Changes in NMDA Receptor Function in Rapid Ischemic Tolerance: A Potential Role for Tri-Heteromeric NMDA Receptors.

In this study, we characterize biophysical changes in NMDA receptor function in response to brief non-injurious ischemic stress (ischemic preconditioning). Electrophysiological studies show NMDA receptor function is reduced following preconditioning in cultured rat cortical neurons. This functional change is not due to changes in the reversal potential of the receptor, but an increase in desensitization. We performed concentration-response analysis of NMDA-evoked currents, and demonstrate that preconditioned neurons show a reduced potency of NMDA to evoke currents, an increase in Mg2+ sensitivity, but no change in glycine sensitivity. Antagonists studies show a reduced inhibition of GluN2B antagonists that have an allosteric mode of action (ifenprodil and R-25-6981), but competitive antagonists at the GluR2A and 2B receptor (NVP-AMM077 and conantokin-G) appear to have similar potency to block currents. Biochemical studies show a reduction in membrane surface GluN2B subunits, and an increased co-immunoprecipitation of GluN2A with GluN2B subunits, suggestive of tri-heteromeric receptor formation. Finally, we show that blocking actin remodeling with jasplakinolide, a mechanism of rapid ischemic tolerance, prevents NMDA receptor functional changes and co-immunoprecipitation of GluN2A and 2B subunits. Together, this study shows that alterations in NMDA receptor function following preconditioning ischemia are associated with neuroprotection in rapid ischemic tolerance.

Tracheal Extubation Under Deep Anesthesia Using Transnasal Humidified Rapid Insufflation Ventilatory Exchange vs. Awake Extubation: An Open-Labeled Randomized Controlled Trial.

Background: Tracheal extubation can be associated with several complications, including desaturation, agitation, hypertension, and tachycardia. We hypothesize that the use of transnasal humidified rapid insufflation ventilator exchange (THRIVE) immediately after extubation under deep anesthesia reduces the incidence of these adverse events. Methods: One hundred patients who underwent elective abdominal surgery under general anesthesia were randomly assigned to undergo tracheal extubation under deep anesthesia employing THRIVE (THRIVE group) or awake extubation (CONTROL group). The primary outcome was the incidence of experiencing desaturation (SpO2 < 90%) at any time during emergence from anesthesia. Secondary outcomes included variations in heart rate and blood pressure, comfort level, bucking, and agitation. Results: The THRIVE group showed a lower incidence of desaturation than the CONTROL group (12 vs. 54%, OR = 0.22 [95% CI, 0.10-0.49], P < 0.001). Less patients in the THRIVE group experienced a 20% (or more) increase in mean arterial pressure (4 vs. 26%, OR = 0.15 [95% CI, 0.04-0.65], P = 0.002). THRIVE patients did not suffer from agitation or bucking, while in the CONTROL group agitation and bucking occurred in 22 and 58% of the patients, respectively. Additionally, the THRIVE group showed a lower incidence of uncomfortable experience than the CONTROL group (8 vs. 36%, OR = 0.22 [95% CI, 0.08-0.61], P = 0.001). Conclusion: Tracheal extubation under deep anesthesia using THRIVE decreases the incidence of desaturation and adverse haemodynamic events and increases patient satisfaction. Extubation under deep anesthesia using THRIVE might be an alternative strategy in selected patient populations.

Influence of ketamine versus fentanyl on pain relief for pediatric orthopedic emergencies: A meta-analysis of randomized controlled studies.

INTRODUCTION: The comparison of ketamine with fentanyl for pain control of pediatric orthopedic emergencies remains controversial. We conduct a systematic review and meta-analysis to explore the influence of ketamine versus fentanyl on pain management among pediatric orthopedic emergencies. METHODS: We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2020 for randomized controlled trials assessing the effect of ketamine versus fentanyl on pain management for pediatric orthopedic emergencies. RESULTS: Five randomized controlled trials are included in the meta-analysis. Overall, compared with fentanyl for pediatric orthopedic emergencies, ketamine led to similar change in pain scores at 15 to 20 minutes (standard mean difference = -0.05; 95% confidence interval [CI] = -0.38 to 0.28; P = .77) and 30 minutes (standard mean difference = 0.11; 95% CI = -0.20 to 0.42; P = .49), as well as rescue analgesia (RR = 0.90; 95% CI = 0.54 to 1.51; P = .69), but revealed the increase in nausea/vomiting (RR = 2.65; 95% CI = 1.13 to 6.18; P = .02) and dizziness (RR = 3.83; 95% CI = 1.38 to 10.60; P = .01). CONCLUSIONS: Ketamine may be similar to fentanyl in terms of the analgesic efficacy for pediatric orthopedic emergencies.

Notch1/TAZ axis promotes aerobic glycolysis and immune escape in lung cancer.

Oncogenic signaling pathway reprograms cancer cell metabolism to promote aerobic glycolysis in favor of tumor growth. The ability of cancer cells to evade immunosurveillance and the role of metabolic regulators in T-cell functions suggest that oncogene-induced metabolic reprogramming may be linked to immune escape. Notch1 signaling, dysregulated in lung cancer, is correlated with increased glycolysis. Herein, we demonstrate in lung cancer that Notch1 promotes glycolytic gene expression through functional interaction with histone acetyltransferases p300 and pCAF. Notch1 signaling forms a positive feedback loop with TAZ. Notch1 transcriptional activity was increased in the presence of TAZ and the activation was TEAD1 independent. Notably, aerobic glycolysis was critical for Notch1/TAZ axis modulation of lung cancer growth in vitro and in vivo. Increased level of extracellular lactate via Notch1/TAZ axis inhibited cytotoxic T-cell activity, leading to the invasive characteristic of lung cancer cells. Interaction between Notch1 and TAZ promoted aerobic glycolysis and immune escape in lung cancer. Our findings provide potential therapeutic targets against Notch1 and TAZ and would be important for clinical translation in lung cancer.

Clinicopathological and molecular characterizations of pulmonary NUT midline carcinoma.

INTRODUCTION: Pulmonary nuclear protein of the testis (NUT) midline carcinoma (NMC) is a aggressive cancer with t (15, 19) translocation. Here we present the clinicopathological characteristics and molecular genetics alterations of primary pulmonary NMC. METHODS: Fluorescence in situ hybridization (FISH) assay was performed to evaluate NUT translocation. Next generation sequencing (NGS) was performed to investigate genomic landscape. A panel of 289 lung cancer tissues with undifferentiation was retrospectively screened for NUT expression by immunohistochemical (IHC) assay. RESULTS: Overall, 2136 lung cancer samples were reviewed. We consecutively identified 12 cases of primary pulmonary NMC. Computed tomography revealed centrally located bulky lung mass with ipsilateral mediastinal lymph node and pleural involvements. Tumor cells presented diffuse poor differentiation and focal squamous differentiation with positive NUT expression. NUT rearrangement was confirmed by FISH assay. Ten NMC samples were investigated by NGS. The most common alterations identified were P53, PIK3CA, AUTS2, ITIH2, and CDKL5 genes. Pulmonary NMC exhibited increased activity of PI3K/AKT pathway. In the screening study, BRD4-NUT rearrangement was identified in two cases. CONCLUSION: NUT rearrangement remains the gold standard in the diagnosis of pulmonary NMC. PI3K inhibition is a potential targeted therapy for pulmonary NMC.

Masseter response to long-term experimentally induced anterior crossbite in Sprague-Dawley rats.

OBJECTIVE: To detect the long-term response to unilateral anterior crossbite (UAC) in masticatory muscles and in molecular biomarkers of peripheral blood leukocytes. DESIGN: Fifty-six six-week-old Sprague-Dawley rats were used. The gene-fold changes in peripheral blood leukocytes were detected by the microarray analysis to compare the rats that received 20-week UAC treatment with age-matched controls (n = 4). Muscle atrophy-related gene Fbxo32 was selected based on the data of the microarray analysis verified by using real-time PCR. The remaining 36 rats were randomly separated in the UAC and control groups at 12 and 20 weeks (n = 12). The protein expression of Fbxo32 and the muscle injury and myogenesis-related markers, αB-crystallin and desmin, were detected in the masseter and lateral pterygoid muscles by western blot assay. RESULTS: In the 20-week UAC group, the masseter muscle weight was lower than that in the age-matched control group, and the expression level of Fbxo32 gene in peripheral blood leukocytes was increased according to the microarray analysis confirmed by real-time PCR detection. The increased protein expression levels of Fbxo32 were detected in the masseter in the 20-week UAC group, and the protein expression levels of desmin and αB-crystallin were decreased at this time point. No similar changes were detected in the lateral pterygoid muscle. CONCLUSIONS: Masseter atrophy is induced by long-term stimulation of UAC. The increased expression of the Fbxo32 gene in peripheral blood leukocytes may be a candidate biological marker of masseter atrophy.

Addition of the Electronic Educational Material to Doctor's Face-to-Face Education Has No Additive Effects on Hypertension Control: A Randomized Single Blind Study.

BACKGROUND: Patient education is effective for HTN treatment. There are many methods of patient education improving HTN control. Are there additive effects of combination of different educational methods for HTN treatment? OBJECTIVE: To assess the effects of addition of the electronic educational material to doctor's face-to-face education for HTN control. METHOD: We designed a randomized single blind study to compare the doctor's face-to-face education alone and its combination with the electronic educational material over the cell phone. Participants were patients with a confirmed diagnosis of primary HTN. Electronic educational material over the cell phone was the intervention. Main measures were standard blood pressure measurements before and after 12 weeks of treatment. RESULT: The baseline characteristics of the intervention and control groups including the age, sex, SBP, DBP, and HTN control rate were not significantly different. After 12 weeks of follow-up, the blood pressure and the HTN control rate seemed worse in the combination group; however, the differences between the intervention group and the control group were not statistically significant. CONCLUSION: There were no additive effects in the combination of the doctor's face-to-face education and the electronic educational material over the cell phone.

Injury responses of Sprague-Dawley rat jaw muscles to an experimental unilateral anterior crossbite prosthesis.

OBJECTIVE: Dental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure. DESIGN: Unilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor. RESULTS: Two weeks of UAC elicited mild injury of the two muscles. Myogenesis and protective reactions were detected as increases in αB-crystallin expression in the masseter after 3 days and in the LPM after 2 weeks, and increases in desmin expression in both muscles after 2 weeks. A switch in fibre types from IIb to IIx occurred in the LPM but not in the masseter. Inflammatory responses, shown by the infiltration of inflammatory cells and increases in TNF-α mRNA expression, and fibrosis responses, shown by increased mRNA expression of Type I and III collagens, appeared very mild in the two muscles. These responses were partially recovered by the cessation of UAC. During the whole process, no obvious changes were observed in mitochondrial function, as indicated by the levels of proliferator-activated receptor γ coactivator 1α, mitofusin-2 and voltage-dependent anion channel. CONCLUSIONS: UAC causes injury and very limited inflammatory and fibrosis adaption in the masseter and LPM. Both muscles respond with myogenesis and protective activity. The LPM responds also with muscle fibre isoform alternations. These alterations were partially recovered by the cessation of dental stimulation at an early stage.

Inhibitory Effect of Sirtuin6 (SIRT6) on Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

BACKGROUND The imbalance between bone resorption and formation is the basic mechanism underlying osteoporosis in the elderly. Osteogenesis is the differentiation of human mesenchymal stem cells (hMSCs) into osteoblasts. Sirtuin6 (SIRT6) regulates various biological functions, including differentiation. Transient receptor potential cation channel subfamily V member 1 (TRPV1) is a non-selective cation channel that can be activated by physical and chemical stimulation. However, experimental data supporting the role of SIRT6 in osteogenic differentiation (OD) of hMSCs are lacking. MATERIAL AND METHODS Differentiation of hMSCs was induced. The expressions of SIRT6, TRPV1, and CGRP were detected by Q-PCR, Western blot, and ELISA, respectively. SIRT6 was overexpressed in hMSCs by transfection. ALP activity and Alizarin Red staining were utilized to detect the effect of SIRT6 on hMSC OD. Then, capsaicin and capsazepine, the TRPV1 agonist and antagonist, respectively, were administrated to assess the role of TRPV1. RESULTS SIRT6 expression was downregulated during hMSC differentiation. SIRT6 overexpression was accompanied by reduced expression of specific genes and alkaline phosphatase (ALP) activity in osteoblasts. Furthermore, TRPV1 channel was also reduced by SIRT6 overexpression via ubiquitinating TRPV1. Capsaicin was utilized in SIRT6-overexpressed cells. Capsaicin therapy counteracted the effect of SIRT6 overexpression on OD, and markedly decreased OD. CONCLUSIONS The SIRT6-TRPV1-CGRP signal axis is the key to regulating OD in hMSCs, which could be a potential therapeutic target for osteoporosis and bone loss-related diseases.

Early growth response 1 reduction in peripheral blood involving condylar subchondral bone loss.

OBJECTIVES: To detect whether early growth response 1 (EGR1) in peripheral blood leucocytes (PBLs) indicates temporomandibular joint (TMJ) osteoarthritis (OA) lesions. MATERIALS AND METHODS: Egr1 mRNA expression levels in PBLs were detected in eight malocclusion patients without temporomandibular disorder (TMD) signs and 16 malocclusion patients with clinical TMD signs with (eight) or without (eight) imaging signs of TMJ OA. Twelve 6-week-old rats were randomized to a control group and a unilateral anterior crossbite (UAC) group and were sampled at 4 weeks. The Egr1 mRNA expression levels in PBLs and protein expression levels in different orofacial tissues were measured. RESULTS: Patients with TMD signs with/without TMJ OA diagnosis showed lower Egr1 mRNA expression levels in PBLs than patients without TMD signs. The lower Egr1 mRNA expression was also found in the PBLs of UAC rats, which were induced to exhibit early histo-morphological signs of TMJ OA lesions. In subchondral bone of UAC rats, EGR1 protein expression was decreased, co-localization of EGR1 with osterix or dentin matrix protein-1 was identified, and the number of EGR1 and osterix double-positive cells was reduced (all p < .05). CONCLUSION: Egr1 reduction in PBLs potentially indicates subchondral bone OA lesions at an early stage.

[Biologics for targeting inflammatory cytokines and their clinical application].

Inflammatory cytokines can mediate many biological processes and are tightly regulated by the body. Loss of control can trigger a range of diseases such as autoimmune inflammation and cancer. Therefore, a number of biological agents that can effectively regulate the biological effects of inflammatory cytokines such as recombinant anti-inflammatory cytokines, cytokine receptors and neutralizing antibodies have been extensively used in the treatment of related diseases caused by the imbalance of inflammatory cytokines. In recent years, in particular, a number of new innovative biological agents for blocking and regulating cytokine activities are emerging. In this article, we review the recent development and clinical use of the biologics targeting TNF-α, IL-1, IL-6 and IL-17, and point out their inherent limitations and clinical risks. Finally, based on the research findings of our own and other scholars, we suggest some approaches and methods for reducing their side-effects and clinical risk. We consider that using modern biotechnology to improve the tissue specificity to inflammatory site and tumor will be an important development direction of such biologics.

Molecular changes in peripheral blood involving osteoarthritic joint remodelling.

Biomarkers of temporomandibular joint (TMJ) osteoarthritis (OA) remain unknown. The objective was to detect whether molecular biomarkers from peripheral blood leucocytes (PBLs) engage in TMJ OA lesions. Thirty-four six-week-old Sprague Dawley rats were used. The top upregulated gene ontology categories and gene-fold changes in PBLs were detected by a microarray analysis comparing rats that received 20-week unilateral anterior crossbite (UAC) treatment with age-matched controls (n = 4). Twenty weeks of UAC treatment had been reported to induce TMJ OA-like lesions. The other twenty-four rats were randomly placed in the UAC and control groups at 12- and 20-week time points (n = 6). The mRNA expression levels of the selected biomarkers derived from the microarray analysis and their protein expression in the alveolar bone and TMJ were detected. The microarray analysis indicated that the three most highly involved genes in PBLs were Egr1, Ephx1 and Il10, which were confirmed by real-time PCR detection. The increased protein expression levels of the three detected molecules were demonstrated in cartilage and subchondral bone (P < 0.05), and increased levels of EPHX1 were reported in discs (P < 0.05); however, increased levels were not present in the alveolar bone. Immunohistochemistry revealed the increased distribution of EGR1-positive, EXPH1-positive and IL10-positive cells predominantly in the osteochondral interface, with EXPH1 also present in TMJ discs. In conclusion, the increased mRNA expression of Egr1, Ephx1 and Il10 in PBLs may serve as potential biomarkers for developed osteoarthritic lesions relating to osteochondral interface hardness changes induced by dental biomechanical stimulation.

Bilateral anterior elevation prosthesis boosts chondrocytes proliferation in mice mandibular condyle.

OBJECTIVE: We aimed to develop a mouse model predominating in a proliferative response in the articular cartilage of the temporomandibular joints. MATERIALS AND METHODS: Bilateral anterior elevation of occlusion was developed by installing metal tubes onto the incisors of mice with edge-to-edge relation to prevent tooth wear, leading to an increase in the vertical height of the dental occlusion with time. Morphological changes and expression changes in Cyclin D1, Aggrecan, and type II and type X collagen in the mandibular condylar cartilage were detected. In addition, cells were isolated from the mandibular condylar cartilage and exposed to cyclic tensile strain (CTS). RESULTS: Compared with age-matched controls, the tooth length was longer at 3 weeks, 7 weeks, and 11 weeks in BAE mice (p < 0.05), with increased condylar cartilage thickness, matrix amount, and cell number (p < 0.05). Compared with the deep zone cells, CTS stimulated the superficial zone cells to express a higher level of proliferating cell nuclear antigen, Cyclin D1, Aggrecan, and type II collagen but a lower level of type X collagen and alkaline phosphatase. CONCLUSION: Bilateral anterior elevation stimulated the proliferative response in the mandibular condylar cartilage, offering a new therapeutic strategy for cartilage degeneration.

The Influence of Etoricoxib on Pain Control for Laparoscopic Cholecystectomy: A Meta-analysis of Randomized Controlled Trials.

INTRODUCTION: The efficacy of etoricoxib on pain control for laparoscopic cholecystectomy remains controversial. We conduct a systematic review and meta-analysis to explore the impact of etoricoxib on pain intensity after laparoscopic cholecystectomy. MATERIALS AND METHODS: We searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2018 for randomized controlled trials assessing the effect of etoricoxib versus placebo on pain management after laparoscopic cholecystectomy. This meta-analysis was performed using the random-effect model. RESULTS: Four randomized controlled trials involving 351 patients are included in the meta-analysis. Overall, compared with control group for laparoscopic cholecystectomy, etoricoxib has no important impact on pain scores within 4 hours [mean difference (MD)=-1.48; 95% confidence interval (CI)=-3.54 to 0.58; P=0.16] and 8 hours (MD=-0.65; 95% CI=-1.43 to 0.12; P=0.10), but can significantly decrease pain intensity within 12 hours (MD=-1.16; 95% CI=-1.93 to -0.38; P=0.003) and 24 hours (MD=-1.10; 95% CI=-1.98 to -0.22; P=0.01), as well as postoperative analgesic consumption (standard MD=-1.21; 95% CI=-2.19 to -0.23; P=0.02), with no increase in nausea and vomiting (risk ratio=0.68; 95% CI=0.42-1.10; P=0.11), and headache (risk ratio=0.96; 95% CI=0.44-2.09; P=0.92). CONCLUSIONS: Etoricoxib can substantially reduce pain intensity in patients with laparoscopic cholecystectomy.

Catabolic changes of rat temporomandibular joint discs induced by unilateral anterior crossbite.

BACKGROUND: The temporomandibular joint (TMJ) disc plays a role in joint movement and in load absorbance and distribution. An experimental unilateral anterior crossbite (UAC) prosthesis induces mandibular condylar cartilage degeneration in rats. However, the changes in the articular disc are still unknown. OBJECTIVE: To describe changes in the TMJ discs of UAC rats. METHODS: The discs of fifty-four Sprague-Dawley rats, equally distributed into a UAC group and an age-matched sham-operated control group at 4, 12 and 20 weeks (n = 9), were evaluated by gross and histomorphological observation and by detection at the mRNA or protein expression levels of the markers related to the matrix elements. RESULTS: No macro- or micro-morphological differences were observed between groups. However, there were catabolic degradative changes at the molecular level in the UAC group, showing a significant reduction in the mRNA and/or protein expression levels of many molecules. The reduction became worse with time (P < 0.05). The reduced molecules included: (a) those related to the extracellular matrix, such as type I collagen, decorin and fibromodulin; (b) those related to chondrogenesis, such as type II collagen and aggrecan; and (c) those related to osteogenesis, such as alkaline phosphatase and runt-related transcription factor 2. The mRNA expression of vascular endothelial growth factor did not change. In contrast, fibronectin, which can promote wound healing, and its N-terminal fragment, which can induce cartilage degradation, were accumulated (P < 0.05). CONCLUSION: TMJ discs were stimulated to catabolic changes by the aberrant dental occlusion and seemed to go to inanimate with time.

Alterations of Notch pathway in patients with adenoid cystic carcinoma of the trachea and its impact on survival.

INTRODUCTION: Adenoid cystic carcinoma (ACC) of the trachea lacks of well-characterized molecular markers. There is currently no specific treatment for metastatic ACC of the trachea. This study aimed to identify genomic mutations of Notch pathway and investigate the efficacy of NOTCH inhibitor in ACC of the trachea. METHODS: 73 Patients with ACC of the trachea at four institutions from 2008 to 2016 were identified. Analysis of hotspot mutations in cancer-related genes of Notch pathway was performed using next generation sequencing. Gene-expression and functional analyses were performed to study the mechanism of activation through mutation. Univariable and multivariable Cox regression models were used to predict overall survival (OS). Patient-derived xenograft (PDX) models were established and treated with NOTCH inhibitor Brontictuzumab. RESULTS: Gain-of-function mutations of the NOTCH1 gene occurred in 12 (16.4%) tumors, leading to stabilization of the intracellular cleaved form of NOTCH1 (ICN1). NOTCH1 mutation was associated with increased NOTCH1 activation and its target gene HES1. Mutations in NOTCH2 (3/73), NOTCH4 (2/73), JAG1 (1/73) and FBXW7 (2/73) were also identified in 8 (11.0%) patients. A strong inverse correlation of expression was observed between FBXW7 and HES1. NOTCH1 mutation was associated with solid subtype (P = 0.02), younger age at diagnosis (P = 0.041) and shorter overall survival (OS) (P = 0.017). NOTCH1 mutation was not an independent prognostic factor in the presence of histologic subtype and resection margin. Brontictuzumab significantly reduced tumor growth in NOTCH1-mutated PDX. CONCLUSION: NOTCH1 mutation is associated with activation of Notch pathway in ACC of the trachea. NOTCH1 is a potential target for therapeutic intervention in patients with ACC of the trachea.

Role of Complement in a Rat Model of Paclitaxel-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a painful and debilitating side effect of cancer chemotherapy with an unclear pathogenesis. Consequently, the available therapies for this neuropathic pain syndrome are inadequate, leading to a significantly reduced quality of life in many patients. Complement, a key component of the innate immune system, has been associated with neuroinflammation, a potentially important trigger of some types of neuropathic pain. However, the role of complement in CIPN remains unclear. To address this issue, we developed a C3 knockout (KO) rat model and induced CIPN in these KO rats and wild-type littermates via the i.p. administration of paclitaxel, a chemotherapeutic agent associated with CIPN. We then compared the severity of mechanical allodynia, complement activation, and intradermal nerve fiber loss between the groups. We found that 1) i.p. paclitaxel administration activated complement in wild-type rats, 2) paclitaxel-induced mechanical allodynia was significantly reduced in C3 KO rats, and 3) the paclitaxel-induced loss of intradermal nerve fibers was markedly attenuated in C3 KO rats. In in vitro studies, we found that paclitaxel-treated rat neuronal cells activated complement, leading to cellular injury. Our findings demonstrate a previously unknown but pivotal role of complement in CIPN and suggest that complement may be a new target for the development of novel therapeutics to manage this painful disease.

Clinical Significance of Plasma Epstein-Barr Virus DNA in Pulmonary Lymphoepithelioma-like Carcinoma (LELC) Patients.

INTRODUCTION: Primary pulmonary lymphoepithelioma-like carcinoma (LELC) is a histologically distinctive subtype of NSCLC and an Epstein-Barr virus (EBV)-associated epithelial neoplasm. We investigated the clinical significance of plasma concentrations of EBV DNA in patients with pulmonary LELC. METHODS: Two independent sets of plasma samples from a total of 429 patients with patients with pulmonary LELC (287 initial and 142 confirmatory) were available for EBV DNA determination. Plasma samples from the patients were subjected to a real-time quantitative polymerase chain reaction before treatment and 3 months after radical resection. Cutoff points were determined for pretreatment plasma EBV DNA concentration (low <4000 copies/mL versus high ≥4000 copies/mL) on the basis of a measure of heterogeneity with the log-rank test statistic with respect to overall survival (OS). The Kaplan-Meier method and Cox regression were used to evaluate the relationship between plasma EBV DNA concentrations and clinical outcome. Among patients with advanced-stage pulmonary LELC who underwent sequential blood draws, we evaluated the relationship between change in disease status and change in EBV DNA concentrations by using nonparametric tests. RESULTS: High EBV DNA concentration was associated with shorter OS in the initial, confirmatory, and combined data sets (combined data set hazard ratio = 3.67, 95% confidence interval: 2.72-4.38, p < 0.001). These findings persisted after multivariable adjustment. Compared with low EBV DNA concentration, high EBV DNA concentration was associated with shorter OS in patients with any stage of disease. High EBV DNA concentration was also associated with shorter disease-free survival (DFS) in patients with stage I/II disease. Patients with persistently detectable plasma EBV DNA had significantly poorer OS (p < 0.001) and DFS (p < 0.001) than did patients with undetectable EBV DNA 3 months after radical resection. In patients who underwent sequential evaluation of EBV DNA, an association was identified between an increase in EBV DNA concentration and a poor response to treatment and disease progression of pulmonary LELC. CONCLUSION: High baseline EBV DNA concentration is an independent poor prognostic marker in patients with pulmonary LELC. These results should be confirmed in larger prospective trials.