TTV and CMV viral load dynamics: Which emerges first during immunosuppression?

Novel biomarkers reflecting the degree of immunosuppression in transplant patients are required to ensure eventual personalized equilibrium between rejection and infection risks. With the above aim, Torque Teno Virus (TTV) viremia was precisely examined in a large cohort of transplanted immunocompromised patients (192 hematological and 60 solid organ transplant recipients) being monitored for Cytomegalovirus reactivation. TTV load was measured in 2612 plasma samples from 448 patients. The results revealed a significant increase in TTV viral load approximately 14 days following CMV reactivation/infection in solid organ transplant (SOT) patients. No recognizable difference in TTV load was noted among hematological patients during the entire timeframe analyzed. Furthermore, a temporal gap of approximately 30 days was noted between the viral load peaks reached by the two viruses, with Cytomegalovirus (CMV) preceding TTV. It was not possible to establish a correlation between CMV reactivation/infection and TTV viremia in hematological patients. On the other hand, the SOT patient cohort allowed us to analyze viral kinetics and draw intriguing conclusions. Taken together, the data suggest, to our knowledge for the first time, that CMV infection itself could potentially cause an increase in TTV load in the peripheral blood of patients undergoing immunosuppressive therapy.

Molecular monitoring of viral infections in immunocompromised patients in a large university hospital in Italy: reflections after thirteen years of real-life activity.

PURPOSE: This study aimed to investigate the prevalence and viral reactivations of clinical interest in the immunocompromised patient with particular focus on hematologic and solid organ transplant recipients. METHODS: Molecular screening data of CMV, EBV, JCV and BKV from 2011 to 2023 were analyzed. This extensive time span allowed the access to more than 100,000 samples from over 20,000 patients treated at Policlinico Umberto I. It was possible to temporally investigate patient attendance patterns, average age distribution, seasonality of infections, and positivity rates of the analyzed viruses. RESULTS: Between 2019 and 2022 a significant reduction in organ transplants performed and in the positive molecular detection of EBV, JCV and BKV was observed. Additionally, there has been a noteworthy decrease in CMV reactivations, with a reduction of up to 50% starting in 2019. A remarkable reduction of 39% in the rate of CMV viral reactivation has been also achieved in SOT between 2016 and 2023. CONCLUSION: The years following 2019 were profoundly impacted by the COVID-19 pandemic era. This period resulted in a substantial reduction in healthcare services and hospital visits. Furthermore, the introduction of the drug Letermovir in Italy in 2019 demonstrated remarkable efficacy, evidenced by a reduction in CMV reactivations. Additionally, the adoption of a novel clinical approach centered on personalized therapy facilitated improved management of immunocompromised patients.

The lack of head-to-head randomised trials and the consequences for patients and national health service: The case of non-small cell lung cancer.

INTRODUCTION: To introduce a drug to the market, it's not mandatory for it to be more effective and safer than the current treatment for the same condition. Consequently, head-to-head studies between the two best treatments for the same condition are not required, and this could result in a lack of information for patients, clinicians, and decision-makers. This study aims to evaluate the presence of head-to-head studies among the drugs used for the treatment of non-small cell lung cancer (NSCLC). METHODS: Taking into account the National Comprehensive Cancer Network (NCCN) guidelines updated to 2022, which list all available treatments for each NSCLC subtype, the search engine Pubmed and the platform clinicaltrials.gov were consulted to find all completed and ongoing head-to-head studies among various treatments for NSCLC. RESULTS: Among the anti-EGFR (epidermal growth factor receptor) drugs, 7 studies were found, with 6 completed and 5 registrational for drug commercialisation. No completed study to date has compared osimertinib and afatinib. For anti-ALK (anaplastic lymphoma kinase) drugs, 7 studies were found, with 5 completed. Alectinib, brigatinib, and lorlatinib have no completed comparison studies, but all were compared with crizotinib. Among various immunotherapy-based regimens, 5 studies were found, with only 1 completed. Therapeutic regimens based on pembrolizumab, atezolizumab, or the combination of nivolumab/ipilimumab have not been compared in studies published to date. CONCLUSION: There are few head-to-head studies comparing treatments for NSCLC; there are no such studies between the latest generation of drugs. Consequently, ambiguous areas exist due to the lack of comparative studies among the available evidence, preventing the clinician's choice of the most effective treatment and risking the patient receiving suboptimal therapy. Simultaneously, the price of the drug cannot be determined correctly, relying only on indirect evaluations from different trials. To dispel this uncertainty, it would be desirable to initiate a process that brings together the demands derived from clinical practice and clinical research to provide clinicians and patients with the best possible evidence.

Steroid use in measles: A retrospective cohort study during the 2017 outbreak in tertiary referral center, Rome and Latina, Italy.

INTRODUCTION: Since early January 2017, a new measles outbreak in Italy has been observed. The aim of the study was to compare features between adults and children measles cases and evaluate the effect of steroid treatment on the above parameters. METHODS: A retrospective multicenter, descriptive study was performed. We analyzed all patients admitted to the Department of Public Health and Infectious Diseases, Sapienza University, Rome and Latina, from January 2017 to December 2017 and discharged with diagnosis of measles. RESULTS: We identified 113 patients discharged with the diagnosis of measles infection cases of which 59 adults and 54 children (≤16 years). In adult population 32 patients (54 %) were males, with a median age of 30.5 years old and all unvaccinated (100 %). Keratoconjunctivitis 30 (50 %) was the most frequent complication. In pediatric population 27 (50 %) patients were males, with a median age of 3 years old. Information on measles vaccination status was available for only 21 (38.8 %) of cases. Keratoconjunctivitis 40 (74 %) was the most frequent complication. Analyzing the differences between adult and pediatric patients we found that children were significantly more likely to have keratoconjunctivitis and diarrhea as complications than adults in which the rate of thrombocytopenia and hepatitis was highest. Thirty-nine adult subjects (66 %) have been treated with systemic corticosteroids. CONCLUSIONS: Pediatric patients differ from adults in complications and liver involvement. Regarding steroids use, although there is no clear indication of steroid use during measles, there is no evidence of a worse outcome in our cases series.

Liquid biopsy: A promising tool for driving strategies and predicting failures in patients with classic Hodgkin lymphoma.

Classic Hodgkin lymphoma (cHL) consists of a heterogeneous group of haematological disorders that covers undifferentiated B cell neoplasms originating from germinal centre B cells. The HL molecular characterization still represents an ongoing challenge due to the low fraction of tumour Hodgkin and Reed-Sternberg cells mixed with a plethora of non-tumour haematological cells. In this scenario, next generation sequencing of liquid biopsy samples is emerging as a useful tool in HL patients' management. In this review, we aimed to overview the clinical and methodological topics regarding the implementation of molecular analysis in cHL, focusing on the role of liquid biopsy in diagnosis, follow-up, and response prediction.

An overview of artemisinin-resistant malaria and associated Pfk13 gene mutations in Central Africa.

Malaria caused by Plasmodium falciparum is one of the deadliest and most common tropical infectious diseases. However, the emergence of artemisinin drug resistance associated with the parasite's Pfk13 gene, threatens the public health of individual countries as well as current efforts to reduce malaria burdens globally. It is of concern that artemisinin-resistant parasites may be selected or have already emerged in Africa. This narrative review aims to evaluate the published evidence concerning validated, candidate, and novel Pfk13 polymorphisms in ten Central African countries. Results show that four validated non-synonymous polymorphisms (M476I, R539T, P553L, and P574L), directly associated with a delayed therapy response, have been reported in the region. Also, two Pfk13 polymorphisms associated to artemisinin resistance but not validated (C469F and P527H) have been reported. Furthermore, several non-validated mutations have been observed in Central Africa, and one allele A578S, is commonly found in different countries, although additional molecular and biochemical studies are needed to investigate whether those mutations alter artemisinin effects. This information is discussed in the context of biochemical and genetic aspects of Pfk13, and related to the regional malaria epidemiology of Central African countries.

Cost saving in implementing ERAS protocol in emergency abdominal surgery.

INTRODUCTION: ERAS (Enhanced Recovery After Surgery) protocol is now proposed as the standard of care in elective major abdominal surgery. Implementation of the ERAS protocol in emergency setting has been proposed but his economic impact has not been investigated. Aim of this study was to evaluate the cost saving of implementing ERAS in abdominal emergency surgery in a single institution. METHODS: A group of 80 consecutive patients treated by ERAS protocol for gastrointestinal emergency surgery in 2021 was compared with an analogue group of 75 consecutive patients treated by the same surgery the year before implementation of ERAS protocol. Adhesion to postoperative items, length of stay, morbidity and mortality were recorded. Cost saving analysis was performed. RESULTS: 50% Adhesion to postoperative items was reached on day 2 in the ERAS group in mean. Laparoscopic approach was 40 vs 12% in ERAS and control group respectively (p ,002). Length of stay was shorter in ERAS group by 3 days (9 vs 12 days p ,002). Morbidity and mortality rate were similar in both groups. The ERAS group had a mean cost saving of 1022,78 € per patient. CONCLUSIONS: ERAS protocol implementation in the abdominal emergency setting is cost effective resulting in a significant shorter length of stay and cost saving per patient.

Factors associated with the occurrence of maternal deaths in the West Region between 2020 - 2022: case control study.

WHO defines maternal mortality as any death of a woman occurring during pregnancy or within 42 days of its termination or after delivery. Our aim was to study the factors associated with the occurrence of maternal deaths in the West Region of Cameroon between 2020 and 2022. This was a case-control study. Cases consisted of maternal deaths that occurred during the study period. The controls for their part were made up of women who normally gave birth in the same health facilities from which the cases came and during the same period as the cases. The only exposure criterion being the status of death. The data useful for our investigation were collected respectively with the investigation sheets, audit reports and via interviews with the heads of the health facilities where the maternal deaths occurred with a view to considerably reducing information bias. Analysis were done with IBM-SPSS 25 and RStudio 2023.03.0. The West Region of Cameroon recorded 161 maternal deaths between 2020 and 2022. 67% of them were housewives. The most frequently identified causes were haemorrhage (ante-, per- and post-partum), followed far behind by complications and sepsis, with respective 42.2%, 12.4% and 10.6%. Slightly more than one child out of 10 had an abnormal presentation. Nearly 50% had a short labor (less than 10 hours), the partograph was used in 38% of the women, and the GATP practiced in 50.1% of them. Abnormal presentation of the fetus (aOR = 2.7 (95% CI: 1.4 - 5.1), p=0.002), failure to use the partograph (aOR = 4.4 (95% CI: 2 .6 - 7.4), p<0.001), the fact of not having an economic activity (aOR = 1.7 (95% CI: 1.0 - 2.7), p = 0.033), the fact of having taken less than 2 doses of VAT ( aOR = 2.8 (95% CI: 1.8 - 4.4), p<0.001) and the absence of practice of GATP (aOR = 1.6 (CI 95%: 1.0 - 2.6), p=0.040) were identified as factors that significantly favored the occurrence of maternal deaths. Several factors negatively influence the occurrence of maternal deaths in the West Region. Operational strategies such as continuous training of maternity ward staff, and the establishment of systematic maternal death audits and review meetings should be implemented to reduce and control these risk factors.

SARS-COV-2 vaccination with BNT162B2 in renal transplant patients: Risk factors for impaired response and immunological implications.

Solid organ transplant patients are at a higher risk for poor CoronaVirus Disease-2019 (COVID-19)-related outcomes and have been included as a priority group in the vaccination strategy worldwide. We assessed the safety and efficacy of a two-dose vaccination cycle with mRNA-based COVID-19 vaccine (BNT162b2) among 82 kidney transplant outpatients followed in our center in Rome, Italy. After a median of 43 post-vaccine days, a SARS-CoV-2 anti-Spike seroprevalence of 52.4% (n = 43/82) was observed. No impact of the vaccination on antibody-mediated rejection or graft function was observed, and no significant safety concerns were reported. Moreover, no de novo HLA-donor-specific antibodies (DSA) were detected during the follow-up period. Only one patient with pre-vaccination HLA-DSA did not experience an increased intensity of the existing HLA-DSA. During the follow-up, only one infection (mild COVID-19) was observed in a patient after receiving the first vaccine dose. According to the multivariable logistic regression analysis, lack of seroconversion after two-dose vaccination independently associated with patient age ≥60 years (OR = 4.50; P = .02) and use of anti-metabolite as an immunosuppressant drug (OR = 5.26; P = .004). Among younger patients not taking anti-metabolites, the seroconversion rate was high (92.9%). Further larger studies are needed to assess the best COVID-19 vaccination strategy in transplanted patients.

Evaluation of the Molecular Landscape in PD-L1 Positive Metastatic NSCLC: Data from Campania, Italy.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) have increased and improved the treatment options for patients with non-oncogene-addicted advanced stage non-small cell lung cancer (NSCLC). However, the role of ICIs in oncogene-addicted advanced stage NSCLC patients is still debated. In this study, in an attempt to fill in the informational gap on the effect of ICIs on other driver mutations, we set out to provide a molecular landscape of clinically relevant oncogenic drivers in programmed death-ligand 1 (PD-L1) positive NSCLC patients. METHODS: We retrospectively reviewed data on 167 advanced stage NSCLC PD-L1 positive patients (≥1%) who were referred to our clinic for molecular evaluation of five driver oncogenes, namely, EGFR, KRAS, BRAF, ALK and ROS1. RESULTS: Interestingly, n = 93 (55.7%) patients showed at least one genomic alteration within the tested genes. Furthermore, analyzing a subset of patients with PD-L1 tumor proportion score (TPS) ≥ 50% and concomitant gene alterations (n = 8), we found that n = 3 (37.5%) of these patients feature clinical benefit with ICIs administration, despite the presence of a concomitant KRAS gene alteration. CONCLUSIONS: In this study, we provide a molecular landscape of clinically relevant biomarkers in NSCLC PD-L1 positive patients, along with data evidencing the clinical benefit of ICIs in patient NSCLC PD-L1 positive alterations.

Next generation sequencing in cytology.

The application of next generation sequencing (NGS) technology to cytological samples has significantly modified molecular cytopathology practice. Cytological samples represent a valid source of high-quality DNA for NGS analysis, especially for predicting patients' response to targeted treatments and for refining the risk of malignancy in indeterminate cytological diagnoses. However, several pre-analytical factors may influence the reliability of NGS clinical analysis. Here, we briefly review the challenges of NGS in cytology practice, focusing on those pre-analytical factors that may negatively affect NGS success rates and routine diagnostic applications. Finally, we address the future directions of the field.

Chest computed tomography score, cycle threshold values and secondary infection in predicting COVID-19 mortality.

This retrospective and observational cohort study investigated chest computed tomography (CT) findings, cycle threshold (Ct) values in RT-PCR of SARS-CoV-2 and secondary infection occurrence to predict prognosis in COVID-19 patients. At hospital admission, CT findings and Ct values were collected. Microbiology tests performed after 48 hours from hospitalization were reviewed. According to in-hospital mortality, patients were grouped into non-survivors and survivors. Among 283 patients evaluated, in-hospital mortality rate was 13.8% (39/283). Secondary infection occurrence was 15.2% (43/283). Cut-off values for CT score >13.5 (AUC=0.682 p=0.0009) and for Ct <23.4 (AUC=0.749, p<0.0001) were predictive of death. Super-additive and synergic effects between high CT score plus secondary infection occurrence as well as between high CT score plus low Ct values affecting patient's outcome were observed. Chest CT score and Ct values in RT-PCR of SARS-CoV-2 could have a combination role for severity stratification of COVID-19 patients.

Knowledge and Attitudes of Population Living in Rural and Semi-Rural Areas towards Covid-19 :Case of the Menoua Division, Cameroon.

BACKGROUND: The pandemic situation the world is facing caused by the new SARS-Cov-2 continues to evolve and still represent a real problem. With more than eight thousand reported cases infection, Cameroon stands as the seventh most affected country in Africa. Prevention remains the best way to fight against this zoonosis. However, the limited information available about this infection is a great barrier to stopping the propagation of the virus within the population, especially in rural and semi-rural areas, where the lack of financial and material resources is a reality. This study aimed to assessing Awareness and attitudes of the population of the Menoua Division on COVID-19 infection. METHODS: A cross-sectional study was conducted from March 9 to April 15 2020 amongst the populations of rural and semi-rural areas of the Menoua Division. Data were collected using a questionnaire administered face to face to each participant. The analysis was carried out using the Statistical Analysis System software (SAS version 9.4). The significance threshold was set at a P value of less than 0.05. RESULTS: A total of 434 participants of which male majority (sex ratio 1.07) were included in this study. The most represented age group was [21 - 40] years old representing 40.29% of the participants. Approximately all participants (98.57%) were aware of the world emergency state due to Coronavirus. 75.56%, 91% and 90.93% of the participants knew respectively that having close contacts, kissing and touching the face with the hands could favor the transmission of the virus. However, nearly 91.14% were not aware of the clinical symptoms of the disease. Moreover, 85.02% responded that they would not be able to comply with the confinement measures if they were applied at national level. The level of awareness varied significantly according to the occupation (p=0.038) and the educational level (p<0.001)of the participants. CONCLUSION: The average level of awareness of the population of the Menoua Division on COVID-19 infection was relatively low. Overcoming this pandemic disease means ensuring the flow of the correct information towards the population. Community outreach activities focus on clinical manifestations and what to do in case of COVID-19 infection as well as material and financial support should be help the population to protect themselves effectively against pandemic, particularly in rural areas and surrounding.

The Ebola virus disease outbreak in Tonkolili district, Sierra Leone: a retrospective analysis of the Viral Haemorrhagic Fever surveillance system, July 2014-June 2015.

In Sierra Leone, the Ebola virus disease (EVD) outbreak occurred with substantial differences between districts with someone even not affected. To monitor the epidemic, a community event-based surveillance system was set up, collecting data into the Viral Haemorrhagic Fever (VHF) database. We analysed the VHF database of Tonkolili district to describe the epidemiology of the EVD outbreak during July 2014-June 2015 (data availability). Multivariable analysis was used to identify risk factors for EVD, fatal EVD and barriers to healthcare access, by comparing EVD-positive vs. EVD-negative cases. Key-performance indicators for EVD response were also measured. Overall, 454 EVD-positive cases were reported. At multivariable analysis, the odds of EVD was higher among those reporting contacts with an EVD-positive/suspected case (odds ratio (OR) 2.47; 95% confidence interval (CI) 2.44-2.50; P < 0.01) and those attending funeral (OR 1.02; 95% CI 1.01-1.04; P < 0.01). EVD cases from Kunike chiefdom had a lower odds of death (OR 0.22; 95% CI 0.08-0.44; P < 0.01) and were also more likely to be hospitalised (OR 2.34; 95% CI 1.23-4.57; P < 0.05). Only 25.1% of alerts were generated within 1 day from symptom onset. EVD preparedness and response plans for Tonkolili should include social-mobilisation activities targeting Ebola/knowledge-attitudes-practice during funeral attendance, to avoid contact with suspected cases and to increase awareness on EVD symptoms, in order to reduce delays between symptom onset to alert generation and consequently improve the outbreak-response promptness.

PCRdrive: the largest qPCR assay archive to date and endless potential for lab workflow revitalization.

BACKGROUND: Primer design is a crucial step in establishing specific and sensitive qPCR assays. Even though numerous tools for primer design exist, the majority of resulting assays still requires extensive testing and optimisation or does not allow for high quality target amplification. We developed a workflow for designing qPCR assays. Unlike other tools, we compute a PCR assay including primer design, concentrations and the optimal PCR program. RESULTS: Gene expression assays were already generated in a total of 283,226 genes from three species and are continued for all genes of the major model species. The results are available online at https://pcrdrive.com/lab#/assay-database . The workflow involves filtering Primer3-generated primers by considering diverse parameters including specificity, single-nucleotide polymorphisms (SNPs), secondary structure as well as compatibility with standard qPCR assay conditions. The resulting assays consist of transcript-specific primer sequences, a reagents protocol as well as instrument settings which are provided in a web-based tool called PCRdrive. PCRdrive was designed to support PCR users in their PCR-related tasks and is equipped with handy functions, components of an electronic lab notebook (ELN) as well as teamworking opportunities. CONCLUSION: High quality ready to use qPCR assays for gene expression analysis are provided within the online platform PCRdrive. A built-in primer designer enables easy generation of assays which is not supported by any other tool. The wet lab optimisation of new assays can be transparently documented and shared within the team. PCRdrive also contains an archive of public PCRs which is updated regularly. Users may use the archive to publish their PCR to the community which makes it easy for other researchers worldwide to reproduce and validate the PCR. PCRdrive is a growing network of PCR users, simplifying and streamlining research through its useful existing features and continuous developments from the active development team.

Dihydroartemisinin-piperaquine treatment failure in uncomplicated Plasmodium falciparum malaria case imported from Ethiopia.

Dihydroartemisinin-piperaquine (DHA-PPQ) is the artemisinin combination therapy that was recently introduced for the treatment of Plasmodium falciparum uncomplicated malaria, but emerging resistance in South-East Asia is threatening its use. This report describes a case of DHA-PPQ treatment failure in uncomplicated malaria occurring in an immigrant living in Italy, after a travel to Ethiopia. Thirty days after malaria recovery following DHA-PPQ therapy, the patient had malaria recrudescence. According to the genotyping analysis, the same P. falciparum was responsible for both episodes. Thus, it seems important to consider possible malaria recrudescence occurring after DHA-PPQ therapy in patients from African countries.

The problem of lost to follow-up of mother-child pairs enrolled in the PMTCT program in Dschang District Hospital-Cameroon.

High rates of lost to follow-up (LTFU) in the Prevention of Mother-To-Child Transmission of HIV (PMTCT) programs in Cameroon will only contribute in hindering the successful implementation of the program. The objective of this study was to determine the reasons of LTFU of mother-child pairs enrolled in the PMTCT program in Dschang District Hospital (DDH): Cameroon. Methods: A retrospective cohort study was carried out in HIV+ exposed children delivered in the DDH from1st Jan 2012 - 31st Dec 2014, who were greater than or equal to 18 months at the study period (1st August - 30th September 2016) and whose mothers were enrolled in the PMTCT program for at least 3 months. Children were considered LTFU if they did not return to the hospital for the establishment of their HIV status at 18 months. A complementary cross-sectional study was done whereby a structured questionnaire was administered to the LTFU group via telephone calls, in order to determine the causes of LTFU. Data was collected from hospital registers and analyses done using Epi info 7.1.3.3 software. Results: A total of 141 mother-child pairs were eligible for the study, 76 were reachable via phone calls and 36 (47.37%) met the case definition of LTFU. Out of the 36 (47.37%) children LTFU, lack of information, 19(65.52%); lack of support from male partners, 4(11.11%); Poor behavior of health personnel, 2 (5.56%); forgetfulness, negligence/time wasting, unavailability of results, fear of child being infected, and family problems were all listed at equal proportions of, 3(6.90%) as well as financial problem, 1 (2.78%) were all causes of LTFU identified in this study.

Knowledge on STIs / HIV / AIDS, Stigma-Discrimination and sexual behaviors AMONG students of the University of Dschang, in Cameroon.

This study reports the results of a survey conducted among students of the University of Dschang, on STI/HIV/AIDS, the Stigma-Discrimination pair and sexual behaviors. METHODS: This was a descriptive cross-sectional study conducted during the months of January and February 2017. We collected data by a face to face questionnaire administered to students of the University of Dschang. The codification, process and analysis have been done using the software EPI-Info 7.3.1.1, with the threshold of significance set at 0.05. RESULTS: A total of 520 individuals participated in this survey, with more than half (62.7%, n = 326/520) aged between 20-30 years, with a male/female sex ratio of 1,031. The vast majority (83%, n = 418/520) of them were in the undergraduate cycle. The main modes of transmission cited included: the combination of items such as blood transfusion / soiled objects / Mother-to-child transmission/ unprotected sex for 36.3% of respondents (n = 186/516) although 21.9 % (n = 112/516) of them admitted not knowing any modes of transmission of STIs / HIV. Also, 74.2% (n = 386/520) of respondents were sexually active, with the estimated age of sex debut being over 18 years (53.9%; 208/386) for half of them. Of the 36.2% (n = 186/514) respondents who reported knowing someone with STI / HIV and AIDS, the first feeling they had with regards to them was pity (86.6%; n = 386/446), followed by fear in 11.7% (n = 52/446) of respondents but yet 40.2% (n = 208/518) admitted they have never heard of discrimination. CONCLUSION: Stigma and discrimination in the student milieu remains a major barrier to students' development who, becoming sexually active at a very early age, are more exposed to the risk of contracting STI / HIV. Sensitization actions should be implemented within university campuses and reproductive health courses for young adults, included in the academic curriculum for a significant reduction in the number of new infections.

Neural Stem Cell Transplantation Induces Stroke Recovery by Upregulating Glutamate Transporter GLT-1 in Astrocytes.

Ischemic stroke is the leading cause of disability, but effective therapies are currently widely lacking. Recovery from stroke is very much dependent on the possibility to develop treatments able to both halt the neurodegenerative process as well as to foster adaptive tissue plasticity. Here we show that ischemic mice treated with neural precursor cell (NPC) transplantation had on neurophysiological analysis, early after treatment, reduced presynaptic release of glutamate within the ipsilesional corticospinal tract (CST), and an enhanced NMDA-mediated excitatory transmission in the contralesional CST. Concurrently, NPC-treated mice displayed a reduced CST degeneration, increased axonal rewiring, and augmented dendritic arborization, resulting in long-term functional amelioration persisting up to 60 d after ischemia. The enhanced functional and structural plasticity relied on the capacity of transplanted NPCs to localize in the peri-ischemic and ischemic area, to promote the upregulation of the glial glutamate transporter 1 (GLT-1) on astrocytes and to reduce peri-ischemic extracellular glutamate. The upregulation of GLT-1 induced by transplanted NPCs was found to rely on the secretion of VEGF by NPCs. Blocking VEGF during the first week after stroke reduced GLT-1 upregulation as well as long-term behavioral recovery in NPC-treated mice. Our results show that NPC transplantation, by modulating the excitatory-inhibitory balance and stroke microenvironment, is a promising therapy to ameliorate disability, to promote tissue recovery and plasticity processes after stroke. SIGNIFICANCE STATEMENT: Tissue damage and loss of function occurring after stroke can be constrained by fostering plasticity processes of the brain. Over the past years, stem cell transplantation for repair of the CNS has received increasing interest, although underlying mechanism remain elusive. We here show that neural stem/precursor cell transplantation after ischemic stroke is able to foster axonal rewiring and dendritic plasticity and to induce long-term functional recovery. The observed therapeutic effect of neural precursor cells seems to underlie their capacity to upregulate the glial glutamate transporter on astrocytes through the vascular endothelial growth factor inducing favorable changes in the electrical and molecular stroke microenvironment. Cell-based approaches able to influence plasticity seem particularly suited to favor poststroke recovery.