Merja Kajosaari

Breastfeeding as prophylaxis against atopic disease: prospective follow-up study until 17 years old

Atopic diseases constitute a common health problem. For infants at hereditary risk, prophylaxis of atopy has been sought in elimination diets and other preventive measures. We followed up healthy infants during their first year, and then at ages 1, 3, 5, 10, and 17 years to determine the effect on atopic disease of breastfeeding. Of the initial 236 infants, 150 completed the follow-up, which included history taking, physical examination, and laboratory tests for allergy. The subjects were divided into three groups: prolonged (> 6 months), intermediate (1-6 months), and short or no (< 1 month) breastfeeding. The prevalence of manifest atopy throughout follow-up was highest in the group who had little or no breastfeeding (p < 0.05, analysis of variance and covariance with repeated measures [ANOVA]). Prevalence of eczema at ages 1 and 3 years was lowest (p = 0.03, ANOVA) in the prolonged breastfeeding group, prevalence of food allergy was highest in the little or no groups (p = 0.02, ANOVA) at 1-3 years, and respiratory allergy was also most prevalent in the latter group (p = 0.01, ANOVA) having risen to 65% at 17 years of age. Prevalences in the prolonged, intermediate, and little or no groups at age 17 were 42 (95% CI 31-52)%, 36 (28-44)%, and 65 (56-74)% (p = 0.02, trend test) for atopy, respectively, and 8 (6-10)%, 23 (21-25)%, and 54 (52-56)% (p = 0.0001, trend test) for substantial atopy. We conclude that breastfeeding is prophylactic against atopic disease--including atopic eczema, food allergy, and respiratory allergy--throughout childhood and adolescence.

PROLONGED BREAST-FEEDING AS PROPHYLAXIS FOR ATOPIC DISEASE

54 babies who had been solely breast-fed for more than 6 months, 77 babies who had been breast-fed for 2--6 months, and 105 babies who had been weaned to cows-milk-based formulas at less than 2 months were followed for the first 3 years of life. All the babies had the same pattern of solid food intake until 1 year of age. Compared with formula feeding, prolonged breast-feeding resulted in a lower incidence of severe or obvious atopic disease particularly in babies with family history of atopy.

Prophylaxis of atopic disease by six months' total solid food elimination. Evaluation of 135 exclusively breast-fed infants of atopic families.

ABSTRACT. One hundred and thirty‐five infants of atopic parents were exclusively breast‐fed for 6 months without any cows milk based supplements. Of these infants 70 received no nourishment except breast milk during the 6 months, and 65 were started on solid foods at the age of 3 months. The diet of all the infants was similar during 6 to 12 months of age. The children were examined at the age of one year. In the exclusive breast milk group atopic eczema and food allergy were less frequent than in the solid food group. The results suggest that total solid food elimination for the first 6 months of life, in addition to exclusive breast milk feeding, is prophylactic for atopic disease in children who are at hereditary risk.

FOOD ALLERGY IN FINNISH CHILDREN AGED 1 TO 6 YEARS

ABSTRACT. Food allergy was studied in a total of 866 Finnish children aged 1, 2, 3 and 6 years in the Helsinki region. The diagnosis was based on history as well as on elimination and challenge performed at home concerning fish, citrus fruit and eggs. The prevalence of food allergy was 19% at one year of age, increased to a peak of 27% at three years, and thereafter decreased to 8% at six years of age. The most common allergenic foods were citrus fruit, tomato, eggs, strawberry and fish. A positive history of food allergy could be confirmed by challenge in about half of the cases in the younger age groups and in 100% at six years of age. The data indicate that food allergy is common in Finnish children.

Prevalence of allergic rhinitis and atopic dermatitis among children in four regions of Finland

The primary aim of the study was to evaluate the prevalences of allergic rhinitis and atopic dermatitis and their regional differences among Finnish children. The secondary objective was to determine whether the responses to the questions used are affected by the pollen season if asked during such a season. In 1994–5, the self‐reported prevalence of allergic symptoms in four regions of Finland was studied among 11607 schoolchildren aged 13–14 years, as part of the International Study of Asthma and Allergies in Childhood (ISAAC). The prevalence of rhinoconjunctivitis during the preceding year was 16% in eastern Finland (Kuopio County, n=2821), 23% in southern Finland (Helsinki area, n=2771), 15% in southwestern Finland (Turku and Pod County, n=2983), and 16% in northern Finland (Lapland, n=3032). The respective prevalences of flexural dermatitis were 15%, 19%, 16%, and 18%. The surveys were performed in winter, except in the Helsinki area where the survey was carried out mainly in the spring pollen season. Among the children studied in autumn in Helsinki, the prevalence of rhinoconjunctivitis was 19% and that of flexural dermatitis 17%. In multivariate analysis, flexural dermatitis was slightly more common in Lapland than in all other areas. In contrast, no significant differences were found in rhinoconjunctivitis. The prevalences of both disorders were twice as high in girls as in boys. In conclusion, regional differences in the prevalence of allergic rhinitis and atopic dermatitis were small in our country, and the prevalence figures were rather similar to those reported from other European countries. Almost half of the children had suffered from at least one atopic disorder, and over one‐third had had symptoms in the past year. A clear season‐of‐response effect was observed; the prevalence of rhinoconjunctivitis was 25% when studied during the pollen seasons in the Helsinki area.

Does dietary elimination in infancy prevent or only postpone a food allergy? A study of fish and citrus allergy in 375 children.

In a study of fish and citrus allergy these foods were strictly avoided in 177 children up to 1 year of age, whereas 152 children had started taking fish before age 6 months and 145 children had started taking citrus fruits beofre 3 months. Both fish and citrus allergy, defined by a positive challenge, were found at age 3 years in a similar frequency (about 3%) in children with and without the first-year elimination. The results suggest that food allergy in childhood can be postponed but not prevented by dietary elimination in infancy.

A dual long-term effect of breastfeeding on atopy in relation to heredity in children at 4 years of age

Background: The long‐term effect of early feeding on atopic sensitization is still unsolved. The aim of this study was to evaluate the long‐term effect of breastfeeding on atopy in groups of 4‐year‐old children stratified by atopic heredity.

IgA Antibodies, TGF-β1 and -β2, and Soluble CD14 in the Colostrum and Development of Atopy by Age 4

Specific defense factors in breast milk together with length of breast-feeding and genetic predisposition may modulate the development of allergy. We studied whether IgA, soluble CD14 (sCD14), or transforming growth factor (TGF)-β in colostrum could affect the development of atopy in children up to age 4. From a cohort of 4676, we selected four groups of children with either long or short exclusive breast-feeding (>3.5 or <0.5 mo); these groups further differed in the presence or absence of atopic heredity. In colostrum from mothers, we measured total IgA, IgA antibodies to cows milk (CM) and casein, sCD14, and TGF-β1 and -β2. The children were divided into three groups: those with no atopic symptoms or IgE, those with allergic symptoms, and those with both outcomes. Mothers of infants later showing atopic symptoms or, in addition, having IgE sensitization (verified atopy) had a lower concentration of IgA casein antibodies in their colostrum than did mothers of infants with no indication of atopy at age 4. Low concentration of IgA casein antibodies was a significant risk for verified atopy. sCD14 levels were lower in colostrum of mothers with infants developing atopic symptoms and IgE sensitization than of those of infants with no atopy. Specific IgA antibodies to CM antigens and sCD14 in colostrum significantly associated with the appearance of both symptomatic and verified atopy by age 4.

Infections in early childhood and risk of atopic disease

Having more siblings has been shown to be associated with lower risk of atopic diseases. This might be due to the higher number of infections in larger families. Because children attending day care centres have more respiratory infections, we analysed the association of number of siblings and day care attendance in children aged 1‐3 y with atopic disease in a cross sectional survey of 8387 schoolchildren aged 13‐14 y and their parents in four regions of Finland. Having no siblings, compared to three or more siblings, was associated with significantly higher risk of lifetime history of hay fever (odds ratios (OR) 1.53, 95% confidence interval (CI) 1.25‐1.86) and atopic eczema (OR 1.28, 95%CI 1.04‐1.56), and higher risk (ns) of doctor‐diagnosed asthma ever (OR 1.26, 95%CI 0.85‐1.88). Less strong associations were observed with the number of older siblings (birth order). No associations were observed with current symptoms of these diseases during the last 12 mo. Attending a day care centre at the age of 1‐3 y was not associated with decreased risk of any of the atopic diseases studied, but, in contrast to the hypothesis, was associated with slightly increased risk of current symptoms of hay fever (OR 1.34, 95%CI 1.12‐1.60). The present results suggest that other factors than early childhood respiratory infections explain the association between number of siblings and future risk of atopic disease. □Atopic disease, early life, infections

Pulmonary autoimmunity as a feature of autoimmune polyendocrine syndrome type 1 and identification of KCNRG as a bronchial autoantigen

Patients with autoimmune polyendocrine syndrome type 1 (APS-1) suffer from multiple organ-specific autoimmunity with autoantibodies against target tissue-specific autoantigens. Endocrine and nonendocrine organs such as skin, hair follicles, and liver are targeted by the immune system. Despite sporadic observations of pulmonary symptoms among APS-1 patients, an autoimmune mechanism for pulmonary involvement has not been elucidated. We report here on a subset of APS-1 patients with respiratory symptoms. Eight patients with pulmonary involvement were identified. Severe airway obstruction was found in 4 patients, leading to death in 2. Immunoscreening of a cDNA library using serum samples from a patient with APS-1 and obstructive respiratory symptoms identified a putative potassium channel regulator (KCNRG) as a pulmonary autoantigen. Reactivity to recombinant KCNRG was assessed in 110 APS-1 patients by using immunoprecipitation. Autoantibodies to KCNRG were present in 7 of the 8 patients with respiratory symptoms, but in only 1 of 102 APS-1 patients without respiratory symptoms. Expression of KCNRG messenger RNA and protein was found to be predominantly restricted to the epithelial cells of terminal bronchioles. Autoantibodies to KCNRG, a protein mainly expressed in bronchial epithelium, are strongly associated with pulmonary involvement in APS-1. These findings may facilitate the recognition, diagnosis, characterization, and understanding of the pulmonary manifestations of APS-1.