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Notes: Carpet and floor dust samples were collected in four different seasons, from 39 Swedish homes of babies with a family history of allergy. House-dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen contents were determined by mab ELISA, and the levels were related to various environmental factors. Both mite and cat antigens were detected in 94% of the samples and in all homes, but the levels were low (Der p 1, range 15 ng–1944 ng/g fine dust; Der f 1, range 14 ng–264 ng/g of fine dust; Fel d 1, range 16 ng–3120 ng/g fine dust). Mite-allergen levels were significantly higher (P〈0.001) in floor dust than in carpets, and D. pteronyssinus predominated. In contrast, the levels of cat antigen were significantly (P〈0.05) higher in carpets than in floor dust. There was no clear relation between mite-allergen levels and type of house, except that the higher values were found in homes with dampness problems. Cat-allergen levels were higher than total mite-allergen content, and the highest levels were found in homes with a cat (P〈0.05). Rather high concentrations of cat allergen were also found in homes without a cat, which may explain why cat sensitization is so common in Sweden. As the prevalence of house-dust mite sensitivity is increasing in Swedish children, and as the individual patient threshold for eliciting symptoms varies, we suggest that sensitization may possibly occur at a lower exposure level than generally accepted as risk level for sensitization (2 μg/g dust).

Notes: The aim of this study was to evaluate the effect of levocabastine, a new H1-blocking antihistamine for topical use, in comparison with sodium cromoglycate on conjunctival symptoms of birch pollinosis. The two drugs were compared in a randomized double-blind comparative study over 5 weeks in 37 children and adolescents (6–19 years of age) with birch pollen conjuncitivitis. Nasal symptoms occurred in 31 of the children and were treated with beclomethasone dipropionate nasal spray. An oral antihistamine was offered as rescue medication for eye symptoms. Initially, the patients received placebo four times a day for a 7-day run-in period. Conjunctival symptoms were recorded daily on diary cards on a 100 mm visual analogue scale. The pollen counts indicated a short but intensive birch pollen season. There was no statistically significant difference between the two treatment groups with regard to eye symptom scores before and during active treatment. However, the patients' evaluation of the efficacy of the therapy was in favour of levocabastine (P 〈0.01). Topical levocabastine, an H1-blocker, applied twice daily, seems to protect from symptoms of allergic conjunctivities as favourably as sodium cromoglycate applied four times a day. There was no difference in number or character of reported adverse reactions between the two treatment groups.

Notes: The prevalence of allergic disease is low in Eastern Europe for reasons that are poorly understood. Our study aimed to investigate the levels of exposure to indoor allergens and living conditions among Estonian infants in relation to sensitization. Dust samples were collected during four winter months in 1993/94 from the homes of 197 infants participating in a prospective study of sensitization. Information about living conditions was collected through home visit and interviewing the mothers when the children were 6 weeks old. Three dust samples were collected from each home: i.e., from the infant's mattress, bedroom floor, and living-room carpet. The levels of allergens were determined by ELISA with monoclonal antibodies. The highest allergen level in a home was regarded as the peak value. The peak geometric mean values (±SD) of Der p 1 and Der f 1 were 0.3 (0.07–1.4) μg/g dust, of Can 1, 0.86 (0.23–3.12) μg/g dust, and of Fel d 1, 0.1 (0.01–0.9) μg/g dust. In 12 homes (9%), the peak value of house-dust mite (HDM) allergens exceeded 2 μg/g dust, with Der p 1 as the dominating allergen. Multivariate analyses indicated that high levels of HDM allergens were more common in apartments that were on the ground floor or first floor, that were heated with stoves, and/or that had a dampness problem. The mean allergen levels at home were similar in children sensitized to HDM (n = 17. 0.29 v.s 0.3 μg/g dust), dog (n=5, 0.55 vs 1.06 μg/g dust, and cat (n= 18, 0.21 vs 0.09 μg/g dust) and in children who were not sensitized to these allergens. Most of the sensitized children were exposed to relatively low allergen levels at home; i.e., below 1 μg/g dust. This level was exceeded in the homes of 4/17 mite-, 5/18 cat-, and 0/5 dog-sensitized children. The similar levels of the major indoor allergens in Estonia and in Scandinavia indicate that the large differences in atopy prevalence among children and young adults in the two regions are not due to differences in allergen exposure. No allergen threshold level for sensitization was identified.

Notes: Björkstén B. Epidemiology of pollution-induced airway disease in Scandinavia and Eastern Europe.Several potential environmental factors, particularly air pollutants, have been implicated as causal factors for the increased prevalence of allergic disease in western industrialized countries. However, even when combined, these factors can only partly explain the increase. Differences in prevalence of allergy are apparent between urban and rural areas of industrialized countries, with positive skin prick tests being more common in children living in urban regions. However, the prevalence of atopy is lower in children in central and Eastern Europe, where air pollution poses a major problem, than in Western Europe. Indeed, preliminary data from the International Study of Asthma and Allergy in Children (ISAAC) confirm that the prevalence of childhood atopy is lower in Eastern Europe than in Scandinavia. Although air pollution is undoubtedly associated with the development of allergic disease, other factors connected with western lifestyle, such as changes in diet and living conditions, may play an important role and provide a possible explanation for the higher prevalence of allergic disease in western industrialized countries.

Notes: Polymorphonuclear leucocyte (PMN) function was studied in pregnant women and related to the serum concentration of pregnancy zone protein (PZP) and to mixed lymphocyte culture (MLC) reactivity. Neutrophil chemotaxis was depressed in pregnant women. Pregnancy serum inhibited the MLC-reaction. The serum levels of PZP were inversely related to chemotactic responsiveness (P〈0.05) and depression of MLC reactivity (P〈0.01). The capacity to reduce nitroblue tetrazolium was depressed in PMNs from pregnant women, and pregnancy scrum inhibited phagocytosis of Escherichia colt by control PMNs. Neutrophils from pregnant women showed increased chemiluminescence during phagocytosis of zymosan. The results may be explained by depression of ingestion by pregnancy serum and increased oxidative metabolism in PMNs from pregnant women.

Notes: The possible protective effect of breast milk against atopic manifestations in infancy, i.e. atopic eczema and food allergy, has been controversial for the last decades. Besides the methodological problems, differences in the composition of human milk could explain these controversies. The aim of this study was to investigate the composition of polyunsaturated fatty acids (PUFA) and secretory immunoglobulin A (S-IgA) levels to food proteins (ovalbumin and β-lactoglobulin) and an inhalant allergen (cat) in milk from mothers of allergic and non-allergic children. Blood samples were obtained at birth and at 3 months from 120 children. Skin prick tests were performed at 6, 12 and 18 months, and the development of atopic diseases was assessed in the children. Breast milk samples were collected from their mothers at birth and monthly during the lactation period. Milk PUFA composition was measured by gas chromatography, and enzyme-linked immunosorbent assay (ELISA) was used to measure total S-IgA, anti-cat S-IgA, anti-ovalbumin S-IgA, and anti-β-lactoglobulin S-IgA. Allergic disease developed in 44/120 children (22/63 children of allergic mothers and 22/57 children of non-allergic mothers). Lower levels of eicosapentaenoic acid, C20:5 n-3 (EPA), docosapentaenoic acid C22:5n-3 (DPA), and docosatetraenoic acid C22:4 n-6 (DHA) (p 〈 0.05 for all) were found in mature milk from mothers of allergic as compared to milk from mothers of non-allergic children. The total n-6 : total n-3 and the arachidonic acid, C20:4 n-6 (AA) : EPA ratios were significantly lower in transitional and mature milk from mothers of allergic children, as compared to milk from mothers of non-allergic children. The PUFA levels in serum of allergic and non-allergic children were largely similar, except for higher levels of C22:4 n-6 and C22:5 n-6 (p 〈 0.05 for both) and a higher AA : EPA ratio in serum phospholipids in the former group (p 〈 0.05). Changes in the levels of milk PUFA were reflected in changes in PUFA serum phospholipids, particularly for the n-6 PUFA. The AA : EPA ratio in maternal milk was related, however, to the AA : EPA only in serum from non-allergic children, while this was not the case in allergic children. The levels of total S-IgA, anti-cat S-IgA, anti-ovalbumin S-IgA, and anti-β-lactoglobulin S-IgA in milk from mothers of allergic, as compared to non-allergic, children were similar through the first 3 months of lactation. Low levels of n-3 PUFA in human milk, and particularly a high AA : EPA ratio in maternal milk and serum phospholipids in the infants, were related to the development of symptoms of allergic disease at 18 months of age. The milk PUFA composition influenced the composition of PUFA in serum phospholipids of the children. We also showed that the lower levels of colostral anti-ovalbumin S-IgA and lower total S-IgA in mature milk from atopic mothers did not influence the development of allergic disease in the children up to 18 months of age. The findings indicate that low α-linolenic acid, C18:3 n-3 (LNA) and n-3 long-chain polyunsaturated fatty acids (LCP) 20–22 carbon chains, but not the levels of S-IgA antibodies to allergens, are related to the development of atopy in children.

Notes: Immune responses to allergens in young children include both Th1- and Th2-like immunity, which may regulate the secretion of immunoglobulin (Ig) G subclass antibodies differently. The time, route and level of exposure to an allergen may be decisive with regard to whether sensitization or tolerance will ensue. To study this, we investigated the development of IgG subclass antibodies to food and inhalant allergens during childhood. The study group comprised a cohort of 96 children participating in a prospective study. IgG subclass antibodies to ovalbumin, Bet v 1 and cat dander were analyzed at birth, 6 and 18 months and 8 years by ELISA. IgG1 and IgG3 subclass antibodies to ovalbumin peaked at 18 months and then declined up to 8 years of age, whereas antibodies to the inhalant perennial allergen cat, but not the inhalant seasonal allergen birch, increased with age. Exposure to cat and birch tended to be associated with high antibody levels to those allergens, whereas antibody levels to ovalbumin were not related to exposure to egg. The presence of positive skin prick tests and circulating IgE antibodies correlated with high levels of IgG subclass antibody responses to the allergens. Atopic symptoms were associated with high levels of IgG subclass, particularly IgG4, antibodies to the allergens. The difference in antibody levels between atopic and non-atopic children was most marked at 6 months for ovalbumin. For the seasonal inhalant allergen birch, the difference was apparent from 18 months, whereas a difference in antibody levels to the perennial inhalant allergen cat was already present at 6 months. In conclusion, IgG subclass antibodies to food allergens peak in early infancy and are then down-regulated, whereas antibodies to the inhalant perennial allergen cat, but not the inhalant seasonal allergen birch, increase with age. Atopy is associated with high levels of IgG subclass, particularly IgG4, antibodies to allergens, supporting a deviation of the immune system towards Th2-like responses in atopic children.

Notes: The aim of this study was to assess the total IgE levels in the supernatants and cellular components of colostrum from atopic and nonatopic mothers. Immunoglobulin E protein was detected in 34/39 milk samples, with a median level of 0. 3 μg/1. In 13 mothers, IgE protein was also detected in the cellular fraction of colostrum, with a median level of 0. 13 μg/1. Of the total IgE content in breast milk, 5-12% was transported intracellularly. The total IgE antibody levels were similar in both milk supernatants and cells from atopic and nonatopic mothers. There was a strong relationship between total IgE antibody levels in serum and in breast milk (r= 1. 0, p〈0.001), suggesting that IgE antibodies were passively transported from blood into breast milk. The levels of total IgE in human milk are probably too low to have a significant effect on the regulation of the IgE antibody levels in the neonate.