Sensitization to Airborne Fungal Allergens Associates with Asthma and Allergic Rhinitis Presentation and Severity in the Singaporean/Malaysian Population

Fungal spores and conidia are the major components of total airspora in the tropical Asia environment, and their sensitization patterns are often associated with allergic diseases such as asthma, allergic rhinitis (AR), and atopic dermatitis. Hence, we recruited a cross-sectional cohort of 9223 Singapore/Malaysia Chinese adults and assessed their sensitization against Curvularia lunata allergen using the skin prick test approach. A subset of this cohort (n = 254) was also screened for specific Immunoglobulin E (sIgE) titers against a panel of 11 fungal allergens. We found significant association of Curvularia lunata sensitization with the risk of asthma (OR = 1.66, 95% CI: 1.17–2.33; p = 0.00391) and AR (OR = 1.69, 95% CI: 1.18–2.41; p = 0.00396). Among asthmatic patients (n = 1680), Curvularia lunata sensitization also increased frequencies of wheezing symptoms (OR = 1.81, 95% CI: 1.05–2.96; p = 0.0239), general practitioner/specialist visits (OR = 2.37, 95% CI: 1.13–4.61; p = 0.0157), and other asthma-related exacerbation events (OR = 2.14, 95% CI: 1.04–4.10; p = 0.0289). In our serum cohort, sensitization to Aspergillus spp. was the most common fungal sensitization, with 23.6% (n = 60) had a class 3 and above sensitization (positive sensitization; sIgE titers of > 3.5 kU/L) against this allergen. Increasing sIgE titer against Aspergillus spp. was also correlated with increased AR risk and AR-related symptoms. In conclusion, our findings emphasize an important role of fungal sensitization in the manifestations of asthma and AR in the Southeast Asian Chinese population.

Evaluation of the Role of Immunotherapy in Allergic Fungal Rhinosinusitis

Background: Allergic fungal rhinosinusitis (AFRS) is a distinct form of chronic rhinosinusitis. Type I hypersensitivity to inhaled fungal allergens has been implicated as key pathogenesis. Immunotherapy as one of the therapeutic options is still controversial. Objective: to evaluate the role of immunotherapy in the management of AFRS patients not responding to medical treatment 3 months following endoscopic surgery. Methodology: A total of 35 patients diagnosed as resistant AFRS were included in this prospective study. Patients were diagnosed following clinical, radiological, and endoscopic examination of nose and paranasal sinuses. Specimens were collected during endoscopy and subjected to microscopic examination and fungal culture. Skin prick test and assessment of total IgE level were performed for all patients. Sublingual immunotherapy (SLIT) was initiated for all patients for 6 months. Clinical efficacy of SLIT was assessed using the 20-item sino-nasal outcome test (SNOT-20) score. Results: Aspergillus spp. was the most frequent fungus isolated (74.3%) from patients. All patients were sensitized to mixed fungi. Elevated total IgE (> 100 IU/mL) was found in all patients with 40% of them had peripheral eosinophilia. A significant improvement (p < 0.001) was recorded in the SNOT-20 score of examined patients recording a mean of 1.2 ± 0.3, 6 months after SLIT compared to 1.93 ± 0.44 before immunotherapy initiation. Conclusion: Immunotherapy appears to be a good adjunctive therapy for the management of resistant cases of AFRS.

Initiation and Pathogenesis of Severe Asthma with Fungal Sensitization

Fungi represent one of the most diverse and abundant eukaryotes on earth, and their ubiquity and small proteolytically active products make them pervasive allergens that affect humans and other mammals. The immunologic parameters surrounding fungal allergies are still not fully elucidated despite their importance given that a large proportion of severe asthmatics are sensitized to fungal allergens. Herein, we explore fungal allergic asthma with emphasis on mouse models that recapitulate the characteristics of human disease, and the main leukocyte players in the pathogenesis of fungal allergies. The endogenous mycobiome may also contribute to fungal asthma, a phenomenon that we discuss only superficially, as much remains to be discovered.

Prevalence of Aspergillus fumigatus skin positivity in adults without an apparent/known atopic disease in Uganda

Background: Skin prick testing (SPT) is an important investigation in the evaluation of allergy to fungal pathogens. However, the background sensitivity to fungal allergens among healthy people in Uganda is unknown. Our aim was to assess the background prevalence of Aspergillus fumigatus SPT positivity in apparently healthy adults without known atopic disease in Uganda. Methods: For this pilot study, we recruited 50 healthy volunteers using convenience sampling, 56% of whom were health workers. We performed the SPT for A. fumigatus according to manufacturer’s instructions. A wheal diameter of ⩾3 mm was considered positive. Results: The prevalence of A. fumigatus skin positivity was 60% (30/50). Participants with a positive A. fumigatus SPT were significantly younger than those with a negative result [median age (years): 28 versus 35; p = 0.005]. Conclusion: There is a high skin positivity against A. fumigatus among non-atopic healthy Ugandan adults. There is an urgent need to establish a normal wheal cut-off value for this population. SPT alone may be an unreliable test for the diagnosis of A. fumigatus associated allergic syndromes. More studies are needed to define the prevalence of A. fumigatus skin positivity among non-atopic healthy population in Africa.

On the results of the aeropalinospore monitoring of urban air: some features of inside and inter-seasonal variability of lower fungi spores level

Public health risks associated with molds include sensitization, allergic symptoms, irritation and/or toxicity. Sensitization to fungal allergens often occurs in patients who are hypersensitive to other groups allergens, including plant pollen. Both plants and molds are characterized by active growth in warm seasons, in temperate latitudes from April to October, which determines the presence of pollen grains of plants and mold spores in the atmospheric air during this period. This determines the needs in monitoring activity aimed to biogenic pollutants evaluation in the air of large cities where many people live compactly. The report presents the monitoring results of Alternaria, Cladosporium and other lower fungi spores in the air of Samara city in 2015 - 2020. It has been established that for the air environment of Samara, lower fungi cannot be considered as the predominant source of allergens. The high concentration of fungal spores is most often caused by fungi of Alternaria genus, which leads to the development of sensitization in 27.7% of children and 14.6% of adults in the region. The results of aeropalinospore monitoring demonstrated the lesser significance of Cladosporium genus fungi as a risk factor, or an allergens source for Samara city (Middle Volga region).

ASSESSMENT OF AIRBORNE FUNGAL ALLERGENS: BIOCHEMICAL AND IMMUNOPROTEOMIC APPROACH : A REVIEW

Atmospheric air contains a wide variety of components like inorganic gaseous, particulate pollutants and biological particles such as fungal spores, pollen grains, dust mites and animal dander that can affect human health. Among biological particles, airborne fungal spores are an essential source of aeroallergens. In India, allergy prevalence has become a major health concern with symptoms ranging from mild rhinitis to severe asthma and even life threatening anaphylaxis. Aerobiological studies provide qualitative and quantitative information about fungal spores of a given region. The proper identification, purification and molecular characterization of fungal allergens are essential for proper diagnosis and to design immunotherapeutic vaccines. Only a few fungal allergens have been characterized by recombinant technology and structural biology. Detailed analysis of fungal biochemistry can be done by using multiple techonologies including Skin Prick Test (SPT), ELISA, immunonoblot, MALDI TOF, genome and transcriptome sequencing, recombinant technology and bioinformatics. The purpose of this review is to describe the different strategies that have been used to identify, purify and characterize the fungal allergens, which may enrich the database of allergy research and help in the implementation of immunotherapy in future.

Comparative aeropalynology of two communities in Lagos State, southwestern Nigeria

Pollen allergy is an abnormal response of the immune system to certain pollen grains and these reactions are gradually on the increase all around the world. The need for consistent and accurate data on aero-pollen density as well as the meteorological conditions under which they are prevalent is imperative for appropriate management of allergic conditions in hypersensitive persons. Therefore, to identify the ‘culprit’ pollen related to allergy cases in Lagos, two locations, Ipaja and Ikeja were sampled. Aero-samplers were harvested weekly from February 2016 to July 2016. Acetolysis was done on the samples collected and meteorological data from Nigerian Meteorological Agency and clinical data from Adefemi Medical Center, Ipaja were assessed against pollen counts. The total pollen count of 2,048 was recorded for Ipaja while Ikeja had 820 with main taxa of Amaranthaceae, Poaceae and Euphorbiaceae. Weekly pollen counts were highest in weeks 8 and 10(April) at Ipaja and Ikeja respectively and lowest in weeks 22 and 24(June) at Ipaja and Ikeja respectively. The pollen counts at Ipaja correlated positively with temperature and from the medical records, there was a positive correlation (p<0.05, r=0.166 and r=0.44) between pollen density at both locations with cold and catarrh. Fungal allergens could have caused the spike in pollinosis in the wetter weeks (12 -19). The quality of the clinical data could also be a suspect which reinforces the need for more accurate and standard recording of clinical conditions across hospitals in Nigeria. This is the first record of weekly aerobiological data in Nigeria.

Aerobiology in South Africa: A new hope!

Pollen and fungal spores (aerospora) are the major atmospheric bioaerosols. Aerospora occurrence and concentration vary by geographical region and blossoming period, and with meteorological factors. Allergic respiratory diseases affect about 20 million South Africans, with pollen and fungal allergens amongst the leading triggers. Asthma triggered by aerospora can be life threatening; allergic rhinitis causes considerable morbidity and carries financial implications for individuals and health systems. Thus, knowledge about geographical variation, seasonal timing and intensity, as well as annual aerospora fluctuations in South Africa, where climate and vegetation are exceptionally diverse, is essential for effective diagnosis and treatment of allergies. Unfortunately, there is a lack of continuous aeropalynological data from South Africa. The longest annual monitoring exists for Cape Town (~20 years), with almost no data out of the Cape since the 1990s, and many parts of South Africa have never been monitored. In this brief review, we highlight the cross-disciplinary need for strengthened and expanded continuous aeropalynological study in South Africa, the history of efforts to date, and the introduction of the interdisciplinary South African Pollen Network (SAPNET). SAPNET was launched in seven major cities in August 2019 in order to monitor weekly variations of aerospora, and provide online data for allergy sufferers and health-care providers (www.pollencount.co.za) with the aim to establish regional pollen calendars.

Sensitization to fungal allergens in patients with respiratory allergy – accuracy in diagnostic process

Introduction. In Bulgaria, mold allergies are common, and sensitization to different fungal species is found in many patients with atopy.The objective of this study is to explore sensitization to the most widespread mold species in Bulgaria, and to determine the extent of sensitization to Alt a1, a major allergen of Alternaria alternata, by using component-resolved diagnosis.Materials and Methods. 21 patients (14 males and 7 females, age range 5-40 years), with respiratory allergy participated in the study. All patients are sensitized to mix of fungal allergens containing: Alternaria alternata, Aspergillus sp., Cladosporium herbarum, Penicillium notatum, proved by in vivo and in vitro methods. All patients underwent the ImmunoCAP test and were assessed for sIgE to individual fungal allergens: m1 Penicillium notatum, m2 Cladosporium herbarum, m3 Aspergillus fumigatus and m6 Alternaria alternata. The component-resolved diagnosis to Alt a1 was performed for 10 patients with increased sIgE to m6 Alternaria alternata.Results. All studied patients (100%) had elevated sIgE to Alternaria alternata. Eight (38%) patients were sensitized to Penicillium notatum. 11 (52%) and 10 (48%) patients were sensitized to Cladosporium herbarum and to Aspergillus fumigatus, respectively. Ten patients (48%) were monosensitized to Alternaria alternata. Nine (90%) patients with sensitization to Alternaria alternata demonstrated elevated levels of IgE to Alt a1.Conclusion. Alternaria alternata most often causes sensitization in patients with respiratory allergy. The component-resolved diagnosis using Alt a1 is a precision marker to prove species-specific sensitization to Alternaria alternata.

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD

IntroductionAllergic sensitisation to fungi such as Aspergillus are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear.MethodsPatients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome.ResultsHigh frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a “highly sensitised fungal predominant” subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD.ConclusionFungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in “sensitised” COPD.