The specific IgE reactivity pattern of weed pollen-induced allergic rhinitis patients

Major Grass Pollen Allergen Components and Cross-Reactive Carbohydrate Determinants in Mugwort-Sensitized Child Patients With Allergic Respiratory Disease in Western China

Mugwort is a common pollen allergen in western China, and this study aimed to investigate the patterns of molecular sensitization to major grass pollen allergens (mugwort, ragweed, bermuda grass, and timothy grass) and cross-reactive carbohydrate determinants (CCD) in children who were sensitized to mugwort in western China. Serum-specific IgE (sIgE) of major allergen components and CCD were detected among 121 mugwort SPT-positive children via the EUROBlotMaster system if the mugwort-sIgE was positive (MSP). A CCD inhibition test was further performed on the serum of patients with positive CCD-sIgE. Latent class analysis was used to identify the patterns of potential sensitization to major grass pollen allergens. Of a total of 100 patients with mugwort-sIgE positive (MSP), 52.0, 41.0, and 31.0% of them were positive to Art v 1, Art v 3, and Art v 4, respectively. An optimal model with three latent classes was determined using grass pollen allergens, components, and CCD. The sensitization patterns can be summarized as (1) MSP and cosensitized to ragweed, bermuda grass, and timothy grass (23.74%); (2) MSP and cosensitized to Art v 1 (54.08%); (3) MSP and cosensitized to Art v 4, Cyn d 12, Phl p 12 (22.18%). Additionally, CCD sIgE levels had a significant positive correlation with ragweed, bermuda grass, and timothy grass (P < 0.05), and CCD-Inhibitor can highly inhibit the above allergens sIgE. Our findings suggest that Art v 4 was the typical cross-reaction component of mugwort, which is cosensitized to Phl p 12 and Cyn d 12. A wide cross-reaction among ragweed, bermuda grass, and timothy grass caused by CCD was observed.

Variation in IgE binding potencies of seven Artemisia species depending on content of major allergens

BACKGROUND

Artemisia weed pollen allergy is important in the northern hemisphere. While over 350 species of this genus have been recorded, there has been no full investigation into whether different species may affect the allergen diagnosis and treatment. This study aimed to evaluate the variations in amino acid sequences and the content of major allergens, and how these affect specific IgE binding capacity in representative Artemisia species.

METHODS

Six representative Artemisia species from China and Artemisia vulgaris from Europe were used to determine allergen amino acid sequences by transcriptome, gene sequencing and mass spectrometry of the purified allergen component proteins. Sandwich ELISAs were developed and applied for Art v 1, Art v 2 and Art v 3 allergen quantification in different species. Aqueous pollen extracts and purified allergen components were used to assess IgE binding by ELISA and ImmunoCAP with mugwort allergic patient serum pools and individual sera from five areas in China.

RESULTS

The Art v 1 and Art v 2 homologous allergen sequences in the seven Artemisia species were highly conserved. Art v 3 type allergens in A. annua and A. sieversiana were more divergent compared to A. argyi and A. vulgaris. The allergen content of Art v 1 group in the seven extracts ranged from 3.4% to 7.1%, that of Art v 2 from 1.0% to 3.6%, and Art v 3 from 0.3% to 10.5%. The highest IgE binding potency for most Chinese Artemisia allergy patients was with A. annua pollen extract, followed by A. vulgaris and A. argyi, with A. sieversiana significantly lower. Natural Art v 1-3 isoallergens from different species have almost equivalent IgE binding capacity in Artemisia allergic patients from China.

CONCLUSION AND CLINICAL RELEVANCE

There was high sequence similarity but different content of the three group allergens from different Artemisia species. Choice of Artemisia annua and A. argyi pollen source for diagnosis and immunotherapy is recommended in China.

Artemisia allergy research in China

Artemisia is the most important outdoor allergen throughout China. It can cause allergic rhinitis, asthma, or both of them. Since it was verified as an allergenic pollen in 1960, it was identified two times in the Chinese National Pollen Survey (1984, 2009). The first oral immunotherapy double-blinded trial for Artemisia pollen asthma research was conducted in China in 1989 and published in 1990. 40 years since that study, there have been many published research reports on Chinese Artemisia allergy. This review summarizes the information regarding the discovery of Artemisia as an allergenic pollen, pollen account, epidemiology, allergen components, immunological changes in hay fever patients, natural course from rhinitis to asthma, diagnosis, and immunotherapies in China.

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.

Antidepressant drug, desipramine, alleviates allergic rhinitis by regulating Treg and Th17 cells

Allergic rhinitis (AR) is characterized by IgE-mediated immediate hypersensitivity and usually progresses to chronic nasal inflammation, with depression as one of its comorbidities. The importance of treating the depression in AR patients has been increasingly recognized. Desipramine is a representative of tricyclic-antidepressant agents. In the present study we investigate whether desipramine has therapeutic effects on AR inflammation. BALB/C mice were sensitized by intraperitoneal injection of ovalbumin (OVA), followed by repeated challenge with OVA intranasally. Desipramine was administered orally to treat the mice. The nasal symptoms (sneezing, nasal scratching etc.) of AR were evaluated to determine the severity of AR. Cytokines in the nasal lavage fluid (NALF), including interferon-gamma (IFN-gamma), interleukin 4 (IL-4) and serum OVA-specific immunoglobulin E (IgE) antibody were measured by ELISA. The regulatory T cells (Treg) and T helper cells 17 (Th17) were quantified by flow cytometric analysis. As a result, the repeated oral administration of desipramine attenuated the nasal symptoms (sneezing and nasal rubbing) in AR mice. Desipramine also suppressed the serum OVA-specific IgE and IL-4 levels, but had no effect on IFN-gamma level. Moreover, desipramine treatment up regulated CD4+CD25+Foxp3+ Treg cells, which were found down-regulated in established AR mice. Meanwhile, desipramine administration attenuated CD4+IL-17+ Th17 cells, which were significantly increased in AR mice. These results suggest that the antidepressant drug, desipramine, also has anti-allergic action, which was possibly achieved by reducing allergen-specific IgE and Th2 cytokine production and maintaining a balance between Treg and Th17 cells. Thus, this study provide the first evidence that desipramine may be utilized to treat allergic diseases, especially for those allergic patients with depression or depression patients with allergy.

Prevalence of sensitization to weed pollens of Humulus scandens, Artemisia vulgaris, and Ambrosia artemisiifolia in northern China

OBJECTIVE

Weed pollens are common sources of allergens worldwide. The prevalence of weed pollen sensitization is not yet fully known in China. The purpose of this study was to investigate the prevalence of sensitization to weed allergens from Artemisia, Ambrosia, and Humulus in northern China.

METHODS

A total of 1144 subjects (aged from 5 to 68 years) visiting our clinic from June to October 2011 underwent intradermal testing using a panel of 25 allergen sources. Subjects with positive skin responses to any pollen were further tested for their serum concentrations of IgE antibodies against Artemisia vulgaris, Ambrosia artemisiifolia, and Humulus scandens, and against the purified allergens, Art v 1 and Amb a 1.

RESULTS

Of 1144 subjects, 170 had positive intradermal reactions to pollen and 144 donated serum for IgE testing. The prevalence of positive intradermal responses to pollens of Artemisia sieversiana, Artemisia annua, A. artemisiifolia, and H. scandens was 11.0%, 10.2%, 3.7%, and 6.6%, respectively. Among the intradermal positive subjects, the prevalence of specific IgE antigens to A. vulgaris was 58.3%, to A. artemisiifolia 14.7%, and to H. scandens 41.0%. The prevalence of specific IgE antigens to the allergen Art v 1 was 46.9%, and to Amb a 1 was 11.2%. The correlation between the presence of IgE antibodies specific to A. vulgaris and to the Art v 1 antigen was very high. Subjects with A. artemisiifolia specific IgE also had A. vulgaris specific IgE, but with relatively high levels of A. vulgaris IgE antibodies. There were no correlations between the presence of IgE antibodies to H. scandens and A. vulgaris or to H. scandens and A. artemisiifolia.

CONCLUSIONS

The intradermal prevalence of weed pollen sensitization among allergic subjects in northern China is about 13.5%. Correlations of specific IgE antibodies suggest that pollen allergens from Artemisia and Humulus are independent sources for primary sensitization.

Correlation of symptoms with total IgE and specific IgE levels in patients presenting with allergic rhinitis

OBJECTIVE

The objective of this study was to investigate the correlation of symptoms in patients with presumed allergic rhinitis on the basis of their medical history and physical examination with the levels of total immunoglobulin E (IgE) and specific IgE, and to question the necessity of these tests in diagnosis.

METHODS

The records of 295 patients, who had at least two complaints of nasal itching, nasal obstruction, runny discharge and sneezing, and/or presumed as allergic rhinitis on physical examination findings were retrospectively screened. The correlation between the levels of IgE, specific inhalant IgE, and food-specific serum IgE were evaluated in these patients.

RESULTS

A total of 70 cases (23.7%) were determined to have a total value of IgE under 20 U/ml, 113 cases (38.3%) with IgE values between 20 U/ml and 100 U/ml, and 100 cases with IgE values above 100 U/ml. Results of total IgE could not be obtained in 12 (4.06%) patients. Dermatophagoides farinae was the most common allergy in this group with 74 (68.5%) cases.

CONCLUSIONS

The determination of IgE in allergic rhinitis is a supportive method. However, it cannot be recommended for routine use because of the time loss and high cost.