Staging and IgA VCA titre in patients with nasopharyngeal carcinoma: changes over a 12-year period

Integration of IgA and IgG Autoantigens Improves Performance of Biomarker Panels for Early Diagnosis of Lung Cancer

Lung cancer (LC) remains the leading cause of mortality from malignant tumors worldwide. In our previous study, we surveyed both IgG and IgM-bound serological biomarkers and validated a panel of IgG-bound autoantigens for early LC diagnosis with 50% sensitivity at 90% specificity. To further improve the performance of these serological biomarkers, we surveyed HuProt arrays, comprised of 20,240 human proteins, for IgA-bound autoantigens because IgAs are a major immunoglobulin isotype in the lung. Integrating with IgG-bound autoantigens, we discovered and validated a combined biomarker panel using ELISA-format tests. Specifically, in Phase I, we obtained IgA-based autoimmune profiles of 69 early stage LC patients, 30 healthy subjects and 25 patients with lung benign lesions (LBL) on HuProt arrays and identified 28 proteins as candidate autoantigens that were significantly associated with early stage LC. In Phase II, we re-purified the autoantigens and converted them into an ELISA-format testing to profile an additional large cohort, comprised of 136 early stage LC patients, 58 healthy individuals, and 29 LBL patients. Integration of IgG autoimmune profiles allowed us to identify and validate a biomarker panel of three IgA autoantigens (i.e. BCL7A, and TRIM33 and MTERF4) and three IgG autoantigens (i.e. CTAG1A, DDX4 and MAGEC2) for diagnosis of early stage LC with 73.5% sensitivity at >85% specificity. In Phase III, the performance of this biomarker panel was confirmed with an independent cohort, comprised of 88 early stage LC patients, 18 LBL patients, and 36 healthy subjects. Finally, a blind test on 178 serum samples was conducted to confirm the performance of the biomarker panel. In summary, this study demonstrates for the first time that an integrated panel of IgA/IgG autoantigens can serve as valuable biomarkers to further improve the performance of early diagnosis of LC.

Evaluation of a semi-quantitative ELISA for IgA antibody against Epstein-Barr virus capsid antigen in the serological diagnosis of nasopharyngeal carcinoma

OBJECTIVES

This study was designed to establish an ELISA method, as well as the cut-off value, for IgA against Epstein-Barr virus (EBV) viral capsid antigen (VCA), as a screening assay for nasopharyngeal carcinoma (NPC) in southern China. In addition, the correlation between relative optical density (rOD) values from ELISA and titers from the immunoenzymatic assay (IEA) was also evaluated.

METHODS

Two hundred and fifty-eight NPC cases, 33 non-NPC head and neck cancer patients, and 1156 healthy controls were recruited for this study. VCA-IgA and early antigen (EA)-IgA were measured by ELISA kits and IEA in parallel.

RESULTS

The total precision of the VCA-IgA ELISA achieved a level of <13.0% coefficient of variation. An rOD value of 1.60 for the VCA-IgA ELISA was determined as the cut-off point for southern China, and the sensitivity and specificity for NPC diagnosis when using this cut-off value were 93.0% and 92.4%, respectively. The area under the receiver operating characteristic curve (ROC-AUC) value was 0.969. The correlation coefficient between titers and rOD values was 0.957. rOD values were correlated with NPC overall stage and lymph node involvement.

CONCLUSIONS

The cut-off level established in our study could be used to facilitate more accurate diagnosis of NPC in southern China. The rOD value might be an index for NPC prognosis, since it shows a good correlation with the titer from IEA.

Trans-Oral Brush Biopsies and Quantitative PCR for EBV DNA Detection and Screening of Nasopharyngeal Carcinoma

Objectives

To evaluate a newly developed noninvasive ambulatory, quantitative polymerase chain reaction (Q-PCR) Epstein-Barr virus (EBV) DNA detection and screening system (NP Screen™) for nasopharyngeal carcinoma (NPC).

Study Design

Correlation of the nasopharyngeal epithelial EBV-DNA levels and clinical findings by nasopharyngoscopy and final pathologic diagnosis of NPC with biopsy.

Setting

Multicenter ENT/Oncology clinics in Hong Kong (Radiation Oncology Clinic at the Queen Elizabeth Hospital and Radiation Oncology Clinic and Head and Neck Clinic, Queen Mary Hospital, University of Hong Kong) and in Toronto, Canada (the Otolaryngology-Head and Neck Clinic at the Rouge Valley Health System and 2 large ENT practices in Toronto).

Methods

A single-use trans-oral brush was used for rapid, nontraumatic nasopharyngeal (NP) epithelial cells DNA harvest in 600 Chinese patients, combined with a preservation and shipping kit for remote, real-time Q-PCR EBV DNA determinations.

Results

All 600 patients had NP brushings using NP Screen in an ambulatory environment, and no adverse events or complications were recorded. A final 578 patients were included with sufficient amount of DNA for completion of the Q-PCR assay. Of these 578 patients, 94 were confirmed positive for NPC histologically. The study yielded a sensitivity of 98.9%, specificity of 99.3%, positive predictive value (PPV) of 96.9%, and negative predictive value (NPP) of 99.7% for NP Screen in detecting NPC. Endoscopy had a sensitivity of 94%, specificity 97.1%, PPV 85%, and NPP 98.9%.

Conclusions

The trans-oral brushing system fulfills the characteristics of a noninvasive, sensitive, specific detection method suitable for routine, large-scale ambulatory NPC risk assessment for high-risk NPC populations.

Evaluation of a multianalyte profiling assay and an enzyme-linked immunosorbent assay for serological examination of Epstein-Barr virus-specific antibody responses in diagnosis of nasopharyngeal carcinoma

Assessment of antibody responses to Epstein-Barr virus (EBV) antigens has been used to assist in nasopharyngeal carcinoma (NPC) diagnosis by several methods. In this study, we evaluated an in-house Luminex multianalyte profiling (xMAP) technology and commercial enzyme-linked immunosorbent assay (ELISA) kits for serological examination of EBV-specific antibody responses in 135 NPC patients and 130 healthy controls. Four EBV biomarkers were measured: immunoglobulin A (IgA) against viral capsid antigen (VCA), EBV nuclear antigen 1 (EBNA1), diffused early antigen (EA-D), and IgG against EA-D. The sensitivities and specificities of the four markers ranged between 71.5 and 90% for xMAP assays and 80 and 92% for ELISA. Logistic regression analysis revealed that the combined markers in the xMAP assay had overall sensitivity and specificity values of 82% and 92%, respectively. The correlation coefficient (r) values for the xMAP assay and ELISA were lowest for IgA-VCA (0.468) and highest for IgA-EBNA1 (0.846); for IgA-EA-D and IgG-EA-D, the r values were 0.719 and 0.798, respectively. The concordances of the two methods for NPC discrimination were good (79 to 88%). Our results suggest that both the xMAP assay and ELISA are satisfactory for EBV antibody evaluation when multiple antigens are included.

Antibodies against Epstein-Barr virus gp78 antigen: a novel marker for serological diagnosis of nasopharyngeal carcinoma detected by xMAP technology

Immunoglobulin (Ig) A and/or IgG reactivities to several Epstein-Barr virus (EBV) antigens have been used to facilitate diagnosis of nasopharyngeal carcinoma (NPC). However, antibodies against gp78, an EBV membrane glycoprotein, have not been examined to this day. In this study, we utilized Luminex multi-analyte profiling (xMAP) technology to analyse antibody responses to a synthetic peptide of gp78 in sera samples from 95 NPC patients and 91 healthy controls. Our results showed the sensitivity and specificity of IgA-gp78 for NPC diagnosis were 79 and 71 %, respectively, while those of IgG-gp78 were 74 and 73 %, respectively. The IgA and IgG responses to different EBV antigens were not identical within an individual and IgA-gp78 and IgG-gp78 could be complementary to antibodies against viral capsid antigen (VCA), the diffused early antigen (EA-D) and the nuclear antigen EBNA1 for NPC diagnosis. When the six EBV parameters for NPC prediction, i.e. IgA-gp78, IgG-gp78, IgA-VCA, IgA-EBNA1, IgA-EA-D and IgG-EA-D, are combined, the combined predictors were able to reach overall sensitivity and specificity of 91 and 95 %, respectively. Thus, simultaneous detection of these EBV serological markers could improve the predictive values of NPC using xMAP technology.

Sensitivity and specificity of Epstein-Barr virus IGA titer in the diagnosis of nasopharyngeal carcinoma: a three-year institutional review

BACKGROUND

IgA antibody titers to the Epstein-Barr virus (EBV) viral capsid antigen (EBV IgA-VCA) and to the EBV early antigen (EBV IgA-EA) are used to screen for nasopharyngeal carcinoma (NPC). This study evaluates the sensitivity and specificity of EBV IgA-VCA and EBV IgA-EA titers in screening patients for NPC and in those diagnosed with NPC at our institution.

METHODS

The NPC status was determined for all patients who had their EBV IgA-VCA and EBV-IgA EA titers measured over a 3-year period, and the sensitivity and specificity were calculated.

RESULTS

Five thousand one hundred ninety-six samples were analyzed. NPC was diagnosed in 215 patients. The sensitivity and specificity of a raised EBV IgA-VCA titer (> or =1:5) for diagnosing NPC were 89% and 80%, respectively, with a raised EbV IgA-EA titer (> or =1:5) having a sensitivity and specificity of 63% and 97%, respectively.

CONCLUSIONS

Although the EBV IgA-VCA titer is sensitive for the diagnosis of NPC, it should not be used as the sole means of screening for NPC in a population in which NPC is endemic.

New aspects in clinicopathologic and oncogene studies of 23 pulmonary lymphoepithelioma-like carcinomas

Lymphoepithelioma-like carcinoma, an uncommon epithelial tumor, has been described as being closely associated with Epstein-Barr virus (EBV) infection in many organs, especially the nasopharynx. We experienced 23 cases of lymphoepithelioma-like carcinoma arising in the lung from 2498 lung cancer patients in the Cancer Registry of our hospital. Seven patients were male and 16 were female. All patients were Chinese. Their ages ranged from 42 to 80 years. Six patients were smokers and 17 were nonsmokers. The tumor sizes ranged from 1.2 to 11.0 cm. All tumors showed the typical syncytial growth pattern of undifferentiated epithelial cells with a significant CD8+ T-lymphocyte reaction. EBV serology revealed prior infection in all 15 serum-available patients, all of whom were also found by in situ hybridization to have the virus genome. In addition, the higher the EBV serology titer, the larger the tumor size and the higher the staging would be. EBV viral capsid antigen IgG level remained elevated despite response to therapy. Nearly all cases had bcl-2 oncoprotein expression, but the detection rate of latent membrane protein-1, p53, and c-erb B-2 expression was extremely low. The encouraging chemotherapy response for advanced stage disease is also discussed.

Adoptive transfer of autologous Epstein-Barr virus-specific cytotoxic T cells for nasopharyngeal carcinoma

Tumor cells from NPC patients are regularly and latently infected with EBV. To examine whether the virus serves as target for immune intervention of the cancer, we determined levels of EBV-specific CTLp in peripheral blood from NPC patients, long-term survivors of the cancer and healthy subjects. CTLp levels of test subjects varied between 3- 3,000/10(6) PBMCs. The plasma EBV burden increased when the CTLp level fell below 150, whereas the EBV burden of PBMCs was not correlated with CTLp level. Compared with healthy carriers, CTLp levels of patients were lower and varied over a wider range, between 3-1,500/10(6) PBMCs. The quantitative immune deficit was probably attributed to the tumor because, first, CTLp in survivors was restored to levels similar to those in healthy carriers after the tumor had been successfully treated. Second, the CTLp level changed as disease progressed, being lower in local disease, increased in locoregional disease and decreased again when the tumor metastasized. Based on these findings, 4 patients with advanced disease were infused with 5 x 10(7)-3 x 10(8) autologous EBV CTLs. The treatment was safe and unaccompanied by inflammatory or other complications, but whether it improved tumor control could not be discerned from the large tumor bulk. Nevertheless, the treatment regularly increased CTLp levels of patients, maintained it at higher levels for protracted periods and, in 3 patients, restored host surveillance of EBV replication, reducing the plasma EBV burden. Taken together, these results provided a rationale to further explore EBV as a target of immune intervention of NPC.

B-lymphotropic viruses in a novel tropical splenic lymphoma

Peripheral blood from patients with a novel tropical splenic lymphoma, characterized by splenomegaly and circulating naïve CD5-negative villous B lymphocytes, has been screened for evidence of an association with the B-lymphotropic viruses, Epstein--Barr virus (EBV), hepatitis C virus (HCV) and human herpesvirus 8 (HHV8). No increased prevalence of EBV, HCV and HHV8 was demonstrated using serological and molecular techniques, compared with a geographical, age-matched control group. However, lymphoma patients had markedly raised EBV antibody levels without a concomitant increase in the rate of detection of viral genomes in the peripheral blood. This phenomenon also occurred in patients with hyper-reactive malarial splenomegaly, a condition that occurs in the same geographical area and that is clinically indistinguishable from tropical splenic lymphoma, adding further weight to the suggestion that there may be an aetiological association between these two disorders.