Allergen-specific IgE and IgG4 patterns among patients with different allergic diseases

Background

In addition to allergen-specific IgE (sIgE), allergen-specific IgG4 (sIgG4) antibodies are also involved in the immune response resulting from an allergen exposure. The aim of our study was to analyze sIgE and sIgG4 patterns in the most common allergic disorders: bronchial asthma, upper airway disorders and atopic dermatitis.

Methods

In this study a screening analysis of blood serum samples from 673 patients aged from 6 months to 17 years with different allergic entities was performed on microarrays. sIgE and sIgG4 levels to the most common allergens were estimated.

Results

sIgE response to most pollen allergens is more strongly associated with respiratory diseases than with atopic dermatitis, while sIgE responses to cat and dog dander are more strongly associated with bronchial asthma than with atopic dermatitis and upper airway disorders such as rhinosinusitis and allergic rhinitis. A lower prevalence of sIgG4 to pollen allergens in cases of atopic dermatitis is observed compared with that in cases of asthma and upper airway disorders. Analyzing all the allergic disorders, one can see that sIgG4 response to inhalant allergens is strongly associated with sensitization to the corresponding allergen.

Conclusion

Allergen-specific IgE and IgG4 patterns that are relevant to concrete allergic diseases differ by sIgE and sIgG4 prevalences to defined allergens.

Electronic supplementary material

The online version of this article (10.1186/s40413-018-0220-5) contains supplementary material, which is available to authorized users.

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.

Microarray analyzer based on wide field fluorescent microscopy with laser illumination and a device for speckle suppression

A microarray analyzer was developed to obtain images and measure the fluorescence intensity of microarrays at three wavelengths from 380 nm to 850 nm. The analyzer contains lasers to excite fluorescence, barrier filters, optics to project images on an image detector, and a device for suppressing laser speckles on the microarray support. The speckle suppression device contains a fibre-optic bundle and a rotating mirror positioned in a way to change the distance between the bundle butt and mirror surface during each mirror revolution. The analyzer provides for measurements with accuracy within ± 5%. Obtaining images at several exposure times allowed a significant expansion in the range of measured fluorescence intensities. The analyzer is useful for high throughput analysis of the same type of microarrays.

Identification of chromosomal translocations in leukemias by hybridization with oligonucleotide microarrays

BACKGROUND AND OBJECTIVES

Identification of chromosomal rearrangements is important for a precise risk-stratified diagnosis of hematologic malignancies. As the number of known translocations, specific for different types of leukemia increases, it takes ever more time and increasing amounts of patient's material to screen a single patient with individual polymerase chain reactions (PCR). The aim of this study was to develop a new approach combining specificity with high-throughput sufficient for rapid screening of clinical samples for the presence of numerous translocations.

DESIGN AND METHODS

We designed an oligonucleotide microarray and used hybridization with microarrays in combination with multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay for accurate and rapid identification of some major leukemias. The following translocations were used as prototypic: t(9;22) p210 and p190, t(4;11), t(12;21), and t(15;17). This approach was tested on five different cell cultures carrying translocations and on 22 clinical samples from leukemic patients.

RESULTS

Distinctive hybridization signals were obtained for all types of chimeric transcripts from cell lines with translocations. Both the type of translocation and the splice variant were determined. The data demonstrated high specificity and reproducibility of the method. Analysis of the 22 clinical samples using the microarray-based approach showed complete agreement with standard PCR analysis.

INTERPRETATION AND CONCLUSIONS

Our data suggest that oligonucleotide microarrays can be used as an efficient, alternative approach to the traditional post-PCR Southern blot analysis. The oligonucleotide microarray approach appears suitable for clinical screening of major risk-stratifying translocations in patients with leukemia.

Detection of single nucleotide polymorphisms of the human mu opioid receptor gene by hybridization or single nucleotide extension on custom oligonucleotide gelpad microchips: potential in studies of addiction

The human mu opioid receptor (MOR) plays a central role in mediating the effects of opioids, both endogenous and exogenous. Epidemiological studies have shown that addiction in general, and especially opiate addiction, has a heritable component. Clinical and laboratory studies suggest that the MOR gene may contribute to the heritable component of vulnerability to develop opiate addiction. Naturally occurring single nucleotide polymorphisms (SNPs) have been identified in the MOR gene by conventional methods. Two coding region SNPs, the A118G and C17T substitutions, occur at high allelic frequencies (10.5% and 6.6%, respectively, in our previous studies). These common SNPs cause amino acid changes in the receptor, and may have implications for differences in individual responses to opioids, as well as decreased or increased vulnerability to opiate addiction. The A118G substitution encodes a variant receptor with binding and signal transduction differences in response to beta-endorphin in cellular assays. Recent innovations in microchip technology offer new potential methods for SNP detection. We report here on the development of two separate approaches using custom oligonucleotide gelpad microarrays for detection of these two common SNPs of the MOR gene in human DNA samples. First, PCR-amplified genomic DNA samples were used to produce target sequences, which were labeled with fluorescent dye and hybridized to custom microchips. Oligonucleotides on these reusable microchips were designed to query nucleotide substitutions at positions 17 and 118 of the MOR gene. Thirty-six human DNA samples were assayed both on these custom microchips and by conventional automated gel sequencing, with highly concordant identification of both heterozygous and homozygous substitutions. A second approach was developed for the C17T SNP utilizing single nucleotide extension on custom microchips. These custom gelpad microchips have potential for the rapid and inexpensive detection of specific SNPs for genetic and genomic studies.

Fractionation, phosphorylation and ligation on oligonucleotide microchips to enhance sequencing by hybridization

Oligonucleotide microchips are manufactured by immobilizing presynthesized oligonucleotides within 0.1 x 0.1 x 0.02 mm or 1 x 1 x 0.02 mm polyacrylamide gel pads arranged on the surface of a microscope slide. The gel pads are separated from each other by hydrophobic glass spacers and serve as a kind of 'microtest tube' of 200 pl or 20 nl volume, respectively. Fractionation of single-stranded DNAs is carried out by their hybridization with chip pads containing immobilized 10mers. DNA extracted separately from each pad is transferred onto a sequencing chip and analyzed thereon. The chip, containing a set of 10mers, was enzymatically phosphorylated, then hybridized with DNA and ligated in a site-directed manner with a contiguously stacked 5mer. Several cycles of successive hybridization-ligation of the chip-bound 10mers with different contiguously stacked 5mers and hybridized with DNA were carried out to sequence DNA containing tetranucleotide repeats. Combined use of these techniques show significant promise for sequence comparison of homologous regions in different genomes and for sequence analysis of comparatively long DNA fragments or DNA containing internal repeats.