Developmental pathways of children with and without familial risk for dyslexia during the first years of life

Comparisons of the developmental pathways of the first 5 years of life for children with (N = 107) and without (N = 93) familial risk for dyslexia observed in the Jyvaskyla Longitudinal study of Dyslexia are reviewed. The earliest differences between groups were found at the ages of a few days and at 6 months in brain event-related potential responses to speech sounds and in head-turn responses (at 6 months), conditioned to reflect categorical perception of speech stimuli. The development of vocalization and motor behavior, based on parental report of the time of reaching significant milestones, or the growth of vocabulary (using the MacArthur Communicative Development Inventories) failed to reveal differences before age 2. Similarly, no group differences were found in cognitive and language development assessed by the Bayley Scales of Infant Development and the Reynell Developmental Language Scales before age 2.5. The earliest language measure that showed lower scores among the at-risk group was maximum sentence length at age 2. Early gross motor development had higher correlation to later language skills among the at-risk group rather than the control children. The most consistent predictor of differential development between groups was the onset of talking. Children who were identified as late talkers at age 2 were still delayed at the age 3.5 in most features of language-related skills-but only if they belonged to the group at familial risk for dyslexia. Several phonological and naming measures known to correlate with reading from preschool age differentiated the groups consistently from age 3.5. Our findings imply that a marked proportion of children at familial risk for dyslexia follow atypical neurodevelopmental paths. The signs listed previously comprise a pool of candidates for early predictors and precursors of dyslexia, which await validation.     

Cytokine responses to allergens during the first 2 years of life in Estonian and Swedish children

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 (beta-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.     

Breast-feeding reduces the risk of asthma during the first 4 years of life

BACKGROUND: The evidence for a preventive effect of breast-feeding on asthma and other allergic diseases in childhood is inconclusive. OBJECTIVE: The aim of this study was to investigate the effect of breast-feeding on asthma and sensitization to airborne allergens among children up to 4 years of age. METHODS: A birth cohort of 4089 children was followed. Exposure data were collected at 2 months and 1 year of age. The total dose of breast milk was estimated by combining periods of exclusive and partial breast-feeding. Outcomes data were collected at 1, 2, and 4 years of age. The response rate at 4 years was 90%, and 73% participated in a clinical investigation, including blood sampling for analysis of specific IgE and lung function testing. Children with onset of wheeze during lactation (n=217) were excluded in some of the analyses to avoid disease-related modification of exposure. RESULTS: Exclusive breast-feeding for 4 months or more reduced the risk of asthma at the age of 4 years (odds ratio [OR], 0.72; 95% CI, 0.53-0.97), irrespective of sensitization to common airborne allergens ( P=.72). Excluding children with wheeze during lactation tended to strengthen the risk estimate (OR, 0.64; 95% CI, 0.46-0.88). A duration of 3 months or more of partial breast-feeding seemed to offer additional protection; exclusive breast-feeding for 3 to 4 months combined with partial breast-feeding for 3 months or more resulted in an OR of 0.44 (95% CI, 0.21-0.87). The effects tended to be stronger in children without heredity for allergy ( P interaction=.36). CONCLUSION: Breast-feeding reduces the risk of asthma during the first 4 years of life.     

Rotavirus infections and development of diabetes-associated autoantibodies during the first 2 years of life

Rotavirus, the most common cause of childhood gastroenteritis, has been implicated as one of the viral triggers of diabetes-associated autoimmunity. To study the possible association between rotavirus infections and the development of diabetes-associated autoantibodies, we measured the prevalence of rotavirus antibodies in serum samples collected at 3-6-month intervals up to the age of 2 years from 177 children selected from consecutive newborns because they carried HLA-DQB1 alleles associated with increased risk for type 1 diabetes. Twenty-nine of the children developed at least two of four diabetes-associated autoantibodies (ICA, IAA, GADA or IA-2A) during the first 2 years of life (the cases), whereas 148 children remained autoantibody-negative matched with the cases for date of birth, gender, living region and HLA-DQB1 alleles. The temporal association between the development of the first-appearing diabetes-associated autoantibody and rotavirus infections was studied by analysing whether the cases had a diagnostic increase in rotavirus antibody titre more often during the 6-month period that preceded seroconversion to autoantibody positivity than the controls. By the age of 12 months one of the 13 case children (7%), who had a serum sample drawn at that age and who had developed at least one type of diabetes-associated autoantibodies, had experienced a rotavirus infection, while 12 of the 61 (20%) autoantibody-negative control children had had a rotavirus infection. By 18 months, four of the 22 autoantibody-positive cases (18%) and 18 of the 89 controls (20%) had rotavirus antibodies, and by the age of 24 months the respective numbers were five of the 27 cases (19%) and 32 of the 113 (28%) controls. A rotavirus infection occurred during the 6 months preceding the sample which was positive for an autoantibody in four of the 25 periods (16%) for which both necessary samples were available, while the controls had a rotavirus infection during 55 of the 370-such periods (15%). Accordingly, our data suggest that rotavirus infections are unlikely triggers of beta-cell autoimmunity in young children with genetic susceptibility to type 1 diabetes.     

Mirror-image response during the first two years of life

Children aged 1–24 months viewed themselves in planar or distorted mirrors that were either clear or partially occluded. Analysis of videotaped records revealed that interest in viewing one's face did not vary with age among the 1- to 24-month-old subjects. All performed the simple behaviors of observing themselves although the older ones performed more complex (related) behaviors. Neither the flat nor the distorted mirror exposure was preferred suggesting that the infant observes the general configuration of the face for its intrinsic interest. Specific developmental trends were noted in the kind and amount of activity during the 1st 2 years of life culminating in a sequence of behaviors that suggested self-recognition.     

Development of allergy and IgE antibodies during the first five years of life in Estonian children

BACKGROUND: Epidemiological studies have demonstrated a low prevalence of allergic diseases and atopic sensitization among schoolchildren and young adults in the formerly socialist countries of Central and Eastern Europe as compared to Western Europe. OBJECTIVE: The aim of our study was to prospectively investigate IgE responses to food and inhalant allergens and the development of allergy during early childhood in a population with a low prevalence of atopic disorders. METHODS: In a population-based prospective study, 273 children were followed from birth through the first 5 years of life, recording manifestations of allergy by questionnaires and clinical examinations at 0.5, 1, 2 and 5 years (n = 213). Skin prick tests (SPT) were performed using natural foods (cow's milk, egg white) and commercial extracts of inhaled allergens (cat, dog, D. pteronyssinus, birch, timothy). In addition, serum IgE levels and circulating IgE antibodies against the seven allergens were determined. RESULTS: The prevalence of allergic diseases at 5 years of life was 19%. Atopic dermatitis was the most common allergic disease at all ages. The point prevalence of positive skin prick tests was 7% at 0.5, 1 and 2 years of age, and 3% at 5 years. Circulating IgE antibodies against food allergens were common at all ages, i.e. 13, 23, 36 and 36%, respectively, at 0.5, 1, 2 and 5 years. The prevalence of circulating IgE antibodies to inhalant allergens increased from 1.5% at 0.5 years to 11% at 1, 19% at 2 and 47% at 5 years. The antibody levels were generally low, however. The value of positive SPT and the presence of IgE antibodies in the diagnosis of clinical allergy were low. CONCLUSION: The results of this prospective study carried out in a previously socialist country with a low allergy prevalence among schoolchildren and young adults indicate that transient sensitization in early childhood is followed by a down-regulation of skin reactivity.     

Prevalence and cumulative incidence of food hypersensitivity in the first 3 years of life

Background:  Prevalence and incidence of food hypersensitivity (FHS) and its trends in early childhood are unclear.
Methods:  A birth cohort born on the Isle of Wight (UK) between 2001 and 2002 was followed-up prospectively. Children were clinically examined and skin prick tested at set times and invited for food challenges when indicated.
Results:  Nine hundred and sixty-nine children were recruited and 92.9%, 88.5% and 91.9% of them respectively were assessed at 1, 2 and 3 years of age. Prevalence of sensitization to foods was 2.2%, 3.8% and 4.5% respectively at these ages. Cumulatively, 5.3% [95% confidence interval (CI): 3.9–7.1] children were sensitized to a food. Using open food challenge and a good clinical history, the cumulative incidence of FHS was 6.0% (58/969, 95% CI: 4.6–7.7). Based on double-blinded, placebo-controlled, food challenge (DBPCFC) and a good clinical history, the cumulative incidence was 5.0% (48/969, 95% CI: 3.7–6.5). There is no evidence to suggest that the incidence of FHS has increased, comparing these results with previous studies. Overall, 33.7% of parents reported a food-related problem and of these, 16.1% were diagnosed with FHS by open challenge and history and 12.9% by DBPCFC and history. Main foods implicated were milk, egg and peanut.
Conclusions:  By the age of 3 years, 5–6% of children suffer from FHS based on food challenges and a good clinical history. There were large discrepancies between reported and diagnosed FHS. Comparing our data with a study performed in the USA more than 20 years ago, there were no significant differences in the cumulative incidence of FHS.     

Lung transfer for carbon monoxide during the first three years of life

Lung transfer for CO (TLCO) was measured in 35 healthy infants. A steady state, non-invasive method using a technique of alveolar sampling was employed [3]. During the first three years of life, TLCO expressed as mmol.min-1.kPa-1 increased linearly with height (cm): y = 0.036x - 1.15 (r = 0.91); with body weight (kg): y = 0.18x - 0.005 (r = 0.85); with body surface area (m2): y = 3.48x - 0.375 (r = 0.88); and with logn of age (months): y = 0.406x + 0.184 (r = 0.88). FRC was also measured in 29 of these infants by the helium dilution technique. FRC expressed in ml increased linearly with logn of age: y = 62.24x + 62.4 (r = 0.86) and was correlated with TLCO: y = 0.05x + 0.084 (r = 0.8). TLCO and FRC were correlated with the number of alveoli [7, 9]. Thus, in the first three years of life, lung volume and lung gas transfer seem to progressively adapt in order to satisfy energetic needs during growth.     

Immune responses to birch in young children during their first 7 years of life

BACKGROUND: The character of immune responses to allergens during the first years of life may decide whether the individual will become tolerant or develop allergy later in life. OBJECTIVE: To study the development of immune responses to the seasonal inhalant allergen birch over the first 7 years of life. METHODS: Blood samples were obtained from 21 children who were followed prospectively from the second to the seventh pollen season of life. Birch-induced cytokine production and IgG subclass antibodies to rBet v 1 were analysed with ELISA, mRNA expression with real time PCR, IgE antibodies to birch with Magic Lite and birch-induced mononuclear cell proliferation with 3H-thymidine incorporation. RESULTS: Birch-induced IFN-gamma and IL-10 production increased with age, both in atopic and non-atopic children, while birch-induced IL-13 production decreased. The two children who were sensitized and developed clinical allergy to birch showed persistent IL-4 and IL-5 production and IL-9 mRNA expression, as well as Th2-associated IgG4 responses. Transient Th2-like responses were observed among the other children. Proliferative responses and IgG1 antibodies were seen in all children. CONCLUSIONS: Immune responses to birch can be demonstrated in all children, during the first 7 years of life, regardless of atopic status. A transient early Th2-like response is down-regulated after the fourth pollen season, except in children who develop clinical allergy to the particular allergen.     

Natural history of IgE-dependent food allergy diagnosed in children during the first three years of life

PurposeThe aim of the study was to analyze: the course of allergy diagnosed during first three years of life, frequency of food tolerance development and impact of factors which have potential meaning in that process.Material and MethodsThe study was performed in 115 children with IgE-dependent allergy, diagnosed during first three years of life, treated in 2nd Department of Pediatrics and Allergology of Polish Mothers Health Center in Lodz. All children were invited to our clinic in order to analyze course of the allergy after period of minimum 5 years since diagnosis.ResultsThe results of the study revealed that food tolerance was acquired by high percentage of examined children (87.9%) among 83 children with food allergy. However among 32 children with initial inhalant allergy there were still no food sensitizations. The frequency of this process increased with age of examined children. The study revealed that such factors as lack of family history of atopy, clinical manifestation limited to one system, lack of inhalant allergy, type of allergen, good social conditions, have positive impact on tolerance development.ConclusionsHigh percentage of children with food allergy is able to develop the status of food immunotolerance. Factors which predispose to development of food allergy have also negative impact on ability to acquiring tolerance to harmful food. The study indicates the need of constant and wide education about decreasing exposure to allergy predisposing factors which could increase chance of food tolerance development.     

Perinatal risk factors for sensitization, atopic dermatitis and wheezing during the first year of life (PIPO study)

Objective To evaluate the influence of perinatal environmental factors on early sensitization, atopic dermatitis and wheezing during the first year. Methods Information on pregnancy‐related factors, parental atopic history, environmental factors and the clinical course of the infant until age one was gathered by questionnaires, as part of a prospective birth cohort study (Prospective study on the Influence of Perinatal factors on the Occurrence of asthma and allergies [PIPO‐study]). Quantification of total and specific IgE was performed in 810 children and their parents. Results Early sensitization was found in 107/810 (13%) of the infants. Multiple regression analysis showed that specific IgE in fathers was a risk factor for early sensitization in their daughters (adjusted odds ratios (OR_adj) 2.21 (95% confidence interval (CI) 1.10–4.49); P=0.03), whereas in boys, day care attendance was shown to be protective for early sensitization (OR_adj 0.38 (95% CI 0.20–0.71); P=0.001). Atopic dermatitis occurred in 195/792 infants (25%). Specific IgE in the mother (OR_adj 1.52 (95% CI 1.06–2.19); P=0.02) and in the infant (OR_adj 4.20 (95% CI 2.63–6.68); P<0.001) were both risk factors for the occurence of atopic dermatitis, whereas postnatal exposure to cats was negatively associated with atopic dermatitis (OR_adj 0.68 (0.47–0.97); P=0.03). Postnatal exposure to cigarette smoke (OR_adj 3.31 (95% CI 1.79–6.09); P<0.001) and day care attendance (OR_adj 1.96 (95% CI 1.18–3.23); P=0.009) were significantly associated with early wheezing, which occurred in 25% (197/795) of the infants. Conclusion The effect of paternal sensitization and day care attendance on sensitization is gender dependent. Maternal sensitization predisposes for atopic dermatitis, whereas postnatal exposure to cats had a protective effect.     

Infant emotion regulation and cortisol response during the first 2 years of life: Association with maternal parenting profiles

This study investigated the prospective associations among emotion expression, behavioral regulation, and cortisol responses in relation to different maternal parenting behaviors during the first 2 years of the infant's life, among a sample of low-income families. Participants included 1,141 mother–child pairs, assessed when the infants were 6, 15, and 24 months old. Maternal parenting behaviors were observed at the 6-month assessment, whereas infant emotion expression, orienting toward mothers, and cortisol responses were measured using a series of emotion-eliciting tasks at all time points. A latent profile analysis revealed four maternal parenting profiles: Detached, Intrusive, Average, and Engaged. Furthermore, a multiple-group path model revealed distinct patterns of emotion development for infants within different maternal parenting groups. Among children with Engaged and Average mothers, orienting behaviors tended to predict less negative emotion and cortisol responses, which was associated with more future orienting behaviors. Conversely, among children with Intrusive and Detached mothers, orienting behaviors tended to predict more negative emotion and cortisol responses, which predicted less future orienting behaviors. Findings of this study enhance current understanding of how different profiles of maternal parenting behaviors impact infant emotional development in poverty, with significant implications for intervention programs targeting early mother–infant interactions.     

Development of seasonal allergic rhinitis during the first 7 years of life

BACKGROUND: Against the background of the controversial discussion about an increase in allergic rhinitis in recent years, intraindividual longitudinal data is lacking for IgE-mediated seasonal allergic rhinitis (SAR). Little is known about the development of SAR in terms of prevalence and incidence rates from birth to school age. OBJECTIVE: In a prospective birth cohort, we investigated the development of sensitization and symptoms of SAR. SAR should be defined with high specificity, and associated risk factors should be determined. METHODS: Annual longitudinal data about seasonal allergic symptoms and sensitization was available for 587 children from birth to their seventh birthday. The definition of SAR was based on a combination of exposure-related symptoms and sensitization. RESULTS: Up to 7 years of age, SAR developed in 15% of the children. Incidence and prevalence of symptoms and sensitization were low during early childhood (<2%) and increased steadily with age. Children in which SAR had already developed in the second year all were born in spring or early summer, resulting in at least two seasons of pollen exposure before manifestation of SAR. Risk factors assessed by multiple logistic regression analysis were male sex (odds ratio [OR] = 2.4), atopic mothers (OR = 2.6) and fathers (OR = 3.6) having allergic rhinitis themselves, first-born child (OR = 2.0), early sensitization to food (OR = 3.3), and atopic dermatitis (OR = 2.5), whereas early wheezing was not associated with SAR. CONCLUSION: The development of SAR is characterized by a marked increase in prevalence and incidence after the second year of life. Our longitudinal data further indicate that in combination with the risk of allergic predisposition, at least 2 seasons of pollen allergen exposure are needed before allergic rhinitis becomes clinically manifest.