Novel high-throughput protein detection technologies are critically needed for population-based large-scale SARS-CoV-2 antibody detection as well as for monitoring quality and duration of immunity against virus variants. Current protein microarray techniques rely heavily on labeled transduction methods that require sophisticated instruments and complex operations, limiting their clinical potential, particularly for point-of-care (POC) applications. Here, we developed a label-free and naked-eye readable microarray (NRM) based on a thickness-sensing plasmon ruler, enabling antibody profiling within 30 min. The NRM chips provide 100% accuracy for neutralizing antibody detection by efficiently screening antigen types and experimental conditions and allow for the profiling of antibodies against multiple SARS-CoV-2 variants in clinical samples. We further established a flexible \"barcode\" NRM assay with a simple tape-based operation, enabling an effective smartphone-based readout and analysis. These results demonstrate new strategies for high-throughput protein detection and highlight the potential of novel protein microarray techniques for realistic clinical applications.

BACKGROUND: To assess the serum autoantibody profile in patients with dry and exudative age-related macular degeneration compared with healthy volunteers to detect potential biomarkers, e.g., markers for progression of the disease.
METHODS: IgG Immunoreactivities were compared in patients suffering from dry age-related macular degeneration (AMD) (n = 20), patients with treatment-naive exudative AMD (n = 29) and healthy volunteers (n = 21). Serum was analysed by customized antigen microarrays containing 61 antigens. The statistical analysis was performed by univariate and multivariate analysis of variance, predictive data-mining methods and artificial neuronal networks were used to detect specific autoantibody patterns.
RESULTS: The immunoreactivities of dry and wet AMD patients were significantly different from each other and from controls. One of the most prominently changed reactivity was against alpha-synuclein (p ≤ 0.0034), which is known from other neurodegenerative diseases. Furthermore, reactivities against glyceraldehyde-3-phosphat-dehydrogenase (p ≤ 0.031) and Annexin V (p ≤ 0.034), which performs a major role in apoptotic processes, were significantly changed. Some immunoreacitvities were antithetic regulated in wet and dry-AMD, such as Vesicle transport-related protein (VTI-B).
CONCLUSIONS: Comparison of autoantibody profiles in patients with dry and wet AMD revealed significantly altered immunoreactivities against proteins particularly found in immunological diseases, further neurodegenerative, apoptotic and autoimmune markers could be observed. A validation study has to explore if these antibody pattern can help to understand the underlying differences in pathogenesis, evaluate their prognostic value and if those could be possibly useful as additional therapeutic targets.

Antibody response to SARS-CoV-2 is a valuable biomarker for the assessment of the spread of the virus in a population and evaluation of the vaccine candidates. Recent data suggest that antibody levels also may have a prognostic significance in COVID-19. Most of the serological studies so far rely on testing antibodies against spike (S) or nucleocapsid (N) protein, however antibodies can be directed against other structural and nonstructural proteins of the virus, whereas their frequency, biological and clinical significance is unknown.
A novel antigen array comprising 30 SARS-CoV-2 antigens or their fragments was developed and used to examine IgG, IgA, IgE and IgM responses to SARS-CoV-2 in sera from 103 patients with COVID-19 including 34 patients for whom sequential samples were available, and 20 pre-pandemic healthy controls.
Antibody responses to various antigens are highly correlated and the frequencies and peak levels of antibodies are higher in patients with severe/moderate disease than in those with mild disease. This finding supports the idea that antibodies against SARS-CoV-2 may exacerbate the severity of the disease via antibody-dependent enhancement. Moreover, early IgG and IgA responses to full length S protein may be used as an additional biomarker for the identification of patients who are at risk of developing severe disease. Importantly, this is the first study reporting that SARS-CoV-2 elicits IgE responses and their serum levels positively correlate with the severity of the disease thus suggesting a link between high levels of antibodies and mast cell activation.
This is the first study assessing the prevalence and dynamics IgG, IgA, IgE and IgM responses to multiple SARS-CoV-2 antigens simultaneously. Results provide important insights into the pathogenesis of COVID-19 and have implications in planning and interpreting antibody-based epidemiological studies.

The diagnosis and management of concussion is hindered by its diverse clinical presentation and assessment tools reliant on subjectively experienced symptoms. The biomechanical threshold of concussion is also not well understood, and asymptomatic concussion or \"subconcussive impacts\" of variable magnitudes are common in contact sports. Concerns have risen because athletes returning to activity too soon have an increased risk of prolonged recovery or long-term adverse health consequences. To date, little is understood on a molecular level regarding concussion and subconcussive impacts. Recent research suggests that neuroinflammatory mechanisms may serve an important role subsequent to concussion and possibly to subconcussive impacts. These studies suggest that autoantibodies may be a valuable tool for detection of acute concussion and monitoring for changes caused by cumulative exposure to subconcussive impacts. Hence, we aimed to profile the immunoglobulin (Ig)A autoantibody repertoire in saliva by screening a unique sport-related head trauma biobank. Saliva samples (n = 167) were donated by male and female participants enrolled in either the concussion (24-48 h post-injury) or subconcussion (non-concussed participants having moderate or high cumulative subconcussive impact exposure) cohorts. Study design included discovery and verification phases. Discovery aimed to identify new candidate autoimmune targets of IgA. Verification tested whether concussion and subconcussion cohorts increased IgA reactivity and whether cohorts showed similarities. The results show a significant increase in the prevalence of IgA toward protein fragments representing 5-hydroxytryptamine receptor 1A (HTR1A), serine/arginine repetitive matrix 4 (SRRM4) and FAS (tumor necrosis factor receptor superfamily member 6) after concussion and subconcussion. These results may suggest that concussion and subconcussion induce similar physiological effects, especially in terms of immune response. Our study demonstrates that saliva is a potential biofluid for autoantibody detection in concussion and subconcussion. After rigorous confirmation in much larger independent study sets, a validated salivary autoantibody assay could provide a non-subjective quantitative means of assessing concussive and subconcussive events.

Detection of antibodies to upper respiratory pathogens is critical to surveillance, assessment of the immune status of individuals, vaccine development, and basic biology. The urgent need for antibody detection tools has proven particularly acute in the COVID-19 era. We report a multiplex label-free antigen microarray on the Arrayed Imaging Reflectometry (AIR) platform for detection of antibodies to SARS-CoV-2, SARS-CoV-1, MERS, three circulating coronavirus strains (HKU1, 229E, OC43) and three strains of influenza. We find that the array is readily able to distinguish uninfected from convalescent COVID-19 subjects, and provides quantitative information about total Ig, as well as IgG- and IgM-specific responses.

Patients treated with chemotherapy have an impaired response to influenza virus vaccination compared to healthy controls. Little is known about the broadness of the antibody response in these patients.
Breast cancer patients on FEC (5-fluorouracil, epirubicin and cyclophosphamide) chemotherapy regimens were vaccinated with influenza virus vaccine. Sera were obtained before and three weeks after vaccination. In addition to the determination of virus-specific antibody titres by hemagglutination inhibition assay, the broadness of the response was assessed by the use of a protein microarray and baseline titres were compared with an age-matched reference group.
We included 38 breast cancer patients and found a wide variety in serum antibody response after vaccination. Patients with a history of influenza vaccination had higher pre-vaccination titres, which were comparable to the reference group. Increasing number of cycles of chemotherapy did not have a negative effect on influenza array antibody levels, nor on the HI antibody response.
Overall there was a broad serum antibody response to the influenza virus vaccine in patients treated with chemotherapy for breast cancer.

In this work, a non-fouling antigen competitive immunoassay microarray based on the polymer brush is reported to detect multiple mycotoxins. The detection is achieved by utilizing highly specific monoclonal antibodies produced in our laboratory. The polymer brush, poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA), is synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP) on standard glass slides. In the polymer brush, the epoxy groups of glycidyl methacrylate (GMA) residues provide covalent binding sites for spotted antigens. Moreover, the abundant poly(ethylene glycol) (PEG) side chains in the brush are able to ultimately suppress the nonspecific protein adsorption in solution (non-fouling). The polymer brush shows a high and uniform protein loading, along with a high resistance to nonspecific protein absorption that are both important to achieve a highly sensitive immunoassay. As a demonstration of a multiplex assay, aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN) are selected as antigen targets for simultaneous detections using the microarray.

Various mycotoxins with strong carcinogenesis and toxicity are fatal threats in food safety, and require highly sensitive and high-throughput detections greatly. Herein a fluorescent competitive immunoassay microarray based on a non-fouling polymer brush, poly[(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) is explored to sensitively detect multiple mycotoxins with aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEN) as template targets. Due to uniformly large protein loading and high resistance to nonspecific protein absorption of the POEGMA-co-GMA brush, the optimal microarray exhibits wide dynamic ranges of three orders of magnitudes and low detection limits of 4, 4 and 3 pg mL(-1), respectively, which is much better than that obtained with an epoxy-functionalized antigen microarray, and is comparable or even better than the conventional ELISA method. This work offers a powerful high-throughput tool to fast screening of toxins in food quality and environmental monitoring.