Veronika Igorevna Butvilovskaya

Multiplex determination of serological signatures in the sera of colorectal cancer patients using hydrogel biochips

Colorectal cancer (CRC) is the third most common malignancy in industrialized countries. Despite the advances in diagnostics and development of new drugs, the 5‐year survival remains only 60–65%. Our approach to early diagnostics of CRC is based on the determination of serological signatures with an array of hemispherical hydrogel cells containing immobilized proteins and oligosaccharides (glycochip). The compounds immobilized on the glycochip include tumor‐associated glycans (SiaTn, Tn, TF, LeC, LeY, SiaLeA, and Manβ1‐4GlcNAcβ) and antibodies against human immunoglobulins IgG, IgA, and IgM. The glycochip detects antibodies against tumor‐associated glycans in patients’ sera. The simultaneous measurement of the levels of immunoglobulins enhances the diagnostic impact of the signatures. In this work, we found previously unreported increase in antibodies against oligosaccharide Manβ1‐4GlcNAcβ in patients with CRC. In parallel with these experiments, we determined the levels of oncomarkers carcinoembryonic antigen (CEA), cancer antigen (CA) 19–9, CA 125, CA 15–3, human chorionic gonadotropin (HCG), and alpha‐fetoprotein (AFP) using another gel‐based biochip with immobilized antibodies (oncochip) developed earlier in our laboratory. In total, 69 samples from healthy donors, 33 from patients with colorectal carcinoma, and 27 from patients with inflammatory bowel diseases were studied. The use of combined signatures of antiglycan antibodies and oncomarkers provides much better predictive value than the conventional measurement of oncomarkers CEA and CA 19–9. Positive predictive value of CRC diagnoses using together glycochip and oncochip reached 95% with the sensitivity and specificity 88% and 98%, respectively. Thus, the combination of antibody profiling with detection of conventional oncomarkers proved to be a promising tool in diagnostics of CRC.

Patterns of sensitization to inhalant and food allergens among pediatric patients from the Moscow region (Russian Federation)

The immunological profiles of human specific IgE (sIgE) and specific IgG4 (sIgG4) vary by genetic predisposition, living conditions in different geographical locations and patient’s age. The aim of our study was to analyze sIgE and sIgG4 patterns and their age-dependent changes in patients from the Moscow region. For identifying sIgE and sIgG4 profiles the blood samples from 513 patients aged 6 months to 17 years who were showing symptoms of allergic diseases were analyzed using microarrays containing 31 allergens. The highest sIgE prevalence was observed for birch pollen (32%) among pollen allergens, cat dander (24%) among indoor allergens, and egg whites (21%) among food allergens. The most common sIgG4 response was developed toward egg whites (80% of patients). Age-related elevation was identified for patients with increased sIgE to pollen allergens and indoor allergens (cat or dog dander and house dust mites). For each allergen, the proportion of cases with significant levels of sIgG4 appeared to increase with patients’ age. The data on allergen-specific sIgE and sIgG4 prevalence show both general trends and some local special aspects that are indicative for the Moscow region. This information should be useful in terms of epidemiology of allergic diseases.

Differential quantification of SCCA1 and SCCA2 cancer antigens using a hydrogel biochip

Methods employing hydrogel-based microarrays (biochips) allow the simultaneous monitoring of protein interactions with different antibodies immobilized in gel elements. The method was applied for the simultaneous differential quantification of two highly homologous antigens of squamous cell carcinomas (SCCs) SCCA1 and SCCA2 in a single analysis. Two panels of monoclonal antibodies against recombinant SCCA1 and SCCA2 were generated, and two antibodies, C5 (anti-SCCA1) and A11 (anti-SCCA2), were selected for further evaluation based on their ability to specifically interact with their cognate antigens. Using a sandwich analysis, these antibodies were further tested in combination with anti-SCCA antibodies (H31 and SCC107) recognizing both of the SCCA antigens, thus allowing a quantitative independent measurement of both antigens. The intra- and inter-assay coefficients of variation for all resultant tests did not exceed 10% for the range of SCCA concentrations tested and were independent of whether SCCA1 and SCCA2 concentrations were determined simultaneously. The lower limit of detection (LOD) was estimated as 0.006 ng ml−1 for SCCA1 and 0.011 ng ml−1 for SCCA2 using the SCC107-Cy5 developing antibody and 0.014 ng ml−1 and 0.01 ng ml−1 concentrations, respectively, of the H31-Cy5 developing antibody. This assay provides a simple and accurate procedure for the differential quantitation of SCCA1 and SCCA2 using a single analysis of human serum on a biochip.

Correction: Differential quantification of SCCA1 and SCCA2 cancer antigens using a hydrogel biochip

Correction for ‘Differential quantification of SCCA1 and SCCA2 cancer antigens using a hydrogel biochip’ by Aleksei A. Tikhonov et al., Anal. Methods, 2016, DOI: 10.1039/c6ay02216b.