Vol 17, No 4 (2020)

Since the middle of the twentieth century, there has been a widespread increase in the prevalence of allergic diseases, especially in developed countries. Much attention is paid to the changing climate and its influence on the development of allergies, mainly of the respiratory system. In many countries, studies are intensifying to study the relationship of various weather phenomena, air pollution, Earth temperature with the course of certain allergic diseases of the respiratory tract. Global strategies for the treatment and prevention of allergic diseases are being developed. This review provides data from international studies demonstrating the negative impact on human health and the development of allergic diseases of the respiratory system, in particular asthma: a global rise in Earth temperature, air pollution, dust storms, forest fires, dampness in rooms and atmospheric mold, thunderstorms and floods.

Allergic diseases are increasingly becoming a global epidemic and pose a considerable and growing public health burden. Allergy is a systemic T2-dependent inflammatory reaction to an allergen that results from a complex interaction between genetic and environmental factors. Allergic diseases occur through a T2-dependent type of allergic reaction, some of them, in particular atopic dermatitis (AD) and asthma, develop involving different types of hypersensitivity or their combination and require revision of allergy diagnostics. Atopy patch test (APT) can be informative in establishing a role of cell-mediated hypersensitivity in pathogenesis of allergic diseases.

The review presents the recent data on the significance of APT in the diagnostics of skin and respiratory allergies.

Differences between individual antihistamines are determined by such pharmacokinetic properties as the rate and completeness of absorption, half-life, the participation of hepatic and renal mechanisms of elimination from the body. Pharmacodynamic features of the antihistamine include selectivity and affinity for histamine H₁-receptors and the presence of central effects. The mechanisms of the development of unwanted drug interactions with second-generation antihistamines are analyzed in detail. Three levels of interaction have been identified: 1) hepatic enzymes of the P450 system; 2) membrane carriers of organic anions (OATP) – transport proteins on the sinusoidal membrane of hepatocytes and the luminal membrane of the epithelium of the proximal nephron tubule; 3) P-glycoprotein (Pgp, ABCB1-protein) of epithelial cells of the small intestine – the area of absorption of oral forms of antihistamines, the epithelium of the proximal tubule and the BBB (blood-brain barrier). The emphasis is made on the description of the dependence of the pharmacological profile of antihistamines on its chemical structure. The “elasticity” of the bilastine molecule, the ability to induce a change in conformation underlies the high complementarity of bilastine to the recognition site of the H₁-receptor which is a high affinity. Experimental evaluation confirms this conclusion: the dissociation constant (Dс) of the bilastin-receptor complex is in the nM concentration range. The bilastine molecule, as a representative of antihistamines with zwitterionic properties, carries both a positive and a negative charge at a physiological pH, making it difficult for its penetration into the brain. The peculiarities of the chemical nature of the bilastine molecule are reflected in the specific pharmacological profile of AGP. In vitro studies have shown a high specific affinity of bilastine for H₁-receptors with a very low affinity for other histamine receptors (H₂, H₃, H₄), serotonin, bradykinin, muscarinic and adrenergic receptors). According to this indicator, bilastine is 3 times higher than cetirizine and 5 times higher than fexofenadine. Bilastine is practically not metabolized in the body and is excreted mainly unchanged, and also does not have a cardiotoxic effect. Bilastine is well tolerated; as a therapeutic dose it has a less pronounced sedative potential compared to other second-generation antihistamines.

BACKGROUND: There is an increase in the proportion of patients suffering from allergic diseases caused by the plant pollen. Aeropalinologic monitoring of the air environment allows us to study the composition of aeroallergens and their role in the formation of pollen allergies. Features of the formation of aerial pollen spectra are closely related to the botanical-geographical and natural-climatic conditions of the region. The Rostov region has its own specific features, which is reflected in the qualitative and quantitative composition of pollen rain.

AIM: To study the dynamics of pollination of allergenic plants in Rostov-on-Don, identify the prevailing taxa and create a calendar of pollination of plants for this region.

MATERIALS AND METHODS: Aeroallergens were detected by using a volumetric Burkard trap. The identification of plant pollen and fungal spores was performed by microscopy of colored slides obtained from a sticky tape covered with a special mixture.

RESULTS: In 2019, 21 taxa were registered in the air environment of Rostov-on-don (trees, meadows, haze, cereals, weeds), fungal spores were found in the air, represented by the mold fungi Cladosporium herbarum and Alternaria alternata in high growing concentrations. An increase in the vegetation period of pollination of trees (07.03.–31.06), mares (02.05–03.10), cereals (02.04–14.09), weeds (18.07–28.10) was detected According to the dynamics of pollen concentration, three periods of its growth were registered: spring-summer, summer and summer-autumn. The presence of birch pollen grains in a clinically significant concentration (36 pollen grain (PG)/m³) in this steppe region, an increase in the peak concentration of ragweed (393 PG/m³) in comparison with the same data for 1971 (265 PG/m³) was found.

CONCLUSION: Regional features of the spectrum of air allergens were identified, and a dusting calendar was compiled for Rostov-on-Don.

BACKGROUND: Allergen-specific immunotherapy (ASIT) helps to reduce spontaneous and to induce basophil reactivity, which is one of the major mechanisms of its effectiveness. A number of studies, though, have not confirmed the informative value of the basophil activation test (BAT), in case of ASIT, with house dust mites, meadow grass pollen, and wasp venom. BAT outcomes are likely to be influenced by the properties of the sensitizing allergen, the duration of ASIT, and the BAT markers that are used.

AIMS: To evaluate the basophils reactivity in the patients sensitized to weed pollen and treated with allergen-specific therapy.

MATERIALS AND METHODS: The study involved 60 patients (aged 16–55) with allergic rhinitis sensitized to weed pollen. The diagnosis was based on the skin test outcomes as well as on identifying specific antibodies to major allergens of ragweed, wormwood, timothy, and birch. The pre-seasonal ASIT involved water-salted extracts of pollen allergens during 2 years. Clinical symptoms and the immunotherapy effectiveness were evaluated 6 and 18 months after the ASIT started. BATs were made before the treatment, after the first and second courses of pre-seasonal ASIT, which corresponded to zero, the 3^rd and the 15^th months of the treatment. The activated basophils were identified based on the CRTH2^pos CD203^brightCD3^neg phenotype.

RESULTS: The first treatment course was completed by 52 patients, while the second one – by 43 patients. A statistically significant decrease in spontaneous basophil reactivity was detected only after the second course of ASIT. The decrease in the allergen-induced basophil activation was identified in 67.4% of the samples obtained after the first ASIT course, and in 67.6% of samples taken after the second immunotherapy course. A decrease in the BAT stimulation index (BAT SI) was identified mainly in the patients featuring positive treatment outcomes.

CONCLUSIONS: ASIT influences on the basophil reactivity indicators in the patients sensitized to weed pollen. The basophil activation test may be considered as a potential predictor of ASIT effectiveness.

The diagnostics and treatment of chronic urticaria is still a pressing problem for specialists of different profiles. Despite the fact that the first line drugs for urticaria treatment are non-sedating H₁- antihistamines, there are a number of patients who do not respond to these medications even in their increased doses. This article presents clinical cases of anti-IgE-therapy efficacy in children suffering from urticaria and angioedema.

CONCLUSION: The clinical cases demonstrate current possibilities of successful and safe anti-IgE-therapy of various clinical manifestations of chronic spontaneous urticaria and angioedema in children.

Today, we can see a great interest in vitamin D because it participates in the regulation of many metabolic processes, and its deficiency is associated with the development of various diseases. Chronic spontaneous urticaria (CSU) is the disease that affects the quality of patient’s life, and the existing strategy of patient management is not always sufficiently effective. Nowadays, there is enough information about the role of vitamin D deficiency and the severity of CSU. That is why it is important to study not only therapeutic schemes, but also a role of genetic variability that may have an impact on vitamin D levels.

Such studies will help to personalize the treatment schemes for patients with CSU. At the same time, the focus of these studies should be not only on the receptor and vitamin D binding protein, but also on P450 system, which plays a key role in the vitamin D metabolism.