Cord blood IgE. II. Prediction of atopic disease. A follow-up at the age of 18 months

Cord blood IgE predicts allergic sensitization, elevation of exhaled nitric oxide, and asthma in schoolchildren

BACKGROUND

Few data are available in Asian children regarding the validity of cord blood immunoglobulin E (IgE) in predicting allergic sensitization and pulmonary function. The relationship between cord blood IgE and fraction of exhaled nitric oxide (FeNO) remains unknown. This study investigated the associations of cord blood IgE with allergic sensitization, FeNO, pulmonary function, and allergic diseases in Asian children.

METHODS

Five hundred and sixty-six Asian children with valid cord blood IgE measurements at birth participated a 6-year follow-up visit including a questionnaire, serum total and allergen-specific IgE, FeNO measurement, and spirometry. Regression-based analyses with covariates adjustment were applied.

RESULTS

Cord blood IgE levels were significantly associated with FeNO levels (β = 0.131, p < .001) and serum total IgE levels (β = 0.325, p < .001). Cord blood IgE levels were positively associated with allergic sensitization (adjusted odds ratio [AOR] = 2.22, p < .001), and sensitization to mites (p = .002), animals (p = .023), and foods (p = .048). Subjects with cord blood IgE ≥0.24 kU/L (the optimal cutoff) were significantly associated with an increased risk of allergic sensitization (AOR = 2.63, p < .001) and asthma (AOR = 2.35, p = .024) than those with cord blood IgE <0.24 kU/L. Subjects with cord blood IgE ≥0.24 kU/L had significantly higher FeNO levels than those with cord blood IgE <0.24 kU/L (p = .028). There were no significant associations between cord blood IgE levels and pulmonary function parameters.

CONCLUSION

Cord blood IgE ≥0.24 kU/L predicts allergic sensitization, FeNO elevation, and asthma among Asian schoolchildren, suggesting cord blood IgE would be useful for identifying newborns at risk of subsequent allergic sensitization and allergic airway inflammation.

Allergen skin prick testing in early childhood: reproducibility and prediction of allergic symptoms into early adulthood

OBJECTIVE

To assess the predictive value of skin prick testing in early childhood on subsequent allergic symptoms up to adult age.

STUDY DESIGN

A cohort of 200 unselected healthy newborns was prospectively followed from birth to 20 years of age. Of them, 163 (82%) were reassessed at age 5 years, 150 (76%) at age 11 years, and 164 (83%) at age 20 years with a skin prick test that included 11 common allergens. On the basis of clinical examination and structured interview, the occurrence of atopic dermatitis, allergic rhinoconjunctivitis, recurrent wheezing, and symptoms of food hypersensitivity were recorded at each of the follow-up visits.

RESULTS

The reproducibility of skin prick test positivity at age 5 years was 100% at ages 11 and 20 years, ie, none of the skin prick-positive subjects turned negative during the follow-up. Gaining of new sensitizations to aeroallergens was common. Skin prick test positivity at age 5 years predicted allergic symptoms at ages 11 (sensitivity 28%, specificity 94%) and 20 years (sensitivity 23%, specificity 91%) but not atopic dermatitis.

CONCLUSIONS

Skin prick test positivity at age 5 years strongly predicts later skin prick test positivity and is associated with respiratory symptoms, ie, allergic rhinoconjunctivitis and recurrent wheezing, at ages 11 and 20 years. However, skin prick test negativity at age 5 years does not exclude sensitization and allergic symptoms at a later age.

Can family history and cord blood IgE predict sensitization and allergic diseases up to adulthood?

BACKGROUND

Long-term studies of the predictive value of family history and cord blood IgE level until adulthood are few, and their conclusions have been contradictory.

METHODS

Screening of total IgE in 1617 cord blood samples was performed in a Danish birth cohort. All infants with cord blood IgE (CB-IgE) ≥ 0.5 kU/l and a corresponding randomly chosen group with CB-IgE <0.5 kU/l were chosen for follow-up. Questionnaire-based interviews, physical examination, specific IgE testing, and from 10 yr also spirometry, were carried out at 1½, 5, 10, 15, and 26 yr. Predefined diagnostic criteria were used.

RESULTS

A total of 455 infants were included, 188 with CB-IgE ≥ 0.5 kU/l and 267 with CB-IgE <0.5 kU/l. Follow-up rates were high, 288 (63%) attended the 26-yr follow-up. Family history and elevated CB-IgE were significantly associated to allergic disease until 26 yr. Concerning any allergic symptoms at 1½ yr the positive and negative predictive values (PPV and NPV), the sensitivity and specificity of CB-IgE ≥ 0.5 kU/l, was 29%, 81%, 54%, and 61%, respectively. The corresponding figures at 26 yr were 46%, 62%, 43%, and 65%. Overall, family history as well as CB-IgE ≥ 0.5 kU/l was associated with high NPV and specificity, but low PPV and sensitivity.

CONCLUSION

Although family history and elevated CB-IgE were significantly associated with primarily atopic disease until 26 yr, none of these were strong predictors for subsequent sensitization and allergic symptoms from childhood until early adulthood. It appears that the predictive capacity of CB-IgE decreases in adolescence and early adulthood.

Asthma Heredity, Cord Blood IgE and Asthma-Related Symptoms and Medication in Adulthood: A Long-Term Follow-Up in a Swedish Birth Cohort

Cord blood IgE has previously been studied as a possible predictor of asthma and allergic diseases. Results from different studies have been contradictory, and most have focused on high-risk infants and early infancy. Few studies have followed their study population into adulthood. This study assessed whether cord blood IgE levels and a family history of asthma were associated with, and could predict, asthma medication and allergy-related respiratory symptoms in adults. A follow-up was carried out in a Swedish birth cohort comprising 1,701 consecutively born children. In all, 1,661 individuals could be linked to the Swedish Prescribed Drug Register and the Medical Birth Register, and 1,227 responded to a postal questionnaire. Cord blood IgE and family history of asthma were correlated with reported respiratory symptoms and dispensed asthma medication at 32-34 years. Elevated cord blood IgE was associated with a two- to threefold increased risk of pollen-induced respiratory symptoms and dispensed anti-inflammatory asthma medication. Similarly, a family history of asthma was associated with an increased risk of pollen-induced respiratory symptoms and anti-inflammatory medication. However, only 8% of the individuals with elevated cord blood IgE or a family history of asthma in infancy could be linked to current dispensation of anti-inflammatory asthma medication at follow-up. In all, 49 out of 60 individuals with dispensed anti-inflammatory asthma medication at 32-34 years of age had not been reported having asthma at previous check-ups of the cohort during childhood. Among those, only 5% with elevated cord blood IgE and 6% with a family history of asthma in infancy could be linked to current dispensation of anti-inflammatory asthma medication as adults. Elevated cord blood IgE and a positive family history of asthma were associated with reported respiratory symptoms and dispensed asthma medication in adulthood, but their predictive power was poor in this long-time follow-up.

Cord blood cellular proliferative response as a predictive factor for atopic dermatitis at 12 months

Since the risk of developing allergic disease increases in individuals exposed to allergens previously, even during the neonatal period, the immunologic status of a fetus may be important in the subsequent development of allergy. We evaluated the fetal factors to predict atopic dermatitis (AD) at 12 months in 412 infants of a COhort for Childhood Origin of Asthma and Allergic Diseases (COCOA) in the general Korean population. Cord blood mononuclear cells (CBMCs) were stimulated with ovalbumin and phytohemagglutinin and cellular proliferative response and concentrations of interleukin-13 and interferon-γ, were measured. The risk of developing AD was greater in boys than girls (OR 1.97, 95% CI 1.26-3.09), infants delivered by cesarean section than vaginally (OR 1.93, 95% CI 1.14-3.26) and infants with than without parental history of AD (OR 2.34, 95% CI 1.29-4.24). The CBMC proliferative response to phytohemagglutinin stimulation was higher in infants with than without AD (P = 0.048), but no difference was observed in ovalbumin-stimulated cells (P = 0.771). Risk factors for the development of AD at 12 months include male gender, delivery by cesarean section and parental history of AD. Increased CBMC proliferative response to phytohemagglutinin stimulation may predict the development of AD at 12 months.

Different implications of paternal and maternal atopy for perinatal IgE production and asthma development

Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma.

The effect of prenatal perfluorinated chemicals exposures on pediatric atopy

BACKGROUND

The role of perfluorinated compounds (PFCs) in the immune system and allergic diseases is not well-known. This study examined the effects of pre-natal exposure to PFCs on immunoglobulin E (IgE) levels and atopic dermatitis (AD).

METHODS

In Taiwan Birth Panel cohort study, newborns with cord blood and peri-natal factors (i.e. birth body weight, weeks of gestation, and type of delivery) gathered at birth were evaluated. At the age of 2 years, information on the development of AD, environmental exposures, and serum total IgE were collected. The AD and non-AD children were compared for the concentration of cord blood serum PFCs measured by Ultra-performance liquid chromatography/triple-quadrupole mass (UPLC-MS/MS). Correlations among cord blood IgE, serum total IgE at 2 years of age, and cord blood PFC levels were made.

RESULTS

Of 244 children who completed the follow-up and specimen collections, 43 (17.6%) developed AD. Concentrations of cord blood serum perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) were median (range) 1.71 (0.75-17.40), 5.50 (0.11-48.36), 2.30 (0.38-63.87), and 0.035 (0.035-0.420)ng/mL, respectively. PFOA and PFOS levels positively correlated with cord blood IgE levels (per ln-unit: β=0.134 KU/l, p=0.047 for PFOA; β=0.161 KU/l, p=0.017 for PFOS). Analyses stratified by gender revealed that PFOA and PFOS levels positively correlated with cord blood IgE levels only in boys (per ln-unit: β=0.206 KU/l, p=0.025 for PFOA; β=0.175 KU/l, p=0.053 for PFOS). When dividing cord blood serum PFCs into quartiles in the fully adjusted models, AD had no significant association with PFOS.

CONCLUSIONS

Pre-natal PFOA and PFOS exposures positively correlated with cord blood IgE levels.

The relationship between cord blood immunoglobulin E levels and allergy-related outcomes in young adults

BACKGROUND

Elevated cord blood IgE may be associated with a higher risk of allergic disease.

OBJECTIVE

To determine whether cord blood IgE is associated with allergic biomarkers or allergic disorders in young adults.

METHODS

Data was collected from 670 subjects 18-21 years of age that were among 835 original participants in the Detroit Childhood Allergy Study, a general risk, population-based birth cohort. Cord blood IgE was assessed in relation to biomarkers associated with allergy and asthma including total IgE, allergen-specific IgE, blood eosinophilia, and spirometry. Cord blood IgE was also analyzed for associations to subsequent allergic disease including atopic dermatitis, allergic rhinitis, and asthma.

RESULTS

Cord blood IgE, analyzed as a continuous measure, was modestly correlated with total IgE (r = 0.18, P < .001) and higher cord IgE was associated with a higher likelihood of sensitization to common allergens in young adults (OR = 1.18, 95% CI, 1.02-1.37; P = .031). The relationship between cord IgE and sensitization was stronger among teens with no pet exposure in the first year of life (OR = 1.43, 95% CI, 1.16-1.77; P = .001). No relationship was found between cord IgE and blood eosinophil counts or lung function. In addition, no consistent association of cord blood IgE to asthma, allergic rhinitis, or atopic dermatitis was apparent.

CONCLUSIONS

An elevated cord blood IgE level modestly correlates with elevated total IgE and is associated with a slightly higher likelihood of allergic sensitization among young adults. However, cord IgE is not a strong predictor of clinical allergic disorders in this age group.

Elevated cord blood IgE is associated with recurrent wheeze and atopy at 7 yrs in a high risk cohort

There is considerable interest in identifying children at high risk for developing atopic diseases for primary prevention. This study evaluates risk factors for detectable cord blood IgE and assesses CB-IgE in predicting asthma and other IgE-mediated allergic diseases in children at high risk because of family history. Cord blood was obtained as part of a randomized controlled trial assessing the efficacy of an intervention program in the primary prevention of IgE-mediated allergic diseases. CB-IgE was measured and the degree to which this was associated with perinatal risk factors was assessed. The cohort was then evaluated for atopic disorders at 7 yrs of age to assess the predictive value of CB-IgE. Fifty-five (19.3%) of infants had detectable CB-IgE (>/=0.5 kU/l). Maternal atopy and birth in winter months were risk factors associated with detectable CB-IgE. CB-IgE was found to be significantly associated with allergic sensitization (OR 2.22; 95% CI 1.11, 4.41) and recurrent wheeze at 7 yrs (OR 2.51, 95% CI 1.09, 5.76) but not with other outcomes. CB-IgE may be a useful measure for identifying children at high risk of atopic diseases for the purpose of primary prevention.

Cord serum immunoglobulin E as a risk factor for allergic symptoms and sensitization in children and young adults

Early markers of atopic predisposition are needed for targeting allergy preventive measures to high-risk infants. An elevated cord serum immunoglobulin E (CS-IgE) level is considered a risk factor for subsequent allergy in childhood. However, the previous studies have not assessed the predictive value of CS-IgE in a follow-up extended to adulthood. We aimed at clarifying whether CS-IgE is useful in predicting subsequent atopic manifestations up to age 20 yr. A cohort of 200 unselected, full-term newborns were prospectively followed up from birth to age 20 yr. The CS-IgE level was successfully measured in 190 subjects at birth. The subjects were re-examined at ages of 5, 11 and 20 yr with assessment of the occurrence of allergic symptoms during the preceding year, skin prick testing and measurement of serum total IgE. An elevated CS-IgE level was associated with allergic symptoms and skin prick test positivity at age 5 yr (p = 0.03 and 0.01), with allergic rhinoconjunctivitis at age 20 yr (p = 0.04) and with an elevated serum total IgE at ages of 11 and 20 yr (p = 0.02 and 0.01). The sensitivity of CS-IgE, i.e. the probability of an elevated CS-IgE in an infant who subsequently develops atopy, in predicting skin prick test-verified atopy at ages of 5 and 20 yr was 50% and 26%, respectively. The combination of elevated CS-IgE and positive family history of allergy was strongly associated with subsequent atopic manifestations. Nevertheless, it showed a reduced sensitivity as compared to CS-IgE or family history of allergy. We conclude that an elevated CS-IgE level predicts subsequent atopy up to age 20 yr.

IgE against food and respiratory allergens in healthy and allergic mothers and their children

IgE against mixtures of common food or respiratory allergens were determined by ELISA in healthy (n = 38) and allergic (n = 62) mothers and their children. Significantly higher level of IgE against respiratory allergens was found in sera of allergic mothers and in cord blood of their children. No correlation between antibody level in maternal and newborn's sera was found; this argues against the transfer of IgE from mother to fetus and points rather to offspring's intrauterine sensitization. Specific IgE level in cord blood was higher in children who developed later allergy than in children who did not. Specific IgE level in colostrum was low both in healthy and allergic mothers; there was no correlation between high concentration of IgE against respiratory allergens in sera of allergic mothers and their colostrum, which does not support the idea of IgE transport from blood to mammary gland. Only slightly increased colostral IgE was detected in allergic mothers whose children manifested allergy later. Allergy of the mother and high level of anti-allergen IgE in her serum and in cord blood are the main predictive factors of future occurrence of allergy in the offspring. A combination of several predictive factors could have higher prognostic value.

Patterns of sensitization in infants and its relation to atopic dermatitis

Longitudinal studies in infant populations using validated diagnostic criteria of atopic dermatitis and sensitization are rarely reported, and disease definitions, testing procedures, age of study population and evaluation of objective markers vary between countries and studies. The objectives of this prospective birth cohort study were to investigate: (i) the prevalence, the cumulative incidence and the pattern of transient and persistent sensitization to common food- and aeroallergens in unselected infants, (ii) the association between sensitization and the development of atopic dermatitis (AD) and (iii) the association between selected perinatal risk factors with respect to AD and post-natal sensitization. During a one-year period a cohort of 562 unselected newborns was established and followed up at the age of 3, 6, 9, 12 and 18 months of age. At all time points infants were examined clinically and by histamine release (HR), total- and specific immunoglobulin E (IgE) and skin prick test (SPT). Sensitization ever to > or =1 allergen at 18 months of age was 59%, 50% and 6% using HR, IgE and SPT, respectively. A transient sensitization to > or =1 allergen was found in 47%, 42% and 4% and a persistent sensitization in 17%, 10% and 3%, respectively. Sensitization to environmental allergens was frequently observed in infancy when testing with HR and IgE. Results of SPT gave much lower frequencies. Reactivity to foods was more frequent than to aeroallergens. The dominant pattern was low-level transient sensitization. This is important to know when sensitization tests are used in the course of examination of infants with eczematous skin diseases. Specific definitions of sensitization like persistent reactivity, high-level sensitization and poly sensitization were clearly associated with AD. A maternal history of AD was a valuable tool in predicting AD in early infancy; a similar finding was less obvious with regard to post-natal sensitization. Cord-specific IgE and cord-HR positive reactivity did not prove better tools than cord-total IgE in predicting AD within the first 18 living months.

A comparison between criteria for diagnosing atopic eczema in infants

BACKGROUND

Epidemiological studies have shown different estimates of the frequency of atopic eczema (AE) in children. This may be explained by several factors including variations in the definition of AE, study design, age of study group, and the possibility of a changed perception of atopic diseases. The role of IgE sensitization in AE is a matter of debate.

OBJECTIVES

To determine the prevalence and cumulative incidence of AE in a group of unselected infants followed prospectively from birth to 18 months of age using different diagnostic criteria; to evaluate the agreement between criteria; and to describe the association between atopic heredity and postnatal sensitization, respectively, and the development of AE according to the different diagnostic criteria.

METHODS

During a 1-year period a consecutive series of 1095 newborns and their parents were approached at the maternity ward at the Odense University Hospital, Denmark and a cohort of 562 newborns was established. Infants were examined and followed prospectively from birth and at 3, 6, 9, 12 and 18 months of age. AE was diagnosed using four different criteria, the Hanifin and Rajka criteria, the Schultz-Larsen criteria, the Danish Allergy Research Centre (DARC) criteria developed for this study and doctor-diagnosed visible eczema with typical morphology and atopic distribution. Additionally, the U.K. diagnostic criteria based on a questionnaire were used at 1 year of age. Agreement between the four criteria was analysed at each time point and over time, and agreement between the four criteria and the U.K. questionnaire criteria was analysed.

RESULTS

The cumulative 1-year prevalence of AE using the Hanifin and Rajka criteria was 9.8% (95% confidence interval, CI 7-13%), for the Schultz-Larsen criteria it was 7.5% (95% CI 5-10%), for the DARC criteria 8.2% (95% CI 6-11%), for visible eczema 12.2% (95% CI 9-16%) and for the U.K. criteria 7.5% (95% CI 5-10%). The pairwise agreement between criteria showed good agreement, with rates varying between 93% and 97% and kappa scores between 0.6 and 0.8. Agreement analysis of diagnoses between the four criteria demonstrated that cumulative incidences showed better agreement than point prevalence values.

CONCLUSIONS

Agreement between different criteria for diagnosing AE was acceptable, but the mild cases constituted a diagnostic problem, although they were in the minority. Repeated examinations gave better agreement between diagnostic criteria than just one examination. Atopic heredity was less predictive for AE than sensitization to common food and inhalant allergens in early childhood.

In search for predictive factors for atopy in human cord blood

Since early prevention is regarded as an important corner stone in the management of atopic diseases, the identification of reliable markers detecting individuals at risk are of major interest. Therefore, many efforts have been made to unravel reliable predictors for atopy which might identify children at risk and allow the initiation of preventive strategies at an early stage. In the past, much scientific energy has been forced in particular on the development of as noninvasive methods as possible to reach this goal. It is obvious that the identification of markers for atopy at the earliest time of life - namely immediately after birth - represents one of the most attractive attempts. In consequence various studies have been initiated to address this issue investigating markers for atopy in cord blood. Most of them have been geared to our current knowledge about cellular and soluble factors which are dysregulated in adolescent atopic individuals. Although the findings of these studies will improve our knowledge about the initial evolution of atopy, several parameters evaluated did not show any association or have led to almost conflicting results. In order to provide an up-date about the current developments in this field, recent research findings on predictive factors for atopy in cord blood are summarized in the following synopsis.

High levels of cord serum eosinophil cationic protein predict the risk of atopy

BACKGROUND

Transient tachypnoea of the newborn is a transient respiratory disturbance characterized by tachypnoea shortly after birth, which resolves within 2 to 5 days. The basic pathogenetic mechanism is the delayed resorption of the alveolar fluid of which the exact triggering mechanism still remains unknown. An etiological link associated with parenteral history of atopy was proposed by several studies. Some laboratory studies also revealed that serum IgE, eosinophil cationic protein (ECP) and cord IgE were higher among infants with maternal history of atopy.

OBJECTIVE

The purpose of this study was to investigate the possible association of parental history of atopy with cord blood ECP and IgE concentrations in infants with transient tachypnoea of the newborn.

METHODS

ECP and IgE levels were quantified in cord blood samples of 30 infants who were diagnosed as having transient tachypnoea of the newborn. The control group (N=30) was selected among healthy newborns with similar birth weight and gestational age.

RESULTS

Cord blood ECP concentrations were significantly higher in the study group (17.6 microg/L) than in healthy control subjects (7.89 microg/L). In addition, transient tachypnoea of the newborn was more frequent in infants with a family history of atopic disease (p<0.01). Cord blood IgE concentrations were also higher in the study group than the controls (4.1 versus 3.28 mg/L) but the difference was not statistically significant (p>0.05).

CONCLUSION

Family history of atopy and elevated levels of cord blood ECP are risk factors for transient tachypnoea of the newborn. In addition cord blood ECP level is a useful marker for predicting the risk of atopy.

Raised cord serum immunoglobulin E increases the risk of allergic sensitisation at ages 4 and 10 and asthma at age 10

BACKGROUND

Evidence suggests that a raised level of cord serum IgE (CS-IgE) is a risk factor for allergic sensitisation. However, whether CS-IgE is a risk for asthma is controversial. A study was undertaken to investigate the association between CS-IgE levels and allergic sensitisation at 4 and 10 years of age and asthma at ages 1-2, 4 and 10.

METHODS

CS-IgE was available for 1358 of 1456 children born between 1989 and 1990. The cohort was evaluated for allergic diseases at ages 1, 2, 4 and 10 years. Skin prick tests for six allergens were performed on 981 children at age 4 and 1036 at age 10. Asthma was defined based on a physician's diagnosis. Using logistic regression analysis, the risk of asthma and allergic sensitisation for raised levels of CS-IgE (> or =0.5 kU/l) was estimated.

RESULTS

At ages 4 and 10 years 20.2% and 27.0% of children, respectively, had allergic sensitisation. The risk of allergic sensitisation was significantly associated with raised CS-IgE levels at ages 4 (OR 2.29) and 10 years (OR 1.73). The prevalence of asthma was 10.3% at age 1-2, 15.2% at age 4, and 12.8% at age 10. CS-IgE was not associated with asthma at age 1-2 and 4 but showed an increased relative risk at age 10 (OR 1.66, 95% CI 1.05 to 2.62). The association was stronger in children who did not develop allergic sensitisation at age 4 or 10 (OR 3.35, 95% CI 1.41 to 7.93).

CONCLUSIONS

Raised cord serum IgE is a risk factor for allergic sensitisation at ages 4 and 10 years. This is the second study suggesting that CS-IgE is also a risk factor for asthma at age 10, probably related to the late onset of asthma. This association is not necessarily mediated by allergic sensitisation.

T cell reactivity in neonates from an East and a West German city--results of the LISA study

BACKGROUND

Within an ongoing birth cohort study (LISA) the cytokine production of cord blood T cells was compared between neonates from Leipzig (East Germany) and Munich (West Germany). The aim of this study was to analyse regional differences and influencing factors of the immune status.

METHODS

Cytokine production was measured in a randomly selected subgroup of 158 children from the LISA (Life style - Immune system - Allergy) cohort by intracellular cytokine staining. Information on family "atopy" history (FAH) and home characteristics was obtained from questionnaires.

RESULTS

Reduced numbers of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) producing T cells were found in association with biparental FAH and housing renovation during pregnancy. In addition, cytokine production was influenced by season. In Munich, the frequency of biparental FAH and of renovation measures during pregnancy was significantly higher as compared to Leipzig. Neonates from Munich showed significantly decreased amounts of IFN-gamma and TNF-alpha and elevated levels of interleukin-4 (IL-4) producing T cells. Differences in cytokine production between Munich and Leipzig were influenced by season (IL-4) and housing renovation (IFN-gamma, TNF-alpha).

CONCLUSIONS

Since differences in the T cell cytokine production of neonates in Munich and Leipzig are independent from FAH our findings may provide evidence for the impact of environmental factors upon the fetal immune system.

Clinical course of cow's milk protein allergy/intolerance and atopic diseases in childhood

A cohort of 1,749 newborns from the municipality of Odense, born during 1995 at the Odense University Hospital, were followed up prospectively for the development of cow's milk protein allergy/intolerance (CMPA/I) during the first year of life. Once a diagnosis of CMPA/I was confirmed, a milk-free diet was continued until a new milk challenge had shown development of tolerance. All infants with CMPA/I were rechallenged at 12 months of age and, in the event of continued clinical sensitivity to cow's milk protein, controlled rechallenges were performed every 6 months up to 3 years of age; and thereafter every 12 months until the age of 15 years. From the same birth cohort, 276 infants were randomly selected at birth for prospective non-interventional follow-up in order to investigate the natural course of sensitization and development of atopic disease during childhood. Standardized questionnaires on atopic heredity, environmental factors and presence of atopic symptoms were answered at 0, 6, 12 and 18 months and at 5, 10 and 15 years of age. Interviews on atopic history and environmental factors as well as physical examination were carried out at 18 months, 5, 10 and 15 years of age. Skin prick test and specific sIgE (Pharmacia CAP) testing were performed at 18 months, 5, 10 and 15 years of age against a panel of inhalant allergens (birch, grass, mugwort, dog, cat, horse, Dermatophagoidespteronyssinus, Dermatophagoides farinae, alternaria and cladosporium herbarum). Furthermore, lung function measurements were performed in children when 10 and 15 years of age. Based on controlled milk elimination and challenge procedures, the diagnosis of CMPA/I was confirmed in 39 out of 117 infants, with symptoms suggestive of CMPA/I, thus resulting in a 1-year incidence of CMPA/I of 2.2%. The overall prognosis of CMPA/I was good, with a total recovery of 56% at 1 year, 77% at 2 years, 87% at 3 years, 92% at 5 and 10 years and 97% at 15 years of age. In children younger than 10 years of age, 41% developed asthma and 31% rhinoconjunctivitis. Children with non-IgE-mediated CMPI had a good prognosis, whereas children with IgE-mediated CMPA in early childhood had a significantly increased risk for persistent CMPA, development of other food allergies, asthma and rhinoconjunctivitis. During early infancy, recurrent wheezing was the most prevalent disease (20%), followed by atopic dermatitis (14%) and food allergy (7%) at 18 months of age. Physician diagnosed asthma increased from 2% at 1.5 years of age to 9% at 10 years of age. Rhinoconjunctivitis increased from <1% at 1.5 years of age to 9% at 10 years of age. Overall, the current prevalence of any atopic disease was 20% at 1.5 years of age, declining to 14% at 5 years of age and followed by an increase to 25% at 10 years of age. Sensitization to inhalant and/or food allergens (specific IgE of > or = class 2; CAP RAST) showed a low rate of sensitization among asymptomatics (3%, 10% and 12%) compared with higher rates of sensitization of 8%, 39% and 30% among symptomatic atopics at 1.5, 5 and 10 years of age respectively. The highest rate of sensitization (53%) was found among children with current asthma at 10 years of age.

Definition of respiratory symptoms and disease in early childhood in large prospective birth cohort studies that predict the development of asthma

We have reviewed the prospective value of early respiratory symptoms for determining the risk of development of asthma later in life by using data from studies based on the general population, hospital population, and general practices. Although "wheezing" in infancy generally has a good prognosis, it is an important risk factor for the development of asthma later in life. The prognostic value of "coughing" and "shortness of breath" in infancy for the later development of asthma is less clear. Despite the fact that no internationally accepted criteria for the definition of asthma in early childhood are available, many studies have been performed on this topic. We also investigated the outcome variables that were used to describe respiratory symptoms and disease in early childhood in the publications of nine large prospective birth cohort studies on the development of asthma. From seven of these studies, we reviewed the original questionnaires. We found that various studies used different outcome variables, but the data actually collected were similar. This is an important observation because it implies that comparisons between studies can be markedly improved by data sharing among investigators.

Exposure to a high concentration of mite allergen in early infancy is a risk factor for developing atopic dermatitis: a 3-year follow-up study

The cause of allergy is multi-factorial, and the development of an allergic disease seems to be the result of an interaction between genetic and environmental factors. The goal for preventing the development of allergic diseases is to avoid sensitization to allergens. The aim of this work was to study whether or not exposure to environmental allergens early in infancy would influence the occurence of various allergic diseases in later life. On an annual basis, a total of 931 healthy newborns were followed-up until they reached 3 years of age. The occurence of allergic diseases was recorded by trained medical students during visits. Measurement of Dermatophagoides pteronyssinus (Der p 1) concentration in house dust was performed when each baby was 18 and 36 months old. Total and specific immunoglobulin E (IgE) antibodies against Der p 1, cow's milk, and egg white were evaluated at birth and at 18 months of age. The following results were obtained: at 3 years of age, 10.4% had bronchial asthma (BA), 21.4% atopic dermatitis (AD), 7.0% urticaria, and 46.8% had experienced wheezing; higher family allergy scores led to a higher incidence of AD (p=0.0012); exposure to a mite allergen concentration of 1 microg/g of dust may be associated with a higher incidence of AD (p=0.0156); the presence of Der p 1 IgE antibody at 18 months of age was associated with a higher incidence of BA (p=0.0001); and children sensitized to egg whites at 18 months of age had an increased risk of developing AD at 3 years of age (p=0.0187). Hence, early exposure to mite allergen is a risk factor for the development of atopic dermatitis, but seems not to be related to the development of bronchial asthma. Early sensitization to egg whites increases the risk of developing AD. The early detection of serum Der p 1 IgE antibody is associated with a higher incidence of bronchial asthma.

Cord blood IgE: its determinants and prediction of development of asthma and other allergic disorders at 12 months

BACKGROUND

The value of cord blood IgE in predicting the development of asthma and other IgE-mediated allergic diseases is unclear.

OBJECTIVE

The purpose of this study is twofold: (1) to determine factors affecting cord blood IgE level and (2) to determine whether cord blood IgE predicts the development of asthma and other IgE-mediated allergic diseases in high risk (defined as those with at least one first degree relative with asthma or 2 first degree relatives with other IgE-mediated allergic diseases) infants at 12 months.

METHODS

The study utilized cord blood obtained from a group of high risk infants who took part in a randomized controlled trial to assess the effectiveness of an intervention program in the primary prevention of asthma and other IgE-mediated allergic diseases. Total IgE and cotinine in the cord blood were measured. Assessment of the infants was done at 12 months for these diseases.

RESULTS

Sixty-four (17.8%) infants had detectable total IgE in cord blood >0.5 kU/L. The proportion of infants with elevated cord blood IgE was significantly higher among nonwhites, birth during winter months, and those with a maternal history of asthma. There was no correlation between cord blood IgE and cord blood cotinine level. Cord blood IgE was found to be a significant predictor for the development of urticaria due to food allergy but not for other outcomes.

CONCLUSION

Both genetic and environmental risk factors play a role in determining the level of IgE in cord blood. Cord blood IgE was a significant risk factor for the development of urticaria due to food allergy at 12 months of life. As urticaria due to food allergy is a prodrome for anaphylaxis, measurement of IgE in cord blood may be indicated in infants at high risk for developing allergic diseases so that preventive measures can be applied.

Cord blood-IgE as risk factor and predictor for atopic diseases

BACKGROUND

Cord blood-IgE as risk factor or predictor for atopic diseases in infants has been discussed in a large number of papers with contradictory results. Our aim was to evaluate cord blood-IgE as risk factor and predictor for atopic dermatitis, recurrent wheezing and sensitization with emphasis on a clear-cut distinction between risk factor and predictor.

METHODS

A cohort of 1314 newborns was recruited in six German obstetric departments and followed-up for 5 years. Four hundred and ninety-nine infants (38%) were considered to be at high risk with at least two atopic family members and/or a cord blood-IgE value above the threshold of 0.9 kU/L. At follow-up visits, parents filled in a questionnaire, the infants were clinically examined, and blood samples were taken.

RESULTS

With regard to early onset atopic dermatitis up to 12 months we found that the odds ratios at the cord blood-IgE cut-off points of 0.70 kU/L and 1.25 kU/L with values of 0.53 and 0.32, respectively, were smaller than one (i.e. protective factors) and highly statistically significant. No significant association was found between elevated cord blood-IgE and recurrent wheezing. There was a strong positive association between elevated cord blood-IgE levels and sensitization at 12 months, but even in this case the predictive performance was rather poor: a maximum positive predictive value of 42% was attained with a cut-off point of 3.0 kU/L, but the sensitivity was only 10%.

CONCLUSION

We conclude that even when elevated cord blood-IgE levels are identified as a strong risk factor for sensitization, their poor predictive performance may make them useless as a basis for preventive measures.

Early life markers of atopy and asthma

Since early intervention could modulate the natural course of atopic disease, the availability of predictive markers is of considerable interest. As long as specific genetic markers are not available, early IgE-responses (hen's egg) together with a positive family history of atopy can be proposed as highly specific and predictive markers, which could define subgroups as potential candidates for secondary prevention.

Factors predicting food allergy

Prediction of food allergies has not been addressed systematically and to date studies have concentrated on prediction of allergic disorders in a general fashion. The current available data suggests that possibly the best predictor is the combined approach of taking into account the family history together with elevated cord blood IgE. Other indicators, such as cord blood lymphocyte responses and γ-interferon production at birth, are also discussed. Although preliminary studies seem to be promising, only studies of an unselected population with long term follow-ups will be able to show whether or not these possible predictors are of value.

Neonatal IgA and IgE levels among infants with paternal heredity for atopic disease

Serum IgA and IgE levels were studied in the postnatal period in 21 infants having a paternal heredity of atopic disease. Three different sampling techniques were used, aspirated cord blood (CB), gravity-collected cord blood, and capillary collected blood at 4-5 days of age. Significant differences among the three sampling techniques were recorded for IgA (P < 0.01), but not for IgE. The IgA levels decreased from birth to 4-5 days of age in 90% (19/21 of infants (P < 0.01). The corresponding decrease in IgE levels was 20%. This postnatal difference in the frequency of decreasing/increasing IgA and IgE levels was significant (P < 0.05). An analysis of CB IgA to detect maternal contamination of CB was found to be of questionable value, since only 50% (2/4) of the cases with an elevated CB-IgA level could be considered contaminated. The results of this study further emphasize that aspiration of CB and capillary collection of blood at 4-5 days of age are the best sampling techniques to avoid contamination. The general finding that paternal heredity had no significant influence on infant IgE contrasts with the strong influence of maternal heredity. Further studies will show whether the explanation lies in genetic or transplacental factors, or in both kinds of factors.

Role of clinical laboratory in allergy testing

The clinical laboratory has a well defined role to play in the diagnosis and management of patients with allergy. Elevated serum levels of total IgE and/or allergen-specific IgE indicate that an IgE mediated event has occurred. Methods such as basophil degranulation and basophil or leukocyte histamine release can provide similar information. Sensitive and precise methods suitable for automation are available for quantitation of histamine in whole blood or plasma. Methyl histamine can be assayed in urine. Eosinophil cationic protein levels in serum can be used as an indicator of eosinophil activation in disorders such as asthma and atopic dermatitis. Similarly, serum mast cell tryptase levels can confirm or exclude an anaphylactic reaction both in life and as a cause of death. This review documents and compares commercially available methods for these assays and discusses their application to screening, diagnosis, and management of patients with allergy.

Several genetic and environmental factors influence cord blood IgE concentration

Cord blood samples were collected from a birth cohort of 2631 infants to elucidate the association between genetic and environmental factors and fetal production of IgE. The cord blood IgE values were treated both as a continuous and as a dichotomous variable in the statistical analyses. Multivariate analysis was used to control for confounding factors. Infants with single and biparental atopic heritage had higher IgE concentrations in cord plasma than children of parents without atopy. Multiple logistic regression analysis revealed a significant association to maternal allergic eczema or perennial rhinitis. The cord blood IgE concentration varied with month of birth with peaks in late autumn. This seasonal variation was not related to parental atopic disease. Boys had significantly higher levels of IgE and more often elevated IgE values (> or = 0.5 kU/l) than girls. Alcohol and caffeine consumption by the mothers during pregnancy were both significantly associated with elevated IgE concentration. There was also a relation between mothers prepregnant weight and elevated CB-IgE levels. No significant association was observed between maternal smoking and cord plasma IgE levels. The fact that many factors presumably not related to child allergy seem to influence the regulation of fetal IgE production, could explain the questionable value of cord blood IgE in predicting allergy in childhood.

Prediction of allergy from family history and cord blood IgE levels. A follow-up at the age of 5 years. Cord blood IgE. IV

Screening of total IgE in 1189 cord blood samples was conducted by Phadebas IgE PRIST in a one-year birth cohort 1983-1984 in Viborg, Denmark. 113 children with cord blood IgE levels > or = 0.5 kU/l and 138 children chosen at random among those with cord blood IgE levels < 0.5 kU/l were seen at a follow-up at 5 years of age. Based upon history and physical examination a diagnosis of definite atopy or no atopy was established. Allergy (IgE mediated) was defined as atopic disease combined with increased total IgE levels at 5 years of age. The cumulative prevalence of atopic disease was not influenced by cord blood IgE levels or atopic predisposition. Cord blood IgE levels had a low sensitivity as a predictor of atopic disease. A statistically significant correlation between serum levels of IgE at birth and at 5 years was however found (p < 0.001), and a significantly greater number of children with elevated cord blood IgE levels developed allergic disease before 5 years of age (p < 0.01). A cut-off limit of 0.3 kU/l was superior to the originally suggested limit of 0.5 kU/l. A total IgE level > 63 kU/l (geometric mean + 1 SD) at the age of 5 years can be regarded as being an elevated level. A cord blood IgE level > or = 0.3 kU/l in combination with atopic predisposition was predictive of allergic disease, especially allergic bronchial asthma. With regard to allergic disease, the positive predictive value was 26%, the sensitivity 33% and the rate ratio for development of allergic disease 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Cord blood IgE. III. Prediction of IgE high-response and allergy. A follow-up at the age of 18 months

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). For follow-up we chose all infants with cord blood IgE greater than or equal to 0.5 kU/l and a randomly chosen group of the same size with cord blood IgE less than 0.5 kU/l. A total group of 762 infants were clinically evaluated at 18 months of age, and in 688 of these we evaluated total and specific IgE. A diagnosis of definite atopy, probable atopy or no atopy was established. In the present study we defined allergic disease as atopic disease combined with elevated total IgE. We found a statistically significant correlation between cord blood IgE and IgE at 18 months of age. Significantly more infants with elevated cord blood IgE had developed allergic disease at 18 months. A cut-off value of 0.3 kU/l for cord blood IgE was superior to the originally suggested 0.5 kU/l. Significantly more infants with elevated cord blood IgE had developed specific IgE antibodies at 18 months. The most frequent specific IgE antibody was towards cow's milk. Specific IgE antibodies were very rarely found when total IgE was not elevated. A total IgE at the age of 18 months greater than 26 kU/l could be regarded as elevated. With regard to allergic disease the positive predictive values of cord blood IgE greater than or equal to 0.3 kU/l in the 2 series were 21% and the corresponding sensitivities 67% and 46%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Cord blood IgE. I. IgE screening in 2814 newborn children

Screening of total IgE in 2814 cord blood samples was analysed by Phadebas IgE PRIST in 2 1-year birth cohorts (1983-1984 and 1985-1986) in Denmark (n = 1189 + 1625). 48.6% of the sera contained less IgE than the detection limit 0.1 kU/l. Cord blood IgE values greater than or equal to 0.5 kU/l were regarded as elevated. 13.2% of the sera contained at least 0.5 kU/l of IgE, with a significant preponderance in boys. Geometric mean cord blood IgE was 0.13 kU/l and 0.12 kU/l, respectively. Geometric mean cord blood IgE was significantly higher in boys. A significant seasonal variation with lowest IgE values in the autumn was found. No correlation between cord blood IgE and birth weight or gestational age was demonstrated. Only few newborns had cord blood IgA values greater than 0.014 g/l, calculated as geometric mean cord blood IgA + 2 SD among children with no detectable cord blood IgE, indicating infrequent contamination with maternal blood.