EssentialsFactor VIII (FVIII) binding IgG detected by ELISA could be an alternative to the Bethesda assay. We studied the performance of anti-FVIII IgG ELISA in patients with acquired hemophilia and controls. Anti-FVIII IgG > 99th percentile of controls was highly sensitive and specific. Patients with high anti-FVIII IgG have a lower chance of achieving remission.Summary. Background: Acquired hemophilia A is a severe bleeding disorder that requires fast and accurate diagnosis as it occurs often unexpectedly in previously healthy men and women of every age. The Nijmegen-modified Bethesda assay is the diagnostic reference standard for detecting neutralizing autoantibodies against factor VIII (FVIII), but is not widely available, not ideal for quantifying the complex type 2 inhibitors seen in acquired hemophilia, and suffers from high inter-laboratory variability. Objectives: To assess the diagnostic and prognostic value of FVIII-binding antibodies as detected by ELISA compared with the Nijmegen Bethesda assay. Methods: Samples from the time of first diagnosis and clinical data were available from 102 patients with acquired hemophilia enrolled in the prospective GTH-AH 01/2010 study. Controls (n = 102) were matched for gender and age. Diagnostic cut-offs were determined by receiver-operator curve analysis. The prognostic value was assessed in 92 of the 102 patients by Cox regression analysis of time to partial remission. Results: Anti-FVIII IgG above the 99th percentile (> 15 arbitrary units per mL) revealed high sensitivity and specificity (both 0.99; 95% confidence interval, 0.95-1.0) for diagnosing acquired hemophilia. The likelihood of achieving partial remission was related to anti-FVIII IgG concentration (< 300 arbitrary units, 1.0; 300-1050, 0.65; > 1050, 0.39). The Bethesda titer was only associated with the likelihood of partial remission when analyzed in the central laboratory, but not when data from local GTH study sites were used. Conclusion: Although the Nijmegen-modified Bethesda assay is the reference standard for demonstrating neutralizing antibodies, the detection of FVIIIbinding antibodies by ELISA is similarly sensitive and specific for diagnosing acquired hemophilia. In addition, anti-FVIII IgG may provide prognostic information.

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Background: Chronic obstructive pulmonary disease (COPD) is a respiratory inflammatory condition with autoimmune features including IgG autoantibodies. In this study we analyze the complexity of the autoantibody response and reveal the nature of the antigens that are recognized by autoantibodies in COPD patients.

Seroreactivity profiling emerges as valuable technique for minimal invasive cancer detection. Recently, we provided first evidence for the applicability of serum profiling of glioma using a limited number of immunogenic antigens. Here, we screened 57 glioma and 60 healthy sera for autoantibodies against 1827 Escherichia coli expressed clones, including 509 in-frame peptide sequences. By a linear support vector machine approach, we calculated mean specificity, sensitivity, and accuracy of 100 repetitive classifications. We were able to differentiate glioma sera from sera of the healthy controls with a specificity of 90.28%, a sensitivity of 87.31% and an accuracy of 88.84%. We were also able to differentiate World Health Organization grade IV glioma sera from healthy sera with a specificity of 98.45%, a sensitivity of 80.93%, and an accuracy of 92.88%. To rank the antigens according to their information content, we computed the area under the receiver operator characteristic curve value for each clone. Altogether, we found 46 immunogenic clones including 16 in-frame clones that were informative for the classification of glioma sera versus healthy sera. For the separation of glioblastoma versus healthy sera, we found 91 informative clones including 26 in-frame clones. The best-suited in-frame clone for the classification glioma sera versus healthy sera corresponded to the vimentin gene (VIM) that was previously associated with glioma. In the future, autoantibody signatures in glioma not only may prove useful for diagnosis but also offer the prospect for a personalized immune-based therapy.

BackgroundLung cancer is a very frequent and lethal tumor with an identifiable risk population. Cytological analysis and chest X-ray failed to reduce mortality, and CT screenings are still controversially discussed. Recent studies provided first evidence for the potential usefulness of autoantigens as markers for lung cancer.MethodsWe used extended panels of arrayed antigens and determined autoantibody signatures of sera from patients with different kinds of lung cancer, different common non-tumor lung pathologies, and controls without any lung disease by a newly developed computer aided image analysis procedure. The resulting signatures were classified using linear kernel Support Vector Machines and 10-fold cross-validation.ResultsThe novel approach allowed for discriminating lung cancer patients from controls without any lung disease with a specificity of 97.0%, a sensitivity of 97.9%, and an accuracy of 97.6%. The classification of stage IA/IB tumors and controls yielded a specificity of 97.6%, a sensitivity of 75.9%, and an accuracy of 92.9%. The discrimination of lung cancer patients from patients with non-tumor lung pathologies reached an accuracy of 88.5%.ConclusionWe were able to separate lung cancer patients from subjects without any lung disease with high accuracy. Furthermore, lung cancer patients could be seprated from patients with other non-tumor lung diseases. These results provide clear evidence that blood-based tests open new avenues for the early diagnosis of lung cancer.