Antibody response against the Epstein-Barr virus-coded nuclear antigen2 (EBNA2) in different groups of individuals

Specific antibody responses against the 2 major subcomponents of EBNA, EBNA1 and EBNA2 were evaluated, in order to study whether this serological study was beneficial compared to classical EBV serology. During this investigation, 491 sera, obtained from blood donors and patients with Burkitt's lymphoma (BL), nasopharyngeal carcinoma (NPC), infectious mononucleosis (IM), Hodgkin's disease, renal transplantation, rheumatoid arthritis and Human Immunodeficiency Virus (HIV) infection, were tested. While the anti-EBNA1 response followed the classical anti-EBNA/Raji response (99% of anti-EBNA/Raji-positive sera also recognize EBNA1), the anti-EBNA2 response was much less frequent and did not correlate with either anti-EBNA/Raji or anti-EA antibodies. In a control population, 8% of individuals had antiEBNA2 antibodies at titers greater than or equal to 10. The percentage was 45% in NPC and 38% in EBV-associated BL; thus, although not detected in all patients with EBV-associated tumors, anti-EBNA2 serology might be a useful marker in BL and NPC. No antibody was detected in the early course of IM, but in rheumatoid arthritis and in HIV-infected patients, the percentage of positive individuals reached 54 and 68, respectively. Seroconversion to EBNA2 was noted in a few cases, including renal transplant recipients, AIDS patients, and complicated IM. This suggests that in these situations, EBNA 2 serology might represent a useful marker related to modulation of the immune status or EBV reactivation.     

Influence of three successive antiviral treatments on viral heterogeneity in nonresponder chronic hepatitis C patients.

The purpose of the present study was to assess the viral diversity of hepatitis C virus (HCV) in six nonresponder patients during three unsuccessful treatments. These patients were treated successively with IFN-alpha2a (IFN-alpha) at a posology of 3.10(6) units (MIU) three times a week, 10 MIU three times a week, and a combination of IFN-alpha (3 MIU) plus ribavirin (1,000 mg/day). However, only two chronically infected patients could be included in the study due to the persistence of HCV RNA during the three successive treatments. The viral diversity was analysed by cloning and sequencing the HVR-1 region. The treatment of the two nonresponder patients was associated with the persistence of a wide diversity in the viral population and with the emergence of new or minor variants. Under the influence of standard doses of IFN-alpha, a rearrangement of the quasispecies present was observed at this time point. No significant change in viral load or in the complexity of the quasispecies was observed. A second treatment with a high dose of IFN-alpha induced a significant decrease in the associated viral load and, in one case, resulted in a radical change of the viral diversity. Administration of a combination of IFN-alpha and ribavirin did not affect the evolution of the variants but was followed by the emergence of various multiple variants. These results reinforce the hypothesis of the presence of preexisting quasispecies best adapted to the host environment, and therefore resistant to any current therapy.     

Association of diagnostic work-up with subsequent attendance in a breast cancer screening program for false-positive cases

Centrosome amplification has been detected in premalignant lesions and in situ tumors in the breast and in over 70% of invasive breast tumors, and has been associated with aneuploidy and tumor development. Based on these observations, the contribution of commonly inherited genetic variation in candidate genes related to centrosome structure and function to breast cancer risk was evaluated in an association study. Seven-hundred and 82 single nucleotide polymorphisms (SNPs) from 101 centrosomal genes were analyzed in 798 breast cancer cases and 843 controls from the Mayo Clinic Breast Cancer Study to assess the association between these SNPs (both individually and combined) and risk of breast cancer in this population. Eleven SNPs out of 782 from six genes displayed associations with breast cancer risk (P < 0.01). Haplotypes in five genes also displayed significant associations with risk. A two SNP combination of rs10145182 in NIN and rs2134808 in the TUBG1 locus (P-interaction = 0.00001), suggested SNPs in mediators of microtubule nucleation from the centrosome contribute to breast cancer. Evaluation of the simultaneous significance of all SNPs in the centrosome pathway suggested that the centrosome pathway is highly enriched (P = 4.76 × 10⁻⁵⁰) for SNPs that are associated with breast cancer risk. Collections of weakly associated genetic variants in the centrosome pathway, rather than individual highly significantly associated SNPs, may account for a putative role for the centrosome pathway in predisposition to breast cancer.     

Translation of research results to simple estimates of the likely effect of a lung cancer screening programme in the United Kingdom

Background:

There is considerable interest in the possibility of provision of lung cancer screening services in many developed countries. There is, however, no consensus on the target population or optimal screening regimen.

Methods:

In this paper, we demonstrate the use of published results on lung cancer screening and natural history parameters to estimate the likely effects of annual and biennial screening programmes in different risk populations, in terms of deaths prevented and of human costs, including screening episodes, further investigation rates and overdiagnosis.

Results:

Annual screening with the UK Lung Screening Study eligibility criteria was estimated to result in 956 lung cancer deaths prevented and 457 overdiagnosed cancers from 330 000 screening episodes. Biennial screening would result in 802 lung cancer deaths prevented and 383 overdiagnosed cancers for 180 000 screening episodes.

Interpretation/conclusion:

The predictions suggest that the intervention effect could justify the human costs. The evidence base for low-dose CT screening for lung cancer pertains almost entirely to annual screening. The benefit of biennial screening is subject to additional uncertainty but the issue merits further empirical research.     

Multicenter Evaluation of a Rapid and Convenient Method for Determination of Cytomegalovirus Immunoglobulin G Avidity

An easy, rapid, and reproducible test to distinguish residual cytomegalovirus (CMV) immunoglobulin M (IgM) antibodies from antibodies produced in primary infection could be useful, especially for pregnant women. The CMV avidity of IgG antibodies with the VIDAS automated enzyme-linked fluorescent assay and 6 M urea was evaluated in a multicenter study to differentiate between primary CMV infections and past infections or reactivations. A total of 416 serum specimens were tested: 159 specimens were from follow-up of primary infections, and 257 were from past infections. All of the specimens from primary infections collected within 4 months (17 weeks) after the onset of the infection had an avidity index lower than 0.8. An avidity index higher than 0.8 excludes a recent primary infection of less than 4 months. However, an avidity index higher than 0.8 cannot confirm all past infections, since 48 specimens (18%) from past infections had an avidity index lower than 0.8 (between 0.5 and 0.8). The exclusion capacity could be improved (96.9%) by using a cutoff of 0.7, but this index would decrease the specificity of the technique, since the avidity index was found to be between 0.7 and 0.8 in two patients with recent primary infection. All specimens from primary infections obtained more than 4 months after the onset of infection had an avidity index more than 0.2. In this study, an avidity index less than 0.2 confirms the presence of a recent primary infection of less than 4 months. The VIDAS CMV IgG avidity test is a rapid, reproducible test with very good performance.     

Complementary determination of Epstein-Barr virus DNA load and serum markers for nasopharyngeal carcinoma screening and early detection in individuals at risk in Tunisia

Because nasopharyngeal carcinoma (NPC) has a close association with Epstein-Barr virus (EBV), measuring serum EBV DNA and anti-EBV serum marker concentrations could be a feasible method for NPC diagnosis, monitoring and probably screening especially in a community at risk. The aim of this study was to determine the EBV pattern in sporadic NPC and in high risk NPC Tunisian families in order to evaluate their risk factors and help for NPC screening. The rates of anti-EBV antibodies and EBV DNA were determined in the serum of 47 healthy members randomly selected from 23 NPC multiplex families with two or more affected members, 93 healthy Tunisian community controls chosen with the same age, sex and geographic origin as unaffected individuals and 66 EBV positive sporadic NPC patients whose serum was available before and after treatment. Unexpectedly, significant lower concentrations of anti-EA (Early Antigen) IgG and anti-VCA (Viral Capsid Antigen) IgG were found in unaffected members from NPC families than in healthy controls while viral loads were negative in all the tested sera. For sporadic NPC patients, anti-EA IgG and anti-VCA IgA concentrations were significantly higher than in healthy controls and these rates decreased after treatment. The level of EBV DNA load varied according to the condition of the tumour. This study suggests that in the Tunisian NPC families, screening for malignancy is based on serum concentrations but not on EBV DNA load while in the sporadic NPC group, serologic markers and EBV DNA load are complementary for diagnosis and follow-up.     

Evaluation of the Epstein-Barr virus R-gene quantification kit in whole blood with different extraction methods and PCR platforms

Reliable real-time quantitative PCR assays to measure Epstein-Barr virus (EBV) DNA load (EBV) are useful for monitoring EBV-associated diseases. We evaluated a new commercial kit, EBV R-gene Quantification kit (Argene, Varilhes, France) to quantify EBV DNA load in whole blood. Assay performance was assessed with two PCR platforms (LightCycler 2.0 and SmartCycler 2.0) and three commercial DNA extraction methods. The assay was compared with our in-house real-time EBV PCR using samples from the Quality Control for Molecular Diagnostics 2006 EBV proficiency program and using 167 whole-blood specimens from individuals with infectious mononucleosis, from transplanted or HIV-infected patients, and from EBV-seropositive healthy carriers. The EBV R-gene assay was sensitive to 500 copies of EBV DNA per milliliter of whole blood with the two PCR platforms and the three extraction methods and was linear across 4 orders of magnitude. Intra- and interassay coefficients of variations were less than 20%. Nine of 10 samples tested with the EBV R-gene were in agreement with the expected qualitative results of the Quality Control for Molecular Diagnostics 2006 EBV proficiency program, and 7 of 10 samples were within +/-0.5 log units of the expected quantitative values, with discrepant results mostly observed for low viral load (ie, <1000 copies/ml). In the clinical specimens, the correlation between the R-gene assay and the in-house PCR was high (r=0.92). In conclusion, the EBV R-gene assay accurately assesses the EBV DNA load in whole blood of patients with various forms of EBV infections.