Plasmalogens: Free Radical Reactivity and Identification of Trans Isomers Relevant to Biological Membranes

Plasmalogens are membrane phospholipids with two fatty acid hydrocarbon chains linked to L-glycerol, one containing a characteristic cis-vinyl ether function and the other one being a polyunsaturated fatty acid (PUFA) residue linked through an acyl function. All double bonds in these structures display the cis geometrical configuration due to desaturase enzymatic activity and they are known to be involved in the peroxidation process, whereas the reactivity through cis-trans double bond isomerization has not yet been identified. Using 1-(1Z-octadecenyl)-2-arachidonoyl-sn-glycero-3-phosphocholine (C18 plasm-20:4 PC) as a representative molecule, we showed that the cis-trans isomerization can occur at both plasmalogen unsaturated moieties, and the product has characteristic analytical signatures useful for omics applications. Using plasmalogen-containing liposomes and red blood cell (RBC) ghosts under biomimetic Fenton-like conditions, in the presence or absence of thiols, peroxidation, and isomerization processes were found to occur with different reaction outcomes due to the particular liposome compositions. These results allow gaining a full scenario of plasmalogen reactivity under free radical conditions. Moreover, clarification of the plasmalogen reactivity under acidic and alkaline conditions was carried out, identifying the best protocol for RBC membrane fatty acid analysis due to their plasmalogen content of 15-20%. These results are important for lipidomic applications and for achieving a full scenario of radical stress in living organisms.

Diagnostic value of plasma p-tau181, NfL, and GFAP in a clinical setting cohort of prevalent neurodegenerative dementias

Background

Increasing evidence supports the use of plasma biomarkers of neurodegeneration and neuroinflammation to screen and diagnose patients with dementia. However, confirmatory studies are required to demonstrate their usefulness in the clinical setting.

Methods

We evaluated plasma and cerebrospinal fluid (CSF) samples from consecutive patients with frontotemporal dementia (FTD) (n = 59), progressive supranuclear palsy (PSP) (n = 31), corticobasal syndrome (CBS) (n = 29), dementia with Lewy bodies (DLB) (n = 49), Alzheimer disease (AD) (n = 97), and suspected non-AD physiopathology (n = 51), as well as plasma samples from 60 healthy controls (HC). We measured neurofilament light chain (NfL), phospho-tau181 (p-tau181), and glial fibrillary acid protein (GFAP) using Simoa (all plasma biomarkers and CSF GFAP), CLEIA (CSF p-tau181), and ELISA (CSF NfL) assays. Additionally, we stratified patients according to the A/T/N classification scheme and the CSF α-synuclein real-time quaking-induced conversion assay (RT-QuIC) results.

Results

We found good correlations between CSF and plasma biomarkers for NfL (rho = 0.668, p < 0.001) and p-tau181 (rho = 0.619, p < 0.001). Plasma NfL was significantly higher in disease groups than in HC and showed a greater increase in FTD than in AD [44.9 (28.1–68.6) vs. 21.9 (17.0–27.9) pg/ml, p < 0.001]. Conversely, plasma p-tau181 and GFAP levels were significantly higher in AD than in FTD [3.2 (2.4–4.3) vs. 1.1 (0.7–1.6) pg/ml, p < 0.001; 404.7 (279.7–503.0) vs. 198.2 (143.9–316.8) pg/ml, p < 0.001]. GFAP also allowed discriminating disease groups from HC. In the distinction between FTD and AD, plasma p-tau181 showed better accuracy (AUC 0.964) than NfL (AUC 0.791) and GFAP (AUC 0.818). In DLB and CBS, CSF amyloid positive (A+) subjects had higher plasma p-tau181 and GFAP levels than A− individuals. CSF RT-QuIC showed positive α-synuclein seeding activity in 96% DLB and 15% AD patients with no differences in plasma biomarker levels in those stratified by RT-QuIC result.

Conclusions

In a single-center clinical cohort, we confirm the high diagnostic value of plasma p-tau181 for distinguishing FTD from AD and plasma NfL for discriminating degenerative dementias from HC. Plasma GFAP alone differentiates AD from FTD and neurodegenerative dementias from HC but with lower accuracy than p-tau181 and NfL. In CBS and DLB, plasma p-tau181 and GFAP levels are significantly influenced by beta-amyloid pathology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13195-022-01093-6.

Fibrinogen Depletion Coagulopathy Predicts Major Bleeding After Thrombolysis for Ischemic Stroke: A Multicenter Study

BACKGROUND

Symptomatic intracerebral hemorrhage (sICH) and major bleeding can be fatal complications of intravenous thrombolysis (IVT) for acute ischemic stroke. We investigated the impact of early fibrinogen depletion after IVT on major bleeding events.

METHODS

This multicenter observational prospective cohort study enrolled 1678 consecutive patients receiving IVT for acute ischemic stroke at 6 Italian centers, undergoing fibrinogen concentration assessment at baseline, 2 hours and 6 hours after IVT. Fibrinogen depletion was defined as a reduction below 200 mg/dL after 2 hours from IVT, or as a reduction below 50% of baseline fibrinogen levels after 2 hours from IVT. Main outcomes were (1) sICH (National Institute of Neurological Disorders and Stroke criteria) and (2) major bleeding defined as fatal bleeding, decrease in the hemoglobin level>2 g/dL/>1 unit transfusion, or bleeding at critical site. Additional outcomes were (1) any ICH, (2) any bleeding, (3) fatal ICH, and (4) sICH according to ECASSII definition. Good functional recovery was defined as modified Rankin Scale score 0 to 2 at 3 months.

RESULTS

Overall, 1678 patients were included (mean age 72 years, 46% female). sICH (n=116) and major bleeding (n=297) were associated with lower rate of good functional recovery (P<0.001). Despite similar fibrinogen levels at admission, fibrinogen depletion after 2 hours from IVT was more common in people with sICH, major bleeding and all additional bleeding outcomes. In the backward stepwise multivariable logistic regression model, fibrinogen depletion remained a significant predictor of sICH (OR, 1.55 [95% CI, 1.04-2.32]) and major bleeding (OR, 1.36 [95% CI, 1.03-1.8]). Thirty-one percent of sICH could be attributable to fibrinogen depletion. The association between fibrinogen depletion and worse clinical outcome at 3 months after stroke (P=0.012) was attributable to the higher risk of major bleeding/sICH.

CONCLUSIONS

Fibrinogen depletion significantly increases the risk of sICH and major bleeding after IVT for acute ischemic stroke. Fibrinogen depletion represents an independent risk factor for bleeding, and routine assessment could be considered to stratify the risk of ICH. Trials on early fibrinogen repletion are needed to investigate mitigation of bleeding risk.

Immune thrombotic thrombocytopenic purpura: Personalized therapy using ADAMTS-13 activity and autoantibodies

Recently, treatment of immune-mediated thrombotic thrombocytopenic purpura (ITTP) has changed with the advent of caplacizumab in clinical practice. The International Working Group (IWG) has recently integrated the ADAMTS-13 activity/autoantibody monitoring in consensus outcome definitions. We report three ITTP cases during the coronavirus disease 2019 pandemic, that received a systematic evaluation of ADAMTS-13 activity and autoantibodies. We describe how the introduction of caplacizumab and ADAMTS-13 monitoring could change the management of ITTP patients and discuss whether therapeutic choices should be based on the clinical response alone. ADAMTS-13 activity/antibodies were assessed every 5 days. Responses were evaluated according to updated IWG outcome definitions. These kinetics, rather than clinical remission, guided the therapy, allowing early and safe caplacizumab discontinuation and sensible administration of rituximab. Caplacizumab was cautiously discontinued after achieving ADAMTS-13 complete remission. These cases illustrate that prospective ADAMTS-13 evaluation and use of updated IWG definitions may improve real-life patients' management in the caplacizumab era.

Emilia-Romagna Regional Blood System accreditation as an example of improvement through application of specific requirements: a retrospective analysis

BACKGROUND

Institutional accreditation in Italy represents the license given by a region to a public or private facility to provide services in the name and on behalf of the National Health Service. This study aims to evaluate the improvement of the Emilia-Romagna Regional Blood System and to highlight its unresolved issues, analysing non-conformities observed during accreditation and maintenance inspections between 2013 and 2018.

METHODS

All the Emilia-Romagna Regional Blood facilities were invited to participate in this study voluntarily and anonymously. Participants had to access a web application that we developed specifically. For each of the three inspections evaluated in this study, they had to enter data about the state of their organisation branches and non-conformities observed by regional inspectors. All data entered were finally exported from the web application database and analysed with spreadsheets. Statistical analysis was performed using Wilcoxon signed-rank test with continuity correction.

RESULTS

17 structures took part in the study, with a total of 174 organisation branches. The number of branches changed over the years because of new openings and closures due to reorganisations or non-conformities that were too difficult to correct. Inspectors observed 2381 non-conformities (291 structural, 611 technological and 1479 organisational). As a result of accreditation inspections and consequent improvement actions, non-conformities were reduced by 88%. The most frequent non-conformities concerned the management software and the transportation of blood and blood components.

CONCLUSION

An improvement in the Emilia-Romagna Regional Blood System over time is evident: institutional accreditation certainly pushed it to change and overcome its problems to comply with specific requirements. The remaining non-conformities after the three inspections were mostly organisational and management software was the most critical issue. Despite these non-conformities, all currently active structures are accredited and guarantee high standards of quality and safety of products and services.

Detection of Specific Antibodies against Toscana Virus among Blood Donors in Northeastern Italy and Correlation with Sand Fly Abundance in 2014

Toscana virus (TOSV) is a Phlebovirus transmitted by phlebotomine sand flies and is an important etiological agent of summer meningitis in the Mediterranean basin. Since TOSV infection is often asymptomatic, we evaluated the seroprevalence in blood donors (BDs) in the Bologna and Ferrara provinces (Northeastern Italy)-the areas with the highest and lowest numbers of TOSV neuroinvasive cases in the region, respectively. A total of 1208 serum samples from BDs were collected in April-June 2014 and evaluated for the presence of specific TOSV-IgG by ELISA. The IgG-reactive samples were confirmed by indirect immunofluorescence assay (IIF) and by microneutralization test (MN). Serum samples were defined as positive for anti-TOSV IgG when reactive by ELISA and by at least one second-level test; TOSV seroprevalence was 6.8% in the Bologna province, while no circulation of TOSV was detected in the Ferrara province. Sand fly abundance in 2014 was also estimated by a geographic information system using a generalized linear model applied to a series of explanatory variables. TOSV seroprevalence rate was strongly associated with the sand fly abundance index in each municipality, pointing out the strong association between sand fly abundance and human exposure to TOSV.

Blood derived treatment from two allogeneic sources for severe dry eye associated to keratopathy: a multicentre randomised cross over clinical trial

AIM

To compare the efficacy of cord blood and peripheral adult donor blood serum eyedrops, controlled for growth factor content, in the treatment of severe dry eye diseases (DED) resistant to conventional therapy.

METHODS

This was a multicentre randomised, double-masked, cross-over clinical trial. Sixty patients diagnosed as severe DED, associated to persistent corneal epithelial defects were randomised and equally assigned to group A (treated with cord blood serum (CBS)) or group B (treated with PBS), eyedrops administered eight times/day for 1 month. Primary outcome was the pretreatment and post-treatment change in corneal fluorescein staining. Secondary outcomes included the pretreatment and post-treatment change in Ocular Surface Disease Index (OSDI) questionnaire and Visual Analogue Score (VAS) of subjective symptoms, Schirmer I test, tear break-up time and conjunctival staining. Patients with relapse in signs or symptoms after further 2 months switched to the remaining group for one additional month. Data were statistically analysed (p<0.05).

RESULTS

Corneal staining was more significantly reduced after the CBS treatment, both VAS and OSDI score reduction was observed in both groups, but group A reported significantly less grittiness and pain. Nineteen patients shifted in the crossover period, the within individual comparison confirmed a better recovery in the CBS treatment period. Reduction in epithelial damage was positively associated with epidermal growth factor, transforming growth factorα and platelet-derived growth factor content. Levels of interleukins (IL-13) were positively associated with symptom decrease.

CONCLUSIONS

Overall, DED signs improved after both CBS and PBS treatments, with potential advantages of CBS for subjective symptoms and corneal damage reduction.

CLINICAL TRIAL REGISTRATION

NCT03064984.

Asymptomatic Leishmania infantum infection in blood donors living in an endemic area, northeastern Italy

OBJECTIVES

Human leishmaniasis can be severe and fatal, yet in the Mediterranean region only a small percentage of infections progress to clinical disease. We evaluated the percentage of asymptomatic Leishmania infection in the Bologna province, northeastern Italy.

METHODS

We examined the presence of specific antibodies by Western Blot (WB) and parasitic DNA by real time PCR in peripheral blood of 240 blood donors residing in the Bologna province.

RESULTS

Anti-Leishmania IgG were detected by WB in 27 subjects (11.2%, 95% CI 7%-15%), while Leishmania kinetoplast DNA was detected in peripheral blood specimens of 4 out of 240 donors (1.7%, 95% CI 0.2%-3.2%). Overall, the prevalence of Leishmania infection in the blood donor cohort was 12.5%, thus indicating an elevated cumulative exposure to the Leishmania parasite in the examined municipality.

CONCLUSIONS

Our results suggest that a surveillance system for monitoring Leishmania infection in blood donors and/or strategies of protozoan inactivation in whole blood should be taken into consideration in areas with circulation of the Leishmania parasite.

Comparison of growth factor and interleukin content of adult peripheral blood and cord blood serum eye drops for cornea and ocular surface diseases

INTRODUCTION

Various blood-derived products have been proposed for the topical treatment of ocular surface diseases. The aim of the study was to compare the different content of Growth Factors (GFs) and Interleukins (ILs) in peripheral blood (PB-S) and Cord Blood (CB-S) sera.

MATERIALS AND METHODS

Sera were obtained from 105 healthy adult donors (PB-S) and 107 umbilical/placental veins at the time of delivery (CB-S). The levels of epithelial-GF (EGF), fibroblast-GF (FGF), platelet-derived-GF (PDGF), insulin-GF (IGF), transforming-GF alpha (TGF-α,) and beta 1-2-3 (TGF-β1-β2-β3), vascular endothelial-GF (VEGF), nerve-GF (NGF), Interleukin (IL)-1β,IL-4,IL-6,IL-10, and IL-13 were assessed by Bio-Plex Protein Array System (Bio-Rad Laboratories, CA, USA). The Mann-Whitney test for unpaired data was applied to compare GFs and ILs levels in the two sources. The associations among each GF/IL level and the obstetric data for CB-S and hematological characteristics for PB-S were also investigated.

RESULTS

The levels of EGF, TGF-α, TGF-β2, FGF, PDGF, VEGF, NGF, IL-1B, IL-4, IL-6, IL-10, and IL-13 were significantly higher in CB-S compared to PB-S. Conversely, the levels of IGF-1, IGF-2, and TGF-β1 were significantly higher in PB-S. The female sex and the weight of the child showed a significant association in predicting EGF and PDGF levels.

CONCLUSION

A significantly different content in those GFs and ILs was demonstrated in the two blood sources. Since each GF/IL selectively regulates different cellular processes involved in corneal healing, the use of PB-S or CB-S should be chosen on the basis of the cellular mechanism to be promoted in each clinical case.

Detection of specific antibodies against West Nile and Usutu viruses in healthy blood donors in northern Italy, 2010-2011

Neutralizing antibodies against West Nile (WNV) and Usutu (USUV) viruses were measured in 6000 samples collected, between 1 September 2010 and 30 June 2011, from blood donors living in different districts of Emilia-Romagna, northeastern Italy. On the basis of the microneutralization assay (MNTA), 47 (0.78%) subjects were positive for WNV and 14 (0.23%) for USUV. These results were compared with those obtained 2 years ago and suggest an increased circulation of USUV among humans in Emilia-Romagna.