THU0044 SINGLE CELL ANALYSIS OF BONE MARROW AND PERIPHERAL ALTERED B CELL DIFFERENTIATION IN PATIENTS WITH ACTIVE SLE AND THE MECHANISM OF ABNORMAL EARLY B CELL DEVELOPMENT

Background:

B cell differentiation and dysfunction play a key role in the pathogenesis of Systemic lupus erythematosus (SLE). Bone marrow (BM) is the development organ of B cells, and also the home and residence place of plasma cells and memory B cells. However, there is a lack of studies on B cells in BM with lupus.

Objectives:

To map the development of BM and peripheral B cells and investigate the mechanism of abnormal early B cell development in SLE.

Methods:

A total of 11 SLE patients and 5 age- and sex-matched controls were recruited.BM and peripheral B cell subsets were measured by flow cytometry. sorting-purified B cell subsets were subject toSingle-cell RNA sequencing (scRNA-seq) and functional studies. Plasma cytokines and secreted immunoglobulins were detected by Luminex or ELISA. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI).

Results:

In the present study, we find out that the percentage of monocytes in MNC (p=0.070) and plasma cells(p=0.001)in CD19+ were significantly decreased in BM of SLE, compared to healthy controls. While, SLE patients had increased T%MNC(p=0.008) and B%CD19+(p=0.002) in BM that controls. In detail, the B cell subsets of bone marrow in patients with active lupus (SLEDAI≥8 score) were seriously disordered, showing the increasing T%MNC(p=0.049), propre-B%CD19+ (p=0.006)and immature B cell%CD19+ (p=0.010) than healthy donors. propre-B%CD19+ exhibited good relationship with SLEDAI. By integrating single B cell expression profiling and repertoire analysis, we map the development of B cells in BM and peripheral and pathogenic characteristics of early B cells, especially propre-B.

Conclusion:

These findings demonstrated that early B cells in BM, especially propre-B are abnormally differentiated with dysregulations. BM is an important organ targeted by SLE. This studyis not only to clarify the internal mechanism of the disorder of differentiation of B cells, but also to provide new clues for the targeted diagnosis and treatment of SLE.

References:

[1]Palanichamy, A., et al.,Neutrophil-mediated IFN activation in the bone marrow alters B cell development in human and murine systemic lupus erythematosus.J Immunol, 2014.192(3): p. 906-18.

[2]Papadaki, H.A., J.C. Marsh, and G.D. Eliopoulos,Bone marrow stem cells and stromal cells in autoimmune cytopenias.Leuk Lymphoma, 2002.43(4): p. 753-60.

[3]Karrar, S. and D.S. Cunninghame Graham,Abnormal B Cell Development in Systemic Lupus Erythematosus: What the Genetics Tell Us.Arthritis Rheumatol, 2018.70(4): p. 496-507.

[4]Woods, M., Y.R. Zou, and A. Davidson,Defects in Germinal Center Selection in SLE.Front Immunol, 2015.6: p. 425.

[5]Upregulation of p16INK4A promotes cellular senescence of bone marrow-derived mesenchymal stem cells from systemic lupus erythematosus patients.Cell Signal, 2012.24(12): p. 2307-14.

Disclosure of Interests:

None declared

THU0075 MIR-21 IN EXOSOMES DRIVED FROM DENTAL PULP STEM CELLS AMELIORATE THE TREGS/TH17 IMMUNE RESPONSE VIA TARGETING STAT3 IN COLLAGEN-INDUCED ARTHRITIS MICE

Background:

Rheumatoid arthritis (RA) is a common and systemic autoimmune disease1.It is vital for deciphering pathogenesis to define the precise CD4+Tcell subsets that are expanded or dysregulated in RA patients2.An increase in the Th17 cell subset and a decrease in Tregs resulting imbalance of Tregs/Th17 may be responsible for the occurrence and development of RA3. Dental pulp stem cells (DPSCs) appear be a new therapeutic tool for immunological diseases4,5.InRA, the mechanism of the effect of miR-21 drivedfromDPSCsexosomes (DPSCs-exo) on the balance of Tregs/Th17 is still unclear.

Objectives:

We explored the effect of exosomes drived from DPSCson RA and investigated the correlation between DPSCs-exo and Tregs/Th17 balance.

Methods:

Exosomes were isolated through differential centrifugation. Collagen-induced arthritis(CIA) mice were builded to detect histological change and Tregs/Th17 ratio.CD4+Tcells were isolated from PBMCs. Exosomes and CD4+T cells were co-cultured to study the regulation of Tregs/Th17 balance.The relationship between miR-21 and Tregs/Th17 balance was studied by flow cytometry, qRT-PCR and Western blotting etc.

Results:

After Dpscs-exo treatment, the clinical scores and paw swelling of CIA mice decreased.At the same time, the expression of Treg cells increased and the expression of Th17 cells decreased in the spleen,changing the ratio of Tregs/Th17.Exosomes and CD4+T cells were co-culture,showing that Treg cellsincreased and Th17 cellsdecreased. MiR-21 is highly expressed in RA patients.MiR-21 in exosomes were Knockout and overexpressed.The balance ofTregs/Th17 decreased when miR-21 were knockout and increased when miR-21were overexpressed. In addition, STAT3 in CD4+T cells were overexpressed and co-culture with DPSCs-exo,which inhibited Tregs/Th17.

Conclusion:

We elucidated the mechanism of the regulation of Tregs/Th17 balance by DPSCs-exo, that is, miR-21 in exosomes drived from dental pulp stem cells ameliorate the Tregs /Th17 immune response via targeting STAT3 in collagen-induced arthritis mice.

References:

[1]MF, B.et al.Hexokinase 2 as a novel selective metabolic target for rheumatoid arthritis.77, 1636-1643,doi:10.1136/annrheumdis-2018-213103 (2018).

[2]CY, F.et al.Mixed-effects association of single cells identifies an expanded effector CD4 T cell subset in rheumatoid arthritis.10,doi:10.1126/scitranslmed.aaq0305 (2018).

[3]Q, S.et al.Impaired Tip60-mediated Foxp3 acetylation attenuates regulatory T cell development in rheumatoid arthritis.100, 27-39,doi:10.1016/j.jaut.2019.02.007 (2019).

[4]L, J.et al.Comparison of immunomodulatory properties of exosomes derived from bone marrow mesenchymal stem cells and dental pulp stem cells.67, 432-442,doi:10.1007/s12026-019-09088-6 (2019).

[5]B, M., A, L., M, B., W, L. & cells, S. B. J. S. Concise Review: Dental Pulp Stem Cells: A Novel Cell Therapy for Retinal and Central Nervous System Repair.35, 61-67,doi:10.1002/stem.2398 (2017).

Disclosure of Interests: None declared

Comprehensive analysis of miRNAs, lncRNAs, and mRNAs reveals potential players of sexually dimorphic and left-right asymmetry in chicken gonad during gonadal differentiation

Despite thousands of sex-biased genes being found in chickens, the genetic control of sexually dimorphic and left-right asymmetry during gonadal differentiation is not yet completely understood. This study aimed to identify microRNAs (miRNAs), long noncoding RNAs (lncRNAs), messenger RNAs (mRNAs), and signaling pathways during gonadal differentiation in chick embryos (day 6/stage 29). The left and right gonads were collected for RNA sequencing. Sex-biased, side-biased miRNAs, lncRNAs, mRNAs, and shared differentially expressed miRNAs (DEmiRNA)–differentially expressed mRNAs (DEmRNA)–differentially expressed lncRNAs (DElncRNA) interaction networks were performed. A total of 8 DEmiRNAs, 183 DElncRNAs, and 123 DEmRNAs were identified for the sex-biased genes, and 7 DEmiRNAs, 189 DElncRNAs, and 183 DEmRNAs for the side-biased genes. The results of quantitative real-time PCR were generally consistent with the RNA-sequencing results. The study suggested that miRNAs and lncRNAs regulation were novel gene-specific dosage compensation mechanism and they could contribute to left-right asymmetry of chicken, but sex-biased and side-biased miRNAs, lncRNAs, and mRNAs were independent of each other. The competing endogenous RNA (ceRNA) networks showed that 17 target pairs including miR-7b (CYP19A1, FSHR, GREB1, STK31, CORIN, and TDRD9), miR-211 (FSHR, GREB1, STK31, CORIN, and TDRD9), miR-204 (FSHR, GREB1, CORIN, and TDRD9), and miR-302b-5p (CYP19A1 and TDRD9) may play crucial roles in ovarian development. These analyses provide new clues to uncover molecular mechanisms and signaling networks of ovarian development.

Single-Layered Graphene/Au-Nanoparticles-Based Love Wave Biosensor for Highly Sensitive and Specific Detection of Staphylococcus aureus Gene Sequences

In this work, a single-layered graphene (SLG)/Au-nanoparticles (NPs)-based Love wave biosensor was prepared for detection of Staphylococcus aureus (S. aureus) gene sequences. The annealing process was proposed to obtain a larger-area interface with ssDNA. The sensitivity was verified by detecting S. aureus gene sequences with a linear detection ranging from 0 to 10 nmol/L, where the limit of detection (LOD) was only 12.4 pg/mL. The stable state of the biosensors based on SLG/Au NPs in the liquid phase could be kept for more than 0.5 h (±0.1°), and the specificity was verified by detecting noncomplementary ssDNA and one- and three-base mismatched ssDNA. The results of our study suggest that a Love wave biosensor based on SLG/Au NPs hold great potential in clinical testing and diagnosis.

Introduction of lactobionic acid ligand into mixed-charge nanoparticles to realize in situ triggered active targeting to hepatoma cells

To overcome the dilemma between passive tissue targeting and active cell targeting, nanomaterials are often required to exhibit the transition from ‘stealth’ to ‘active targetable’ in response to the pathological microenvironment. Here, we introduced a ternary surface modification method that incorporating active targeting ligand lactobionic acid with pH-sensitive mixed-charge surface. The resulted mixed-charge gold nanoparticles (LA@MC-GNPs) showed resistance to non-specific adsorption of proteins and uptake by HepG2 cells at normal tissue pH 7.4, while they underwent pH-sensitive aggregation and recovered active targeting capability at tumor acidic pH 6.5. The ternary surface modification method provided a simplest strategy to solve the dilemma between passive and active targeting of nanomedicine.

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Gold nanoparticles (GNPs) were ternary modified with lactobionic acid ligand and mixed-charge ligands.

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The resulted GNPs showed pH-sensitive aggregation in response to tumor acidic pH.

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Resistance to non-specific protein adsorption and cell uptake of the ternary modified GNPs was observed at pH 7.4.

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Cell uptake was greatly enhanced because of the recalled active targeting ability at pH 6.5.

An aptamer-based shear horizontal surface acoustic wave biosensor with a CVD-grown single-layered graphene film for high-sensitivity detection of a label-free endotoxin

The thickness of the sensitive layer has an important influence on the sensitivity of a shear horizontal surface acoustic wave (SH-SAW) biosensor with a delay-line structure and lower layer numbers of graphene produce better sensitivity for biological detection. Therefore, a label-free and highly sensitive SH-SAW biosensor with chemical vapor deposition (CVD-)-grown single-layered graphene (SLG) for endotoxin detection was developed in this study. With this methodology, SH-SAW biosensors were fabricated on a 36° Y-90° X quartz substrate with a base frequency of 246.2 MHz, and an effective detection cell was fabricated using acrylic material. To increase the surface hydrophilicity, chitosan was applied to the surface of the SLG film. Additionally, the aptamer was immobilized on the surface of the SLG film by cross-linking with glutaraldehyde. Finally, the sensitivity was verified by endotoxin detection with a linear detection ranging from 0 to 100 ng/mL, and the detection limit (LOD) was as low as 3.53 ng/mL. In addition, the stability of this type of SH-SAW biosensor from the air phase to the liquid phase proved to be excellent and the specificity was tested and verified by detecting the endotoxin obtained from Escherichia coli (E. coli), the endotoxin obtained from Pseudomonas aeruginosa (P. aeruginosa), and aflatoxin. Therefore, this type of SH-SAW biosensor with a CVD-grown SLG film may offer a promising approach to endotoxin detection, and it may have great potential in clinical applications.

Effects of sodium butyrate on intestinal health and gut microbiota composition during intestinal inflammation progression in broilers

Butyric acid is a beneficial feed additive used in animal production, including poultry production. However, there are few reports on butyric acid as a prophylactic treatment against intestinal inflammation in broilers. The current study explored the effect of sodium butyrate (SB) as a prophylactic treatment on the intestinal health and gut microbiota of broilers with intestinal inflammation induced by dextran sulfate sodium (DSS) by monitoring changes in intestinal histopathology, gut leakiness indicators, inflammatory cytokines, and gut microbiota composition. Sodium butyrate supplementation prior to DSS administration significantly reduced the lesion scores of intestinal bleeding (P < 0.05) and increased villus height and the total mucosa of the ileum (P < 0.05). Regardless of intestinal inflammation, supplementation with SB at 300 mg/kg significantly decreased the levels of D (-)-lactate (P < 0.05), interleukin-6, and interleukin-1β (P < 0.05) but increased the level of interleukin-10 (P < 0.05). The SB treatment did not affect the alpha diversity of intestinal microbiota during intestinal inflammation progression but altered their composition, and the microbial community structure of treated broilers was similar to that of control broilers. Taken together, our results reveal the importance of SB in improving intestinal development, inducing an anti-inflammatory effect during intestinal inflammation progression, and modulating the microbial community in broilers. Sodium butyrate seems to be optimized for anti-inflammatory effects at higher doses (300 mg/kg SB).

[Relationship between SHP-1 gene methylation and STAT3 phosphorylation and prognosis in patients with myelodysplastic syndrome]

Objective: To assess the methylation level of SHP-1 promoter region and the effects on the phosphorylation of the Signal Transducers and Activators of Transcription 3 (STAT3) protein in bone marrow specimen of patients with myelodysplastic syndrome (MDS), and to explore the relationship of SHP-1 methylation and prognosis of the patients. Method: Bone marrow specimens of 93 patients with MDS were collected from the General Hospital of Tianjin Medical University from September 2010 to June 2014. The enrolled subjects included 54 males and 39 females and they were divided into the low-risk group (IPSS score:0-1.0, median: 0.5) and the high-risk group (IPSS score: 1.5-3.0, median: 2.5) according to the International Prognostic Score System (IPSS). The methylation level of SHP-1 was detected by methylation-specific polymerase chain reaction, and the level of p-STAT3 was detected using Western blot. Results: In the high-risk group, 64.44% (29/45) of the patients had methylation in the SHP-1 promoter region, which was significantly higher than the low-risk group 22.92% (11/48). Therefore, SHP-1 methylation was frequently presented in the patients of the high-risk group. Similarly, 66.67% (30/45) of the patients in the high-risk group had positive STAT3 phosphorylation status, whereas only 20.83% (10/48) were tested positive in the low-risk group. In addition, correlation analysis also revealed that the SHP-1 methylation rate was positively correlated with the positive rate of STAT3 phosphorylation (r=0.57,P<0.001). Conclusions: SHP-1 methylation is significantly correlated with the risk of MDS patients. It may be used as an independent predictor of shorter survival in patients of the high-risk group. The increased level of SHP-1 methylation will lead to the uncontrolled activation of the downstream JAK/STAT3 pathway, which in turn can cause further positive feedback to amplify the carcinogenic signal.

A radiomics model for determining the invasiveness of solitary pulmonary nodules that manifest as part-solid nodules

AIM

A nomogram model was developed to predict the histological subtypes of lung invasive adenocarcinomas (IAs) and minimally invasive adenocarcinomas (MIAs) that manifest as part-solid ground-glass nodules (GGNs).

MATERIALS AND METHODS

This retrospective study enrolled 119 patients with histopathologically confirmed part-solid GGNs assigned to the training (n=83) or testing cohorts (n=36). Radiomic features were extracted based on the unenhanced computed tomography (CT) images. R software was applied to process the qualitative and quantitative data. The CT features model, radiomic signature model, and combined prediction model were constructed and compared.

RESULTS

A total of 396 radiomic features were extracted from the preoperative CT images, four features including MaxIntensity, RMS, ZonePercentage, and LongRunEmphasis_angle0_offset7 were indicated to be the best discriminators to establish the radiomic signature model. The performance of the model was satisfactory in both the training and testing set with areas under the curve (AUCs) of 0.854 (95% confidence interval [CI]: 0.774 to 0.934) and 0.813 (95% CI: 0.670 to 0.955), respectively. The CT morphology of the lesion shape and diameter of the solid component were confirmed to be a significant feature for building the CT features model, which had an AUC of 0.755 (95% CI: 0.648 to 0.843). A nomogram that integrated lesion shape and radiomic signature was constructed, which contributed an AUC of 0.888 (95% CI: 0.82 to 0.955).

CONCLUSIONS

The radiomic signature could provide an important reference for differentiating IAs from MIAs, and could be significantly enhanced by the addition of CT morphology. The nomogram may be highly informative for making clinical decisions.

[The inhibition of 18β-sodium glycyrrhetinic acid on thymic stromal lymphopoietin expression in the nasal mucosa of allergic rhinitis rats]

Objective: To explore the effect of 18β-sodium glycyrrhetinic acid on thymic stromal lymphopoietin (TSLP) in nasal mucosa of allergic rhinitis (AR) rats. Methods: One hundred Wistar rats,half male and half female,were randomly divided into 5 groups by random number table method: control group, AR model group,budesonide group,18β-sodium glycyrrhetinic acid at dose of 20 mg/kg and 40 mg/kg groups, with 20 rats in each group. AR animal models were established by ovalbumin (OVA) sensitization in the other four experimental groups. After successful modeling, budesonide and 18β-sodium glycyrrhetinic acid were given in each group,and the detection time points were 2 weeks and 4 weeks. The distribution of TSLP in rat nasal mucosa was detected by immunohistochemistry,and the expression of TSLP in rat nasal mucosa was determined by Western blot at the protein level. The expression of TSLP-mRNA in rat nasal mucosa was detected and compared by real-time fluorescence quantitative PCR (RT-PCR) at mRNA level. The concentrations of IL-4 and OVA-sIgE in rat serum were measured and compared by ELISA. One-way analysis of variance and the least significant difference method were used for the comparison among groups, LSD t test was used for the comparison between the two groups,and the difference was statistically significant (P<0.05). Results: Immunohistochemistry confirmed existence of TSLP in rat nasal mucosa, especially in epithelial cells,endothelial cells and epithelial cilia. Western blot and RT-PCR suggested that the expression of TSLP and TSLP-mRNA in nasal mucosa of AR model group was significantly higher than that of control group (2 weeks TSLP: 1.795 9±0.131 4 vs 0.990 5±0.164 2, 4 weeks TSLP: 1.809 7±0.253 4 vs 0.870 3±0.124 4; 2 weeks TSLP-mRNA:4.582 9±0.697 7 vs 1.108 7±0.081 1, 4 weeks TSLP-mRNA:4.814 4±0.662 8 vs 1.001 0±0.155 3; all P<0.05). After 2 weeks and 4 weeks of drug intervention,the expression of TSLP and TSLP-mRNA was inhibited in nasal mucosa of budesonide group,18β-sodium sodium glycyrrhetinic acid at dose of 20 mg/kg and 40 mg/kg group,which was significantly different from that of AR model group (2 weeks TSLP: (0.897 8±0.081 8)/(1.072 1±0.113 6)/(1.396 6±0.133 9) vs 1.795 9±0.131 4; 4 weeks TSLP: (1.191 0±0.161 3)/(1.141 0±0.152 3)/(1.200 5±0.189 6) vs 1.809 7±0.253 4; 2 weeks TSLP-mRNA: (1.175 6±0.100 9)/(1.254 4±0.078 2)/(2.037 2±0.559 2) vs 4.582 9±0.697 7; 4 weeks TSLP-mRNA: (1.158 3±0.104 3)/(1.224 0±0.034 0)/(1.275 2±0.099 6) vs 4.814 4±0.662 8; all P<0.05), and not significantly different from control group. With the inhibition of TSLP, the concentrations of IL-4 and OVA-sIgE in rat serum were also decreased. Conclusion: 18β-sodium glycyrrhetinic acid has obvious inhibitory effect on TSLP in nasal mucosa of AR rats, which can control Th2 type immune inflammatory reaction.

[Effectiveness of P-Gemox chemotherapy combined with radiotherapy in newly diagnosed,stage ⅠE to ⅡE, extranodal nasal type natural killer/T-cell lymphoma]

Objective: To investigate the efficacy and safety of pegaspargase, gemcitabine, and oxaliplatin(P-Gemox) chemotherapy combined with radiotherapy in the treatment of newly diagnosed, stage IE to IIE of Extranodal nasal type natural killer/T-cell lymphoma(ENKTL) patients.Method: P-Gemox chemotherapy combined with radiotherapy was used to analyze its clinical value and the factors affecting the prognosis in the treatment of 43 newly diagnosed ENKTL patients. In addition, toxicity related to chemotherapy was assessed. Result: The complete remission rate was 86.05% in 43 patients,the partial remission rate was 6.98%, and the total effective rate was 93.02%.Chi-square analysis showed tumor diameter, clinical stage and ECOG points were significant independent factors impacting on complete remission rate(P =0.025, 0.042, 0.037).The 1-year and 3-year overall survival rate and progression-free survival rate of 43 patients were 95.35% and 83.7%, 93.02% and 79.07%, respectively. Coxproportional analysis showed that tumor diameter and Ann Arbor stage were signifcant factors affecting overall survival(P =0.016,0.025).Adverse reactions caused by the P-Gemox chemotherapy regimen are mild and more common in grades I to II. Conclusion: The P-Gemox regimen combined with radiotherapy may be a promising option in the treatment of newly-diagnosed ENKTL due to its high efficacy yet low toxicity, and clinical stage has an important effect on CR and OS.

Biodiversity of the microbiota in Spodoptera exigua (Lepidoptera: Noctuidae)

AIMS

Spodoptera exigua is a serious pest of many agricultural crops. However, the bacterial communities of S. exigua are poorly studied, particularly over their entire life cycle. We aimed to study the biodiversity of the microbiota across the life cycle of S. exigua and to provide a better and obtain insight into new pest control strategies.

METHODS AND RESULTS

The bacterial diversity across the life cycle of S. exigua was studied using Illumina MiSeq sequencing of 16S rRNA genes. Spodoptera exigua is dominated by Proteobacteria and Firmicutes, with a total relative abundance of 90·03%. Enterococcus (24·6%), Pseudomonas (12·2%) and Asaia (45·9%) were abundant and active in eggs, while Methylobacterium (18·7%) and Halomonas (16·5%) dominated freshly eclosed larvae. The 3rd and 5th instar larvae were dominated by Enterococcus (76·3 and 62·0%). Pupal stages had the highest microbial diversity. There was no significant difference between newly emerged males and females. Symbionts of eggs were extremely similar and probably vertically transmitted by males during mating.

CONCLUSIONS

The result showed that the bacterial community was affected by the host developmental stages. Our results also suggest that symbionts of egg mass are probably vertically transmitted control by male spawning adults.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study documents the symbiont bacteria across the life cycle of S. exigua. Understanding the microbial symbionts may provide clues to develop potential biocontrol techniques against this pest.

[Value of 18F-FDG PET/CT and PET in diagnosing and staging extranodal nasal type natural killer/T-cell lymphoma:A Meta-analysis]

Objective:The aim of this study is to comprehensively evaluate the values of 18F-FDG PET/CT and PET in diagnosing extranodal nasal type natural killer/T cell lymphoma (ENKTL). Method:Studies about ENKTL diagnosed by 18F-FDG PET/CT and PET until June 2018 were searched in the databases such as PubMed, Embase, Cochrane, Web of Science, CNKI, CBM, VIP and Wanfang. Two reviewers independently screened literature and extracted data strictly according to included and excluded criterion, and assessed bias risk by 11 items using QUADAS-2 gulidline. Meta-analysis was performed by Revmann 5.3 and Stata 12.0 software. The pooled weighted Sentivity (Sen), Specificity (Spe), Diagnostic odds ratio (DOR) were calculated,summary receiver operator curve (SROC) and area under SROC curve (AUC) were also drawn. Result:Ten studies with 457 patients and 5 092 foci on 18F-FDG PET/CT and 4 studies with 169 patients and 384 foci on PET were finally included in our Meta-analysis.Our research showed that pooled Sen, Spe, DOR and AUC of 18F-FDG PET/CT diagnosing ENKTL were 0.97 (95%CI 0.93-0.99), 0.97(95%CI 0.88-0.99), 1 131.07(95%CI 167.77-7 625.28), 0.99(95%CI 0.98-1.00), and they were 0.81 (95%CI 0.70-0.89), 0.90(95%CI 0.66-0.98), 39.63(95%CI 6.41-244.85), 0.86(95%CI 0.82-0.89), respectively. Z test result reveled that 18F-FDG PET/CT had better diagnostic value in detecting ENKTL compared to PET: AUC=0.99(95%CI 0.98-1.00) vs AUC=0.86(95%CI 0.82-0.89), Z=2.95, P=0.003. Conclusion:In comparasion with PET, 18F-FDG PET/CT had excellent diagnostic value in detecting and staging ENKTL and may served as a non-invasive imaging in diagnosing and staging ENKTL.