-47 → Ser mutation in the double mutant enzyme induces a positive cooperativity between the two subunits when ligands with affinity to G-site bind to enzyme. However, this mutation does not seem to affect the thermodynamic properties of ligand binding to the electrophilic binding site (H-site) and the thermal or chemical stability of this double mutant does not significantly affect the unfolding mechanism in either the absence or presence of ligand. Crystal structures of apo and an EASG complex are essentially identical with a few exceptions in the H-site and in the water network at the dimer interface.

Amyloid-beta 1-42 (Abeta1-42), peptide detectable in cerebrospinal fluid (CSF), has been extensively studied as diagnostic marker for Alzheimer's disease; however, results are variable. We investigated whether Abeta1-42 detection in CSF may be affected by handling temperature after lumbar puncture. CSF was collected from patients affected by probable AD (n=27), other dementias (OD) (n=24), or other neurological disorders without cognitive impairment (OND) (n=23). After lumbar puncture, CSF samples were either maintained at 37 degrees C, or handled according to standard procedures and centrifuged at 4 degrees C for 10 min; thereafter, one aliquot was further stored at 4 degrees C and another at 37 degrees C, before freezing all samples 90 min later at -80 degrees C, pending analysis. Abeta1-42 and total tau were determined using a commercially available sandwich enzyme-linked immunosorbent assay ELISA. Reduced Abeta1-42 and increased total tau CSF levels were confirmed as characteristic hallmarks of the OD and AD groups, providing standard measurement in samples stored at 4 degrees C before freezing. However, avoiding cooling or reheating CSF from 4 to 37 degrees C before freezing strikingly increased the Abeta1-42 concentration detectable in the AD group (P

Background: Data have accumulated implicating the involvement of oncogenic human papillomaviruses (HPVs) in bronchial carcinogenesis. We recently described the presence of oncogenic HPV transcripts in non-small cell lung cancers. Objective: To investigate the role of oncogenic HPVs in lung carcinogenesis. Material and Methods: The lung cell line A549 stably infected with HPV16E6, HPV16E7 and HPVE6/E7 constructs was used to investigate the protein profile changes associated with the expression of these oncogenes. Replicated two-dimensional gel electrophoresis gels from uninfected and stably HPV16E6-, E7-, and E6/E7-infected A549 cells were compared for changes in protein profile. Protein identification was achieved by peptide mass fingerprinting by MALDI-TOF-MS and nLC-ESI-Q-TOF-MS/MS peptide ladder sequencing. Results: We identified 17 different polypeptides whose average normalized spot intensity was statistically significant (p < 0.05) and differed by 2-fold. Relationships between differentially expressed proteins and the HPV-induced infection mechanism have been clustered by knowledge-base database functional association network analysis. Conclusion: The impact of Hsp27, annexin III, annexin IV, Gp96 and TPT1 on the cellular response mechanism to HPV infection is presented and discussed.

Arsenic trioxide (As2O3) is a highly effective agent in the treatment of acute promyelocytic leukemia (APL), whereas other hematopoietic tumors are less responsive to this agent and mechanisms underlying As2O3,-resistance are poorly understood. To better understand the complex network of GSH-related pathways in As2O3 sensitivity, we investigated the role of GSH and GSH-relevant enzymes in an APL cell line sensitive to As2O3 (NB4) and in a resistant subclone (AsR). Cell proliferation, viability, and apoptosis were investigated in NB4 cells before and after treatment with 1 muM As2O3 and in AsR cells. In these experimental cell models, GSTP1-1, JNK1 and JNK2 proteins were analyzed by immunoblotting, and a kinase assay for JNK1 was performed. GSH levels as well as the activities of the enzymes glutathione peroxidase, glutathione transferase, gamma-Glutamylcysteynilsinthetase and superoxide dismutase were measured. NB4 cells treated with As2O3 showed a high level of oxidative stress and an increase of GSH levels. GSTP1-1 polymerization and JNK1 activation were detectable after 24 h and were followed by an increase of the apoptotic rate starting at 72 h. Neither GSTP1-1 polymerization nor JNK activation was found in AsR cells that showed a very low apoptotic rate. Our results suggest that APL sensitivity to As2O3 might be, at least in part, mediated by the balance between association and dissociation of JNK from GSTP1-1, depending on the redox status of the cell. Further investigation is warranted to find a way to interfere with this balance, whenever it might represent a mechanism of drug resistance.

The nitric oxide molecule (NO) is involved in many important physiological processes and seems to be stabilized by reduced thiol species, such as S-nitrosoglutathione (GSNO). GSNO binds strongly to glutathione transferases, a major superfamily of detoxifying enzymes. We have determined the crystal structure of GSNO bound to dimeric human glutathione transferase P1-1 (hGSTP1-1) at 1.4 A resolution. The GSNO ligand binds in the active site with the nitrosyl moiety involved in multiple interactions with the protein. Isothermal titration calorimetry and differential scanning calorimetry (DSC) have been used to characterize the interaction of GSNO with the enzyme. The binding of GSNO to wild-type hGSTP1-1 induces a negative cooperativity with a kinetic process concomitant to the binding process occurring at more physiological temperatures. GSNO inhibits wild-type enzyme competitively at lower temperatures but covalently at higher temperatures, presumably by S-nitrosylation of a sulfhydryl group. The C47S mutation removes the covalent modification potential of the enzyme by GSNO. These results are consistent with a model in which the flexible helix alpha2 of hGST P1-1 must move sufficiently to allow chemical modification of Cys47. In contrast to wild-type enzyme, the C47S mutation induces a positive cooperativity toward GSNO binding. The DSC results show that the thermal stability of the mutant is slightly higher than wild type, consistent with helix alpha2 forming new interactions with the other subunit. All these results suggest that Cys47 plays a key role in intersubunit cooperativity and that under certain pathological conditions S-nitrosylation of Cys47 by GSNO is a likely physiological scenario.

We investigated whether the cerebrospinal fluid (CSF) biomarkers beta-amyloid 1-42 (Abeta1-42), total tau (t-tau) protein and tau protein phosphorylated at threonine 181 (p-tau181) could discriminate Alzheimer's disease (AD) from vascular dementia (VD) patients. CSF samples of Abeta1-42, t-tau, and p-tau181 were collected from probable AD (n=35), probable AD with white matter changes (WMC) indicative of concomitant cerebrovascular disorder (CVD, n=31), VD (n=20), and an age-matched subgroup of patients with other neurological disorders (OND) without cognitive impairment (n=24). AD patients showed very low Abeta1-42 levels (median=393 pg/ml). Abeta1-42, but not t-tau, differentiated AD from VD patients. However, the markers did not discriminate AD vs. AD plus WMC. In particular, both subgroups showed similar CSF biomarkers but they were significantly different from VD. ROC analysis showed that Abeta1-42 could discriminate AD from VD (AUC=0.85). The cutoff of 493 pg/ml gave sensitivity and specificity values of 77% and 80%, respectively. Similar results were obtained when Abeta1-42 was employed to discriminate AD with WMC from VD (95% specificity and 60% sensitivity, but with cutoff of 750 pg/ml). T-tau increased aspecifically in all cognitively impaired patients. P-tau181 performed better than t-tau in discriminating AD (with or without WMC) vs. VD. In conclusion, Abeta1-42 proved to be a valuable tool to discriminate AD vs. VD patients and possibly to improve diagnostic accuracy in clinical forms, improperly classified as "mixed dementia" based on radiological vascular lesions.

The possible role of the hydroxyl group of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1 has been investigated by means of site-directed mutagenesis, steady-state kinetic analysis, and crystallographic studies. Three representative cosubstrates have been used, i.e. ethacrynic acid, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole, and 1-chloro-2,4-dinitrobenzene. In the presence of ethacrynic acid, the enzyme follows a rapid equilibrium random bi-bi mechanism with a rate-limiting step which occurs after the addition of the substrates and before the release of products. The replacement of Tyr 108 with Phe yields a 14-fold decrease of k(cat), while it does not change appreciably the affinity of the H site for the substrate. In this case, it would appear that the role of the hydroxyl function is to stabilize the transition state for the chemical step, i.e. the Michael addition of GSH to the electrophilic substrate. Crystallographic data are compatible with this conclusion showing the hydroxyl group of Y108 in hydrogen bonding distance of the ketone moiety of ethacrynic acid [Oakley, A. J., Rossjohn, J., Lo Bello, M., Caccuri, A. M., Federici, G., & Parker, M. W. (1997) Biochemistry, 36, 576-585]. Moreover, no structural differences are observed between the Y108F mutant and the wild type, suggesting that the removal of the hydroxyl group is solely responsible for the loss of activity. A different involvement of Tyr 108 appears in the catalyzed conjugation of 7-chloro-4-nitrobenz-2-oxa- 1,3-diazole with GSH in which the rate-limiting step is of a physical nature, probably a structural transition of the ternary complex. The substitution of Tyr 108 yields an approximately 7-fold increase of k(cat) and a constant k(cat)/K-m(NBD-Cl) value. Lack of a critical hydrogen bond between 7-chloro-4-nitrobenz-2-oxa- 1,3-diazole and Tyr 108 appears to be the basis of the increased k(cat). In the 1-chloro-2,4-dinitrobenzene/GSH system, no appreciable changes of kinetics parameters are found in the Y108F mutant. We conclude that Y108 has a multifunctional role in glutathione transferase P1-1 catalysis, depending on the nature of the electrophilic cosubstrate.

The Spike-Receptor Binding Domain (S-RBD) is considered the most antigenic protein in SARS-CoV-2 and probably the key player in SARS-CoV-2 immune response. Quantitative immunoassays may help establish an anti-RBD Abs threshold as an indication of protective immunity. Since different immunoassays are commercial, the standard reference method for the neutralizing activity is the live Virus Neutralization Test (VNT). In this study, anti-RBD IgG levels were detected with two chemiluminescent immunoassays in paucisymptomatic, symptomatic and vaccinated subjects, and their neutralizing activity was correlated to VNT titer, using SARS-CoV-2 original and British variant strains. Both immunoassays confirmed higher anti-RBD Abs levels in vaccinated subjects. Furthermore, despite different anti-RBD Abs median concentrations between the immunoassays, a strong positive correlation with VNT was observed. In conclusion, although the SARS-CoV-2 immune response heterogeneity, the use of immunoassays can help in large-scale monitoring of COVID-19 samples, becoming a valid alternative to VNT test for diagnostic routine laboratories.

A large number of immunoassays have been developed to detect specific anti-SARS-CoV-2 antibodies; however, not always they are functional to neutralize the virus. The reference test for the anti-spike neutralizing antibodies (nAbs) ability to counteract the viral infection is the virus neutralization test (VNT). Great interest is developing on reliable serological assays allowing antibodies concentration and antibody protective titer correlation. The aim of our study was to detect nAbs serum levels in paucisymptomatic, symptomatic and vaccinated subjects, to find a cut-off value able to protect from virus infection. nAbs serum levels were detected by a competitive automated immunoassay, in association to VNT with the SARS-CoV-2 original and British variant strains. The median nAbs concentrations were: 281.3 BAU/ml for paucisymptomatics; 769.4 BAU/ml for symptomatics; 351.65 BAU/ml for the vaccinated cohort; 983 BAU/ml considering only the second dose vaccinated individuals. The original strain VNT analysis showed 1:80 median neutralization titers in paucisymptomatic and vaccinated subjects; 1:160 in symptomatic patients; 1:160 in the second dose groups. The British variant VNT analysis showed lower neutralization titers in paucisymptomatic and vaccinated groups (1:40); the same titer in symptomatic patients (1:160); the second dose group confirmed the original strain titer (1:160). In conclusion, our data showed optimal correlations with a proportional increase between neutralizing activity and antibody concentration, making nAbs detection a good alternative to virus neutralization assays, difficult to carry out in routine laboratories. Finally, ROC curve analysis established a cut-off of 408.6 BAU/ml to identify subjects with a low risk of infection.