Role of allergen sensitization in older adults

Profile of aeroallergen sensitizations in allergic patients living in southern Vietnam

Background

Climatic and geographical characteristics may alter the plant distribution and thereby the patterns of allergens.

Objective

To evaluate the profile of allergen sensitization in patients in southern Vietnam and its association with allergic diseases.

Methods

We collected data of 423 patients who visited the Unit of Allergy and Clinical Immunology, University Medical Center, Vietnam from 2014 to 2021, from their medical records. Patients underwent skin prick tests to the 12 most common aeroallergens. Clinical evaluation and diagnosis of allergic diseases was done in consert with their allergen sensitization status.

Results

Mites and cockroach were the most prevalent sensitizing allergens, with the sensitization prevalences as followed: Dermatophagoides farinae (Df) (59.8%), Dermatophagoides pteronyssinus (Dp) (50.4%), Blomica tropicalis (Bt) (49.6%), storage mites mix (10.4%), and cockroach (10.2%). Sensitization to Df was more predominant in males than in females (66% vs 54.1%). Dp-sensitized patients were younger than non-sensitized patients (29.01 ± 13.60 vs. 32.17 ± 14.89) whereas storage mites-sensitized patients were older than the non-sensitized groups (36.25 ± 13.53 vs. 28.76 ± 13.39) (p < 0.05 for all). A considerable proportion of patients with urticaria, allergic rhinitis, and atopic dermatitis were sensitized to mites. Polysensitization to different species of house dust mites (Dp, Df) and storage mites (Bt) was prevalent among patients sensitized to any kind of mites.

Conclusions

Among people living in southern Vietnam, HDM mites, and cockroach were the predominant allergens. Further studies on the factors regulating the association between allergen sensitization with allergic diseases and polysensitization are crucial.

Rhinitis Phenotypes

Rhinitis is an umbrella term of a group of upper airway diseases with nasal symptoms and signs with different etiologies and various clinical features or traits. It can be classified into different "phenotypes," based on these observable traits. A proper differential diagnosis is necessary to adequately manage the disease. The objective of this review is to clarify the concept of rhinitis phenotypes while analyzing the clinical features and/or traits of each in order to determine a proper differential diagnosis and appropriate treatment.

Retinol-binding protein-4 was associated with sensitization to inhalant allergens in the elderly population

BACKGROUND/AIMS

Recent evidence suggests an association between allergic sensitization and metabolic markers. However, this association has rarely been examined in the elderly. Retinol-binding protein-4 (RBP-4) is a recently identified adipokine that acts on the muscle and liver affecting insulin sensitivity. We evaluated the association between metabolic parameters and allergic sensitization in the elderly.

METHODS

We analysed the database of the Korean Longitudinal Study on Health and Aging cohort study conducted during 2005 to 2006. Atopy was identified by inhalant allergen skin prick test. Metabolic conditions were assessed using anthropometric indices and serum biomarkers such as fasting glucose, lipid, adiponectin, and RBP-4.

RESULTS

Among the 854 elderly subjects, 17.2% had atopy. Plasma RBP-4 levels were significantly higher in the atopic elderly than nonatopic elderly (p = 0.003). When RBP-4 percentiles were categorized as under three groups, the prevalence of atopy and current rhinitis increased significantly with percentiles of RBP-4 levels (p = 0.019 and p = 0.007, respectively). Log RBP-4 was associated with atopy (odds ratio [OR], 4.10; p = 0.009) and current rhinitis (OR, 2.73; p = 0.014), but not with current asthma (OR, 1.17; p = 0.824). Higher RBP-4 level in atopic elderly was also observed in current rhinitis patients. Atopy, but not current rhinitis, showed significant relationships with log RBP-4 levels in multivariate analyses adjusted for other metabolic markers including body mass index.

CONCLUSION

RBP-4 positively associated with atopy in the general elderly population irrespective of other metabolic markers.

A cross-sectional observational study on allergen-specific IgE positivity in a southeast coastal versus a southwest inland region of China

Few studies addressed trans-regional differences in allergen sensitization between areas within a similar latitudinal range but with distinct geomorphological features. We investigated specific IgE (sIgE) positivity to common allergens in populations from two southern China provinces. Using a uniformed protocol, serum samples were collected from 2778 subjects with suspected atopy in coastal Guangdong and inland Yunnan. The overall prevalence of sIgE positivity were 57.8% (95% CI: 56.0%, 59.6%) from Guangdong vs 60.9% (95% CI: 59.1%, 62.7%) from Yunnan. House dust mite (d1) was the most common allergen in both regions. Among d1-sensitized subjects, only 35.7% (208/583) in Guangdong and 22.9% (147/642) in Yunnan tested positive for d1 alone. Among those poly-sensitized d1-positive subjects, cockroach was the most common co-sensitizing aeroallergen. 41.9% of the d1-sensitized Guangdong subjects showed high-class sIgE reactivity (≥class 4), in contrast to a very low percentage of such reactivity in Yunnan. However, 36.3% of d1-sensitized subjects in Yunnan were concomitantly positive for tree pollen mix. Surprisingly, Yunnan subjects showed high prevalence of sIgE positivity for crabs and shrimps, either by overall or by age-group analysis, compared with their Guangdong counterparts (both P < 0.05). These findings may add to data about local allergies in China and worldwide.

Allergy and Aging: An Old/New Emerging Health Issue

Allergy reactions are the most common immunological diseases and represent one of the most widespread and fast growing chronic human health problems among people over 15 years of age in developed countries. As populations get older worldwide, allergy manifestations in aged persons will occur more often in the future. To date, there has been much more studies on allergies in children than in adults. As the population ages, clinicians must be prepared to meet all the elderly's health care needs, including these new and emerging health issue. Allergic diseases represent an old/new emerging health issue. Because many common illnesses masquerade as atopic disease, the differential diagnosis of suspected allergic diseases becomes more expanded in an aging population. Research in the field needs to focus on both human and animal model systems to investigate the impact of the aging process on the immunologic pathways underpinning allergy and its different facets.

Challenges in the pharmacological treatment of geriatric asthma

Asthma in older populations is characterized by frequent comorbid conditions, which increase the risk of side effects and of detrimental interactions between respiratory and non-respiratory drugs. These observations lead to the need to manage asthma in older populations by applying a multidimensional assessment and a multidisciplinary treatment; therefore, we favor the use of the 'geriatric' term to define asthma in the elderly. Geriatric asthma is a complex disease, which may not necessarily imply that it is also complicated, although the two conditions may often coexist. On this basis, the switch from an organ-driven management to the holistic approach may be the key factor to attain optimal control of the disease in this age range. The current review discusses the age-related factors affecting asthma treatment in the oldest individuals, such as the comorbid conditions, and age-related changes of metabolism and excretion that can impair the efficacy and safety of drugs.

[Allergic asthma in central Tunisia]

L'asthme allergique pose un réel problème de santé publique vu sa prévalence et son coût de prise en charge élevés. Etudier le profil clinique, fonctionnel respiratoire, allergologique, thérapeutique et évolutif de l'asthme allergique dans une région du centre tunisien. Etude rétrospective portant sur 1132 dossiers de patients porteurs d'asthme allergique suivis dans le service de pneumologie et d'allergologie à l'hôpital de Monastir (Tunisie). L’âge moyen est de 27 ± 12,5 ans. 61,1% des patients sont âgés entre 16 et 39 ans. Une prédominance féminine est notée (56,7%). L'identification de l'allergène en cause s'est basée essentiellement sur les tests cutanés allergologiques (99,4%). Les principaux pneumallergènes identifiés sont les acariens (91,2%), suivis par les pollens (22,8%) et les phanères des animaux (12%). La classification selon la sévérité a conclu à un asthme intermittent à persistant léger chez 87.1% de nos patients. Le traitement s'est basé essentiellement sur la corticothérapie inhalée (67,6%). L'asthme dans notre étude a été jugé contrôlé dans 68,3% des cas, partiellement contrôlé dans 24,8% et non contrôlé dans 6,9% des cas. L'asthme allergique est une affection répandue qui touche essentiellement le sujet jeune en pleine activité. Une prise en charge adéquate permet de contrôler la maladie et de réduire ses répercussions sur le patient et la collectivité.

Advances in the diagnosis and management of asthma in older adults

Global estimates on aging predict an increased burden of asthma in the older population. Consequently, its recognition, diagnosis, and management in clinical practice require optimization. This review aims to provide an update for clinicians, highlighting advances in the understanding of the aging process and immunosenescence together with their applicability to asthma from a diagnostic and therapeutic perspective. Aging impacts airway responses and immune function, and influences efficacy of emerging phenotype-specific therapies when applied to the elderly patient. Differentiating eosinophilic and neutrophilic disease accounts for atopic illness and distinguishes long-standing from late-onset asthma. Therapeutic challenges in drug delivery, treatment adherence, and side-effect profiles persist in the older patient, while novel recording devices developed to aid detection of an adequate inhalation evaluate treatment effectiveness and compliance more accurately than previously attainable. Anticytokine therapies improve control of brittle asthma, while bronchial thermoplasty is an option in refractory cases. Multidimensional intervention strategies prove best in the management of asthma in the older adult, which remains a condition that is not rare but rarely diagnosed in this patient population.

A distinct sensitization pattern associated with asthma and the thymic stromal lymphopoietin (TSLP) genotype

BACKGROUND

Atopy is a phenotypically heterogeneous condition, and the extent to which atopy accounts for asthma is controversial. In this study, we aimed to identify the presence of distinct sensitization patterns to common inhaled allergens and their association with asthma, allergic rhinitis and TSLP genotypes.

METHODS

We studied 1683 adults from Tsukuba, a city in central Japan and 297 adults from Kamishihoro, a cedar-free, birch-dominant town in northern Japan. Levels of total serum IgE and specific IgE antibodies towards 14 major inhaled allergens were measured. With the use of these measures, cluster analysis was applied to classify the subjects' sensitization patterns. We also examined the genetic effects of 2 TSLP functional SNPs on the development of each sensitization pattern.

RESULTS

In the Tsukuba study, cluster analysis identified four clusters, including "Dust mite dominant", "Multiple pollen", "Cedar dominant", and "Low reactivity". In the Kamishihoro study, "Dust mite dominant", "Multiple pollen" and "Low reactivity" clusters were also identified, but a "Cedar dominant" cluster was not formed. The association with asthma was strongest for the "Dust mite dominant" cluster in both the Tsukuba and the Kamishihoro studies. In never smokers, both SNPs were associated with the "Dust mite dominant" cluster (OR > 1.2). In contrast, in current or past smokers, these alleles were inversely associated with the "Multiple pollen" cluster (OR < 0.5).

CONCLUSIONS

Cluster analysis identified the presence of distinct sensitization patterns to common inhaled allergens. TSLP may cause asthma by promoting innate allergic responses to indoor allergens and this contribution is significantly modified by smoking.