Lung function, airway remodeling, and inflammation in infants: outcome at 8 years.

BACKGROUND: Associations between early deficits of lung function, infant airway disease, and outcome at school age in symptomatic infants are still unclear. OBJECTIVE: To report follow-up data on a unique cohort of children investigated invasively in infancy to determine predictive value of airway disease for school-aged respiratory outcomes. METHODS: Fifty-three infants previously studied using bronchoscopy and airway conductance were approached at 8 years of age. Symptoms, lung volumes, and airway responsiveness were reassessed. Data on lifetime purchase of asthma medication were obtained. Lung function was compared with that of 63 healthy nonasthmatic children. RESULTS: Forty-seven children were reevaluated. Physician-diagnosed asthma was present in 39 children (83%). Twenty-five children (53%) had current and 14 children (30%) had past asthma. No pathologic feature in infancy correlated with any outcome parameter. As expected, study children had significantly reduced lung function and increased airway responsiveness compared with healthy controls, and very early symptoms were risk factors for reduced lung function. Current asthma was associated with reduced infant lung function and parental asthma. Reduced lung function in infancy was associated with purchase of inhaled corticosteroids when 6 to 8 and 0 to 8 years of age. CONCLUSION: The lack of predictive value of any pathologic measure in infancy, reported here for the first time to our knowledge, demonstrates that pathologic processes determining the inception of asthma, which are as yet undescribed, are different from the eosinophilic inflammation associated with ongoing disease.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness.

BACKGROUND: The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation. OBJECTIVE: To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW). METHODS: Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests. RESULTS: Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW. CONCLUSION: We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Early recovery from cow's milk allergy is associated with decreasing IgE and increasing IgG4 binding to cow's milk epitopes.

BACKGROUND: The dynamics and balance of allergen-specific IgE, IgG4, and IgA binding might contribute to the development of tolerance in patients with cow's milk allergy (CMA). Profiling of antibody binding to cow's milk (CM) protein epitopes might help in predicting the natural history of allergy. OBJECTIVE: We sought to investigate differences in IgE, IgG4, and IgA binding to CM epitopes over time between patients with early recovery or with persisting CMA. METHODS: We studied serum samples at the time of diagnosis (mean age, 7 months), 1 year later, and at follow-up (mean age, 8.6 years) from 11 patients with persisting IgE-mediated CMA at age 8 to 9 years and 12 patients who recovered by age 3 years. We measured the binding of IgE, IgG4, and IgA antibodies to sequential epitopes derived from 5 major CM proteins with a peptide microarray-based immunoassay. We analyzed the data with a novel image-processing method together with machine learning prediction. RESULTS: IgE epitope-binding patterns were stable over time in patients with persisting CMA, whereas binding decreased in patients who recovered early. Binding patterns of IgE and IgG4 overlapped. Among patients who recovered early, the signal of IgG4 binding increased and that of IgE decreased over time. IgE and IgG4 binding to a panel of alpha(s1)-, alpha(s2)-, beta-, and kappa-casein regions predicted outcome with significant accuracy. CONCLUSIONS: Attaining tolerance to CM is associated with decreased epitope binding by IgE and a concurrent increase in corresponding epitope binding by IgG4.

Specific antibodies to cow's milk proteins in infants: effect of early feeding and diagnosis of cow's milk allergy.

PURPOSE: To investigate whether specific IgA, IgG, IgG1 and IgG4 responses to cow's milk proteins differ between infants with cow's milk allergy and infants with cow's milk related symptoms (control subjects), and whether early feeding affects these responses as well as specific IgE. METHODS: A cohort of 6,209 healthy, full-term infants in a double-blind randomized trial received, as supplementary feeding at maternity hospitals (mean duration 4 days), either cow's milk formula, extensively hydrolyzed whey formula or donor breast milk. Infants who developed cow's milk associated symptoms (n = 223) underwent an open oral cow's milk challenge (mean age 7 months), which confirmed cow's milk allergy in 111 and was negative in 112. We measured in sera cow's milk specific IgE levels with UniCAP (Phadia, Uppsala, Sweden), and ß-lactoglobulin and α-casein specific IgA, IgG1, IgG4 and IgG levels with enzyme-linked immunosorbent assay. RESULTS: Infants with IgE-mediated cow's milk allergy had lower ß-lactoglobulin and α-casein specific IgG1, IgG4 and IgG levels (p < 0.05) than infants with non-IgE-mediated cow's milk allergy or control subjects. Within the group of infants with cow's milk allergy, exposure to cow's milk during the first few days after birth led to higher ß-lactoglobulin and α-casein specific IgG4 levels (p < 0.005) compared to infants fed with either breast milk or extensively hydrolyzed formula. CONCLUSIONS: Subdued IgG class responses to cow's milk proteins characterized IgE-mediated cow's milk allergy. In infants who developed cow's milk allergy early exposure to cow's milk resulted in a heightened specific IgG4 response.

Combined T regulatory cell and Th2 expression profile identifies children with cow's milk allergy.

The role of T regulatory cells in spontaneous recovery from cow's milk allergy (CMA) is unclear. We investigated the mRNA expression of 12 T-cell markers and the protein expression of CD4, CD25, CD127, FoxP3 after in vitro beta-lactoglobulin stimulation of peripheral blood mononuclear cells from children with persisting CMA (n=16), early recovery (n=20) or no atopy (n=21). Artificial neural networks with exhaustive search for all marker combinations revealed that markers FoxP3, Nfat-C2, IL-16 and GATA-3 distinguished patients with persisting CMA most accurately from other study groups. FoxP3 mRNA expression following beta-lactoglobulin stimulation was highest in children with persisting CMA. Also the FoxP3 intensity in CD4(+) CD25(high)CD127(low) cells was higher in children with CMA compared with non-atopic children. The expression profile of both Th2- and T regulatory cell-related genes thus reflects the clinical activity of CMA. Tolerance, in contrast, is not characterized by activation of circulating T regulatory cells.

Human leukocyte antigen (DR1)-DQB1*0501 and (DR15)-DQB1*0602 haplotypes are associated with humoral responses to early food allergens in children.

BACKGROUND: Infants' immunological responses to cow's milk (CM) proteins, which in 2-3% result in allergy, may partially depend on genetic factors. We evaluated whether genes with immunological functions, i.e. human leukocyte antigen (HLA) II, the protein tyrosine phosphatase, non-receptor type 22 (PTPN22) and filaggrin, modulate immune responses to dietary antigens. METHODS: We analyzed 14 HLA class II haplotypes, the PTPN22 1858 SNP (R620W allele) and 5 known filaggrin null mutations from blood samples of 87 patients with CM allergy (CMA) and 76 control subjects (age 8.0-9.3 years). Serum levels of IgA, IgG, IgG1 and IgG4 antibodies to beta-lactoglobulin, alpha-casein and ovalbumin were measured with enzyme-linked immunosorbent assay, levels of IgE antibodies to CM, ovalbumin and birch with UniCap (Phadia, Uppsala, Sweden). RESULTS: In children with CMA, the HLA (DR15)-DQB1*0602 haplotype was associated with high levels of beta-lactoglobulin-specific total IgG (p < 0.001) and IgG4 (p < 0.001) and alpha-casein-specific total IgG (p = 0.003) and IgG4 (p = 0.002), but not among control subjects. (DR1/10)-DQB1*0501 was associated with lower levels of beta-lactoglobulin-specific total IgG (p < 0.001) and IgG4 (p < 0.001), ovalbumin-specific total IgG (p = 0.002) and IgG4 (p < 0.001), particularly in control subjects (p < 0.001). Six children with eczema (3 with CMA) had the filaggrin mutation del22824. PTPN22 was not associated with specific antibody responses or CMA. CONCLUSION: The HLA II, but not PTPN22 or filaggrin, genotype modulates humoral responses to early food allergens, whereas none of these genes was associated with CMA.

Early infant feeding and type 1 diabetes.

BACKGROUND: Infant feeding practices, particularly the type of milk feeding, have been associated with the development of type 1 diabetes. AIM OF THE STUDY: We studied the relationship between early infant feeding (during the first year of life) and diabetes in a large population-based cohort. METHODS: In 1994-1995, 6,209 healthy full-term newborns participated in a study examining the effect of supplementary feeding, on development of allergy to cow's milk, in maternity hospitals. All supplements in the maternity hospitals were known. Mothers recorded the feeding of infants prospectively at home. In August 2006, from a nationwide diabetes registry, 45 children from our cohort were listed as having type 1 diabetes. RESULTS: The distribution of cases was similar in the randomized feeding groups: 9/1,789 in the group that received adapted cow's milk-based formula; 12/1,737 in those who received extensively hydrolyzed formula; 16/1,859 in those who received banked human milk; and 8 among those 824 exclusively breast-fed in the hospital. When children who had received cow's milk-based formula in the maternity hospital were compared with those without such exposure, less number of children in the former group had diabetes by age 8 (P = 0.026), but by the end of the follow-up (11.5 years) the difference disappeared (P = 0.16). Length of breast-feeding and introduction of cereals and other solid foods were similar among those developing type 1 diabetes and those remaining healthy, while early regular daily feeding with cow's milk-based formula tended to associate with lower risk for type 1 diabetes (OR 0.66; 95% confidence interval 0.38-1.13; P = 0.08). CONCLUSIONS: In an extended, secondary analysis of a population-based cohort, very early exposure to cow's milk is not a risk factor for type 1 diabetes; it may in fact diminish its appearance before age 8.

Colostrum TGF-beta-1 associates with the duration of breast-feeding.

BACKGROUND: Several stressful environmental factors are associated with short-term breast-feeding. A high concentration of sodium in colostrum has predicted early failure. AIM OF THE STUDY: We studied the association of growth factors in colostrum and the length of breast-feeding (BF). METHODS: We measured concentrations of TGF-beta1 and -beta2; epidermal growth factor, total protein, and sodium and compared their concentrations in colostral samples from mothers who either breast-fed their infants exclusively less than 0.5 months (n = 109) or longer than 3.5 months (n = 119). RESULTS: In the short BF group more mothers smoked and were primiparous more frequently and had less often a university education. They also provided the colostral samples significantly later than did those with long BF. Geometric mean concentration for TGF-beta1 was 1.9 times as high in the samples from short BF mothers as in those with long BF; significant difference remained in comparisons of samples taken equally long postpartum. Samples from the short BF group showed higher levels for sodium, TGF-beta2 and total protein, whereas concentrations of epidermal growth factor were similar between groups. CONCLUSIONS: We thus infer that concentrations of factors in breast milk with an effect on the development and involution of the mammary gland, like TGF-beta1 in milk, may be one of many biological factors having an impact on the successful initiation of breast-feeding.

Molecularly defined adult-type hypolactasia in school-aged children with a previous history of cow's milk allergy.

AIM: To assess the role of lactase non-persistence/persistence in school-aged children and their milk-related symptoms. METHODS: The genotypes for the C/T(-13910) variant associated with lactase non-persistence/ persistence were determined using PCR-minisequencing in a group of 172 children with a mean age of 8.6 years (SE = 0.02, 93 boys) participating in a follow-up study for cow's milk allergy. The parents were asked to assess their children's milk consumption and abdominal symptoms. RESULTS: The presence of allergy to cow's milk was not associated with the C/C(-13910) genotype related with a decline of lactase enzyme activity during childhood (lactase non-persistence). The frequency of the C/C(-13910) genotype (16%) was similar to published figures for the prevalence of adult-type hypolactasia in Finland. The majority of the children (90%) in this series consumed milk but 26% of their families suspected that their children had milk-related symptoms. Forty-eight percent of the children with the C/C(-13910) genotype did not drink milk at all or consumed a low lactose containing diet prior to the genotyping (P < 0.004 when compared to the other genotypes). CONCLUSION: Analysis of the C/T(-13910) polymorphism is an easy and reliable method for excluding adult-type hypolactasia in children with milk-related symptoms. Genotyping for this variant can be used to advise diets for children with a previous history of cow's milk allergy.

IgA antibodies, TGF-beta1 and -beta2, 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)-beta 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 cow's milk (CM) and casein, sCD14, and TGF-beta1 and -beta2. 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.

Clinical course and prognosis of cow's milk allergy are dependent on milk-specific IgE status.

BACKGROUND: Large, prospective population-based studies on clinical course, development of tolerance, and risk for other atopy in children with cow's milk allergy (CMA) are lacking. OBJECTIVE: We investigated the development of tolerance and the risk for asthma, rhinoconjunctivitis, atopic dermatitis, and sensitization in children with CMA followed to school age. METHODS: We followed 118 children with CMA until recovery and repeatedly measured their sensitization to cow's milk (CM). At age 8.6 years, 94 allergic subjects and 80 control subjects from the same cohort were studied for atopic diseases and sensitization. In addition, the parents of 12 allergic subjects and 26 control children returned a questionnaire on atopy, respectively. RESULTS: IgE-mediated CMA was detected in 86 (73%) children; at age 8.6 years, 13 (15%) had persistent CMA. All children with IgE-negative CMA were tolerant by age 5.0 years (P < .0001). Risk factors for persistent CMA at age 2.0 years were sensitization to CM at age 1.6 years (odds ratio, 6.3; 95% CI, 2.6-15.2), urticaria at diagnostic challenge (odds ratio, 3.3; 95% CI, 1.4-7.8), CM exposure at the maternity hospital (odds ratio, 3.2; 95% CI, 1.4-7.8), and early sensitization to egg (odds ratio, 2.8; 95% CI, 1.2-6.6). By age 8.6 years, children with IgE-positive CMA more frequently had asthma (31% vs 13%, P < or = .01), rhinoconjunctivitis (66% vs 21%, P < or = .001), atopic eczema (81% vs 26%, P < or = .001), and sensitization to any allergen (88% vs 39%, P < or = .001) than control subjects. CMA and family history of atopy were independent risk factors for atopic diseases, and CMA was also a risk factor for sensitization to inhalant allergens. CONCLUSION: IgE-mediated CMA often persists to school age and is a risk factor for other atopy; non-IgE-mediated CMA, by contrast, is a benign infantile condition.

Markers of inflammation in the feces of infants with cow's milk allergy.

Growing evidence exists that exposure to cow's milk elicits inflammation in the gut of infants with cow's milk allergy, irrespective of symptoms. To demonstrate inflammation and increased protein leakage from the gut during a cow's milk elimination-challenge test in fecal samples of infants presenting with different symptoms suggestive of cow's milk allergy, we measured the concentrations of alpha1-antitrypsin (AT), eosinophil cationic protein (ECP), immunoglobulin (Ig) A, and cow's milk-specific IgA antibodies, in fecal samples of 208 infants with a mean age of 7 months. Prechallenge samples were collected after a mean 3-week elimination period, and post-challenge samples were obtained 4 days after starting the challenge. Fecal levels of prechallenge total IgA (p = 0.02) and post-challenge AT (p = 0.001) were higher in infants with a positive challenge. Of these infants, pre- and post-challenge levels of ECP were higher in those reacting after 24 h than in those reacting within 1 h (p = 0.006 and p = 0.045). Prechallenge levels of ECP were higher in those showing intestinal symptoms (p = 0.008), and both pre- and post-challenge levels of total IgA were higher in those with an IgE-mediated reaction to cow's milk (p = 0.04 and p = 0.008). Regardless of the challenge result, total IgA increased during the challenge (p < 0.001 for both challenge-positive and -negative infants) and was higher in those breast-fed until the challenge than in those fed formula only (p < 0.01). Hence, in infants reacting to the cow's milk challenge, higher prechallenge levels of fecal IgA indicate increased antigenic stimuli in the gut, and higher post-challenge levels of AT reflect increased protein loss as a result of intestinal inflammation. In infants with slowly evolving gastrointestinal symptoms, increased fecal ECP may help in distinguishing patients from those who tolerate cow's milk. Individual serial follow-up of fecal IgA and ECP can be used to estimate the degree of inflammation in the gut and an appropriate time for a challenge test, but are not diagnostic tools for cow's milk allergy.