Detection Of Serum Carcinoembryonic Antigen Research Articles

Dual-mode photothermal/chemiluminescence vertical flow assay for sensitive point-of-care detection of carcinoembryonic antigen using Cu2-xAgxS@liposome on a filter membrane

Conventional lateral flow assays based on colorimetry and fluorescence still have shortages in sensitivity and selectivity due to the severe background interference from complex human fluid sample matrices. In this work, Cu2-xAgxS nanocrystals with high photothermal conversion efficiency and good peroxidase-like activity were synthesized and applied in the construction of a dual-mode near-infrared-photothermal/chemiluminescence (CL) vertical flow assay of carcinoembryonic antigen (CEA). These two-mode principles showed nearly zero background and the synthesized Cu2-xAgxS exhibited a high photothermal conversion efficiency of 75.23%, enabling the luminol-H2O2 CL system to have over 4 min of chemiluminescence. By combining filter membrane enrichment, Cu2-xAgxS@liposome encapsulation amplification, and nanozyme catalysis, a dual-mode photothermal/CL portable assay was constructed for sensitive and accurate detection of CEA in serum, with linear ranges of 0.02-40 and 0.001-30 ng mL-1, and detection limits of 0.0023 and 0.00029 ng mL-1, respectively. Furthermore, a smartphone application and a 3D printing device were combined for point-of-care testing. This assay can be completed within 20 min, with simple operation and no need for large instruments. It exhibited good sensitivity, selectivity, and stability, and is expected to be used in early diagnosis and prevention of relevant diseases in resource-limited areas.

Immunosensor with Enhanced Electrochemiluminescence Signal Using Platinum Nanoparticles Confined within Nanochannels for Highly Sensitive Detection of Carcinoembryonic Antigen.

Rapid, highly sensitive, and accurate detection of tumor biomarkers in serum is of great significance in cancer screening, early diagnosis, and postoperative monitoring. In this study, an electrochemiluminescence (ECL) immunosensing platform was constructed by enhancing the ECL signal through in situ growth of platinum nanoparticles (PtNPs) in a nanochannel array, which can achieve highly sensitive detection of the tumor marker carcinoembryonic antigen (CEA). An inexpensive and readily available indium tin oxide (ITO) glass electrode was used as the supporting electrode, and a layer of amino-functionalized vertically ordered mesoporous silica film (NH2-VMSF) was grown on its surface using an electrochemically assisted self-assembly method (EASA). The amino groups within the nanochannels served as anchoring sites for the one-step electrodeposition of PtNPs, taking advantage of the confinement effect of the ultrasmall nanochannels. After the amino groups on the outer surface of NH2-VMSF were derivatized with aldehyde groups, specific recognition antibodies were covalently immobilized followed by blocking nonspecific binding sites to create an immunorecognition interface. The PtNPs, acting as nanocatalysts, catalyzed the generation of reactive oxygen species (ROS) with hydrogen peroxide (H2O2), significantly enhancing the ECL signal of the luminol. The ECL signal exhibited high stability during continuous electrochemical scanning. When the CEA specifically bound to the immunorecognition interface, the resulting immune complexes restricted the diffusion of the ECL emitters and co-reactants towards the electrode, leading to a reduction in the ECL signal. Based on this immune recognition-induced signal-gating effect, the immunosensor enabled ECL detection of CEA with a linear range of 0.1 pg mL-1 to 1000 ng mL-1 with a low limit of detection (LOD, 0.03 pg mL-1). The constructed immunosensor demonstrated excellent selectivity and can achieve CEA detection in serum.

Performance Evaluation of Combined Detection of Serum CEA, CYFRA21-1, CA125, and NSE in Patients with Lung Cancer by Fluorescence Flow Cytometry

Objective: To investigate the effect of combined detection of serum carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), cancer antigen 125 (CA125), and neuron-specific enolase (NSE) in patients with lung cancer by fluorescence flow cytometry. Methods: From August 2019 to July 2022, 200 patients with lung cancer diagnosed by pathology in our hospital were retrospectively analyzed. 2 mL venous blood was collected in a fasting state and centrifuged to separate the serum (containing human chorionic gonadotropin antibody [anti-hCG antibody], hepatitis B surface antibody [anti-HBs antibody], and CEA). Results: The sensitivities of CEA and CYFRA21-1 detected via enzyme-linked immunosorbent assay (ELISA) were 100%, and the detection limits were 0.5 ng/mL and 0.1 ng/mL, respectively; the sensitivities of CA125 and NSE detected via flow cytometry were 100%, and the detection limits were 10 U/mL and 2 ng/mL, respectively. Compared with ELISA, the sensitivities of CA125 and NSE detected via flow cytometry were higher. When the concentration of CEA was 10–40 ng/mL, the sensitivities of the three markers CYFRA21-1, CA125, and NSE showed no significant changes (P > 0.05); when the concentration of CEA was 40–80 ng/mL, the sensitivity of CEA significantly decreased (P < 0.01), but the sensitivities of the three markers CYFRA21-1, CA125, and NSE showed no significant changes (P > 0.05); when the concentration of CEA was 80–200 ng/mL, the sensitivities of all four markers showed no significant changes (P > 0.05). Conclusion: Compared with the double-antibody sandwich ELISA, fluorescence flow cytometry has certain advantages, including high sensitivity, good precision, short detection time, low sample usage, and low medical cost; thus, it is worthy of clinical promotion.

Reagentless Electrochemical Detection of Tumor Biomarker Based on Stable Confinement of Electrochemical Probe in Bipolar Silica Nanochannel Film.

The development of simple and probe-integrated aptamer sensors for the electrochemical detection of tumor biomarkers is of great significance for the diagnosis of tumors and evaluation of prognosis. In this work, a probe-integrated aptamer sensor is demonstrated based on the stable confinement of an electrochemical probe in a bipolar nanochannel film, which can realize the reagentless electrochemical detection of the tumor biomarker carcinoembryonic antigen (CEA). To realize the stable immobilization of a large amount of the cationic electrochemical probe methylene blue (MB), a two-layer silica nanochannel array (SNF) with asymmetric charge was grown on the supporting electrode from bipolar SNF (bp-SNF). The inner SNF is negatively charged (n-SNF), and the outer-layer SNF is positively charged (p-SNF). The dual electrostatic interaction including the electrostatic adsorption from n-SNF and the electrostatic repulsion from p-SNF achieve the stable confinement of MB in bp-SNF. The recognitive interface is fabricated by the covalent immobilization of the CEA aptamer on the outer surface of bp-SNF, followed by the blocking of non-specific binding sites. Owing to the stable and abundant immobilized probes and highly specific aptamer interface, the developed aptamer sensor enables the sensitive detection of CEA in the range of 1 pg/mL to 1 μg/mL with a low limit of detection (LOD, 0.22 pg/mL, S/N = 3). Owing to the high selectivity and stability of the developed biosensor, reagentless electrochemical detection of CEA in serum was realized.

Construction of a Carcinoembryonic Antigen Surface-Enhanced Raman Spectroscopy (SERS) Aptamer Sensor Based on the Silver Nanorod Array Chip.

Carcinoembryonic antigen (CEA) is a cancer-related tumor marker, which is commonly used for preventive screening, auxiliary diagnosis, and recurrence monitoring. Therefore, it is of great significance to develop a new CEA detection method. In this paper, we developed an SERS aptasensor for CEA based on silver nanorod array chip, thiol aptamer, and 4-mercaptophenylboronic acid (4-MPBA). The silver nanorod array chip modified by CEA thiol aptamer (aptamer-SH) was used as SERS capture substrates. Ag@4-MPBA was used as a surface-enhanced Raman spectroscopy (SERS) tag. This proposed SERS aptasensor could detect CEA down to 0.447 pg·mL-1 with a wide linear range from 1 pg·mL-1 to 100 ng·mL-1 (R2 = 0.9907). The recovery of the standard addition test for CEA in serum was between 97.25% and 102.67%, and the RSD ≤ 2.52% (n = 3). The sensor has the advantages of good specificity, high sensitivity, and a wide linear range. It provides a new method for the detection of CEA in serum.

A Silicon Nanowire Array Biosensor Fabricated by Complementary Metal Oxide Semiconductor Technique for Highly Sensitive and Selective Detection of Serum Carcinoembryonic Antigen.

In this paper, we present a highly sensitive and selective detection of serum carcinoembryonic antigen (CEA) based on silicon nanowire (SiNW) array device. With the help of traditional microfabrication technology, low-cost and highly controllable SiNW array devices were fabricated. After a series of surface modification processes, SiNW array biosensors show rapid and reliable response to CEA; the detection limit of serum CEA was 10 fg/mL, the current signal is linear with the logarithm of serum CEA concentration in the range of 10 fg/mL to 100 pg/mL. In this work, SiNW array biosensors can obtain strong signal and high signal-to-noise ratio; these advantages can reduce the production cost of the SiNW-based system and promote the application of SiNWs in the field of tumor marker detection.

Clinical value of combined detection of serum CEA, CA199, CA125 in the diagnosis of lung cancer

Objective To investigate the diagnostic value of combined detection of carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199) and carbohydrate antigen 125 (CA125) in lung cancer. Methods From July 2017 to February 2019, 64 patients with lung cancer, 40 cases of benign pulmonary lesions and 40 healthy people were selected by random lottery in Fuyang Hospital Affiliated to Anhui Medical University.Serum CEA, CA199 and CA125 levels of each group were analyzed. Results The levels of serum CEA, CA199 and CA125 in patients with lung cancer were significantly higher than those in patients with benign lung disease, the differences were statistically significant (t=18.355, P<0.001; t=11.757, P<0.001; t=10.754, P<0.001). The serum CA125 of lung benign disease group was significantly higher than the healthy group, and the difference was statistically significant(t=6.942, P<0.001). The positive rates of serum CEA, CA199 and CA125 in patients with lung cancer were significantly higher than those in the benign lung disease group and healthy group, the differences were statistically significant(χ2=22.110, P<0.001; χ2=13.321, P=0.002; χ2=15.125, P=0.001). The serum levels of CEA, CA199, and CA125 in patients with middle and advanced stage were significantly higher than those in the early stage, the differences between the advanced group and the early group were statistically significant (t=5.587, P<0.001; t=5.068, P<0.001; t=8.962, P<0.001). Those between the mid-term group and the early group had statistically significant differences (t=4.44, P<0.001; t=4.716, P<0.001; t=12.700, P<0.001). The CEA level of patients with advanced lung cancer was significantly higher than that of the intermediate patients.There was statistically significant difference in the CEA level between the advanced group and the mid-term group (t=3.860, P=0.001). Serum CA125 was the most sensitive in the diagnosis of lung cancer (60.84%), but had the lowest specificity (65.17%). CA125 compared with CA199, CEA, the difference was statistically significant (sensitivity: χ2=10.723, P<0.001 specificity: χ2=4.203, P=0.023). The sensitivity of CEA+ CA199+ CA125 combined detection was significantly higher than single detection, the difference was statistically significant(χ2=26.047, P<0.001), Conclusion The combined detection of serum CEA, CA125 and CA199 has high sensitivity in the diagnosis of lung cancer, which can improve the detection rate of early lung cancer and is worthy of clinical application. Key words: Lung neoplasms; Carcinoembryonic antigen; Antigens, tumor-associated, carbohydrate; Tumor markers, biological; Sensitivity; Specificity

Measurement of Carcinoembryonic Antigen in Clinical Serum Samples Using a Centrifugal Microfluidic Device.

Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker used in clinical applications. The primarily clinical method for measuring CEA is based on chemiluminescence in serum during enzyme-linked immunosorbent assays (ELISA) in 96-well plates. However, this multi-step process requires large and expensive instruments, and takes a long time. In this study, a high-throughput centrifugal microfluidic device was developed for detecting CEA in serum without the need for cumbersome washing steps normally used in immunoreactions. This centrifugal microdevice contains 14 identical pencil-like units, and the CEA molecules are separated from the bulk serum for subsequent immunofluorescence detection using density gradient centrifugation in each unit simultaneously. To determine the optimal conditions for CEA detection in serum, the effects of the density of the medium, rotation speed, and spin duration were investigated. The measured values from 34 clinical serum samples using this high-throughput centrifugal microfluidic device showed good agreement with the known values (average relative error = 9.22%). These results indicate that the high-throughput centrifugal microfluidic device could provide an alternative approach for replacing the classical method for CEA detection in clinical serum samples.

Value of combined detection of serum carcino-embryonic antigen, carbohydrate antigen 19-9 and cyclooxygenase-2 in the diagnosis of colorectal cancer.

The aim of the present study was to investigate the value of combined detection of serum carcino-embryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and cyclooxygenase-2 (COX-2) in the diagnosis of colorectal cancer. A total of 50 patients with colorectal cancer were selected as Group A and 50 healthy subjects as the control group. A sample of 2 ml fasting venous blood was drawn from patients in each group, and serum CEA, CA19-9 and COX-2 were detected using electrochemiluminescence analyzer and ELISA. Receiver operating characteristic curve analysis was performed on analyze the sensitivity and specificity of diagnostic methods for colorectal cancer patients at different stages. The expression levels of CEA, CA199 and COX-2 in the cancer patients group were significantly higher than those in the healthy group (P<0.05). The coincidence rates of CEA, CA199, COX-2 and combined detection were 56.0, 64.0, 62.0 and 88.0%, respectively. The coincidence rate of combined detection was significantly higher than that of diagnosis using a single factor (P<0.05). Sensitivity of combined detection of colorectal cancer patients with stage I, II, III and IV were 82.9, 85.3, 86.4 and 88.7%, respectively. The specificities were 65.3, 68.7, 57.8 and 58.6%, respectively. Thus, CEA, CA199 and COX-2 in serum are highly expressed in colorectal cancer patients, and may useful as effective indicators for the early diagnosis of colorectal cancer.

Clinical value of preoperative serum carcinoembryonic antigen detection in the prediction of esophageal cancer lymph node metastasis

Objective To investigate the clinical value of preoperative serum carcinoembryonic antigen (CEA) detection in the prediction of esophageal cancer lymph node metastasis. Methods The clinical data of 111 patients with esophageal cancer who were admitted to the Chaoyang Hospital of Capital Medical University between December 2010 and January 2014 were retrospectively analyzed. Patients received preoperative serum CEA examination and enhanced CT of the chest. The surgical procedures were selected according to the condition of patients, including radical resection of esophageal cancer via left thoracic approach, transabdominal right thoracic approach (open and laparoscopic surgeries), cervico-thoracic-abdominal triple incision (open and laparoscopic surgeries) and transabdominal incision. The international standard was used for tumor location and TNM stage of esophageal cancer. The count data and comparison of ordinal data in the univariate analysis were analyzed using the chi-square test, Fisher exact probability and rank-sum test, respectively. The multivariate analysis was done using the stepwise logistic regression. The ROC curve was used for evaluating diagnostic value of serum CEA examination and enhanced CT of the chest. All the 111 patients were divided into 4 groups according to the interquartile range results of the CEA examination, and the lymph node metastasis rates of 4 groups were compared by the chi-square test. Results All the 111 patients underwent successful radical resection of esophageal cancer after preoperative serum CEA detection and enhanced CT of the chest, including 40 via left thoracic approach, 56 via transabdominal right thoracic approach, 8 via cervico-thoracic-abdominal triple incision and 7 via transabdominal incision. There were 3 patients with upper thoracic esophageal cancer, 52 with middle thoracic esophageal cancer, 36 with lower thoracic esophageal cancer and 20 with cancer of gastro-esophageal junction. The postoperative pathological type included 84 squamous cell carcinomas, 23 adenocarcinomas and 4 other carcinomas. There were 44 patients with negative lymph node metastases and 67 with positive lymph node metastases. The positive rate of elevated serum CEA in the 111 patients was 36.04%(40/111). Tumor location, pathological type and N stage of tumor were clinical pathological factors affecting the positive rate of serum CEA of patients (Z=6.815, 6.608, 16.928, P 4.21 μg/L by the stratified analysis, respectively, with a significant difference among the 4 groups (χ2=16.026, P<0.05). The areas under the curve of CEA level and enhanced CT of the chest for lymph node metastasis were 0.687 (95% CI: 0.590-0.785) and 0.689 (95% CI: 0.591-0.788) by ROC curve, which were significantly different from the area under the guides (P<0.05). The areas under the curve of CEA level and enhanced CT of the chest for lymph node metastasis were 0.785 (95%CI: 0.697-0.873, P<0.05). Conclusions Serum CEA detection not only has certain predictive value for lymph node metastasis of esophageal cancer, but has a higher predictive value combined with enhanced CT of the chest. There is a risk of lymph node metastasis for patients with deep tumor invasion and elevated CEA level, and the range of lymph node dissection should be expanded. Key words: Esophageal neoplasms; Carcinoembryonic antigen; Lymph node metastasis

Correlation of carcinoembryonic antigen with prognosis of hepatocellular carcinoma after hepatectomy

To investigate the correlation between carcinoembryonic antigen (CEA) and prognosis of hepatocellular carcinoma after hepatectomy. This study retrospectively analyzed the surgical outcomes of hepatocellular carcinoma (HCC) in 562 patients who underwent hepatectomy between January 2002 and December 2009 in the Cancer Hospital, Chinese Academy of Medical Sciences. Postoperative prognostic factors were analyzed using univariate Kaplan-Meier analysis and multivariate Cox proportional hazards model. The sensibility of serum CEA and CEA-AFP combined in the detection of HCC was 7.1% (40/562) and 55.3% (311/562), respectively. The 1-, 3- and 5-year overall survival rates and disease free survival rates of CEA-negative group (CEA<5 ng/ml) were 93.8%, 75.6%, 59.4%, and 75.0%, 55.9%, 44.5%, respectively (P = 0.003); and the 1-, 3- and 5-year overall survival rates and disease free survival rates of CEA-positive group (CEA ≥ 5 ng/ml) were 87.5%, 60.5%, 46.6% and 52.6%, 36.2%, and 25.4%, respectively (P = 0.045). In the univariate analysis, better prognosis for overall survival (OS) was associated with small tumor ( ≤ 5 cm), single lesion, high-grade histological differentiation, no vascular tumor embolus, negative serum AFP expression, negative serum CEA expression, no/mild cirrhosis, no regional lymph node metastasis, no major vascular invasion, no direct invasion of adjacent organs or with perforation of visceral peritoneum, no transfusion as well as earlier BCLC staging (P < 0.05 for all). In the Cox multivariate analysis, serum AFP-negative expression, serum CEA-negative expression, no/mild cirrhosis, no direct invasion of adjacent organs or with perforation of visceral peritoneum, no transfusion and earlier BCLC staging were independent factors for longer disease free survival (P < 0.05 for all). Serum CEA-positive expression is correlated to alcoholism and HCC multiple occurrences. Although serum CEA detection has limited value for HCC diagnosis, its positive expression does affect poor prognosis. Higher serum CEA level is an independent prognostic factor for poorer disease free survival.

Clinical Observations on the Association Between Diagnosis of Lung Cancer and Serum Tumor Markers in Combination

To evaluate the association of a diagnosis of lung cancer and combined detection of serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), neuron specific enolase (NSE) as well as the cytokeratin 19 fragment (CYFRA21-1). Serum CEA, CA19-9, NSE and CYFRA21-1 were assessed in 150 patients with lung cancer, 100 patients with benign lung disease and 100 normal control subjects, and differences of expression were compared in each group, and joint effects of these tumor markers in the diagnosis of lung cancer were analyzed. Serum CEA, CA19-9, NSE and CYFRA21-1 in patients with lung cancer were significantly higher than those with benign lung disease and normal controls (p<0.01). It is suggested that these four tumor markers combined together could produce a positive detection rate of 90.2%, significantly higher than that of any single test. Combination detection of CEA, CA19-9, NSE and CYFRA21-1 could significantly improve the sensitivity and specificity in diagnosis of lung cancer, and could be important in early detection.

Multiple tumor marker chip for detection of serum carcinoembryonic antigen in various malignant tumors: results and diagnostic value analysis

Objective To analyze the expression of carcinoembryonic antigen(CEA) in various populations and the simultaneous expression of other markers using multiple tumor marker protein chip,and to discuss the possible clinical relevance.Methods A total of 25 076 profiles of multiple tumor marker protein chip were collected in our hospital for analysis.The elevation of CEA in various populations and commonly-seen tumors was analyzed,and the combined elevation of CEA and other markers was also analyzed in tumors.Results Elevation of CEA in patients with malignant tumors was significantly more than those in patients with benign lesions and normal controls(P0.01),with the highest positive rate of CEA seen in the colorectal cancer(41.85%),followed by pancreatic cancer(37.97%) and lung carcinoma(37.16%).CEA was always accompanied by other markers in tumor patients,with the mostly seen elevated marker being CA125,followed by CA19-9 and CA242.The CEA/CA125 was often seen in pancreatic cancer(74.26%),ovarian cancer(69.57%),hepatocellular carcinoma(62.13%),and lung cancer(51.68%);CEA/CA19-9 was often seen in pancreatic cancer(77.23%) and hepatocellular carcinoma(72.34%);CEA/CA242 was often seen in pancreatic cancer(77.23%) and colorectal cancer(57.61%);CEA+CA19-9+CA242 was usually seen in pancreatic cancer(76.24%),ovarian cancer(52.17%),and colorectal cancer(51.32%);and CEA+CA19-9+CA242+CA125 was mostly seen in pancreatic cancer(61.39%).Conclusion CEA is widely expressed in malignant tumors,but it is not specific for malignant tumors.Single elevation of CEA has high value for diagnosis of colorectal cancer,pancreatic cancer,and lung carcinoma.CEA combined with CA125,CA19-9 or CA242 can help to improve the positive rate for diagnosis of pancreatic cancer,ovarian cancer and colorectal cancer.

Surface-enhanced Raman scattering study of carcinoembryonic antigen in serum from patients with colorectal cancers

In this work, we developed a SERS platform for quantitative detection of carcinoembryonic antigen (CEA) in serum of patients with colorectal cancers. Anti-CEA-functionalized 4-mercaptobenzoic acid–labeled Au/Ag core-shell bimetallic nanoparticles were prepared first and then used to analyze CEA antigen solutions of different concentrations. A calibration curve was established in the range from 5 × 10−3 to 5 × 105 ng/mL. Finally, this new SERS probe was applied for quantitative detection of CEA in serum obtained from 26 colorectal cancer patients according to the calibration curve. The results were in good agreement with that obtained by electrochemical luminescence method, suggesting that SERS immunoassay has high sensitivity and specificity for CEA detection in serum. A detection limit of 5 pg/ml was achieved. This study demonstrated the feasibility and great potential for developing this new technology into a clinical tool for analysis of tumor markers in the blood.

Toxicology study of repeat intracerebral administration of a measles virus derivative producing carcinoembryonic antigen in rhesus macaques in support of a phase I/II clinical trial for patients with recurrent gliomas.

Gliomas have a dismal prognosis, with the median survival of patients with the most common histology, glioblastoma multiforme, being only 12-15 months. Development of novel therapeutic agents is urgently needed. We have previously demonstrated that oncolytic measles virus strains derived from the Edmonston vaccine lineage have significant antitumor activity against gliomas [Phuong, L.K., Allen, C., Peng, K.W., Giannini, C., Greiner, S., Teneyck, C.J., Mishra, P.K., Macura, S.I., Russell, S.J., Galanis, E.C. (2003). Cancer. Res. 63, 2462-2469]. MV-CEA is an Edmonston vaccine lineage measles virus strain engineered to express the marker peptide carcinoembryonic antigen (CEA): CEA levels can serve as a correlate of viral gene expression. In support of a phase I clinical trial of intratumoral and resection cavity administration of MV-CEA to patients with recurrent gliomas, we assessed the neurotoxicity of MV-CEA in adult immune male rhesus macaques (Macaca mulatta). The animals ' immune status and administration schedule mimicked the trial population and proposed administration schema. Macaca mulatta represents the prototype animal species for assessment of measles neurotoxicity. The animals were stereotactically administered either vehicle (n = 1) or MV-CEA at 2 x 10(5)or 2 x 10(6) TCID(50) (each, n = 2) in the right frontal lobe in two injections on days 1 and 5. Macaques were closely monitored clinically for neurotoxicity. Body weight, temperature, complete blood count, CEA, clinical chemistries, coagulation, complement levels, immunoglobulin, measles antibody titers, viremia, and shedding (buccal swabs) were tested at multiple time points. Furthermore, cisterna magna spinal taps were performed on day 9 and 1 year after the first viral dose administration, and samples were analyzed for protein, glucose, cell differential, and presence of MV-CEA. Magnetic resonance imaging (MRI) was performed between 4 and 5 months after article administration to assess for subclinical neurotoxicity. To date, 36+ months from study initiation there has been no clinical or biochemical evidence of toxicity, including lack of neurological symptoms, fever, or other systemic symptoms and lack of immunosuppression. Quantitative RT-PCR analysis of blood, buccal swabs, and cerebrospinal fluid (CSF) was negative for MV-CEA at all time points, with the exception of viral genome deletion in the blood of one asymptomatic animal at the 2 x 10(6) TCID(50) dose level on day 85. Vero cell overlays of CSF cells and supernatant were negative for viral recovery. There was no detection of CEA in serum or CSF at any time point. MRI scans were negative for imaging abnormalities and showed no evidence of encephalitis. Our results support the safety of CNS administration of MV-CEA in glioma patients. A clinical trial of intratumoral and resection cavity administration of MV-CEA in patients with recurrent glioblastoma multiforme is currently ongoing.

297. Safety of Repeat Intracerebral Administration of MV-CEA in Rhesus Macaques in Support of a Phase I/II Clinical Trial for Patients with Recurrent Gliomas

Novel therapies for patients with recurrent gliomas are urgently needed, given their dismal prognosis,. Oncolytic measles virus strains derived from the Edmonston vaccine lineage are an attractive option for glioma therapy, because of their significant antitumor effect (Phuong et al, 2003). MV-CEA is an Edmonston lineage measles virus strain engineered to express the marker protein carcinoembryonic antigen (CEA), the levels of which can be monitored by a simple blood test and serve as a correlate of viral gene expression. In support of a clinical trial administering MV-CEA intracerebrally to patients with recurrent gliomas, we assessed the neurotoxicity of MV-CEA in five adult male rhesus macaques (Macaca mulatta).The animals were stereotactically administered either vehicle (n=1), 2|[times]|105 (n=2), or 2|[times]|106 (n=2) TCID50 MV-CEA in the right frontal lobe in two injections five days apart. Macaques were intensely monitored through clinical observations for neurotoxic effects, body weights, temperatures, CBC, CEA, clinical chemistries, coagulation, complement levels, immunoglobulin, measles antibody titers, viremia, and shedding (buccal swabs). Additionally, cisterna magna spinal taps were performed on day 9 post first article administration, and samples were analyzed for protein, glucose, cell differential, and presence of MV-CEA. After the first 3 month close follow-up period, the macaques entered a long-term observational period for an additional 9 months. MRIs were performed between 4 and 5 months post administration to assess for subclinical neurotoxicity. At the time of this abstract submission, and with a median follow up of 11 months, macaques have been remarkably tolerant of the treatment. There was no clinical or biochemical evidence of toxicity, including lack of neurological symptoms, fever, or other systemic symptoms and lack of immunosuppression. QRT- PCR analysis of blood, buccal swabs, or CSF was negative for MV- CEA at all time points. Vero cell overlays of CSF cells and supernatant have been negative for measles-related pathology. There was no CEA detection in serum or CSF at any time point. MRIs were negative for imaging abnormalities and showed no signs of encephalitis. Conclusions: Our results support the safety of CNS administration of MV-CEA. A clinical trial in patients with recurrent gliomas is planned to be activated later this year.