Early detection of hepatitis C virus (HCV) is an important step in preventing progression to cirrhosis and hepatocellular carcinoma. Serologic assays for anti-hepatitis C (anti-HCV) antibody are valuable first-line tests in the screening and diagnosis of HCV infection. The aim of this multicenter study was to compare the Elecsys(®) Anti-HCV assay with alternative CE-marked Anti-HCV antibody assays against a range of samples that included 1,138 blood donors, 3,553 unselected routine daily specimens, and 46 pre-selected seroconversion panels. Specificity of the Elecsys Anti-HCV assay was 99.5% with blood donor samples and 99.4% with routine clinical specimens. These were similar to those obtained with the Prism(®) Anti-HCV, Architect(®) Anti-HCV assay, ADVIA(®) Centaur Anti-HCV assay and Vitros(®) Eci aHCV assays. Seroconversion sensitivity for the Elecsys Anti-HCV assay was similar to that of the Architect Anti-HCV, AxSYM HCV version 3.0, ADVIA Centaur Anti-HCV, and Vitros Eci aHCV assays. In fact, seroconversion testing on 46 commercially available panels showed that the difference in first detecting a positive blood sample was less than one day between assays (not statistically significant). The Elecsys Anti-HCV assay as well as the Architect, Prism, and Vitros Anti-HCV immunoassays revealed a seroconversion sensitivity of 100%, whereas the ADVIA Centaur HCV immunoassay showed a sensitivity of only 97.5% (39/40). Overall, the performance of the Elecsys Anti-HCV assay was similar to the performances of the comparator CE-marked Anti-HCV antibody assays.

In a multicenter study a new, fully automated Roche Diagnostics Elecsys HBsAg II screening assay with improved sensitivity to HBsAg mutant detection was compared to well-established HBsAg tests: AxSYM HBsAg V2 (Abbott), Architect HBsAg (Abbott), Advia Centaur HBsAg (Bayer) Enzygnost HBsAg 5.0 (Dade-Behring), and Vitros Eci HBsAg (Ortho). A total of 16 seroconversion panels, samples of 60 HBsAg native mutants, and 31 HBsAg recombinant mutants, dilution series of NIBSC and PEI standards, 156 HBV positive samples comprising genotypes A to G, 686 preselected HBsAg positive samples from different stages of infection, 3,593 samples from daily routine, and 6,360 unselected blood donations were tested to evaluate the analytical and clinical sensitivity, the detection of mutants, and the specificity of the new assay. Elecsys HBsAg II showed a statistically significant better sensitivity in seroconversion panels to the compared tests. Fifty-seven out of 60 native mutants and all recombinant mutants were found positive. Among 156 HBV samples with different genotypes and 696 preselected HBsAg positive samples Elecsys HBsAg II achieved a sensitivity of 100%. The lower detection limit for NIBSC standard was calculated to be 0.025 IU/ml and for the PEI standards ad and ay it was <0.001 and <0.005 U/ml, respectively. Within 2,724 daily routine specimens and 6.360 unselected blood donations Elecsys HBsAg II showed a specificity of 99.97 and 99.88%, respectively. In conclusion the new Elecsys HBsAg II shows a high sensitivity for the detection of all stages of HBV infection and HBsAg mutants paired together with a high specificity in blood donors, daily routine samples, and potentially interfering sera.

Recent evidence suggests that Chlamydia trachomatis can persist in the female upper genital tract in an unculturable state. Since unsuspected C. trachomatis infection has been associated with adverse in-vitro fertilization (IVF) outcome we sought to detect further evidence of C. trachomatis in the genital tracts of women undergoing IVF. The prevalence and distribution of antibodies to the major structural proteins of C. trachomatis in paired follicular fluid and sera of women undergoing IVF were examined. Sera and follicular fluid samples from 149 women were assayed for immunoglobulin (Ig)G and IgA antibodies to two C. trachomatis antigens, the major outer membrane protein (MOMP) and a recombinant lipopolysaccharide (rLPS) fragment. Additionally, the expression of human 60 kDa heat shock protein (hsp 60) in follicular fluid was determined. All cervical and follicular fluid samples were negative for C. trachomatis by polymerase chain reaction, ligase chain reaction and DNA probe. Sera from 60% of the subjects were positive for antichlamydial rLPS IgG; 36% were positive for anti-MOMP IgG. Similarly, rLPS-directed and MOMP-directed IgA were detected in sera of 34 and 14% of the subjects respectively. IgG antibodies to MOMP and rLPS were detected in 42 and 41% of the follicular fluid examined respectively. Anti-MOMP IgA was identified in 8.7% of the follicular fluid while 27.5% were positive for anti-rLPS IgA. Human hsp 60 expression was documented in 11.6% of the follicular fluid tested. IgA antibodies to both MOMP (P = 0.03) and rLPS (P = 0.02) in follicular fluid were associated with a failure to become pregnant after embryo transfer. IgG antibodies in sera and follicular fluid and IgA antibodies in sera were unrelated to IVF outcome. Similarly only anti-MOMP IgA (P = 0.02) and anti-rLPS IgA (P = 0.04) in follicular fluid were correlated with human hsp 60 expression in follicular fluid. The unique association between IgA antibodies to two chlamydial antigens in follicular fluid and both hsp 60 expression and IVF failure provides further support for the possibility that a persistent upper genital tract chlamydial infection contributes to IVF failure in some women.

The neuropathology of Alzheimer's disease (AD) has been linked recently to non-fibrillar forms of neurotoxic amyloid-β (Aβ) oligomers of which high levels are observed in the brain of AD patients. This suggests that Aβ oligomers play a key role in the early events of AD, underlining their potential for the early diagnosis of the disease. We have developed an extremely sensitive assay for the detection of oligomeric and fibrillar structures of Aβ that is based on multiparametric analysis of data obtained by flow cytometry and fluorescence resonace energy transfer (Fret). The assay readily detects Aβ oligomers in human cerebrospinal fluid (CSF) as verified by dot blot of the isolated particles. By measuring 174 CSF samples of non-demented control patients with various neurological disorders a high reliability and reproducibility of the method could be demonstrated.