Exploring the effects of seasons, diurnal cycle, and heights on airborne pollen load in a Southeast Asian atmospheric condition

Monitoring, distribution and clinical relevance of airborne pollen and fern spores in Southeast Asia - A systematic review

Southeast Asia is witnessing a rapid increase in the prevalence of allergic diseases, including asthma and allergic rhinitis. Pollen grains stand out as one of the primary triggers for allergy, and monitoring aeroallergens plays a pivotal role in allergy prevention. However, our understanding of the diversity and abundance of allergenic pollen in tropical regions, as well as their clinical significance, remains limited. This review aims to address this issue by identifying the most potentially allergenic plants in Southeast Asia, examining sensitization rates to their pollen allergens, describing the dynamics of pollen seasons, and discussing the current state of aerobiological monitoring in the region. The selection of plants was conducted through a systematic review process (following PRISMA guidelines), by screening the Scopus and PubMed databases, and focusing on studies that provided clinical and aerobiological data. As a result, 73 studies related to pollen allergy in Southeast Asia were identified and reviewed. The list of potentially allergenic plants posing the highest risk in Southeast Asia has been narrowed down to 10, including 5 woody species, 2 primarily weed families, grasses, palms, and ferns. The descriptions of these plants are supplemented with information on their ecology, pollen seasons dynamics, and clinical significance.

Immunoproteomic analysis and identification of possible allergenic proteins in Artemisia annua pollen

BACKGROUND

Artemisia annua (A. annua) is a wind-pollinated weed and a major allergen responsible for allergic respiratory diseases in Northern China.

METHODS

This study involved the separation of pollen proteins from A. annua utilizing SDS-PAGE and Coomassie Blue staining techniques. The effectiveness of extracting allergens from Artemisia annua pollen (AAP) were confirmed both in vivo and in vitro. A mouse model was established using A. annua pollen (AAP) extracts. In vitro, the interaction between allergenic proteins in the AAP extract and specific IgE antibodies present in patients' sera was analyzed, using IgE-immunoblotting and ELISA methods. Protein bands were subsequently analyzed by mass spectrometry. The recombinant Art an 3 (rArt an 3) protein was obtained via recombination, expression, and purification. Finally, the binding activity of rArt an 3 specific IgE was subsequently examined using Western blot and inhibition ELISA (iELISA).

RESULTS

The electrophoretic profiles of AAP showed band patterns ranging from 10 to 70 kDa, with the most prominet IgE-binding pollen proteins detected at approximately 12 kDa. After stimulation of AAP, the sensitized group of mice exhibited significant allergic symptoms compared to the control group. Mass spectrometry analysis identified 7 proteins, including putative aldehyde oxidase Art an 7, Art v 1-like protein, Art an 3.0101 allergen precursor, Art an 3.0102 allergen precursor, Art an 3.0201 allergen precursor, lipid transfer protein 3, and non-specific lipid-transfer protein. The results of immunoblotting and iELISA showed that rArt an 3 could bind to IgE antibodies in the patient sera, and co-incubation of rArt an 3 with serum, the binding serum significantly inhibited IgE binding to the crude AAP.

CONCLUSIONS

The Art an 3 is a key allergenic protein in AAP with a high IgE sensitization rate in the studied population sample. These findings enhance our understanding of the sensitization components of AAP and its sensitization characteristics within the Chinese population, thereby promoting the development of precise molecular diagnostics and therapeutic interventions.

Local spatiotemporal dynamics of particulate matter and oak pollen measured by machine learning aided optical particle counters

Conventional techniques for monitoring pollen currently have significant limitations in terms of labour, cost and the spatiotemporal resolution that can be achieved. Pollen monitoring networks across the world are generally sparse and are not able to fully represent the detailed characteristics of airborne pollen. There are few studies that observe concentrations on a local scale, and even fewer that do so in ecologically rich rural areas and close to emitting sources. Better understanding of these would be relevant to occupational risk assessments for public health, as well as ecology, biodiversity, and climate. We present a study using low-cost optical particle counters (OPCs) and the application of machine learning models to monitor particulate matter and pollen within a mature oak forest in the UK. We characterise the observed oak pollen concentrations, first during an OPC colocation period (6 days) for calibration purposes, then for a period (36 days) when the OPCs were distributed on an observational tower at different heights through the canopy. We assess the efficacy and usefulness of this method and discuss directions for future development, including the requirements for training data. The results show promise, with the derived pollen concentrations following the expected diurnal trends and interactions with meteorological variables. Quercus pollen concentrations appeared greatest when measured at the canopy height of the forest (20-30 m). Quercus pollen concentrations were lowest at the greatest measurement height that is above the canopy (40 m), which is congruent with previous studies of background pollen in urban environments. The attenuation of pollen concentrations as sources are depleted is also observed across the season and at different heights, with some evidence that the pollen concentrations persist later at the lowest level beneath the canopy (10 m) where catkins mature latest in the season compared to higher catkins.

Association Between Clinical Remission of Infantile-Onset Allergic Rhinitis During the School-Age Period and the Type of Housing: A Longitudinal Population-Based Japanese Study

This study investigated the association between housing type and clinical remission of infantile-onset allergic rhinitis (AR) in 53,575 children born in 2001 in Japan. Infantile-onset AR was defined as the presence of AR symptoms reported between ages 1.5 and 4.5 years, and remission was assessed between ages 10 and 12. The type of housing was categorized into detached houses and multi-unit residential buildings with 1-2, 3-5, or ≥6 floors. Among the 4,352 infantile-onset AR, 42.9% experienced remission. Notably, living in multi-unit residential buildings, particularly those with 1-2 and ≥6 floors, was positively associated with AR remission.

Incidence of grass and weed sensitization in Bangkok, Thailand: a clinical study

Background

Allergic rhinitis (AR) is a prevalent public health concern globally, significantly impacting quality of life. In Thailand, the prevalence of AR is rising, with grass and weed pollen identified as primary outdoor triggers.

Objectives

This study aimed to (1) assess patterns of pollen sensitization in Thai AR patients and (2) investigate correlations between demographics/clinical data and SPT results.

Methods

A total of 121 individuals aged ≥18 years with clinically diagnosed AR were recruited. Skin prick testing (SPT) was performed using a panel of commonly encountered tropical grass and weed pollen extracts. SPT wheal sizes and clinical symptom scores were recorded. Correlations between SPT outcomes and symptom scores were analyzed.

Results

Among the participants, 104 (85.95%) exhibited positive SPT reactions to at least one pollen type. Nutsedge (76/121), para grass (57/121), and Bermuda grass (48/121) were the most frequently identified allergens. Hurricane grass elicited the strongest reaction, evidenced by the highest average wheal size (6.2 mm). Poly-sensitization was observed in 77 (63.6%) of the SPT-positive individuals, with most cases involving two different pollen extracts (35/77). Notably, AR severity positively correlated with both average wheal size and the number of positive SPT tests.

Conclusion

This study highlights nutsedge, para grass, and Bermuda grass as major allergenic pollen sources for Thai AR patients. Including nutsedge, hurricane grass, and careless weed in clinical SPT panels is recommended for improved diagnostic accuracy. Additionally, the positive correlation between AR severity and pollen reaction strength emphasizes the importance of implementing patient education and avoidance strategies.