Diagnostic value of pleural interleukin 17 and carcinoembryonic antigen in lung cancer patients with malignant pleural effusions

Interleukin 17 (IL-17) has been found to be increased in some human cancers; however, the possible implication of IL-17 in regulating antitumor responses in lung cancer patients with malignant pleural effusions (MPE) remains to be elucidated. This study aimed to investigate the diagnostic value of pleural IL-17 and carcinoembryonic antigen (CEA) in MPE and benign pleural effusions (BPE). Pleural effusion samples from 108 patients were classified on the basis of diagnosis as MPE (n?=?56) and BPE (n?=?52). The concentration of IL-17 was determined by enzyme-linked immunosorbent assay (ELISA). The CEA levels were also determined in all patients. A significant difference was observed in the levels of CEA (P?<?0.01) between MPE and BPE. The concentration of IL-17 in MPE was significantly higher compared to that in BPE (P?<?0.01). With a cutoff point of 15.7 pg/ml, IL-17 had a sensitivity of 76.8 % and a specificity of 80.8 % for differential diagnosis. The combined detection of IL-17 and CEA had a sensitivity of 96.4 % and a specificity of 92.3 % to distinguish MPE from BPE. The combined detection of IL-17 and CEA may be more valuable in the differential diagnosis between MPE and BPE.     

microRNA expression profile in a large series of bladder tumors: Identification of a 3‐miRNA signature associated with aggressiveness of muscle‐invasive bladder cancer

The aim of this study was to evaluate the expression levels of microRNAs (miRNAs) in bladder tumors in order to identify miRNAs involved in bladder carcinogenesis with potential prognostic implications. Expression levels of miRNAs were assessed by quantitative real‐time RT‐PCR in 11 human normal bladder and 166 bladder tumor samples (86 non‐muscle‐invasive bladder cancer (NMIBC) and 80 muscle‐invasive bladder cancer (MIBC)). The expression level of 804 miRNAs was initially measured in a well‐defined series of seven NMIBC, MIBC and normal bladder samples (screening set). The most strongly deregulated miRNAs in tumor samples compared to normal bladder tissue were then selected for RT‐PCR validation in a well‐characterized independent series of 152 bladder tumors (validation set), and in six bladder cancer cell lines. Expression levels of these miRNAs were tested for their association with clinical outcome. A robust group of 15 miRNAs was found to be significantly deregulated in bladder cancer. Except for two miRNAs, miR‐146b and miR‐9, which were specifically upregulated in MIBC, the majority of miRNAs (n = 13) were deregulated in the same way in the two types of bladder tumors, irrespective of pathological stage : three miRNAs were upregulated (miR‐200b, miR‐182 and miR‐138) and the other 10 miRNAs were downregulated (miR‐1, miR‐133a, miR‐133b, miR‐145, miR‐143, miR‐204, miR‐921, miR‐1281, miR‐199a and miR‐199b). A 3‐miRNA signature (miR‐9, miR‐182 and miR‐200b) was found to be related to MIBC tumor aggressiveness and was associated with both recurrence‐free and overall survival in univariate analysis with a trend to significance in the multivariate analysis (p = 0.05). Our results suggested a promising individual prognostic value of these new markers.     

血清及胸腔积液中四种肿瘤标志物联合应用对良恶性肿瘤鉴别诊断价值的评估

目的探讨肿瘤标志物CEA、CA125、CA15-3及CA19-9联合应用对鉴别良性胸腔积液(BPE)和恶性胸腔积液(MPE)的价值。方法收集327例2013-01-01-2015-06-30在首都医科大学附属北京朝阳医院(174例)和华中科技大学同济医学院附属协和医院呼吸与危重症医学科(153例)住院的胸腔积液(PE)患者,其中MPE患者119例,BPE患者208例。取PE标本及配对血清标本,应用化学发光法检测CEA、CA125、CA15-3及CA19-9在血清及PE中的浓度,应用二元Logistic回归模型和L1正则化(LASSO)方法将患者基本信息与PE、血清中4种肿瘤标志物CEA、CA125、CA15-3及CA19-9进行不同方式的联合,通过受试者工作特征(ROC)曲线分析和比较不同联合诊断模型的诊断价值。结果PE中CEA+CA15-3+CA19-9的联合模型对应ROC曲线下面积(AUC)值最大(0.90),血清中此联合模型对应的AUC值也是最佳(0.863),PE中的联合模型优于血清中的联合诊断模型,P=0.0125,综合预测能力最强。PE与血清肿瘤标志物浓度差值中CEA+CA15-3+CA19-9的联合模型对应的灵敏度最佳(80.2%),特异度为79.1%。基于LASSO变量选择方法的联合模型在PE中的特异度最佳(96%),此时灵敏度为73%,阳性似然比22。以上结果均P<0.001。PE中CEA+CA15-3+CA19-9的联合模型对应的AUC值(0.90)优于PE中CEA对应的AUC值(0.824),P<0.001。结论联合应用CEA、CA15-3及CA19-9在诊断效能、灵敏度、特异度、阳性似然比等方面优于其他组合,且优于PE中的CEA对BPE/MPE的鉴别诊断价值。     

Up-regulation of pro-angiogenic factors and establishment of tolerance in malignant pleural effusions

Introduction

Malignant pleural effusions (MPEs) are a significant source of cancer morbidity and mortality. Currently there is no cure for MPEs and treatments only palliate the symptoms. The purpose of this study was to determine if there are differences in markers of angiogenesis and immune phenotypes between adenocarcinoma-induced MPEs and benign pleural effusions (BPEs).

Methods

Pleural effusions were collected from patients with MPEs and BPEs. Cells were isolated from effusions and characterized using fluorescent cell sorting (FACS). Pleural effusions were evaluated by ELISA for VEGF-A. An angiogenesis protein array was completed to compare protein expression in malignant and non-malignant effusions.

Results

FACS analysis demonstrated lower accumulation of cytotoxic T-cells and significantly higher accumulation of monocytes, dendritic cells, mesothelial and tumor cells in MPEs compared to benign pleural effusions. MPEs were found to have 77-fold higher VEGF-A levels compared to BPEs. The angiogenesis protein array demonstrated elevated levels of pro-angiogenic factors VEGF-A, CXCL4 and MMP-8, and low levels of pro-inflammatory cytokines IL-8, MCP-1, and TGF-β1 in MPEs.

Conclusions

MPE is biased toward a Th2 dominant state. There is an increase in expression of VEGF-A and other pro-angiogenic factors in MPE. These data suggest there is a role for anti-angiogenesis therapy in patients with MPEs.     

Meta‐analysis of microRNA expression in lung cancer

The prognostic and diagnostic value of microRNA (miRNA) expression aberrations in lung cancer has been studied intensely in recent years. However, due to the application of different technological platforms and small sample size, the miRNA expression profiling efforts have led to inconsistent results between the studies. We performed a comprehensive meta‐analysis of 20 published miRNA expression studies in lung cancer, including a total of 598 tumor and 528 non‐cancerous control samples. Using a recently published robust rank aggregation method, we identified a statistically significant miRNA meta‐signature of seven upregulated (miR‐21, miR‐210, miR‐182, miR‐31, miR‐200b, miR‐205 and miR‐183) and eight downregulated (miR‐126‐3p, miR‐30a, miR‐30d, miR‐486‐5p, miR‐451a, miR‐126‐5p, miR‐143 and miR‐145) miRNAs. We conducted a gene set enrichment analysis to identify pathways that are most strongly affected by altered expression of these miRNAs. We found that meta‐signature miRNAs cooperatively target functionally related and biologically relevant genes in signaling and developmental pathways. We have shown that such meta‐analysis approach is suitable and effective solution for identification of statistically significant miRNA meta‐signature by combining several miRNA expression studies. This method allows the analysis of data produced by different technological platforms that cannot be otherwise directly compared or in the case when raw data are unavailable.     

MicroRNA expression signatures for the prediction of BRCA1/2 mutation‐associated hereditary breast cancer in paraffin‐embedded formalin‐fixed breast tumors

Screening for germline mutations in breast cancer‐associated genes BRCA1 and BRCA2 is indicated for patients with breast cancer from high‐risk breast cancer families and influences both treatment options and clinical management. However, only 25% of selected patients test positive for BRCA1/2 mutation, indicating that additional diagnostic biomarkers are necessary. We analyzed 124 formalin‐fixed paraffin‐embedded (FFPE) tumor samples from patients with hereditary (104) and sporadic (20) invasive breast cancer, divided into two series (A and B). Microarray expression profiling of 829 human miRNAs was performed on 76 samples (Series A), and bioinformatics tool Prophet was used to develop and test a microarray classifier. Samples were stratified into a training set (n = 38) for microarray classifier generation and a test set (n = 38) for signature validation. A 35‐miRNA microarray classifier was generated for the prediction of BRCA1/2 mutation status with a reported 95% (95% CI = 0.88–1.0) and 92% (95% CI: 0.84–1.0) accuracy in the training and the test set, respectively. Differential expression of 12 miRNAs between BRCA1/2 mutation carriers versus noncarriers was validated by qPCR in an independent tumor series B (n = 48). Logistic regression model based on the expression of six miRNAs (miR‐142‐3p, miR‐505*, miR‐1248, miR‐181a‐2*, miR‐25* and miR‐340*) discriminated between tumors from BRCA1/2 mutation carriers and noncarriers with 92% (95% CI: 0.84–0.99) accuracy. In conclusion, we identified miRNA expression signatures predictive of BRCA1/2 mutation status in routinely available FFPE breast tumor samples, which may be useful to complement current patient selection criteria for gene testing by identifying individuals with high likelihood of being BRCA1/2 mutation carriers.     

MicroRNA expression profiles distinguish liposarcoma subtypes and implicate miR‐145 and miR‐451 as tumor suppressors

Liposarcomas are rare, heterogeneous and malignant tumors that can be divided into four histological subtypes with different characteristics and clinical behavior. Treatment consists of surgery in combination with systemic chemotherapy, but nevertheless mortality rates are high. More insight into the biology of liposarcoma tumorigenesis is needed to devise novel therapeutic approaches. MicroRNAs (miRNAs) have been associated with carcinogenesis in many tumors and may function as tumor suppressor or oncogene. In this study we examined miRNA expression in an initial series of 57 human liposarcomas (including all subtypes), lipomas and normal fat by miRNA microarrays. Supervised hierarchical clustering of the most differentially expressed miRNAs (p < 0.0002) distinguished most liposarcoma subtypes and control tissues. The distinction between well differentiated liposarcomas and benign lipomas was blurred, suggesting these tumor types may represent a biological continuum. MiRNA signatures of liposarcoma subtypes were established and validated in an independent series of 58 liposarcomas and control tissues. The expression of the miR‐143/145 and miR‐144/451 cluster members was clearly reduced in liposarcomas compared to normal fat. Overexpression of miR‐145 and miR‐451 in liposarcoma cell lines decreased cellular proliferation rate, impaired cell cycle progression and induced apoptosis. In conclusion, we show that miRNA expression profiling can be used to discriminate liposarcoma subtypes, which can possibly aid in objective diagnostic decision making. In addition, our data indicate that miR‐145 and miR‐451 act as tumor suppressors in adipose tissue and show that re‐expression of these miRNAs could be a promising therapeutic strategy for liposarcomas.     

Evaluation of cytokeratin 19 fragment (CYFRA 21-1) as a tumor marker in malignant pleural effusion

BACKGROUND: The aim was to investigate the diagnostic utility of CYFRA 21-1 (cytokeratin 19 fragment) as a tumor marker in pleural effusion and evaluate the value of combining CYFRA 21-1 and carcinoembryonic antigen (CEA) assays as a diagnostic aid in the malignant pleural effusion. METHODS: One hundred and twenty-six patients (72 malignant and 54 benign pleural effusion) were included in this retrospective study. The effusion levels of CYFRA 21-1 and CEA were measured using radioimmunometric assay. RESULTS: The median values of CYFRA 21-1 in benign and malignant pleural effusion are 15 and 70 ng/ml, respectively. Using a cut-off value of 50 ng/ml, defined at 94% specificity, the diagnostic sensitivity of CYFRA 21-1 for non-small cell lung carcinoma (n = 61), squamous cell carcinoma (n = 21), adenocarcinoma (n = 40) and small cell lung cancer (n = 11) was 64, 71, 60 and 18%, respectively. Regardless of cell types, the diagnostic sensitivity of CYFRA 21-1 and CEA in malignant pleural effusion (n = 72) was 57 and 60%, respectively (cut-off value of 10 ng/ml in CEA assay). Combining CEA with CYFRA 21-1, the diagnostic sensitivity may increase up to 72%, which was defined at 89% specificity. CONCLUSION: CYFRA 21-1 assay may be a useful tumor marker for discriminating benign from malignant pleural effusion, especially in those of non-small cell lung cancer. The combined use of CEA and CYFRA 21-1 assay in the malignant effusion may increase the diagnostic yield compared with CEA or CYFRA 21-1 alone.     

MicroRNA‐493‐5p‐mediated repression of the MYCN oncogene inhibits hepatic cancer cell growth and invasion

Primary hepatic tumors mainly include hepatocellular carcinoma (HCC), which is one of the most frequent causes of cancer‐related deaths worldwide. Thus far, HCC prognosis has remained extremely poor given the lack of effective treatments. Numerous studies have described the roles played by microRNAs (miRNAs) in cancer progression and the potential of these small noncoding RNAs for diagnostic or therapeutic applications. The current consensus supports the idea that direct repression of a wide range of oncogenes by a single key miRNA could critically affect the malignant properties of cancer cells in a synergistic manner. In this study, we aimed to investigate the oncogenes controlled by miR‐493‐5p, a major tumor suppressor miRNA that inactivates miR‐483‐3p oncomir in hepatic cancer cells. Using global gene expression analysis, we highlighted a set of candidate genes potentially regulated by miR‐493‐5p. In particular, the canonical MYCN protooncogene (MYCN) appeared to be an attractive target of miR‐493‐5p given its significant inhibition through 3′‐UTR targeting in miR‐493‐5p‐rescued HCC cells. We showed that MYCN was overexpressed in liver cancer cell lines and clinical samples from HCC patients. Notably, MYCN expression levels were inversely correlated with miR‐493‐5p in tumor tissues. We confirmed that MYCN knockdown mimicked the anticancer effect of miR‐493‐5p by inhibiting HCC cell growth and invasion, whereas MYCN rescue hindered miR‐493‐5p activity. In summary, miR‐493‐5p is a pivotal miRNA that modulates various oncogenes after its reexpression in liver cancer cells, suggesting that tumor suppressor miRNAs with a large spectrum of action could provide valuable tools for miRNA replacement therapies.     

Circulating Epstein‐Barr virus–encoded micro‐RNAs as potential biomarkers for nasal natural killer/T‐cell lymphoma

Nasal natural killer/T‐cell lymphoma (NNKTL) is an Epstein‐Barr virus (EBV)–associated malignancy and is characterized by local invasion and widespread dissemination, with a consequent poor prognosis. Micro‐RNAs (miRNAs) play roles in the pathogenesis of several malignancies by regulating gene expression and have been recently identified as stable entities in serum. Here, we investigated the value of circulating EBV‐miRNAs as biomarkers for NNKTL. Sera of patients with NNKTL were subjected to miRNA polymerase chain reaction (PCR)–array analysis, after which serum EBV‐miRNA levels were verified using quantitative PCR. The latter analysis revealed high miR‐BART2‐5p, miR‐BART7‐3p, miR‐BART13‐3p, and miR‐BART1‐5p expression levels in sera of patients with NNKTL and indicated accurate values for discriminating patients with NNKTL from healthy controls. Levels of these 4 EBV‐miRNAs, which were secreted from NNKTL cells, significantly decreased after treatment compared with those before treatment. Furthermore, a high circulating miR‐BART2‐5p level was associated with disease progression and poor prognosis in patients with NNKTL. Our findings demonstrate that circulating EBV‐miRNAs, particularly miR‐BART2‐5p, may serve as potential diagnostic and prognostic biomarkers in patients with NNKTL.     

Validation for histology‐driven diagnosis in non‐small cell lung cancer using hsa‐miR‐205 and hsa‐miR‐21 expression by two different normalization strategies

Targeted therapy of non‐small cell lung cancer (NSCLC) demands a more accurate tumor classification that is crucial for patient selection in personalized treatment. MicroRNAs constitute a promising class of biomarkers and a helpful tool for the distinction between lung adenocarcinoma (AC) and squamous cell lung carcinoma (SCC). The aim of this study was to evaluate the impact of two different normalization strategies, using U6 snRNA and hsa‐miR‐103 as reference genes, on hsa‐miR‐205 and hsa‐miR‐21 expression levels, in terms of the classification of subtypes of NSCLC. By means of a quantitative real‐time polymerase chain reaction (qRT‐PCR) microRNA expression levels were evaluated in a classification set of 98 surgically resected NSCLC fresh‐frozen samples, and validated findings in an independent set of 42 NSCLC samples. The microRNA expression levels were exploited to develop a diagnostic test using two data normalization strategies. The performance of microRNA profiling in different normalization methods was compared. We revealed the microRNA‐based qRT‐PCR tests to be appropriate measures for distinguishing between AC and SCC (the concordance of histologic diagnoses and molecular methods greater than 88%). Performance evaluation of microRNA tests, based on the two normalization strategies, showed that the procedure using hsa‐miR‐103 as reference target has a slight advantage (sensitivity 83.33 and 100% in classification and validation set, respectively) compared to U6 snRNA. Molecular tests based on microRNA expression allow a reliable classification of subtypes for NSCLC and can constitute a useful diagnostic strategy in patient selection for targeted therapy.     

Branched rolling circle amplification method for measuring serum circulating microRNA levels for early breast cancer detection

Serum circulating microRNAs (c‐miRNAs) are serving as useful biomarkers for cancer diagnosis. Here, we describe the development of a one‐step branched rolling circle amplification (BRCA) method to measure serum c‐miRNAs levels for early diagnosis of breast cancer. Four c‐miRNAs, c‐miRNA16 (c‐miR‐16), c‐miRNA21 (c‐miR‐21), c‐miRNA155 (c‐miR‐155), and c‐miRNA195 (c‐miR‐195) were isolated from the serum of 49 breast cancer patients (stages I‐IV) and 19 healthy controls, and analyzed using one‐step BRCA. The serum levels of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 were higher (P < 0.0001) in stage I breast cancer patients than healthy controls. These levels were also higher in several breast cancer molecular subtypes (HER‐2 over‐expression, Luminal A, Luminal B, and triple negative breast cancer) than in healthy control subjects. The diagnostic accuracy of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 for early diagnosis of breast cancer was confirmed by receiver operating characteristic (ROC) curve assay. These results show that the BRCA method can be used to measure serum c‐miRNAs levels, and that this method has high accuracy, sensitivity, and specificity. Moreover, both BRCA approach and quantitative real‐time PCR (qRT‐PCR) method show that the serum levels of c‐miR16, c‐miR21, c‐miR155, and c‐miR195 could be used as biomarkers to improve the early diagnosis of breast cancer, and distinguish different breast cancer molecular subtypes.     

Four PTEN‐targeting co‐expressed miRNAs and ACTN4‐ targeting miR‐548b are independent prognostic biomarkers in human squamous cell carcinoma of the oral tongue

The purpose of this study was to determine the prognostic value and oncogenic pathways associated to miRNA expression in squamous cell carcinoma of the oral tongue and to link these miRNA candidates with potential gene targets. We performed a miRNA screening within our institutional cohort (n = 58 patients) and reported five prognostic targets including a cluster of four co‐expressed miRNAs (miR‐18a, miR‐92a, miR‐103, and miR‐205). Multivariate analysis showed that expression of miR‐548b (p = 0.007) and miR‐18a (p = 0.004, representative of co‐expressed miRNAs) are independent prognostic markers for squamous cell carcinoma of the oral tongue. These findings were validated in The Cancer Genome Atlas (TCGA) cohort (n = 131) for both miRNAs (miR‐548b: p = 0.027; miR‐18a: p = 0.001). Bioinformatics analysis identified PTEN and ACTN4 as direct targets of the four co‐expressed miRNAs and miR‐548b, respectively. Correlations between the five identified miRNAs and their respective targeted genes were validated in the two merged cohorts and were concordantly significant (miR‐18a/PTEN: p < 0.0001; miR‐92a/PTEN: p = 0.0008; miR‐103/PTEN: p = 0.008; miR‐203/PTEN: p = 0.019; miR‐548b/ACTN4: p = 0.009).     

Diagnostic and prognostic implications of microRNA profiling in prostate carcinoma

This study aimed to investigate the microRNA (miRNA) profile in prostate carcinoma tissue by microarray analysis and RT‐qPCR, to clarify associations of miRNA expression with clinicopathologic data and to evaluate the potential of miRNAs as diagnostic and prognostic markers. Matched tumor and adjacent normal tissues were obtained from 76 radical prostatectomy specimens. Twenty‐four tissue pairs were analyzed using human miRNA microarrays for 470 human miRNAs. Differentially expressed miRNAs were validated by TaqMan RT‐qPCR using all 76 tissue pairs. The diagnostic potential of miRNAs was calculated by receiver operating characteristics analyses. The prognostic value was assessed in terms of biochemical recurrence using Kaplan–Meier and Cox regression analyses. Fifteen differentially expressed miRNAs were identified with concordant fold‐changes by microarray and RT‐qPCR analyses. Ten microRNAs (hsa‐miR‐16, hsa‐miR‐31, hsa‐miR‐125b, hsa‐miR‐145, hsa‐miR‐149, hsa‐miR‐181b, hsa‐miR‐184, hsa‐miR‐205, hsa‐miR‐221, hsa‐miR‐222) were downregulated and 5 miRNAs (hsa‐miR‐96, hsa‐miR‐182, hsa‐miR‐182*, hsa‐miR‐183, hsa‐375) were upregulated. Expression of 5 miRNAs correlated with Gleason score or pathological tumor stage. Already 2 microRNAs classified up to 84% of malignant and nonmalignant samples correctly. Expression of hsa‐miR‐96 was associated with cancer recurrence after radical prostatectomy and that prognostic information was confirmed by an independent tumor sample set from 79 patients. That was shown with hsa‐miR‐96 and the Gleason score as final variables in the Cox models build in the 2 patient sets investigated. Thus, differential miRNAs in prostate cancer are useful diagnostic and prognostic indicators. This study provides a solid basis for further functional analyses of miRNAs in prostate cancer.     

Diagnostic and prognostic significance of miRNA signatures in tissues and plasma of endometrioid endometrial carcinoma patients

The aim of our study was to define tissue and plasma miRNA signatures, which could potentially serve as diagnostic and prognostic markers in endometrioid endometrial cancer (EEC) and to investigate miRNA profiles in regard to clinicopathological characteristics. Tissue and plasma samples were collected from 122 women (77 EEC and 45 controls). Expression profiling of 866 human miRNAs and 89 human viral miRNAs was performed in 24 samples and was followed by qPCR validation in 104 patients. Expression of 16 miRNAs was analyzed in 48 plasma samples. Microarray study revealed regulation of 21 miRNAs in EEC tissues comparing to normal endometrium. Altered expression of 17 miRNAs was confirmed by qPCR performed in 104 tissue samples. Seven miRNAs were upregulated and two were downregulated in EEC plasma samples. Expression of a number of miRNAs was associated with International Federation of Gynecology and Obstetrics stage, grade, relapse and nodal metastases. Two miRNA signatures: miR‐92a/miR‐410 and miR‐92a/miR‐205/miR‐410 classified tumor tissues with higher accuracy in comparison to single miRNAs (AUC: 0.977, 95% CI: 0.927–0.996 and 0.984, 95% CI: 0.938–0.999, respectively). miRNA signature composed of miR‐205 and miR‐200a predicted relapse with AUC of 0.854 (95% CI: 0.691–0.951). Tissue miRNA signatures were independent prognostic markers of overall (miR‐1228/miR‐200c/miR‐429, HR: 2.98) and progression‐free survival (miR‐1228/miR‐429, HR: 2.453). Plasma miRNA signatures: miR‐9/miR‐1228 and miR‐9/miR‐92a, classified EEC plasma samples with high accuracy yielding AUCs of 0.909 (95% CI: 0.789–973) and 0.913 (95% CI: 0.794–0.976), respectively. We conclude that miRNA signatures hold a great promise to become noninvasive biomarkers for early EEC detection and prognosis.     

Diagnostic Value of Interleukin 21 and Carcinoembryonic Antigen Levels in Malignant Pleural Effusions

The aim of this study was to evaluate the diagnostic value of interleukin 21(IL-21) and carcinoembryonicantigen (CEA) in tuberculous pleural effusions (TPEs) and malignant pleural effusions (MPEs). Pleuraleffusion samples from 103 patients were classified on the basis of diagnosis as TPE (n=51) and MPE (n=52). Theconcentration of IL-21 was determined by ELISA. Lactate dehydrogenase (LDH), adenosine dehydrogenase(ADA) and CEA levels were also determined in all patients. A significant difference was observed in the levelsof ADA and CEA (P<0.01), but not in the levels of LDH (P>0.05) between TPE and MPE. The concentration ofIL-21 in MPE was significantly higher compared to TPE (P<0.01). With a threshold value of 4.32 pg/ml, IL-21had a sensitivity of 76.9% (40/52) and a specificity of 80.4% (41/51). Combined detection of IL-21 and CEAhad a sensitivity of 69.2% (36/52) and a specificity of 92.2% (47/51). These two markers can contribute to thedifferential diagnosis of MPEs.