51 research outputs found

    The EBV Immunoevasins vIL-10 and BNLF2a Protect Newly Infected B Cells from Immune Recognition and Elimination

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    Lifelong persistence of Epstein-Barr virus (EBV) in infected hosts is mainly owed to the virus' pronounced abilities to evade immune responses of its human host. Active immune evasion mechanisms reduce the immunogenicity of infected cells and are known to be of major importance during lytic infection. The EBV genes BCRF1 and BNLF2a encode the viral homologue of IL-10 (vIL-10) and an inhibitor of the transporter associated with antigen processing (TAP), respectively. Both are known immunoevasins in EBV's lytic phase. Here we describe that BCRF1 and BNLF2a are functionally expressed instantly upon infection of primary B cells. Using EBV mutants deficient in BCRF1 and BNLF2a, we show that both factors contribute to evading EBV-specific immune responses during the earliest phase of infection. vIL-10 impairs NK cell mediated killing of infected B cells, interferes with CD4+ T-cell activity, and modulates cytokine responses, while BNLF2a reduces antigen presentation and recognition of newly infected cells by EBV-specific CD8+ T cells. Together, both factors significantly diminish the immunogenicity of EBV-infected cells during the initial, pre-latent phase of infection and may improve the establishment of a latent EBV infection in vivo

    Diagnostic value of fine-needle aspiration biopsy for breast mass: a systematic review and meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>Fine-needle aspiration biopsy (FNAB) of the breast is a minimally invasive yet maximally diagnostic method. However, the clinical use of FNAB has been questioned. The purpose of our study was to establish the overall value of FNAC in the diagnosis of breast lesions.</p> <p>Methods</p> <p>After a review and quality assessment of 46 studies, sensitivity, specificity and other measures of accuracy of FNAB for evaluating breast lesions were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall accuracy. The sensitivity and specificity for the studies data (included unsatisfactory samples) and underestimation rate of unsatisfactory samples were also calculated.</p> <p>Results</p> <p>The summary estimates for FNAB in diagnosis of breast carcinoma were as follows (unsatisfactory samples was temporarily exluded): sensitivity, 0.927 (95% confidence interval [CI], 0.921 to 0.933); specificity, 0.948 (95% CI, 0.943 to 0.952); positive likelihood ratio, 25.72 (95% CI, 17.35 to 28.13); negative likelihood ratio, 0.08 (95% CI, 0.06 to 0.11); diagnostic odds ratio, 429.73 (95% CI, 241.75 to 763.87); The pooled sensitivity and specificity for 11 studies, which reported unsatisfactory samples (unsatisfactory samples was considered to be positive in this classification) were 0.920 (95% CI, 0.906 to 0.933) and 0.768 (95% CI, 0.751 to 0.784) respectively. The pooled proportion of unsatisfactory samples that were subsequently upgraded to various grade cancers was 27.5% (95% CI, 0.221 to 0.296).</p> <p>Conclusions</p> <p>FNAB is an accurate biopsy for evaluating breast malignancy if rigorous criteria are used. With regard to unsatisfactory samples, futher invasive procedures are required in order to minimize the chance of a missed diagnosis of breast cancer.</p
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