The SARS-CoV-2 Omicron (B.1.1.529) variant exhibits altered pathogenicity, transmissibility, and fitness in the golden Syrian hamster model

The newly emerging SARS-CoV-2 Omicron (B.1.1.529) variant first identified in South Africa in November 2021 is characterized by an unusual number of amino acid mutations in its spike that renders existing vaccines and therapeutic monoclonal antibodies dramatically less effective. The in vivo pathogenicity, transmissibility, and fitness of this new Variant of Concerns are unknown. We investigated these virological attributes of the Omicron variant in comparison with those of the currently dominant Delta (B.1.617.2) variant in the golden Syrian hamster COVID-19 model. Omicron-infected hamsters developed significantly less body weight losses, clinical scores, respiratory tract viral burdens, cytokine/chemokine dysregulation, and tissue damages than Delta-infected hamsters. The Omicron and Delta variant were both highly transmissible (100% vs 100%) via contact transmission. Importantly, the Omicron variant consistently demonstrated about 10-20% higher transmissibility than the already-highly transmissible Delta variant in repeated non-contact transmission studies (overall: 30/36 vs 24/36, 83.3% vs 66.7%). The Delta variant displayed higher fitness advantage than the Omicron variant without selection pressure in both in vitro and in vivo competition models. However, this scenario drastically changed once immune selection pressure with neutralizing antibodies active against the Delta variant but poorly active against the Omicron variant were introduced, with the Omicron variant significantly outcompeting the Delta variant. Taken together, our findings demonstrated that while the Omicron variant is less pathogenic than the Delta variant, it is highly transmissible and can outcompete the Delta variant under immune selection pressure. Next-generation vaccines and antivirals effective against this new VOC are urgently needed. One Sentence SummaryThe novel SARS-CoV-2 Omicron variant, though less pathogenic, is highly transmissible and outcompetes the Delta variant under immune selection pressure in the golden Syrian hamster COVID-19 model.

An elite broadly neutralizing antibody protects SARS-CoV-2 Omicron variant challenge

The strikingly high transmissibility and antibody evasion of SARS-CoV-2 Omicron variant have posted great challenges on the efficacy of current vaccines and antibody immunotherapy.Here, we screened 34 BNT162b2-vaccinees and cloned a public broadly neutralizing antibody (bNAb) ZCB11 from an elite vaccinee. ZCB11 neutralized all authentic SARS-CoV-2 variants of concern (VOCs), including Omicron and OmicronR346K with potent IC50 concentrations of 36.8 and 11.7 ng/mL, respectively. Functional analysis demonstrated that ZCB11 targeted viral receptor-binding domain (RBD) and competed strongly with ZB8, a known RBD-specific class II NAb. Pseudovirus-based mapping of 57 naturally occurred single mutations or deletions revealed that only S371L resulted in 11-fold neutralization resistance, but this phenotype was not observed in the Omicron variant. Furthermore,prophylactic ZCB11 administration protected lung infection against both the circulating pandemic Delta and Omicron variants in golden Syrian hamsters. These results demonstrated that vaccine-induced ZCB11 is a promising bNAb for immunotherapy against pandemic SARS-CoV-2 VOCs.

Experimental analysis of clinical applicability of homemade in homogeneous phantom / 中国辐射卫生

@#<b>Objective</b> To conduct experimental analysis of clinical applicability of a homemade phantom which is equivalent to multiple tissue densities of human body. <b>Methods</b> Materials with densities close to bone, lung, cavity, and soft tissue were manufactured and combined to obtain a homemade in homogeneous phantom. The electron density of equivalent materials was compared with the organs. Ten lung cancer patients in our department were recruited for dose verification of intensity modulated radiation therapy in the homemade phantom and solid-water phantom. The two phantoms were compared for characteristics in dose verification, and the dosimetric differences of the homemade phantom between the calculated values on treatment planning systemand measured values were statistically analyzed by SPSS 21.0 software. <b>Results</b> In the dose verification, the gamma pass rates (3 mm/3%) were more than 90% using both the homemade phantom and solid-water phantom. The measured values in homemade phantom were larger than those in solid-water phantom, and the maximum deviation was 11.5%. The AD and RD values of gamma pass rate in dose verification showed no significant differences between the two phantoms (<i>P</i> > 0.05). <b>Conclusion</b> The homemade phantom meets the accuracy requirement of clinical application and can be used in dose verification of intensity modulated radiation therapy plan.

Neutralization of SARS-CoV-2 Omicron variant by sera from BNT162b2 or Coronavac vaccine recipients

BackgroundThe SARS-CoV-2 Omicron variant, designated as a Variant of Concern(VOC) by the World Health Organization, carries numerous spike protein mutations which have been found to evade neutralizing antibodies elicited by COVID-19 vaccines. The susceptibility of Omicron variant by vaccine-induced neutralizing antibodies are urgently needed for risk assessment. MethodsOmicron variant strains HKU691 and HKU344-R346K were isolated from patients using TMPRSS2-overexpressing VeroE6 cells. Whole genome sequence was determined using nanopore sequencing. Neutralization susceptibility of ancestral lineage A virus and the Omicron, Delta and Beta variants to sera from 25 BNT162b2 and 25 Coronavac vaccine recipients was determined using a live virus microneutralization assay. ResultsThe Omicron variant strain HKU344-R346K has an additional spike R346K mutation, which is present in 8.5% of strains in GISAID database. Only 20% and 24% of BNT162b2 recipients had detectable neutralizing antibody against the Omicron variant HKU691 and HKU344-R346K, respectively, while none of the Coronavac recipients had detectable neutralizing antibody titer against either Omicron isolates. For BNT162b2 recipients, the geometric mean neutralization antibody titers(GMT) of the Omicron variant isolates(5.43 and 6.42) were 35.7-39.9-fold lower than that of the ancestral virus(229.4), and the GMT of both omicron isolates were significantly lower than those of the beta and delta variants. There was no significant difference in the GMT between HKU691 and HKU344-R346K. ConclusionsOmicron variant escapes neutralizing antibodies elicited by BNT162b2 or CoronaVac. The additional R346K mutation did not affect the neutralization susceptibility. Our data suggest that the Omicron variant may be associated with lower COVID-19 vaccine effectiveness.

Striking Antibody Evasion Manifested by the Omicron Variant of SARS-CoV-2

The Omicron (B.1.1.529) variant of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) was only recently detected in southern Africa, but its subsequent spread has been extensive, both regionally and globally1. It is expected to become dominant in the coming weeks2, probably due to enhanced transmissibility. A striking feature of this variant is the large number of spike mutations3 that pose a threat to the efficacy of current COVID-19 (coronavirus disease 2019) vaccines and antibody therapies4. This concern is amplified by the findings from our study. We found B.1.1.529 to be markedly resistant to neutralization by serum not only from convalescent patients, but also from individuals vaccinated with one of the four widely used COVID-19 vaccines. Even serum from persons vaccinated and boosted with mRNA-based vaccines exhibited substantially diminished neutralizing activity against B.1.1.529. By evaluating a panel of monoclonal antibodies to all known epitope clusters on the spike protein, we noted that the activity of 17 of the 19 antibodies tested were either abolished or impaired, including ones currently authorized or approved for use in patients. In addition, we also identified four new spike mutations (S371L, N440K, G446S, and Q493R) that confer greater antibody resistance to B.1.1.529. The Omicron variant presents a serious threat to many existing COVID-19 vaccines and therapies, compelling the development of new interventions that anticipate the evolutionary trajectory of SARS-CoV-2.

Nasal prevention of SARS-CoV-2 infection by intranasal influenza-based boost vaccination

BackgroundVaccines in emergency use are efficacious against COVID-19, yet vaccine-induced prevention against nasal SARS-CoV-2 infection remains suboptimal. MethodsSince mucosal immunity is critical for nasal prevention, we investigated an intramuscular PD1-based receptor-binding domain (RBD) DNA vaccine (PD1-RBD-DNA) and intranasal live attenuated influenza-based vaccines (LAIV-CA4-RBD and LAIV-HK68-RBD) against SARS-CoV-2. FindingsSubstantially higher systemic and mucosal immune responses, including bronchoalveolar lavage IgA/IgG and lung polyfunctional memory CD8 T cells, were induced by the heterologous PD1-RBD-DNA/LAIV-HK68-RBD as compared with other regimens. When vaccinated animals were challenged at the memory phase, prevention of robust SARS-CoV-2 infection in nasal turbinate was achieved primarily by the heterologous regimen besides consistent protection in lungs. The regimen-induced antibodies cross-neutralized variants of concerns. Furthermore, LAIV-CA4-RBD could boost the BioNTech vaccine for improved mucosal immunity. InterpretationOur results demonstrated that intranasal influenza-based boost vaccination is required for inducing mucosal and systemic immunity for effective SARS-CoV-2 prevention in both upper and lower respiratory systems. FundingThis study was supported by the Research Grants Council Collaborative Research Fund (C7156-20G, C1134-20G and C5110-20G), General Research Fund (17107019) and Health and Medical Research Fund (19181052 and 19181012) in Hong Kong; Outbreak Response to Novel Coronavirus (COVID-19) by the Coalition for Epidemic Preparedness Innovations; Shenzhen Science and Technology Program (JSGG20200225151410198); the Health@InnoHK, Innovation and Technology Commission of Hong Kong; and National Program on Key Research Project of China (2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); and donations from the Friends of Hope Education Fund. Z.C.s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).

Low dose inocula of SARS-CoV-2 B.1.1.7 variant initiate more robust infections in the upper respiratory tract of hamsters than earlier D614G variants

There is a lack of experimental evidence to explain how the B.1.1.7 variant spreads more quickly than pre-existing variants in humans. We found that B.1.1.7 displays increased competitive fitness over earlier D614G lineages in an in-vitro system. Furthermore,, we demonstrated that B.1.1.7 variant is able to replicate and shed more efficiently in the nasal cavity than other variants with lower dose and shorter duration of exposure.

Plumbagin Enhanced Inhibitory Effect of Temozolomide on Migration and Invasion of Human Glioma U251 Cells Through E-cadherin / 肿瘤防治研究

Objective To investigate the inhibitory effect and mechanism of temozolomide on migration and invasion of U251 human glioma cells enhanced by plumbagin. Methods CCK-8 method was used to study the effects of plumbagin, temozolomide and plumbagin+temozolomide on the proliferation of glioma U251 cells. Cell scratch test was used to detect the migration of U251 cells in the control (DMSO), plumbagin, temozolomide and plumbagin+temozolomide groups for 48h. Transwell assay was used to detect the effect of the combination therapy on the invasion of U251 cells. Western blot was used to detect the relative expression levels of E-cadherin in three groups. Results CCK-8 showed that the proliferation inhibition rate of U251 cells treated with plumbagin (1.25 μmol/L) combined with temozolomide (200 μmol/L) for 48h was 75.69%, significantly higher than that treated with plumbagin alone (P=0.012) or temozolomide alone (P=0.034). Cell scratch assay showed that the combination of plumbagin and temozolomide could significantly enhance the inhibition effect of temozolomide on the migration of U251 cells (P=0.023). Transwell assay showed that the invasion ability of U251 cells was significantly decreased after the combination therapy (P < 0.05). The protein expression of E-cadherin in the combination group was significantly higher than those in plumbagin or temozolomide groups (P < 0.05). Conclusion Plumbagin combined with temozolomide can inhibit the migration and invasion of glioma cells and enhance the sensitivity of glioma cells to temozolomide. And the effect is achieved by the protein expression of E-cadherin.

Development and prospect of Traditional Chinese Medicine in the Sultanate of Oman / 国际中医中药杂志

Traditional Chinese Medicine (TCM) has become an important part of the health system in the Sultanate of Oman. Although there is no independent law, the local health department has implemented the administrative measures such as the admittance assessment system of TCM doctors and the standardized examination and approval of TCM clinics. The development of TCM in the Sultanate of Oman is supported by the policies of the two governments, with the characteristics likemedical cooperation starting with high-level personnel, the cooperation in economy, trade and medical treatment, TCM and local traditional medicine showing inclusive with good base, and the advantages of TCM theory and treatment meeting the needs of the local medical market. The prospect of cooperation in TCM market is broad. It is suggested that the local government should promote the legislation of traditional medicine and improve the admittance system of practitioners. China needs to promote the formulation of international standards of TCM and optimize the cooperation platform of TCM by using Internet and other technologies. The practitioners in China need to carry out medical activities on the premise of understanding and respecting the local cultural background.In order to promote the development of TCM in Arab countries, the Sultanate of Oman will radiate the whole Middle East through the above strategies.

Topoisomerase 1 inhibition therapy protects against SARS-CoV-2-induced inflammation and death in animal models.

The ongoing pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is currently affecting millions of lives worldwide. Large retrospective studies indicate that an elevated level of inflammatory cytokines and pro-inflammatory factors are associated with both increased disease severity and mortality. Here, using multidimensional epigenetic, transcriptional, in vitro and in vivo analyses, we report that Topoisomerase 1 (Top1) inhibition suppresses lethal inflammation induced by SARS-CoV-2. Therapeutic treatment with two doses of Topotecan (TPT), a FDA-approved Top1 inhibitor, suppresses infection-induced inflammation in hamsters. TPT treatment as late as four days post-infection reduces morbidity and rescues mortality in a transgenic mouse model. These results support the potential of Top1 inhibition as an effective host-directed therapy against severe SARS-CoV-2 infection. TPT and its derivatives are inexpensive clinical-grade inhibitors available in most countries. Clinical trials are needed to evaluate the efficacy of repurposing Top1 inhibitors for COVID-19 in humans.

Global analysis of protein-RNA interactions in SARS-CoV-2 infected cells reveals key regulators of infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19. SARS-CoV-2 relies on cellular RNA-binding proteins (RBPs) to replicate and spread, although which RBPs control SARS-CoV-2 infection remains largely unknown. Here, we employ a multi-omic approach to identify systematically and comprehensively which cellular and viral RBPs are involved in SARS-CoV-2 infection. We reveal that the cellular RNA-bound proteome is remodelled upon SARS-CoV-2 infection, having widespread effects on RNA metabolic pathways, non-canonical RBPs and antiviral factors. Moreover, we apply a new method to identify the proteins that directly interact with viral RNA, uncovering dozens of cellular RBPs and six viral proteins. Amongst them, several components of the tRNA ligase complex, which we show regulate SARS-CoV-2 infection. Furthermore, we discover that available drugs targeting host RBPs that interact with SARS-CoV-2 RNA inhibit infection. Collectively, our results uncover a new universe of host-virus interactions with potential for new antiviral therapies against COVID-19.

SARS-CoV-2 spike D614G variant exhibits highly efficient replication and transmission in hamsters

SARS-CoV-2 causes disease varying in severity from asymptomatic infections to severe respiratory distress and death in humans. The viral factors which determine transmissibility and pathogenicity are not yet clearly characterized. We used the hamster infection model to compare the replication ability and pathogenicity of five SARS-CoV-2 strains isolated from early cases originating in Wuhan, China, in February, and infected individuals returning from Europe and elsewhere in March 2020. The HK-13 and HK-95 isolates showed distinct pathogenicity in hamsters, with higher virus titers and more severe pathological changes in the lungs observed compared to other isolates. HK-95 contains a D614G substitution in the spike protein and demonstrated higher viral gene expression and transmission efficiency in hamsters. Intra-host diversity analysis revealed that further quasi species were generated during hamster infections, indicating that strain-specific adaptive mutants with advantages in replication and transmission will continue to arise and dominate subsequent waves of SARS-CoV-2 dissemination.

Pathogenicity, immunogenicity, and protective ability of an attenuated SARS-CoV-2 variant with a deletion at the S1/S2 junction of the spike protein

SARS-CoV-2 contains a PRRA polybasic cleavage motif considered critical for efficient infection and transmission in humans. We previously reported that virus variants with spike protein S1/S2 junction deletions spanning this motif are attenuated. Here we characterize a further cell-adapted SARS-CoV-2 variant, Ca-DelMut. Ca-DelMut replicates more efficiently than wild type or parental virus in cells, but causes no apparent disease in hamsters, despite replicating in respiratory tissues. Unlike wild type virus, Ca-DelMut does not induce proinflammatory cytokines in hamster infections, but still triggers a strong neutralizing antibody response. Ca-DelMut-immunized hamsters challenged with wild type SARS-CoV-2 are fully protected, demonstrating sterilizing immunity.

The application of self-made adjustable wedge plate in radiotherapy positioning / 中华放射医学与防护杂志

Objective To investigate the repeatability of precise radiotherapy placement of self-made adjustable angle wedge plate,negative pressure vacuum pad and conmon soft pillow,corresponding to 3 groups.The study is demonstrated with a thermoplastic membrane immobilization technology in kyphotic deformity patients with head and neck cancer (including primary and secondary),respectively.Methods From Jun 2014 to Apr 2016,48 cases of severe head and neck cancer patients received radiotherapy humpback who were randomly divided into 3 groups.Combined with thermoplastic head and neck shoulder film position fixation,the right foot direction at the end of the skull styloid process layer center was set as a reference point.On the left foot at the end of the direction of styloid process layer center,localization of the origin of the coordinate system in patients around the head and foot,dorsoventrally (x,y,z) analysis of the direction change of position measurement was performed.Results There was no significant difference between the adjustable angle wedge plate and negative pressure vacuum pad groups of the coordinate system (P ＞ 0.05).Compared with common soft pillow group,three dimensional positioning errors and three dimensional coordinate system transfer errors of the adjustable angle wedge plate and negative pressure vacuum pad groups were statistically significantly different (t =-6.99 to-2.69,-5.13 to-2.71,P＜0.05).Conclusions The self-made adjustable angle wedge plate has good repeatability,saves time and money,is simple and durable on precise radiotherapy positioning of kyphotic deformity patients with head and neck cancer.

Study of radiotherapy positioning repeatability of kyphosis patients with head and neck cancer / 肿瘤研究与临床

Objective To compare the repeatability of radiotherapy placement between negative pressure vacuum pad (A group) and common soft pillow (B group) combined with a thermoplastic membrane immobilization technology in severe kyphosis patients with head and neck cancer.Methods From September 2013 to December 2014,22 cases of severe kyphosis patients with primary or secondary head and neck cancer who received radiotherapy were randomly divided into group A and group B.Padding waist hips with negative pressure vacuum pad and ordinary soft pillow were used so that the patients could lay in CT-Sim bed,and the head cushion was set on the headrest.After the fixing of thermoplastic head and neck shoulder membrane,CT-Sim was located.Every five times of radiotherapy were accompanied by CT-Sim school position once.In the direction of the last layer of right styloid process center point as the reference point,CT-sim software was used to measure the location change with left and right sides,head,and under direction (x,y,z,respectively) in patients,and the data were analyzed.Results Group A significantly reduced the osseous placement error between tags compared with group B (P ＜ 0.05).The average placement errors were as follows,x:(0.68±0.14) mm vs (1.15±0.77) mm,y:(0.48±0.23) mm vs (1.49±1.24) mm,z:(0.76±0.54) mm vs (2.11±1.02) mm,while the average transfer errors were as follows,x:(0.70±0.21) mm vs (1.15±0.93) mm,y:(0.50±0.31) mm vs (1.50±1.28) mm,z:(0.85±0.26) mm vs (1.77±0.88) mm.Conclusion Vacuum suction pad combined with thermoplastic membrane has good repeatability on radiotherapy positioning for severe kyphosis patients with head and neck cancer.

Evaluation of objective structured clinical examination for clinical skills on interns in the department of car-diothoracic surgery / 医学研究生学报

Objective Objective Structured Clinical Examination (OSCE) is one of the most important methods for evalua-ting the medical students′clinical ability .The aim of this study was to analyze the value of OSCE on practice examination in the depart -ment of cardiothoracic surgery . Methods Through the use of standardized patients and the six-station clinical examination , we as-sessed the clinical skills of interns in the department of cardiothoracic surgery . Results OSCE could appraise interns′clinical ability objectively and accurately , which obtained the recognition from students . Conclusion OSCE is applicable to the clinical skills tes-ting in the department of cardiothoracic surgery .

Comparative study on radiation pneumonitis occurred in lung cancer with mediastinal tumors and esophageal after radiotherapy / 肿瘤研究与临床

Objective A comparative study of clinical factors and dose-volume histogram (DVH)parameters on the impact of radiation pneumonitis occurred in the three-dimensional conformal radiotherapy of lung cancer (lung target)and mediastinal tumors and esophageal (mediastinal target).Methods Review 83cases lung cancer,mediastinal tumors and esophageal patients,and analyzed with chi-square tests on the correlation of the clinical factors (gender,age,tumor location,stage,chemotherapy) with radiation pneumonitis;have relevance analysis between the DVH parameters of two targets and radiation pneumonitis; lung target and mediastinal target volume DVH parameters compared to the t-test.Results ≥2 radiation pneumonitis was 36.5 ％.≥2 radiation pneumonitis occurred in various clinical factors had no significant effect.DVH parameters of the two targets,V5,V10,V20,V30,whole lung dose (MLD) were significantly related to RP.Two targets of RP patients V5 [(50.9±17.8) ％,(69.9±20.4) ％],V10 [(38.6±15.2) ％,(53.5±18.8) ％] were statistically significant by t-test (t =2.434,P ＜ 0.05),while V20 (t =0.388,P ＞ 0.05),V30 (t =0.005,P ＞ 0.05) and MLD (t =0.138,P ＞0.05) were no significant difference (P ＞ 0.05),so the same results with the two targets of patients without RP obtained.Conclusion In the lung target and mediastinal target of radiotherapy radiation pneumonitis is related with DVH parameters,especially V20,V30 and MLD impact on the occurrence of RP.

Control study in 0.45% sodium chloride solution and sterile water for injection in airway humidification of patients with mechanical ventilation / 中国实用护理杂志

Objective To observe the two different wetting fluid in airway humidification of patients with mechanical ventilation.Methods 40 patients with mechanical ventilation after cardiac surgery in our hospital from January to April,2009,were divided randomly into group A and group B,group A was given 0.45% sodium chloride solution 100ml plus ambroxol 15mg as airway humidification fluid,group B was given sterile water for injection100 ml plus ambroxol 15mg as airway humidification liquid.The amount of sputum aspiration,color,viscosity,the body temperature of patients,the lungs auscultation and chest X-ray were observed.Results No statistical difference was seen in sputum volume,color,viscosity,the body temperature of patients,lungs auscultation as well as chest X ray after mechanical ventilation for 4 hours,8 hours,16 hours,24 hours,1～2 d,3～5 d,6～7 d.No statistical difference was also seen in auscultation of the lung after mechanical ventilation for 4 hours,16 hours,24 hours,1～2 d,3～5 d,6～7 d.But auscultation of the lung in group B was better than that of group A after mechanical ventilation for 8 hours.Conclusions No sufficient fact can prove that different effect exists between 100 ml 0.45% sodium chloride solution plus ambroxol 15mg and 100 ml sterile water for injection plus ambroxol 15mg as airway humidification fluid during mechanical ventilation.

Prevalence of Avian Influenza Virus Receptor in Human Respiratory Tract / 生物化学与生物物理进展

SAαt2,6 and SAα2,3 linked sialic acid molecules on epithelial cell membrane served as receptors for influenza virus, which axe specifically recognized by human and avian influenza viruses, respectively. The distribution of these two species of sialic acids in human respiratory tract from different anatomical sites and different age groups was investigated. The results showed that SAα2,3Gal species was prevalent in respiratory bronchiole and lung alveolar epithelium, but was infiequent in trachea, bronchus and bronchiole. On the contrary, the SAα2,6Gal species was more common in the trachea and bronchus and to a lesser degree in the alveolar epithelium. When compared the expression levels of SAα2,6Gal and α2,3Gal in the respiratory tract among different age groups, no significant difference was found. In the ex vivo H5N1 virus infection study, alveolus epithelium were found to be more susceptible to avian influenza than trachea and bronchus epithelial cells. These results suggest that the human respiratory tract, to some extent, is permissive for avian influenza viruses. The currently-observed limited human to human transmission of H5N1 virus may be associated with the different abundance of SAα2,3Gal linkages in human upper respiratory tract among individuals.

Assessment of nasopharyngeal carcinoma risk by EB virus antibody profile / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the risk of nasopharyngeal carcinoma (NPC) through EB virus antibody profile by enzyme linked immunosorbent assay (ELISA).</p><p><b>METHODS</b>EBNA 1/IgA, EBNA 1/IgG and zta/IgG by ELISA and VCA/IgA by immmunoenzymatic method were detected in 121 NPC patients and 332 healthy subjects (HS) in the Pearl river estuary.</p><p><b>RESULTS</b>The sensitivity rates were 85%, 83% and 79% for EBNA 1/IgA, EBNA 1/IgG and zta/IgG, all three of which if combined was the highest 92%. The specificity rates were 86%, 86% and 80% for EBNA 1/IgA, EBNA 1/IgG and zta/IgG, all three of which if combined was also the highest 93%. According to the level of odds ratio, nasopharyngeal carcinoma risk could be divided into 3 groups: low, moderate and high-risk groups. 93% of HS had low risk of NPC with the odds ratio 0.0 to 0.3. 0.4% of HS had high risk of NPC with the odds ratio of 137.9%.</p><p><b>CONCLUSION</b>ELISA is more objective than the traditional immunoenzymatic method in the detection and diagnosis of NPC. The combination of EBNA 1/IgA, EBNA 1/IgG and zta/IgG is able to evaluate the risk of NPC.</p>