IgE reactivity patterns in patients with allergic rhinoconjunctivitis to ragweed and mugwort pollens

Profile of cross-reactivity to common pollen allergens in Northwest China based on component resolved diagnosis

The prevalence of allergic diseases such as Allergic Rhinitis and Asthma is steadily increasing globally, with pollen allergy being one of the most significant sensitizing factors. However, the cross-reactivity of different pollen allergies remains unclear, posing challenges in the diagnosis and treatment of individuals with multiple sensitivities. In this study, the Component Resolved Diagnosis technique was performed to simultaneously measure the specific IgE concentrations of 52 patients against Art v and its components (Art v 1), Phl p and its components (Phl p 1, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 12), Bet v and its components (Bet v 1, Bet v 2), Amb a and its component (Amb a 1), and Amb p. Additionally, sIgE inhibition tests were conducted by Art v, Phl p, and Bet v extracts. Among Art v-positive patients, 64.6% showed positivity for Art v 1. In Phl p-positive patients, Phl p 12 had the highest positivity rate (75.0%). Among Bet v-positive patients, 75.6% exhibited positivity for Bet v 2, whereas for Amb a and Amb p-positive patients, 23.7% and 29.0% respectively showed positivity for Amb a 1. The sIgE inhibition assays results revealed that Art v extract had inhibition rates greater than 73.2% against Phl p and its component Phl p 12, as well as Bet v and its component Bet v 2. Simultaneously, Phl p extract showed inhibition rates of 80.70-89.87% against Phl p 12, Bet v and Bet v 2. Bet v extract showed inhibition rates ranging from 21.9 to 59.8% against Phl p and Bet v 2, with a better inhibition rate (76.80%) against Phl p 12. In conclusion, Art v 1 is identified as the principal component of Art v. The profilin proteins of Phl p and Bet v (Phl p 12 and Bet v 2), are implicated as potential cross-reactive elements contributing to polysensitization in patients with respiratory allergies in the Northwest region of China. This cross-reactivity leads to a shared sensitization mechanism among pollen allergens such as Art v, Phl p, and Bet v.

Allergic Rhinitis to Weed Pollen in Germany: Dominance by Plantain, Rising Prevalence, and Polysensitization Rates over 20 Years

BACKGROUND

In contrast to the 3 major aeroallergens tree pollen, grass pollen, and house dust mites, allergic rhinitis caused by herbal pollen has received comparatively little attention in recent clinical studies. Since various weeds flower during summer until fall, allergic rhinitis to weeds may be underdiagnosed and/or mistakenly diagnosed as grass pollen allergy.

OBJECTIVE

To investigate (i) the currently most frequent weed allergy between mugwort, ragweed, plantain, chamomile, nettle, and oilseed rape and (ii) time trends in prevalence of sensitization to weed pollen in the middle of Germany over the last 20 years.

METHODS

This study, the largest of its kind to date, monocentrically evaluated the prick test results of a total of 6,220 patients with suspected RCA over a period of 20 years (1998-2017).

RESULTS

In the study cohort, sensitization rates to plantain almost doubled from 26.6% in the decade 1998-2007 to 50.5% in 2008-2017. Identical increases were observed for ragweed, while sensitization rates for mugwort stayed largely unchanged. The most prominent increase in positive skin prick tests to plantain and ragweed pollen was mainly observed in younger patients. Further, we identified a trend toward polysensitization, currently dominated by plantain and ragweed. Sensitization to weed pollen was found to be highly associated with additional sensitizations to grass and/or birch pollen.

CONCLUSION

Plantain is currently the best choice to screen rhinitis patients for weed allergy which identifies 86% of all weed-sensitized individuals, at least in Germany. Over the last 20 years, we demonstrate a significant rise in the total number of weed pollen sensitization as well as increases in polysensitization, predominantly in younger patients.

Pathogenicity-associated protein domains: The fiercely-conserved evolutionary signatures

Proteins have highly conserved domains that determine their functionality. Out of the thousands of domains discovered so far across all living forms, some of the predominant clinically-relevant domains include IENR1, HNHc, HELICc, Pro-kuma_activ, Tryp_SPc, Lactamase_B, PbH1, ChtBD3, CBM49, acidPPc, G3P_acyltransf, RPOL8c, KbaA, HAMP, HisKA, Hr1, Dak2, APC2, Citrate_ly_lig, DALR, VKc, YARHG, WR1, PWI, ZnF_BED, TUDOR, MHC_II_beta, Integrin_B_tail, Excalibur, DISIN, Cadherin, ACTIN, PROF, Robl_LC7, MIT, Kelch, GAS2, B41, Cyclin_C, Connexin_CCC, OmpH, Bac_rhodopsin, AAA, Knot1, NH, Galanin, IB, Elicitin, ACTH, Cache_2, CHASE, AgrB, PRP, IGR, and Antimicrobial21. These domains are distributed in nucleases/helicases, proteases, esterases, lipases, glycosylase, GTPases, phosphatases, methyltransferases, acyltransferase, acetyltransferase, polymerase, kinase, ligase, synthetase, oxidoreductase, protease inhibitors, nucleic acid binding proteins, adhesion and immunity-related proteins, cytoskeletal component-manipulating proteins, lipid biosynthesis and metabolism proteins, membrane-associated proteins, hormone-like and signaling proteins, etc. These domains are ubiquitous stretches or folds of the proteins in pathogens and allergens. Pathogenesis alleviation efforts can benefit enormously if the characteristics of these domains are known. Hence, this review catalogs and discusses the role of such pivotal domains, suggesting hypotheses for better understanding of pathogenesis at molecular level.

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Proteins have highly conserved regions or domains across pathogens and allergens.

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Knowledge on these critical domains can facilitate our understanding of pathogenesis mechanisms.

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Such immune manipulation-related domains include IENR1, HNHc, HELICc, ACTIN, PROF, Robl_LC7, OmpH etc.

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These domains are presnt in enzyme, transcription regulators, adhesion proteins, and hormones.

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This review discusses and hypothesizes on these domains.

[Respiratory allergies in children and adolescents: the role of component-resolved diagnosis and specific immunotherapy]

Respiratory allergies of children and adolescents are an important issue in allergology. In parallel to increasing prevalence rates also research has rapidly been developing for the last 10 years. Today we can better understand complex systems to improve our diagnostic and therapeutic accuracy. In addition to medical history, skin-prick-testing and analysis of specific IgE to allergen extracts, component resolved diagnosis has gained importance in the last years. While being increasingly helpful in the diagnosis of insect-venom and food-allergies, component-based diagnosis can also improve the management of patients with respiratory allergies. Concerning different therapeutic approaches like allergen-avoidance or symptomatic therapy, specific immunotherapy (SIT) is one of the most interesting therapy-options, as it is still the only causal therapy available. After reasonable patient-selection and the selection of the right allergen and product, SIT has a very good risk/benefit-ration and can induce long-term immuno-tolerance to specific allergens.

Ragweed-induced allergic rhinoconjunctivitis: current and emerging treatment options

Ragweed (Ambrosia spp.) is an annually flowering plant whose pollen bears high allergenic potential. Ragweed-induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population. The invasive occurrence of ragweed (A. artemisiifolia) poses an increasing challenge to public health in Europe and Asia as well. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds. Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed-induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed-induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists. The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy. An approach targeting toll-like receptor 9 by synthetic cytosine phosphate–guanosine oligodeoxynucleotides promises a new treatment paradigm that aims to modulate the immune response, but it has yet to be proven in clinical trials.

Marker allergens of weed pollen - basic considerations and diagnostic benefits in the clinical routine: Part 16 of the Series Molecular Allergology

The term weed is referring to plants used as culinary herbs and medicinal plants as well as ecologically adaptive and invasive segetal plants. In Europe, pollen of ragweed, mugwort, English plantain and pellitory are the main elicitors of weed pollen allergies. Presently, 35 weed pollen allergens have been identified. The most relevant belong to the protein families of pectate lyases, defensin-like proteins, non-specific lipid transfer proteins, and Ole e 1-like proteins. The sensitization frequency depends on geographic regions and might affect more than 50 % of pollen allergic patients in distinct regions. Due to overlapping flowering seasons, similar habitats, polysensitizations and cross-reactive (pan)-allergens, it is difficult to diagnose genuine weed pollen sensitization using pollen extracts. Marker allergens for component-resolved diagnostics are available for the important weed pollen. These are Amb a 1 (ragweed), Art v 1 (mugwort), Pla l 1 (English plantain) and Par j 2 (pellitory). Molecule-based approaches can be used to identify the primary sensitizer and thus enable selection of the appropriate weed pollen extracts for allergen immunotherapy.