10560 Background: Comparison between real-time RT-PCR and histological analysis for the detection of lymph node metastasis in breast cancer patients is difficult because of the necessary use of different tissue for the two tests. In order to minimize this challenge this study used histology sections taken every 0.2 mm and all tissue between the sections was analyzed by real-time RT-PCR. Methods: 129 Lymph nodes (LNs) were obtained by Sentinel LN biopsy and/or axillary dissection from 80 breast cancer patients. All LNs were cut in half. One half of each LN was used for the routine intra-operative diagnosis. The other half was used for the 0.2mm histological interval analysis. All 10μm sections cut for histology at 0.2 mm intervals were analyzed using frozen section H&E under a light microscope. All remaining tissue between the sections used for histological analysis was assayed by real-time RT-PCR using the genetic markers mammaglobin and cytokeratin-19 (investigational GeneSearch Breast Lymph Node Assay, Veridex, LLC, Warren, NJ, USA). Cutoffs were pre- set for the real-time RT-PCR to detect only metastasis greater than 0.2 mm. Results: Compared to the histological diagnosis using 0.2 mm interval frozen sections, the real-time RT-PCR results were as follows; sensitivity of 100.0% (34/34), specificity of 93.7% (89/95) and overall accuracy of 95.3% (123/129). Conclusions: These data suggest by utilizing the 0.2 mm histological interval analysis, sampling discrepancies are minimized and a high level of sensitivity and overall accuracy is seen for the real-time RT-PCR assay. Assay specificity calculations may be less than 100% due to interpretation challenges in frozen section histology, especially in the cases of smaller metastases and/or lobular cancer, causing a small percentage of clinically relevant metastasis to be missed. [Table: see text]

Background and Objectives: Despite improvements in assays for anti–HCV, there remains a significant delay before the appearance of antibodies following infection, during which, circulating viral RNA is present. We have evaluated a prototype assay for the serological detection of hepatitis C virus (HCV) core antigen with specimens derived from the early phase of HCV infection. Materials and Methods: Serial specimens from 24 individuals undergoing HCV seroconversion were tested for the presence of anti–HCV, HCV RNA and HCV core antigen. Results: HCV antigen was detected at the same time as HCV RNA in 83% (20/24) cases. The mean time to the first detection of HCV antigen was approximately 1 day later than HCV RNA. Overall, 87% of HCV–RNA–positive specimens contained detectable HCV core antigen. Conclusion: These results indicate that HCV core antigen can be identified by routine serological ELISA in specimens from the early antibody–negative phase of HCV infection. A test for HCV core antigen may be a useful test for identifying window phase blood donations from antibody negative donors infected with HCV.