Sensitization profiles to house dust mite Dermatophagoides pteronyssinus molecular allergens in the Lithuanian population: Understanding allergic sensitization patterns.

BACKGROUND: House dust mite (HDM) allergy is a prevalent global health concern, with varying sensitization profiles observed across populations. We aimed to provide a comprehensive assessment of molecular allergen sensitization patterns in the Lithuanian population, with a focus on Dermatophagoides pteronyssinus (Der p), and investigate patterns of concomitant reactivity among different allergens to enhance the accuracy of HDM allergy diagnostics. METHODS: A comprehensive analysis of 1520 patient test results in Lithuania from 2020 to 2022 was performed. Sensitization patterns to major (Der p 1, Der p 2, and Der p 23) and minor (Der p 5, Der p 7, and Der p 21) Der p allergen components were described using molecular-based diagnostics. Additionally, we investigated sensitization to allergen components from other allergen sources, including tropomyosins (Der p 10, Per a 7, Pen m 1, Ani s 3, Blo t 10) and arginine kinases (Pen m 2, Bla g 9, Der p 20). RESULTS: This study reveals a high prevalence of HDM sensitization in Lithuania - 481 individuals (45.38% of the sensitized group) exhibited sensitization to at least one Der p allergen component. Importantly, within the sensitized group, 37.21% of patients were sensitized to Der p 5, Der p 7, or Der p 21 in addition to major allergenic components. Distinct sensitization patterns were observed across different age groups, indicating the influence of age-related factors. Furthermore, we confirmed cross-reactivity between Der p 5 and Blo t 5 as well as between Der p 21 and Blo t 21, emphasizing the clinical relevance of these associations. We also highlighted the complexity of sensitization patterns among tropomyosins and arginine kinases. CONCLUSION: This study provides valuable insights into HDM allergy sensitization profiles in Lithuania, emphasizing the importance of considering major and minor HDM allergen components for accurate diagnosis and management of HDM-related allergic diseases. Differences between populations and age-related factors impact sensitization patterns. Understanding concomitant reactivity among allergens, such as Der p 5 and Blo t 5, Der p 21 and Blo t 21, tropomyosins, and arginine kinases, is crucial for improving diagnostic strategies and developing targeted interventions for allergic individuals.

Molecular sensitization patterns to cat and dog allergens in Lithuanian children population.

Background: Over the last few decades, there was observed an increase of asthma and allergic rhinitis cases caused by allergy to pets. Objective: This study aimed to analyze molecular sensitization patterns to dog and cat allergens in Lithuanian children who were experiencing allergy-like symptoms. Materials and methods: A total of 574 children (0-18 years) were tested for allergen-specific immunoglobulin E (sIgE) levels with ALEX2 (ALEX2®, Allergy Explorer Test System). Positive sera were further analyzed for sensitization to cat (Fel d 1, Fel d 2, Fel d 4, and Fel d 7) and dog (Can f 1, Can f 2, Can f 3, Can f 4, Can f 5, and Can f 6) allergen components. Results: Two hundred forty-seven children tested positive (sIgE ≥0.3 kUA/L) to at least 1 dog or cat allergen component. There were 61.1% children sensitized to components from both sources, 29.2% - exclusively to cat, and 9.7% - to dog components. The major sensitizers were Fel d 1 (84.8%) and Can f 1 (59.4%). There were 42.9% patients sensitized to 3 or more different mammalian protein families and 40.4% - to 3 or more lipocalins. There were 5.7% of children sensitized both to Fel d 1 + Fel d 4 and Can f 1/2 + Can f 5, indicating the high risk of severe asthma. Monosensitization to Fel d 1 was the dominant pattern among Lithuanian children (26.3%). Conclusion: The majority of children were cat/dog-polysensitized, although sensitization only to cat allergens was most observed. Extensive molecular profiling can be an useful tool for accurate true sensitization diagnosis and prognosis of disease severity.

Molecular peanut sensitization patterns in Lithuanian children with suspected allergic symptoms.

Introduction: There are no in-depth studies describing the peanut sensitization molecular patterns in Lithuanian children. Aim: To investigate the age-related patterns of molecular peanut sensitization profiles in Lithuanian children with suspected allergic symptoms. Material and methods: We performed a retrospective analysis of peanut sensitization profiles in 576 Lithuanian children with possible allergic symptoms. Patient data were categorized according to age groups: 0-2, 3-6, 7-12, and 13-18 years. Specific immunoglobulin E levels to peanut molecular components: Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 8, Ara h 9, Ara h 15, and birch major allergen component Bet v 1 were analyzed. Results: Sensitization to at least one peanut protein was observed in 148 (25.7%) children. In children aged ≤ 2 years, most children were sensitized to Ara h 1 - 11 (12.1%). In children aged from 3 to 6 years, the sensitization to Ara h 1 remained the most prevalent in 40 (16.6%) children. The most prevalent sensitization in children aged from 7 to 12 years was to Ara h 8 in 39 (24.5%) of them. In children aged ≥ 13 years, Ara h 8 remained the most prevalent sensitizer in 21 (24.7%) of them. Conclusions: One-fourth of children with suspected allergic symptoms are sensitized to at least one peanut molecular component in Lithuania. Infants and preschool children are most commonly sensitized to seed storage proteins, while school-age children to Ara h 8 allergen.

Spread of carbapenem-resistant Acinetobacter baumannii carrying a plasmid with two genes encoding OXA-72 carbapenemase in Lithuanian hospitals.

OBJECTIVES: To study the molecular epidemiology of Acinetobacter baumannii isolates from Lithuanian hospitals with an emphasis on the characterization of plasmids and antibiotic-resistance genes and their relationship with European clones (ECs) I and II. METHODS: PFGE, PCR analysis of ECs and resistance genes, plasmid replicon typing, DNA transformation and sequencing were employed to characterize A. baumannii. RESULTS: Of the 444 isolates studied, 230 (52%) and 202 (45%) belonged to ECI and ECII clones, respectively, and showed clone-specific resistance gene profiles. Five plasmids from 6 to 100 kb in size in different combinations (one to four plasmids) were found in A. baumannii isolates, the combination of 9 + 70 kb plasmids in ECI isolates (60%, 137/230) and an 11 kb plasmid in ECII isolates (52%, 106/202) being the most frequent. GR2 and GR6 replicon groups, alone or in combination, were found, with a prevalence of GR2 + GR6 in ECI isolates of 90% (206/230) and a prevalence of GR2 in ECII isolates of 56% (113/202). The vast majority (95%, 165/174) of carbapenem-resistant A. baumannii ECII isolates carried a novel GR2-type plasmid of 11 kb, designated pAB120, which had two copies of a blaOXA-72 gene, flanked by XerC/XerD-like sites and conferred resistance to carbapenems when introduced into a carbapenem-susceptible A. baumannii strain. CONCLUSIONS: The spread of carbapenem-resistant A. baumannii in Lithuanian hospitals is strongly associated with strains belonging to ECII and carrying a GR2 plasmid encoding two blaOXA-72 genes. The genetic environment of pAB120 supports the role of site-specific recombination associated with the acquisition of carbapenem-hydrolysing class D ß-lactamases.