Effect of two periodontal treatment modalities in patients with uncontrolled type 2 diabetes mellitus: A randomized clinical trial.

AIM: To evaluate the impact of two non-surgical periodontal treatment modalities on metabolic and periodontal clinical parameters in subjects with type 2 diabetes mellitus (T2DM) and poor glycaemic control and chronic periodontitis. MATERIAL AND METHODS: A randomized controlled clinical trial was conducted. Ninety-three T2DM subjects with glycosylated haemoglobin (HbA1c) > 7% were randomly assigned to one of two groups receiving scaling with root planing in multiple sessions quadrant-by-quadrant (Q by Q) or within 24 hr (one stage). Periodontal parameters, HbA1c, glycaemia blood levels (FPG) and C-reactive protein (CRP) values were assessed at baseline and at 3 and 6 months post-therapy. RESULTS: At 6 months, HbA1c had decreased by 0.48% in the Q by Q group and by 0.18% in the one-stage group (p = 0.455). After therapy, subjects with an initial HbA1c < 9% showed an increase of 0.31% (p = 0.145), compared with a decrease of 0.88% (p = 0.006) in those with an initial HbA1c ≥ 9%. Periodontal parameters improved significantly (p < 0.0001) post-therapy, with similar results for both treatment modalities. CONCLUSION: Periodontal therapy had the greatest impact on HbA1c reduction on patients with an HbA1c > 9% regardless of treatment modality. Both modalities resulted in significant improvements in periodontal parameters.

Mesenchymal stem cells from the oral cavity and their potential value in tissue engineering.

Periodontal disease is one of the most common conditions affecting humans, and current treatment strategies, which focus on the removal and long-term control of dental plaque, are generally successful in eliminating active disease and promoting tissue repair. However, regeneration of the supporting structures of the tooth remains an elusive goal and a challenge. The formation of new bone and cementum with supportive periodontal ligament is the ultimate objective, but current regeneration therapies are incapable of achieving this in a predictable way. The regeneration of periodontal tissue requires a combination of fundamental events, such as appropriate level and sequencing of regulatory signals, the presence of progenitor cells, an extracellular matrix or carrier and an adequate blood supply. Based on tissue-engineering concepts, the regeneration process may be modulated by manipulating the signaling pathways of regulatory molecules, the extracellular matrix or scaffold, or the cellular components. The identification of mesenchymal stem cells from bone marrow started a new era in regenerative medicine. Tissue engineering using mesenchymal stem cells became a therapeutic option with several advantages, including high-quality regeneration of damaged tissues without the formation of fibrous tissue, minimal donor-site morbidity compared with autografts and a low risk of autoimmune rejection and disease transmission. The aim of this review was to describe the main sources of mesenchymal stem cells from tissues in the oral cavity and the potential of these cells in regenerative therapy. Special attention is paid to gingival tissue-derived mesenchymal stem cells because they represent the most accessible source of stem cells in the human mouth.

Does the calcineurin inhibitor have influence on cytomegalovirus infection in heart transplantation?

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in heart transplant (HTx). Our aim was to analyze the rate of CMV infection in HTx patients receiving treatment with cyclosporine (CsA) or tacrolimus (Tac). Ninety-five patients were randomized to receive either CsA (53.7%) or Tac (46.3%). We performed prophylaxis with valganciclovir in patients with the highest risk of CMV infection. We considered CMV infection as an increased viral load or the presence of CMV in histological samples. We analyzed baseline characteristics, CMV infection, and other complications. Event-free rates were calculated using the Kaplan-Meier method. There were no significant differences in baseline characteristics between both groups. CMV infection was detected in 31.6% of patients (in 66.7% due to asymptomatic replication). The group treated with Tac had a lower rate of CMV infection (15.9% vs. 45.1%, p = 0.002) and longer CMV infection-free survival time (1440 vs. 899 d, p = 0.001). No differences were observed in the complications analyzed in both groups. The independent risk factors for infection identified in the multivariate analysis were treatment with CsA and bacterial infections. This was the first study to demonstrate a lower rate of CMV infection in patients treated with Tac vs. those treated with CsA after HTx.

Entire papilla preservation technique for treatment of periodontal intrabony defects: a series of cases.

OBJECTIVE: Periodontitis is characterized by bone resorption. Vertical bone loss results in an intraosseous defect. Multiple surgical approaches for treating intrabony defects have shown different grades of effectiveness. Recently, the entire papilla preservation technique has been proposed, improving clinical parameters, such as pocket depth and clinical attachment level. This series of cases aimed to describe the use of the entire papilla preservation surgical technique without using biomaterials to regenerate periodontal intrabony defects. The influence on the clinical periodontal parameters and radiographic parameters was measured through CBCT, the latter not described until now, and analyzed the possible postoperative complications. METHOD AND MATERIALS: A total of six intrabony periodontal defects associated with at least one periodontal pocket with probing depths equal to or greater than 6 mm were treated with the entire papilla preservation technique. The clinical and radiographic parameters were evaluated at the beginning and 6 months after surgery. RESULTS: The mean probing pocket depth reduction was 4.00 ± 0.63 mm, the mean clinical attachment level gain was 3.67 ± 1.03 mm, and the mean radiographic intrabony filling was 2.41 ± 2.03 mm. Early healing was uneventful; the mean visual analog scale at 7 days was 0. CONCLUSIONS: This minimally invasive technique results in an improvement in clinical and radiographic parameters, the latter showing a filling of the bone defect observed during the 6-month evaluation after surgical treatment. These results confirm the importance of clot and flap stability in regenerating intraosseous defects.

Impact of basal heart rate on long-term prognosis of heart transplant patients.

Previous studies in patients with heart failure have shown that an elevated basal heart rate (HR) is associated with a poor outcome. Our aim with this study was to investigate if this relationship is also present in heart transplantation (HTx) recipients. From 2003 until 2010, 256 HTx performed in our center were recruited. Patients who required pacemaker, heart-lung transplants, pediatrics, retransplants, and those patients with a survival of less than 1 year were excluded. The final number included in the analysis was 191. Using the HR obtained by EKG during elective admission at 1 year post-HTx and the survival rate, an ROC-curve was performed. The best point under the curve was achieved with 101 beats per minute (bpm), so patients were divided in two groups according to their HR. A comparison between survival curves of both groups was performed (Kaplan-Meier). Subsequently, a multivariate analysis considering HR and other variables with influence on survival according to the literature was carried out. A total of 136 patients were included in the group with HR ≤100 bpm, and 55 in the one with HR >100 bpm. There were no basal differences in both groups except for primary graft failure, which was more frequent in the >100 bpm group (30.9 vs. 17%, P = 0.033). Patients with ≤100 bpm had a better long prognosis (P < 0.001). The multivariate analysis proved that high HR was an independent predictor of mortality. Our study shows that HR should be considered as a prognosis factor in HTx patients.

Serum proteomic changes in adults with obstructive sleep apnoea.

To examine whether differentially expressed proteins are present in the serum of patients with obstructive sleep apnoea (OSA), iTRAQ techniques (isobaric tags for relative and absolute quantification) were employed in a prospective study. Individuals were assigned to either a non-OSA control group (apnoea-hypopnoea index, AHI <5) or an OSA group (AHI ≥5). Blood samples were collected, aliquoted and frozen at -80 °C. Protein digestion and tagging with iTRAQ4plex® and mass spectrometry analysis was then performed (MALDI TOF/TOF). Ten male subjects were included in the control group (age = 45 ± 9.7 years) and 30 male patients in the OSA group (age = 45 ± 10.7 years), the latter being then subdivided into three severity groups. A total of 103 proteins were identified with differential levels between patients with OSA and controls. Of these, 11 proteins were underexpressed and 19 were overexpressed in patients with OSA. C4BPA and thrombospondin were underexpressed in all three OSA severity groups. Among the overexpressed proteins, 13 were overexpressed in the mild OSA group, seven in the moderate group and five in the severe group. Analysis of interactions between the identified proteins revealed that protein alterations in OSA are primarily associated with derangements in lipid and vascular metabolic pathways. This study provides initial evidence that differential protein expression occurs in adults with OSA, and that such proteins change according to disease severity, and appear to primarily involve lipid and vascular metabolic pathways.

Serum markers of apoptosis in the early period of heart transplantation.

CONTEXT AND OBJECTIVE: To assess the relationship between levels of serum markers of apoptosis and rejection grades in heart transplant (HTx). MATERIALS AND METHODS: A prospective study was conducted in 91 HTx. We correlated apoptosis markers and biopsy samples. The apoptosis markers were: TRAIL, TRAIL-R1, TRAIL-R2, TRAIL-R3, TRAIL-R4, sFas, sTNF-R1 and sTNF-R2. RESULTS: The only significant correlation with rejection grade was sFas (r=0.329; p=0.005). Cyclosporine showed a proapoptotic effect (sTNF-R1 0.02 and sTNF-R2 0.02) and everolimus an antiapoptotic effect (sTNF-R1 r= -0.523; p=0.0001 and sTNF-R2 r= -0.405; p=0.0001). CONCLUSIONS: The utility of specific apoptosis markers in peripheral blood for diagnosis of acute cellular rejection is low. Everolimus may have an anti-apoptotic effect.

Nurse-led and Interdisciplinary Secondary Cardiovascular Prevention Programmes: Spanish Cohort of the EUROACTION Project.

BACKGROUND: Cardiovascular prevention and rehabilitation programmes (CVPRP) are a preventive tool, which can reverse unhealthy behaviours and improve risk factor management. They have been successfully implemented in a variety of settings in patients with coronary heart disease (CHD). OBJECTIVE: The objective of this study is to evaluate an interdisciplinary and nurse-led cardiovascular prevention and rehabilitation programme in patients with coronary heart disease. METHODS: Six pairs of hospitals were randomised between intervention (INT) and usual care (UC) patients. The interdisciplinary team in the intervention hospital carried out a 16-week CVPRP to reach European risk factor goals. The trial is registered as ISRCTN 71715857. RESULTS: The proportion of patients achieving European cardiovascular recommendations in Spain increased in the intervention hospital, mainly regarding fruit and vegetable consumption (INT 98% vs. UC 53%, p<0.001), oily fish consumption (INT 42% vs. UC 19.5%, p<0.001), self-reported physical activity (INT 31% vs. UC 12.4%, p=0.04), blood pressure (INT 69% vs. UC 47.1%) p< 0.05) and LDL concentrations (INT 86.1% vs. UC 67.6%, p=0.04). CONCLUSION: The EUROACTION nurse-led model of CVPR programme has shown that therapeutic goals in cardiovascular disease prevention are affordable and sustainable in everyday clinical practice. EUROACTION model adapted in Spain has produced a healthier lifestyle.

Phosphoproteome analysis of Lotus japonicus roots reveals shared and distinct components of symbiosis and defense.

Plant roots form an intracellular symbiosis with nitrogen-fixing bacteria while maintaining the capacity for defending themselves against bacterial pathogens. To investigate the molecular relationship between these opposing cellular responses, we compared changes in the root phosphoproteome of the legume Lotus japonicus occurring within minutes after perception of nodulation factor (NF), a symbiotic signaling molecule, to those elicited by flagellin peptide (flg22), a conserved pathogen-associated peptide motif present in flagellar protein of a wide range of bacteria. Phosphoproteins were visualized by autoradiography of two-dimensional polyacrylamide gels after in vivo labeling with 33P-orthophosphate. Comparisons of NF- and flg22-induced phosphoprotein patterns revealed signal-specific responses but also a surprisingly large overlap. Specificity of the responses was observed because the NF receptor kinases NFR1 and NFR5 were both required for NF- but not for flg22-mediated changes in the phosphoproteome. Moreover, NF did not stimulate an oxidative burst or activation of mitogen-activated protein kinases, two common markers for early defense responses that were induced by flg22. Inhibitor studies revealed that phosphorylation of at least some of the proteins in response to NF requires phospholipase D (PLD) whereas regulation of the flg22 phosphoproteome is PLD-independent. Although plant signal transduction during symbiosis and defense utilizes distinct components, phosphorylation of overlapping sets of proteins is achieved.

Horizontal Bone Augmentation in the Posterior Atrophic Mandible and Dental Implant Stability Using the Tenting Screw Technique.

The aim of this study was to analyze horizontal bone augmentation using the tenting screw technique in the posterior mandible. Included subjects had a 3-mm bone width and 9-mm bone height, measured by CBCT. After the surgical approach, two to four screws were inserted, leaving 4 mm of extraosseous space; reconstruction was achieved using allogeneic biomaterial and leukocyte- and platelet-rich fibrin together with an absorbable membrane. After 4 months, a new CBCT scan was obtained to compare the bone gain and implant placement. Early and secondary stability were measured by the implant stability quotient (ISQ); prosthetic load was performed 16 weeks later. Student t test was used to compare bone gains and implant stability, with significance set at P < .05. Fourteen subjects and 27 surgical sites initially exhibited a mean bone width of 2.95 ± 0.75 mm. Four months after augmentation, the bone width was 7.15 ± 1.87 mm, confirming a significant bone gain (4.2 ± 1.26 mm). Twenty-seven implants were placed with a minimum insertion torque of 35 Ncm; the primary stability was 69.3 ± 7.16 ISQ, and the secondary stability was 75.9 ± 3.29 ISQ (P > .05). It may be concluded that the tenting screw technique is predictable in terms of bone gain and that it facilitates implant stability.

Diagnostic potential of peri-implant crevicular fluid microRNA-21-3p and microRNA-150-5p and extracellular vesicles in peri-implant diseases.

BACKGROUND: To explore the diagnostic usefulness of extracellular vesicles (EVs), and their subpopulations (micro-vesicles and exosomes), and microRNAs (miRNA-21-3p, miRNA-150-5p, and miRNA-26a-5p) in peri-implant crevicular fluid (PICF) of subjects with healthy, peri-implant mucositis and peri-implantitis implants. METHODS: A total of 54 patients were enrolled into healthy, peri-implant mucositis, and peri-implantitis groups. PICF samples were collected, EVs subpopulations (MVs and Exo) were isolated and characterized by nanoparticle tracking analysis and transmission electron microscopy. The expression of miRNA-21-3p, miRNA-150-5p and miRNA-26a-5p was quantified by qRT-PCR. Logistic regression models and accuracy performance tests were estimated. RESULTS: PICF samples show the presence of EVs delimited by a bi-layered membrane, in accordance with the morphology and size (< 200 nm). The concentration of PICF-EVs, micro-vesicles and exosomes was significantly increased in peri-implantitis implants compared to healthy implants (P = 0.023, P = 0.002, P = 0.036, respectively). miRNA-21-3p and miRNA-150-5p expression were significantly downregulated in patients with peri-implantitis in comparison with peri-implant mucositis sites (P = 0.011, P = 0.020, respectively). The reduced expression of miRNA-21-3p and miRNA-150-5p was associated with peri-implantitis diagnosis (OR:0.23, CI 0.08-0.66, P = 0.007 and OR:0.07, CI 0.01-0.78, P = 0.031, respectively). The model which included the miRNA-21-3p and miRNA-150-5p expression had a sensitivity of 93.3%, a specificity of 76.5%, a positive predictive value of 77.8%, and a negative predictive value of 92.9%. The positive and negative likelihood ratios were 3.97 and 0.09, respectively. The area under the receiver operating characteristics curve for the model was 0.84. CONCLUSIONS: An increase concentration of EVs with a downregulation expression of miRNA-21-3p and miRNA-150-5p could be related with the peri-implantitis development.

Psycho-Social Factors in Patients with Cardiovascular Disease Attending a Family-Centred Prevention and Rehabilitation Programme: EUROACTION Model in Spain.

BACKGROUND: Coronary heart disease (CHD) persists as the leading cause of death worldwide. Cardiovascular prevention and rehabilitation (CVPR) has an interdisciplinary focus, and includes not only in physiological components, but it also addresses psycho-social factors. METHODS: The study analysed the Spanish psycho-social data collected during the EUROACTION study. In Spain, two hospitals were randomised in the Valencia community. Coronary patients were prospectively and consecutively identified in both hospitals. The intervention hospital carried out a 16-week CVPR programme, which aimed to assess illness perceptions and establish healthy behaviours in patients and their partners. RESULTS: Illness perceptions were significantly and inversely associated with anxiety and depression. Low levels of anxiety were associated with better self-management of total cholesterol (p = 0.004) and low-density lipoprotein-cholesterol (p = 0.004). There was concordance at one year among patients and partners who participated in the programme related to anxiety (p < 0.001), fruit consumption (p < 0.001), and vegetable consumption (p < 0.001). CONCLUSIONS: The EUROACTION study emphasised the importance of assessing psycho-social factors in a CVPR programme and the inclusion of family as support in patients' changes in behaviour.

Lipid Profile Results after Cardiovascular Prevention Programme: Euroaction Model in Spain.

BACKGROUND: Cardiovascular prevention and rehabilitation programmes (CVPRP) are an established model of care designed to improve risk factor management. They have been successfully implemented in a variety of settings, in patients with coronary heart disease (CHD). OBJECTIVE: To assess the long term impact of a nurse-coordinated, multidisciplinary, CVPRP in patients with CHD in the reduction of lipid profile and medication prescription in clinical practice. METHODS: The study used an analytical, experimental, population based, prospective and longitudinal design. In Spain, the study was conducted in the Valencian Community, including two randomized hospitals. Coronary patients were prospectively and consecutively identified in both hospitals. The intervention hospital carried out an 8-week CVPRP. RESULTS: The proportion of patients achieving improved standards of preventive care increased in the intervention hospital compared with the usual care hospital, mainly regarding LDL-C concentrations. Furthermore, an increased prescription of statins was found in the intervention group. However, there were no statistically significant differences in triglycerides and glucose levels. CONCLUSION: The EUROACTION nurse-led CVPRP enabled coronary patients to control lipid profile to the European targets. A large proportion of patients were prescribed statin therapy as cardioprotective medication with favorable changes in medication for coronary patients. To improve the potential for cardiovascular prevention, we need local preventive cardiology programmes adapted to the health policy of individual countries.

Mechanical Recycling of Partially Bio-Based and Recycled Polyethylene Terephthalate Blends by Reactive Extrusion with Poly(styrene-co-glycidyl methacrylate).

In the present study, partially bio-based polyethylene terephthalate (bio-PET) was melt-mixed at 15-45 wt% with recycled polyethylene terephthalate (r-PET) obtained from remnants of the injection blowing process of contaminant-free food-use bottles. The resultant compounded materials were thereafter shaped into pieces by injection molding for characterization. Poly(styrene-co-glycidyl methacrylate) (PS-co-GMA) was added at 1-5 parts per hundred resin (phr) of polyester blend during the extrusion process to counteract the ductility and toughness reduction that occurred in the bio-PET pieces after the incorporation of r-PET. This random copolymer effectively acted as a chain extender in the polyester blend, resulting in injection-molded pieces with slightly higher mechanical resistance properties and nearly the same ductility and toughness than those of neat bio-PET. In particular, for the polyester blend containing 45 wt% of r-PET, elongation at break (εb) increased from 10.8% to 378.8% after the addition of 5 phr of PS-co-GMA, while impact strength also improved from 1.84 kJ·m-2 to 2.52 kJ·m-2. The mechanical enhancement attained was related to the formation of branched and larger macromolecules by a mechanism of chain extension based on the reaction of the multiple glycidyl methacrylate (GMA) groups present in PS-co-GMA with the hydroxyl (-OH) and carboxyl (-COOH) terminal groups of both bio-PET and r-PET. Furthermore, all the polyester blend pieces showed thermal and dimensional stabilities similar to those of neat bio-PET, remaining stable up to more than 400 °C. Therefore, the use low contents of the tested multi-functional copolymer can successfully restore the properties of bio-based but non-biodegradable polyesters during melt reprocessing with their recycled petrochemical counterparts and an effective mechanical recycling is achieved.

[Usefulness of the N-terminal fraction of brain natriuretic peptide for deciding when to refer patients with sleep apnea-hypopnea syndrome to the cardiologist]. / ¿Cuándo remitir al cardiólogo al paciente con síndrome de apneas-hipopneas durante el sueño? Utilidad del NT-proBNP.

INTRODUCTION AND OBJECTIVE: When sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease. PATIENTS AND METHODS: NT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities. RESULTS: Data for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular end-diastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively. CONCLUSIONS: NT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.

A lateral flow assay for the rapid diagnosis of Mycobacterium bovis infection in wild boar.

The native Eurasian wild boar (Sus scrofa) is a reservoir of Mycobacterium bovis, the causative agent of animal tuberculosis (TB), a chronic disease in livestock, companion animals and wild mammals. Cases of M. bovis infection in wild boar or feral pig have been reported worldwide, making early detection a priority in the eradication of the disease. Point-of-care diagnostic tests, such as low cost lateral flow assays, provide high specificity and sensitivity and can be performed on site, an essential requirement for a rapid screening of wildlife. A lateral flow assay, LFA, (INgezim TB CROM Ab) for the detection of M. bovis-specific antibodies in wild boar serum and blood has been developed based on MPB83, one of the major immunogenic antigens of the bacterium. A total of 140 samples of wild boar serum, well-characterized by Mycobacterium tuberculosis complex culture and TB compatible post-mortem lesions, have been analysed with LFA, and results were compared with one in-house and two commercial Enzyme-linked Immunosorbent Assays (ELISA), INgezim TB Porcine and INgezim Tuberculosis DR. In experimental samples, the achieved values of sensitivity of the different techniques ranged from 84.3% to 92.1% and the specificity was 100% in all of them. In field animals, specificity ranged from 96% to 100%, whereas sensitivity ranged from 48% to 64% in juvenile wild boar, increasing to 93.3%-100% in adult wild boar. In particular, the total sensitivity and specificity values obtained with the new LFA were 83% and 97%, respectively, indicating that INgezim TB CROM Ab could be used as a first approach for the surveillance of TB in wild boar, with a special applicability for animal-side testing.

Effect of platelet-rich plasma on cell adhesion, cell migration, and myofibroblastic differentiation in human gingival fibroblasts.

BACKGROUND: Platelet-rich plasma is a blood-derived fraction that contains a high concentration of platelets and growth factors. It was proposed that the use of this platelet concentrate stimulates tissue repair. However, little is known about the biologic response of gingival fibroblasts to platelet's derived growth factors. In the present study, we evaluated whether platelet-rich plasma modulated cell adhesion, cell migration, and myofibroblastic differentiation in primary cultures of human gingival fibroblasts. METHODS: We studied the response of primary cultures of gingival fibroblasts to thrombin-activated platelet-rich plasma fractions. Cell adhesion was evaluated through a colorimetric assay. Cell spreading, actin cytoskeleton remodeling, and focal adhesion distribution were assessed through light and immunofluorescence microscopy. Cell migration was analyzed using a bicameral cell culture system. Smooth muscle actin production was studied through Western blotting. RESULTS: Exposure of gingival fibroblasts to platelet-rich plasma stimulated adhesion and spreading of cells on fibronectin matrices, the development of actin-enriched cellular extensions, and formation of focal adhesions. Platelet-rich plasma also promoted cell migration and invasion through a reconstituted basement membrane matrix. Differentiation into the myofibroblastic phenotype, assessed through the production of smooth muscle actin, was also stimulated by platelet-rich plasma preparations. CONCLUSION: Platelet-rich plasma may modulate several cell responses potentially involved in wound healing such as cell adhesion, cell migration, and myofibroblastic differentiation.

Diagnostic aptitude of West Nile virus-like particles expressed in insect cells.

West Nile virus is a globally spread zoonotic arbovirus. The laboratory diagnosis of WNV infection relies on virus identification by RT-PCR or on specific antibody detection by serological tests, such as ELISA or virus-neutralization. These methods usually require a preparation of the whole virus as antigen, entailing biosafety issues and therefore requiring BSL-3 facilities. For this reason, recombinant antigenic structures enabling effective antibody recognition comparable to that of the native virions, would be advantageous as diagnostic reagents. WNV virions are enveloped spherical particles made up of 3 structural proteins (C, capsid; M, membrane and E, envelope) enclosing the viral RNA. This study describes the co-expression of these 3 proteins yielding non-infectious virus-like particles (VLPs) and the results of the initial assessment of these VLPs, used instead of the whole virus, that were shown to perform correctly in two different ELISAs for WNV diagnosis.

Monitoring Anti-NS1 Antibodies in West Nile Virus-Infected and Vaccinated Horses.

West Nile virus (WNV) is a zoonotic arboviral pathogen affecting humans, birds, and horses. Vaccines are available for veterinary use, which efficiently prevent the infection in horses. Most common diagnostic tools rely on the identification of the agent (RT-PCR, virus isolation), or on the detection of antibodies (IgM and IgG) recognizing structural proteins of the virus or neutralizing virus infection in cell cultures (virus-neutralization tests). The recent emergence of WNV in different parts of the world has resulted in an increase in the vaccination of horses in many countries. Methods for differentiation between infected and vaccinated animals ("DIVA" assays) would be useful for surveillance and control purposes but are still not available. A usual approach in this regard is the use of antibodies to nonstructural proteins as markers of nonvaccinated, infected animals, and the nonstructural NS1 protein of WNV has been proposed as a candidate for such a marker. The aim of this study was to test the hypothesis that NS1 can be a useful antigen in DIVA assays for differentiating WNV vaccinated and infected horses in field conditions. For that, we examined serum samples from either vaccinated and infected horses both from experimental infections/vaccinations (under controlled conditions) and from the field, exposed to natural infection or vaccinated in response to a risk of infection. The overall conclusion of the study is that NS1 antigen can effectively differentiate WNV infected from vaccinated horses in experimental (controlled) conditions, but this differentiation might be difficult depending on the conditions prevailing in the field.