Fernando Lourenço Pereira

Mite and cat allergen exposure in Brazilian public transport vehicles

BACKGROUND Mites and pets are important sources of indoor allergens. OBJECTIVES To determine Dermatophagoides pteronyssinus (Der p 1), Dermatophagoides farinae (Der f 1), and Felis domesticus (Fel d 1) allergen levels in buses and taxis and to evaluate the predominant allergen in each vehicle type. METHODS Mite and cat allergens were measured using enzyme-linked immunosorbent assay in dust samples collected from upholstered seats in 60 natural-ventilation buses (NVBs), 60 artificial-ventilation buses (AVBs), and 60 taxis. Thirty dust samples from AVB air-conditioning filters were also included. RESULTS Levels of Der p 1 and Der f 1 were significantly higher in AVBs than in NVBs, whereas Fel d 1 levels were not significantly different between bus types. No significant differences were found in mite allergen levels in various sites in both types of buses, whereas Fel d 1 levels were significantly higher in rear and middle seats than in front seats in NVBs. Mite and cat allergen levels in taxis were significantly higher in passengers rear seats than in drivers seats. A high proportion of dust samples from the vehicles, especially AVBs (82% for Der p 1 and 58% for Der f 1) had sensitizing levels of mite allergens, whereas more than 60% of samples from all vehicles had sensitizing levels of Fel d 1 allergen. In AVBs, samples from seats showed significantly higher levels of mite and cat allergens than those from air-conditioning filters. CONCLUSIONS Public transport vehicles constitute an important allergen reservoir for continuous contamination of the indoor environment.

Modulation of mucosal/systemic antibody response after sublingual immunotherapy in mite-allergic children

There have been no data on sublingual immunotherapy (SLIT) in Brazilian patients sensitized to house dust mites. This study aimed to evaluate the mucosal/systemic antibody response changes and clinical efficacy after SLIT using Dermatophagoides pteronyssinus (Dpt) allergens with or without bacterial extracts in mite‐allergic Brazilian children.

Mite and pet allergen exposure in Brazilian private cars.

BACKGROUND The role of mite and pet allergens in the development of allergic diseases has been recognized for many years. OBJECTIVE To determine mite (Dermatophagoides pteronyssinus [Der p 1] and Dermatophagoidesfarinae [Der f 1]), cat (Felis domesticus [Fel d 1]), and dog (Canis familiaris [Can f 1]) allergen levels in Brazilian private cars. METHODS Mite, cat, and dog allergens were measured in dust samples collected from 60 upholstered seats of private vehicles using enzyme-linked immunosorbent assays. RESULTS Mean levels of Der p 1 (0.24 microg/g of dust; range, 0.06-2.05 microg/g of dust) and Der f 1 (0.29 microg/g of dust; range, 0.06-2.07 microg/g of dust) were extremely low in most dust samples analyzed. In contrast, sensitizing mean levels of Can f 1 (1.51 microg/g of dust; range, 0.14-30.96 microg/g of dust) and Fel d 1 (0.43 microg/g of dust; range, 0.02-5.75 microg/g of dust) were observed in 32 (53%) and 12 (20%) samples, respectively. Mean Can f 1 levels were significantly higher in cars whose owners kept dogs at home (3.27 microg/g of dust) than in those without pets (0.57 microg/g of dust; P = .008). There were no significant differences in allergen levels regarding the age of the vehicle or the number of users and whether the owners transport pets inside the vehicles. CONCLUSIONS Private cars constitute an important pet, but not mite, allergen reservoir for continuous contamination of the indoor environment. Pet allergens may be present even in cars whose owners do not have pets. Effective measures to reduce allergen exposure in cars should be taken routinely, especially for pet-allergic patients.

Diversity of allergen exposure: implications for the efficacy of environmental control

UNLABELLED The prevalence of allergic diseases such as asthma, rhinitis, allergic conjunctivitis and atopic dermatitis has increased in the last decades. The relationship between allergen exposure, atopic sensitization and development of allergic diseases is widely described in the literature. AIM To evaluate measures for reducing allergen exposure as part of the treatment of allergic diseases. METHODS An analysis was made of previous studies on allergen exposure done with a similar methodology in the central region of Brazil; the study included homes, hotels, cinemas, cars, taxis, buses and scholar transportation. RESULTS High levels of Der p 1 and Der f 1 mite allergens were found in a large proportion of the sample in most of the environments included in those studies; there were higher levels of pet allergens in cars and school transportation vehicles. CONCLUSION The diversity of allergen exposure demonstrates the need for education about allergic diseases for patients and their families, as well as measures of reducing allergens in homes. This should be part of a global strategy of the management of allergic diseases, given that individuals live in society, not only in their houses.

Diversidade da exposição alergênica: implicações na obtenção da eficácia do controle ambiental

The prevalence of allergic diseases such as asthma, rhinitis, allergic conjunctivitis and atopic dermatitis has increased in the last decades. The relationship between allergen exposure, atopic sensitization and development of allergic diseases is widely described in the literature. AIM: To evaluate measures for reducing allergen exposure as part of the treatment of allergic diseases. METHODS: An analysis was made of previous studies on allergen exposure done with a similar methodology in the central region of Brazil; the study included homes, hotels, cinemas, cars, taxis, buses and scholar transportation. RESULTS: High levels of Der p 1 and Der f 1 mite allergens were found in a large proportion of the sample in most of the environments included in those studies; there were higher levels of pet allergens in cars and school transportation vehicles. CONCLUSION: The diversity of allergen exposure demonstrates the need for education about allergic diseases for patients and their families, as well as measures of reducing allergens in homes. This should be part of a global strategy of the management of allergic diseases, given that individuals live in society, not only in their houses.

201 Clinical Efficacy and Mucosal/Systemic Antibody Response Changes After Sublingual Immunotherapy in Mite-Allergic Children: A Randomized Double-Blind, Placebo-Controlled Study in Brazil.

Background This study aimed to evaluate the clinical efficacy and mucosal/systemic antibody response changes after sublingual immunotherapy (SLIT) using Dermatophagoides pteronyssinus (Dpt) allergens with or without bacterial extracts in mite-allergic Brazilian children. Methods One-hundred and 2 patients presenting allergic rhinitis with or without asthma were selected for a randomized double-blind, placebo-controlled trial and distributed into 3 groups: DPT (Dpt allergen extract, n = 34), DPT + MRB (Dpt allergen plus mixed respiratory bacterial extracts, n = 36), and Placebo (n = 32). Clinical evaluation and immunological analyses were carried out before and after 12 and 18 months of treatment, including rhinitis/asthma symptom and medication scores, skin prick test (SPT) to Dpt extract, and measurements of Dpt-, Der p 1-, Der p 2-specific IgE, IgG4, and IgG1 in serum and -specific IgA in saliva and nasal lavage fluid. Results Clinical results showed a significant decline in rhinitis/asthma symptom scores in all groups, but medication use decreased only in active DPT group at 12 months. SPT results showed no significant changes and SLIT was generally safe, with no severe systemic reactions. SLIT using Dpt allergen alone induced increased serum IgG4 levels to Dpt, Der p 1 and Der p 2, and increased serum IgG1 and salivary IgA levels to Dpt and Der p 1. SLIT using DPT+MRB was able to decrease IgE levels, particularly to Der p 2, to increase salivary IgA levels to Der p 1, but had no changes on specific IgG4 and IgG1 levels. Conclusions Therefore, SLIT seems to be effective in ameliorating clinical symptoms, but only active SLIT was able to modulate the mucosal and systemic antibody responses. These findings support the role of specific serum IgG4 and IgG1, in addition to salivary IgA, as protective or blocking antibodies as well as biomarkers of tolerance that may be useful for monitoring activation of tolerance-inducing mechanisms during allergen immunotherapy.