Ethnicity influences disease characteristics and symptom severity in allergic rhinitis patients in Malaysia: Ethnicity in severity of allergic rhinitis

Frequent IgE recognition of Blomia tropicalis allergen molecules in asthmatic children and young adults in equatorial Africa

Background

Asthma is not well investigated in equatorial Africa and little is known about the disease-associated allergen molecules recognized by IgE from patients in this area. The aim was to study the molecular IgE sensitization profile of asthmatic children and young adults in a semi-rural area (Lambaréné) of an equatorial African country (Gabon), to identify the most important allergen molecules associated with allergic asthma in equatorial Africa.

Methods

Fifty-nine asthmatic patients, mainly children and few young adults, were studied by skin prick testing to Dermatophagoides pteronyssinus (Der p), D. farinae (Der f), cat, dog, cockroach, grass, Alternaria and peanut. Sera were obtained from a subset of 35 patients, 32 with positive and 3 with negative skin reaction to Der p and tested for IgE reactivity to 176 allergen molecules from different allergen sources by ImmunoCAP ISAC microarray technology and to seven recombinant Blomia tropicalis (Blo t) allergens by IgE dot blot assay.

Results

Thirty-three of the 59 patients (56%) were sensitized to Der p and 23 of them (39%) were also sensitized to other allergen sources, whereas 9 patients (15%) were only sensitized to allergen sources other than Der p. IgE serology analyses (n=35) showed high IgE-binding frequencies to the Blo t allergens Blo t 5 (43%), Blo t 21 (43%) and Blo t 2 (40%), whereas the Der p allergens rDer p 2, rDer p 21 and rDer p 5 (34%, 29% and 26%) were less frequently recognized. Only few patients showed IgE reactivity to allergens from other allergen sources, except to allergens containing carbohydrate determinants (CCDs) or to wasp venom allergens (i.e., antigen 5).

Conclusion

Our results thus demonstrate that IgE sensitization to mite allergens is very prevalent in asthmatics in Equatorial Africa with B. tropicalis allergen molecules representing the most important ones associated with allergic asthma.

The Trend of the Burden of Allergic Rhinitis Pre- and Post-COVID-19 Pandemic in the Urban Population of Perak, Malaysia

Aims

This study aims to determine the trend of allergic rhinitis (AR) prevalence in a tertiary hospital between 2017 and 2022, and to compare its prevalence pre- and post-COVID-19 pandemic.

Methods

This was a cross-sectional study involving the extraction of all Malaysian patients' medical records who were diagnosed with AR and attended the otorhinolaryngology outpatient clinic of a government-funded tertiary hospital in Malaysia between 2017 and 2022.

Results

3,744 cases out of the 57,968 first-encounter outpatient visits to the otorhinolaryngology clinic were extracted for analysis. Overall, the prevalence of AR cases ranged from 1.83 to 9.23% between 2017 and 2022. There was a significant drop of 21.38 to 70.22% between the pre- and post-COVID-19 pandemic (p < 0.001). Males (0.34 to 1.60%) were more prevalent in the 6 to 18 year old than females (0.09 to 1.23%). The trend shifted with age, whereby females (0.50 to 2.45%) experienced a higher prevalence than males (0.21 to 1.77%) as they aged from 19 to 59. The Malay (1.01 to 4.59%) demonstrated a two-time higher prevalence than the Chinese (0.30 to 2.01%) and Indian (0.40 to 2.14%) ethnicities. After stratifying by gender and ethnicity, Indian women (0.17 to 1.09%) had a higher rate of AR than their Chinese counterparts (0.12 to 0.99%) across all years.

Conclusion

The AR prevalence consistently ranged from 8.14 to 9.23% pre-pandemic. A remarkable drop was observed post-pandemic, ranging from 1.83 to 6.40%. A gender shift from male to female predominance as age progressed. The Malay had the highest prevalence of AR.

House dust mite allergy: The importance of house dust mite allergens for diagnosis and immunotherapy

House dust mite (HDM) allergy belongs to the most important allergies and affects approximately 65-130 million people worldwide. Additionally, untreated HDM allergy may lead to the development of severe disease manifestations such as atopic dermatitis or asthma. Diagnosis and immunotherapy of HDM allergic patients are well established but are often hampered by the use of mite extracts that are of bad quality and lack important allergens. The use of individual allergens seems to be a promising alternative to natural allergen extracts, since they represent well-defined components that can easily be produced and quantified. However, a thorough characterization of the individual allergens is required to determine their clinical relevance and to identify those allergens that are required for correct diagnosis of HDM allergy and for successful immunotherapy. This review gives an update on the individual HDM allergens and their benefits for diagnosis and immunotherapy of HDM allergic patients.

Malaysian Society of Allergy and Immunology Consensus Statement on Sublingual Immunotherapy in Allergic Rhinitis

Allergic rhinitis (AR) is an IgE-mediated inflammatory disease of the upper airway. AR affects the patients' quality of life, is a known risk factor for asthma and a socio-economic burden. Allergen-specific immunotherapy (AIT), comprising sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT), involves administering increasing doses of the causative allergen to induce clinical and immunologic tolerance to the allergens. It is the only currently available treatment for AR that has been proven to induce disease-modifying effects (i.e., long-term remission of allergic symptoms or potential prevention of asthma and new sensitizations). Although AIT is conventionally recommended for patients who are non-responsive to symptom-relieving pharmacotherapy, it is presently recommended as a first-line treatment for patients with moderate to severe AR who prefer a treatment with the potential for long-term remission. In light of the relatively recent implementation of AIT in Malaysia, guidelines on its appropriate indication and application are important to attain optimal outcomes. This consensus statement was developed by an expert group formed by the Malaysian Society of Allergy and Immunology to provide evidence-based recommendations for the practice of AIT in Malaysia. Patient and product selection, choice of AIT, and strategy towards an effective treatment outcome in AIT are presented.

Prevalence, causes and treatments of allergic rhinitis in Malaysia: a literature review

Recently, allergic rhinitis (AR) cases have been surging rapidly in many developing countries. However, the prevalence, risk factors and treatment modalities for AR within the Malaysian population have not been thoroughly evaluated. The present study aimed to provide a complete review of literature on allergic rhinitis in Malaysia. Available data indicated that the prevalence of AR varied across different age groups and regions in Malaysia, but there is an increasing trend among the younger population. The key contributing factor is exposure and sensitization towards several airborne allergens, mainly house dust mites, cat fur and fungi, with possible genetic predispositions. In addition, variations in the symptom severity may be associated with racial orientations. For management of the disease, standard prescriptions of conventional drugs (antihistamines, intranasal corticosteroids and nasal decongestants) remain as the treatment of choice. A small proportion of the native residents tend to resort to alternative approaches of self-healing through aromatherapy and natural food consumption such as tiger’s milk mushroom and Tualang honey. In conclusion, the increase in the cases of AR in Malaysia is due to environmental and genetic factors which requires proper medical intervention as treatment strategies. The utilization of holistic approaches requires further studies and clear understanding prior to their integration into the standard of care. There are still many gaps in the knowledge and management of allergic rhinitis which demands further attention from the research community.

Characteristics of allergen profile, sensitization patterns and Allergic Rhinitis in SouthEast Asia

PURPOSE OF REVIEW

To highlight the characteristics of allergic rhinitis, local allergic rhinitis (LAR), and importance of allergens in Southeast Asian countries.

RECENT FINDINGS

The Asia-Pacific region is very diverse with disparities in the epidemiological data between countries as well as in the unmet needs. The prevalence of allergic rhinitis has markedly increased in the past decades, with a high variation between countries, ranging from 4.5--80.3%. In terms of LAR, the reported prevalence in Southeast Asia is similar to that of other Asian countries (3.7-24.9%) but lower than that in western countries. House dust mites, cockroach, pollens, and molds are major allergens that are known triggers for of allergic rhinitis in this region, whereas the association with helminth infection requires further investigation.

SUMMARY

There are gaps and high variation between countries in Southeast Asia regarding the prevalence of allergic rhinitis and LAR. Further studies are needed to fully elucidate the association between allergens and allergic rhinitis in Southeast Asia.

Effect of multi-ethnicity and ancestry on prevalence of allergic disease

BACKGROUND/PURPOSE

Differences exist among racial and ethnic groups in the prevalence and severity of allergic diseases. However, influence of population admixing on allergic disease has not been studied. We examined the effect of population admixing on the occurrence of allergic disease.

METHODS

We reviewed the data of 68,043 adolescents who participated in the 11th Korea Youth Risk Behavior Web-based Survey, which provides a sample that is representative of the entire Korean middle school and high school student population. Multi-ethnic status was determined by using parental country of birth and prevalence of asthma, allergic rhinitis (AR), and atopic dermatitis (AD) was determined by questionnaire.

RESULTS

Multi-ethnic adolescents accounted for approximately 0.9% of the total adolescents. Prevalence of asthma was significantly higher in multi-ethnic group than non multi-ethnic group while that of AR and AD was significantly higher in non multi-ethnic group than multi-ethnic group. Parental region of country at birth showed a significant difference in prevalence of allergic disease. Univariate analysis found that urbanity, perceived economic status (PES), parental region of country at birth, and environmental tobacco smoke (ETS) showed a significant odds ratio (OR) in asthma, AR, and AD. Body mass index (BMI) showed a significant OR in asthma and AD. After adjusting for urbanity, PES, BMI and ETS, multiethnicity showed significantly lower OR in AR and AD.

CONCLUSION

Population admixing appears to have significant effect on the prevalence of allergic disease. Further study will be needed to clarify the effect of population admixing on prevalence of allergic disease.

Early Intervention Improves Clinical Responses to House Dust Mite Immunotherapy in Allergic Rhinitis Patients

BACKGROUND

Allergen immunotherapy (AIT) is the unique causal treatment for respiratory allergy. As AIT is expensive and of long duration, the availability of a marker predicting AIT responders is of crucial relevance.

OBJECTIVE

To investigate clinical parameters correlated with effective AIT in allergic rhinitis (AR) patients.

METHODS

This is a prospective, nonrandomized open study in which a total of 284 AR patients who had received house dust mite (HDM) subcutaneous AIT were enrolled from January 2011 to December 2015, and then followed up for 3 consecutive years. Demographic data, clinical history, laboratory tests (specific and total IgE levels), symptoms score, concomitant medication, and adverse reactions during AIT were collected. An AIT responder patient was defined when a visual analog score (assessing global symptoms) had decreased by >30% compared to baseline and concomitant medication was equal to or less than before AIT.

RESULTS

Thirty-three patients dropped out, so 251 patients were analyzed; 175 (69.7%) patients were responders. This group had a higher baseline symptom score than the AIT nonresponder group (7.5 vs. 6.9). A significant negative correlation was found between AR symptom duration and the clinical response to AIT. Local reactions (LRs) during AIT had a positive correlation. Other variables such as a family history of atopy, combined asthma history, and the levels of specific and total IgE had no correlations with effective AIT.

CONCLUSION

Early intervention with AIT helps to improve the efficacy of AR treatment. LRs might predict successful AIT. Highly symptomatic AR patients may develop increased clinical responses to AIT.