Shairbek A. Sulaimanov, Mukhtar E. Asheraliev, Kalia T. Turatbekova

National Center of Maternity and Childhood Care, Ministry of Health of the Kyrgyz Republic, Bishkek, Kyrgyzstan

Abstract

Objective: The evaluate efficacy  and the diagnostic accuracy of Allergy Explorer 2 (ALEX-2) test system in pediatric patients with bronchial asthma (BA) and allergic rhinitis (AR) in conditions of limited access to skin tests in Kyrgyz Republic.

Methods: Overall, 60 children with clinically confirmed BA and/or AR were included in the study.  Molecular allergy diagnostics using the ALEX-2 test system was conducted for patients in the study cohort. The methodology included serum analysis to evaluate total IgE levels and detect specific to IgE 295 allergens.

Results: The mean total serum IgE level was 1255.37 (150.43) kUA/L. Boys exhibited significantly higher IgE concentrations compared to girls (p<0.01). A high degree of sensitization was identified to pollen allergens, epidermal allergens and domestic common allergens.  ALEX-2 test allowed individualizing allergy diagnostics and facilitating precise indications for allergen-specific immunotherapy (ASIT).

Conclusions:. ALEX-2 testing showed high clinical significance in the absence of standard skin tests. Further studies with inclusion of comparative methods of diagnostics are required.

Key words: Diagnostic accuracy, molecular allergology, ALEX-2, children, immunoglobulin E, Kyrgyzstan

Introduction

Allergic diseases (AD) are a major health problem.  There is a high incidence of allergic diseases worldwide, and the number of severe allergic reactions is increasing; this pathology affects patients of any age category and only progresses over time;  significantly deteriorates the quality of life of the patient and his family (1, 2). 

In modern conditions, molecular allergy research of patients has become possible, which allows at the molecular level to identify allergens that are causally important in the development of allergic diseases (4, 5). This method also allows to effectively diagnose and carry out cross- and multivalent sensitization prophylaxis in patients (3).

Allergy Explorer-2 (ALEX -2) is a multi-component testing method that allows both the detection of antibodies to both molecular components and allergen extracts in the blood, and provides an almost complete picture of each patient’s sensitization. 

ALEX is equipped with adapted software that allows analyzing individual allergen panels according to clinical needs –it  has multiplex technology (on demand).  ALEX-2 is a new generation test for the diagnosis of type 1 allergic reactions (in vitro).                                                                                             

Graphical abstract

The ALEX-2 test covers more than 99% of all standard diagnostic tests, detecting 295 species: 178 different allergen molecules and 117 extracts, including a common immunoglobulin E (IgE) level (1, 3, 5).

The aim of the study was to evaluate  the spectrum of allergic sensitization in children living in the city of Bishkek and Chuy region suffering from bronchial asthma and allergic rhinitis using modern molecular allergic test ALEX-2.

Methods

Study design and population

The study design is a descriptive observational study, conducted on the basis of the Department of Allergology and Clinical Immunology of the National Center for Maternal and Child Health of the Ministry of Health of the Kyrgyz Republic.  The aim of the study was evaluation of diagnostic possibilities ALEX-2 test-system in children with BA and AR. There are no standard skin tests in Kyrgyz Republic, the scarification method is being used, that is not recommended by international guidelines. That is why we did not compare ALEX-2 test results with reference methods.

The study included 60 children with confirmed bronchial asthma (BA) and allergic rhinitis (AR) diagnosis who sought an outpatient or inpatient care.  Patients represented the city of Bishkek (73%) and the Chuy region (27%) of Kyrgyz Republic.

The study protocol was approved by local Ethics Committee of the  National Center for Maternal and Child Health. Informed consent to participate in the study was obtained from parent or legal guardians of patients.

Baseline variables

We assessed age and sex of patients, and duration of diseases: BA or AR.

Allergy testing

Patients underwent molecular allergy testing using the ALEX-2 test system (Vendor, Country), which allows for the analysis of sensitization of 295 allergen molecules and allergen extracts, as well as determination of total IgE levels in blood serum. The technique allowed to identify both allergens and individual protein components responsible for the immune response. Positive test results indicated specific sensitization, but the absence of specific IgE did not rule out allergic disease. The data obtained were compared with the historical information.

Statistical analysis

Statistical analysis was performed using XXX software. Data are presented as number, number (percentage), mean and standard deviation. To evaluate differences between groups we used Students t test. Statistical significance was accepted at p<0.05 level.

Results

The age category of children was from 3 to 14 years. Boys predominated among the surveyed (n=37;  61.6%) compared to girls (n=23;  38,3%). The duration of the disease varied from 1 to 7 years.

The serum IgE total was 1255.37 (150.43) kUA/L. IgE concentration was statistically higher in boys (1331.41 (197.38) kUA/L) than in girls (1133.04 (233.78) kUA/L) (p<0.01).  The obtained indicators show a high sensitization to various allergens, which confirms the expressed allergic load in the studied cohort.

As shown in Table 1, high sensitization was observed for the allergens of grass pollen in 35% of patients, for the allergens of weeds in 28.3%, for the allergens of domestic animals in 23.3%, and for the allergens of trees in 13.3%.

Therefore, the analysis of the concentration of total IgE in blood depending on group affiliation of BA and AR allergies in children showed that the highest and very high levels of IgE in patients with sensitization to pollen of cereals, weeds and allergens of domestic animals. Next in importance was sensitization to allergens of fruits, molds and yeast fungi.

We have given below a spectrum of causally significant allergies in patients using pollen sensitization (Table 2).

The number of patients with very high sensitization in descending order was on molecules of pollen of the long-lived (Lol p 1) at 18 (64.3%), meadow fescue (Phl p 1) at 18 (60%), creeping thistle (Cyn d) at 15 (45.4%), creeping thistle (Cyn d 1) at 15 (45.4%), and wormwood (Art v 3) at 10 (21.3%).

Therefore, the results of molecular allergy testing may have a significant influence on the formation of indications for allergen-specific immunotherapy, increase its effectiveness, allow objectively assessing the risk of anaphylactic reactions and optimize the prognosis and tactics of patients with allergic pathology.

Discussion

Our study demonstrated that use of the Allergy Explorer-2 test system provides a component allergy diagnosis, allowing to identify dominant sensitizing allergens in children with bronchial asthma and allergic rhinitis.

The  total IgE level has  an average serum concentration of 1 255.37 (150.43) kUA/L in children, being markedly higher in boys than in girls. Our data show a pronounced sensitization to causally significant allergens. Molecular allergy testing in children with respiratory allergies allows to identify allergens causing pathological reactions with high accuracy. In the studied group, sensitization to allergens of pollen was found in 35% of patients, to allergens of pollen of weeds - 28.3%, to epidermal allergens of domestic animals - 23.3%, to allergens of pollen of trees - 13.3%.

- Perennial ryegrass pollen molecules (Lolium perenne, component Lol p 1) - 18 patients (64,3%),

- Meadow fescue pollen molecules (Phleum pratense, Phl p 1 component) - 18 patients (60%),

- Creeping thistle pollen molecules (Cynodon dactylon, components Cyn d and Cyn d 1) - 15 patients (45.4%),

- Common wormwood pollen molecules (Artemisia vulgaris, component Art v 3) - 10 patients (21,3%).

Thus, results of our study demonstrated high efficacy of molecular diagnostic methods ALEX-2 in the conditions of limited availability of skin tests. In Kyrgyzstan the skin test are not used (only scarification test is available), thus reducing possibilities of allergy diagnostics in vivo.

Method ALEX -2 allows identifying specific IgE to 295 allergens and its components, that is important for prescription of i for allergen-specific immunotherapy (ASIT) (1, 3, 5). Comparison of our data with similar study conducted in Europe and Asia (4), confirms high sensitivity of multicomponent diagnostics.

Study limitations

The main limitations of the study is absence of comparison with referent methods sensitivity to allergens, as well as  small sample size of patients. Future studies should address inclusion of skin –prick test and use of molecular diagnostics of efficacy of ASIT in dynamics.

Conclusion

The results of the study highlight the importance of molecular allergy diagnosis in the detection of individual allergens, which is crucial for developing personalized strategies to treat allergic diseases in children.

Ethics: The study protocol was approved by local Ethics Committee of the  National Center for Maternal and Child Health. Informed consent to participate in the study was obtained from parent or legal guardians of patients.

Peer-review: External and internal

Conflict-of-interest: None to declare

Authorship: S.A.S., M.E.A., and K.T. T. equally contributed to the study and fulfilled authorship criteria.

Acknowledgement and Funding:  None to declare

Statement on  A.I.-assisted technologies use:  The author did not use AI technology in preparing the manuscript

Availability of data and materials: Contact authors. Any data share should be conducted in frame of fair use, acknowledgement of data source and/collaboration