Development and exacerbation of asthma have long been associated with exposure and sensitization to allergens. While exposure to respiratory allergens such as German cockroach, mouse, cat, and dust mite is thought to occur largely by inhalation, the best method to measure the exposure remains unclear. Similarly ambiguous are the ideal measurement and allergic or respiratory effects of exposure to fungi. As most people in the industrialized world, especially small children, spend the majority of their time indoors, the home environment is of prime importance. Previous researchers have shown that poor housing quality or maintenance lead to growth of fungi, increased pest populations, and higher concentrations of other allergens and irritants. These elevated levels in turn are associated with greater rates of sensitization and asthma in the occupants. This dissertation focused on exposure measurement, assessment of sensitization to common molds, and estimating the effects of neighborhood-level pest prevalence and housing quality on asthma symptoms. The study subjects and homes were part of either the Puerto Rican Asthma Study (PRAS), a longitudinal cohort study focused on identifying how multiple risk factors affected allergic sensitization and asthma development in U.S.-born Puerto Rican children with atopic mothers, or the Head Start Study (HSS), which examined allergen exposure and sensitization in young children of low-income families. From 199 of these New York City homes, settled dust, high-volume air, and nasal air sample measurements were simultaneously collected and analyzed for cockroach, mouse, dog, cat, rat, and mite allergens. Cockroach and mouse allergens were quantified from all three sample types while the other allergens were measured from air samples only. Ninety-three women from PRAS were tested for sensitization to six species of mold using the halogen immunoassay and four mold species using ImmunoCAP. The results were compared to previously quantified specific-IgE to other inhalant allergens as well as to self-reported allergy and asthma symptoms and demographic characteristics. Finally in a cross-sectional sample of 225 children from both study populations, the impacts of housing conditions and pests on current asthma at both the individual and neighborhood level were examined. Questionnaire data on demographics, housing factors, asthma symptoms, and health behaviors were evaluated with allergic sensitization and environmental sampling results for each child. They were also grouped and contrasted by neighborhood using United States Census neighborhood-level data on reported pest prevalence and housing quality. The effects of individual and neighborhood factors on current asthma symptoms were estimated using a generalized linear model. Allergen concentrations were generally highest in settled dust, followed by high-volumetric air, and then nasal air samples. Mouse allergen was most frequently detected in air samples, followed by dog, cat, and cockroach. No samples contained rat or any of three types of mite allergens above the detection limit. While all three measurements enhanced the exposure picture for mouse allergen, air samples rarely had detectable cockroach allergen despite being detected in settled dust. This led to the conclusion that settled dust sampling is still crucial when assessing a child's exposure to cockroach allergen but may be less important for buoyant mammalian allergens such as mouse. Nearly one-third of the 93 mothers were sensitized to one or more molds as determined by either assay. Being sensitized was positively associated with sensitization to tree, grass, or pigeon allergens but not to other inhalant allergens. Moreover there was no association seen between sensitization to the fungal species and asthma or allergy symptoms. Of note, however, interesting differences between the halogen immunoassay and ImmunoCAP were identified that merit additional investigation. For the 225 children, current asthma symptoms were positively associated with early respiratory infections, presence of environmental tobacco smoke, having higher concentrations of cockroach allergen in bed dust, a higher intensity sensitization level to one or more inhalant allergens, and current asthma in the mothers. After adjusting for individual-level factors (cockroach allergen in bed dust, environmental tobacco smoke, and study population), no effect of neighborhood-level characteristics could be associated with current asthma prevalence. The lack of effect was likely due to a combination of factors including: small sample size, self and other selection biases, and insufficient diversity across the study population and neighborhoods

Abstract not available

Immunoglobulin E (IgE) mediated allergy is a major and seemingly increasing health problem in the Western countries. The combined usage of databases of molecular and clinical information on allergens (allergenic proteins) as well as new experimental platforms capable of generating huge amounts of allergy-related data from a single blood test holds great potential to enhance our knowledge of this complex disease. To maximally benefit from this development, however, both novel and improved methods for computational analysis are urgently required. This thesis concerns two types of important and practical computational analyses of allergens: allergenicity/IgE-cross-reactivity risk assessment and characterization of IgE-reactivity patterns. Both directions rely on development and implementation of bioinformatics and statistical learning algorithms, which are applied to either amino acid sequence information of allergenic proteins or on quantified human blood serum levels of specific IgE-antibodies to allergen preparations (purified extracts of allergenic sources, such as e.g. peanut or birch). The main application for computational risk assessment of allergenicity is to prevent unintentional introduction of allergen-encoding transgenes in genetically modified (GM) food crops. Two separate classification procedures for potential protein allergenicity are introduced. Both protocols rely on multivariate classification algorithms that are educated to discriminate allergens from presumable non-allergens based on their amino acid sequence. Both classification procedures are thoroughly evaluated and the second protocol shows state-of-the-art performance in comparison to current top-ranked methods. Moreover, several pitfalls in performance estimation of classifiers are demonstrated and procedures to circumvent these are suggested. Visualization and characterization of IgE-reactivity patterns among allergen preparations are enabled by application of bioinformatics and statistical learning methods to a multivariate dataset holding recorded blood serum IgE-levels of over 1000 sensitized individuals, each measured to 89 allergen preparations. Moreover, a novel framework for divisive hierarchical clustering including graphical representation of the resulting output is introduced, which greatly simplifies analysis of the abovementioned dataset. Important IgE-reactivity relationships within several groups of allergen preparations are identified including well-known groups of clinically relevant cross-reactivities.

Background The prevalence of atopic disease among children in the formerly socialist countries in Europe, with a life style similar to that prevailing in Western Europe 30–40 years ago, is low, whereas there has been a pronounced increase in industrialized countries over the last decades. The environment during infancy influences the risk of developing allergy for many years, perhaps even for life. Objective To investigate the development of allergen-specific cytokine responses during the first 2 years of life in two geographically adjacent countries with marked differences in living conditions and incidence of atopic diseases, i.e. Estonia and Sweden. Methods The development of immune responses to food (β-lactoglobulin (BLG) and ovalbumin (OVA)) and inhalant (cat and birch) allergens was studied from birth up to the age of 2 years in 30 Estonian and 76 Swedish infants. Clinical investigation and skin prick tests were performed and blood samples were obtained at birth and at 3, 6, 12 and 24 months. Results The levels of IL-5, IL-10 and IL-13 secreted by peripheral blood mononuclear cells stimulated with BLG, OVA and cat allergen in Estonian and Swedish infants declined during the first 3 months of life. All cytokines then progressively increased in the Swedish infants, indicating the replacement of non-specifically responding immature cord blood T cells with specific T memory cells, which are primed postnatally. The resurgence of allergen-specific responses in the Estonian infants was less marked. These differences were particularly notable for birch-specific T cell responses, which correlated with development of atopic disease in the Swedish children. Conclusions The development of specific T cell memory to food and inhalant allergens during the first 2 years of life differs between infants living in Sweden and Estonia, and mirrors the disparate patterns of expression of allergic disease which subsequently develops in the respective populations.

This indoor environment study formed part of the South Durban Health Study (SDHS) that investigated the health effects of exposure to ambient air pollution. Homes of children from seven communities corresponding schools were recruited to participate. This study was designed to determine characteristics in the homes that are associated with higher or lower levels of allergens and fungal aerosols. Homes were inspected using a field tested walkthrough checklist to collect data on home characteristics associated to adverse health effects. The characteristics include dampness, visible mould, type of flooring, type of bedding, type of heating systems, and building type and age. Dust samples for allergen analysis were collected from the bedding and the floor of the sleep area used by the children. Air samples from all rooms in the house were collected on malt extract agar, the media used for identifying and quantifying airborne fungal aerosols. More than 70% of the homes were single units standing on their own, 20% were attached houses (flats or apartments) and the rest (10%) were informal houses. Construction material of the homes comprised of bricks (93%), wood (5%) and other material (2%) such as corrugated iron of which 94% were formally constructed. Dampness signs were observed in 51% of the homes and visible mould growth 13% of them. In all them, at least one characteristic that is hypothetically associated to elevated house dust mite allergens was found. Levels of mould (Asp f 1) allergen and house dust mite (Der p 1 and Der f 1) allergen were comparable to levels found in other parts of the world. Asp f 1 allergen levels ranged between 0.32-1.379g/g and Der p 1 and Der f 1 allergen levels ranged from undetectable to 49.61 and from undetectable to 39.319g/g of dust respectively. Some home characteristics from walkthrough checklist were associated with Asp f 1, Der p1 and Der f 1 allergen levels when simple regression analysis was performed. Asp f 1 was significantly associated with single family home [OR= 0.004 (95%CI 0.004–0.35)] and polyester filled pillows [OR= 0.07 (95%CI 0.01– 0.61)] in logistic regression models. Der p 1 allergen was associated with observed extent of roof dampness [OR= 0.33 (95%CI 0.13–0.81)]. Fungal aerosol mixture consisted of Cladosporium spp. as the predominant genus together with other genera such as Aspergillus, Penicillium and Fusarium were, to a lesser extent, identified in the samples from the homes. Mean concentration of total indoor fungal aerosol of indoor and outdoor were 1108 CFU/m3 and 1298 CFU/m3 respectively. Individual genera of fungi in the childrens sleep area had mean levels of 783 CFU/ m3, 30CFU/ m3, 64CFU/ m3, 48CFU/ m3 and 43 CFU m3 for Cladosporium spp., Aspergillus spp., Penicillium, spp., Fusarium spp. and Rhizopus spp. respectively. Simple regression showed some conditions in the homes to be predictors of higher levels of total fungal aerosols. In a linear regression models, total outdoor fungal levels were a protective effect on total indoor fungal levels [C= 0.542 (95%CI 0.437–0.647)] whilst homes with hard floors had about 25 CFU/m3 [C= 5.235 (95%CI 0.557–9.913)] in the homes were significantly associated. This study showed the need to adapt observational instrument/ checklist/ questionnaire to suit the environment or the study area of interest. As other studies and findings indicated, the best way to assess exposure to biological pollutants indoors needs a combination of two or more methods, i.e. direct and indirect methods. / Thesis (MMedSc-Occupational and Environmental Health)-University of KwaZulu-Natal, 2007.

Darbo tikslas – įvertinti dermatitu sergančių pacientų įsijautrinimą kontaktiniams alergenams ir su juo susijusius veiksnius. Darbo uždaviniai: 1. Nustatyti įsijautrinimo kontaktiniams alergenams dažnumą tarp dermatitu sergančių pacientų. 2. Įvertinti įsijautrinimo kontaktiniams alergenams dažnumo sąsajas su tiriamųjų amžiumi, lytimi ir profesija. 3. Nustatyti įsijautrinimo kontaktiniams alergenams klinikos ypatumus. 4. Įvertinti įsijautrinimo kontaktiniams alergenams sąsajas su atopiniu dermatitu, lėtine (-ėmis) kojos (-ų) opa (-omis) ir kitais veiksniais. Išvados: 1. Kontaktiniams alergenams įsijautrinę pusė dermatitu sergančių pacientų, dažniausiai – metalui nikeliui (17,1 proc.). Iš aromatinių medžiagų dažniausias yra įsijautrinimas Peru balzamui (8 proc.). Į pagrindinį alergenų rinkinį neįtrauktini retai (0,1 proc.) nustatyti alergenai: gumų medžiagos merkaptobenzotiazolas ir N-zopropil-N’-fenil-parafenilendiaminas. 2. Įsijautrinimas kontaktiniams alergenams jaunesniems nei 40 metų dermatitu sergantiems pacientams pasireiškia du kartus dažniau nei vyresniems, o moterims – du kartus dažniau nei vyrams. Žemės ūkio ir miškininkystės darbuotojai kontaktiniams alergenams įsijautrinę tris kartus dažniau nei kiti dirbantieji. Vertinant atskirus alergenus, jaunesni nei 40 metų pacientai dažniau nei vyresni yra įsijautrinę nikeliui, kobaltui ir kvaterniumui-15, o 40 metų ir vyresni – Peru balzamui, kanifolijai, aromatų mišiniui I, lanolinui, seskviterpenlaktonams ir... [toliau žr. visą tekstą] / The aim of the study: To evaluate contact sensitization and its associated factors in patients with dermatitis. The objectives of the study: 1. To determine the frequency of sensitization to contact allergens in patients with dermatitis. 2. To evaluate associations between the frequency of sensitization to contact allergens and age, sex and occupation in patients with dermatitis. 3. To determine clinical features of contact sensitization. 4. To evaluate associations between sensitization to contact allergens and atopic dermatitis, chronic leg ulcers and other factors. CONCLUSIONS 1.Half of the patients with dermatitis were sensitized to contact allergens, most frequently to metal nickel (17.1%). From the fragrances, bal¬sam of Peru was the most frequent contact allergen (8%). Rare allergens that should not be included in the baseline series are the substances present in the composition of rubber – mercaptobenzothiazole and N-isopropyl-N'-phenyl-p-phenylene diamine (IPPD). 2.Patients under 40 years of age are two times more frequently sensitized than the older ones. In women contact allergy is twice as more frequent as in men. Agricultural and forestry workers are sensitized to contact allergens three times as more often as other employees. What regards individual allergens, among patients under 40 years of age sensitization to nickel, cobalt and quaternium-15 is more prevalent than in the older ones. Among patients who are 40 years of age and over contact sensitization to... [to full text]

Diss. (sammanfattning) Stockholm : Univ. / Återtagen utgåva. Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 1999. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.