IgE sensitization to food allergens and airborne allergens in relation to biomarkers of type 2 inflammation in asthma

BACKGROUND

We have recently reported that sensitization to food allergens and sensitization to airborne allergens had independent associations with increased fraction of exhaled nitric oxide (FeNO) and blood eosinophils in middle-aged adults and in young subjects with asthma.

OBJECTIVE

To investigate the relation between IgE sensitization and several type 2 inflammation biomarkers in adult asthmatics.

METHODS

FeNO, urinary eosinophil-derived neurotoxin (U-EDN), serum eosinophil cationic protein (S-ECP) and periostin were measured in 396 asthmatics, aged 17-76 years, from the Swedish GA2LEN study. Sensitization to airborne allergens was examined with skin prick tests (≥3 mm wheal) and sensitization to food allergens with measurement of specific IgE (≥0.35 kU/L).

RESULTS

Asthmatics sensitized to food allergens had higher FeNO, 22.3 ppb (18.6, 26.7) vs 16.1 ppb (14.2, 18.2) (P = .005), S-ECP, 17.7 mg/L (14.8, 21.1) vs 12.8 mg/L (10.9, 14.9) (P = .01), and periostin, 73.7 (67.5, 80.3) ng/mL vs 59.9 (55.8, 64.2) ng/mL (P = .003), than non-sensitized subjects. Periostin levels in this group were also significantly higher than in the group sensitized only to airborne allergens (P = .01). Sensitization to food allergens related independently to FeNO (P = .02), S-ECP (P = .006) and periostin (P = .004), whereas sensitization only to airborne allergens related only to FeNO (P = .02) after adjustments for age, sex, height, weight and smoking history. FeNO correlated weakly with S-ECP (r = .17, P < .001), periostin (r = .19, P < .001) and U-EDN (0.16, P < .001). S-ECP also correlated weakly with U-EDN (r = .12, P = .02). None of the correlations between the remaining pairs of markers of type 2 inflammation were significant.

CONCLUSIONS & CLINICAL RELEVANCE

Sensitization to food allergens related to several local and systemic type 2 inflammation markers, such as FeNO, S-ECP and periostin. Assessing the profile of allergic sensitization, including to food allergens, might improve the understanding and interpretation of inflammatory markers and potentially improve asthma management.

Sensitization to minor cat allergen components is associated with type-2 biomarkers in young asthmatics

BACKGROUND

Cat allergy is a major trigger of asthma world-wide. Molecular patterns of cat sensitization vary between individuals, but their relationship to inflammation in asthmatics has not been extensively studied.

OBJECTIVE

To investigate the prevalence and levels of IgE antibodies against different cat allergen components and their relationship to type-2 inflammation and total IgE among young asthmatic subjects sensitized to furry animals.

METHODS

Patients with asthma (age 10-35 years; n = 266) and IgE sensitization to cat, dog or horse extract (ImmunoCAP), were analysed for IgE to the cat allergen components Fel d 1 (secretoglobin), Fel d 2 (serum albumin), Fel d 4 and Fel d 7 (lipocalins). Independent associations between IgE-antibody concentrations, and fraction of exhaled nitric oxide (FeNO), blood eosinophil (B-Eos) count, and total IgE were analysed by multiple linear regression after adjustment for possible confounders.

RESULTS

The level of IgE against Fel d 2 was independently related to FeNO (P = .012) and total IgE (P < .001), and IgE against Fel d 4 associated with Β-Eos count (P = .009) and total IgE (P < .001). IgE antibodies against Fel d 1 or cat extract did not independently relate to these inflammatory markers (P = .23-.51).

CONCLUSIONS

Levels of IgE to lipocalin (Fel d 4) and serum albumin (Fel d 2), but not to secretoglobin (Fel d 1) or cat extract, were independently associated with type-2 biomarkers and total IgE in young asthmatics.

CLINICAL RELEVANCE

We suggest that measurement of IgE to minor cat allergen components may be useful when investigating asthma morbidity in cat allergic subjects.

The absence of serum IgE antibodies indicates non-type 2 disease in young asthmatics

BACKGROUND

Atopic asthma is associated with elevated type-2 biomarkers such as fraction of exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) count. However, increased type 2 markers have also been reported in traditionally defined non-atopic asthma.

OBJECTIVE

To determine a clinically useful level of IgE sensitization for ruling out type 2 asthma.

METHODS

Asthmatics (N = 408; age 10-35 years) were analysed using the multi-allergen tests Phadiatop and fx5 (ImmunoCAP). Subjects were grouped based on IgE-antibody concentrations: ≥0.35 kU_A /L for at least one test (n = 326) or <0.35 kU_A /L for both tests (n = 82). Τhe latter group was subsequently divided into 2 groups: IgE 0.10-0.34 kU_A /L (n = 34) and IgE < 0.10 kU_A /L (n = 48). The relationships between type 2 biomarkers, and inadequate asthma control (ACT < 20), reduced lung function (FEV₁  < 80%), recent asthma attacks and airway hyperresponsiveness (AHR) to methacholine were determined.

RESULTS

In univariate analyses, at least one type 2 marker related to each asthma outcome in subjects with IgE ≥0.35 kU_A /L. In subjects with IgE 0.10-0.34 kU_A /L, elevated FeNO related to reduced lung function (P = .008) and B-Eos to AHR (P = .03). No associations were found in subjects with IgE < 0.10 kU_A /L. In multivariate analysis, a relationship between FeNO and reduced lung function remained in subjects with IgE < 0.35 kU_A /L (P = .03).

CONCLUSION AND CLINICAL RELEVANCE

Clinically relevant elevation of type 2 biomarkers was seen in young asthmatics with IgE antibodies <0.35 kU_A /L, but not those with IgE < 0.10 kU_A /L. It seems possible to define non-type 2 asthma through sensitive IgE-antibody measurement.

Allergen extract vs. component sensitization and airway inflammation, responsiveness and new-onset respiratory disease

BACKGROUND

The absence of IgE sensitization to allergen components in the presence of sensitization to the corresponding extract has been reported, but its clinical importance has not been studied.

OBJECTIVE

To evaluate the clinical significance of IgE sensitization to three aeroallergen extracts and the corresponding components in relation to the development of respiratory disease.

METHODS

A total of 467 adults participated in the European Community Respiratory Health Survey (ECRHS) II and 302 in ECRHS III, 12 years later. IgE sensitization to allergen extract and components, exhaled nitric oxide (FeNO) and bronchial responsiveness to methacholine were measured in ECRHS II. Rhinitis and asthma symptoms were questionnaire-assessed in both ECRHS II and III.

RESULTS

A good overall correlation was found between IgE sensitization to extract and components for cat (r = 0.83), timothy (r = 0.96) and birch (r = 0.95). However, a substantial proportion of subjects tested IgE positive for cat and timothy allergen extracts but negative for the corresponding components (48% and 21%, respectively). Subjects sensitized to both cat extract and components had higher FeNO (P = 0.008) and more bronchial responsiveness (P = 0.002) than subjects sensitized only to the extract. Further, subjects sensitized to cat components were more likely to develop asthma (P = 0.005) and rhinitis (P = 0.007) than subjects sensitized only to cat extract.

CONCLUSION

Measurement of IgE sensitization to cat allergen components would seem to have a higher clinical value than extract-based measurement, as it related better to airway inflammation and responsiveness and had a higher prognostic value for the development of asthma and rhinitis over a 12-year period.

Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control

BACKGROUND

Classic spirometry is effort dependent and of limited value in assessing small airways. Peripheral airway involvement, and relation to poor control, in asthma, has been highlighted recently. Forced oscillation technique (FOT) offers an effort-independent assessment of overall and peripheral lung mechanics. We studied the association between lung function variables, obtained either by spirometry or multifrequency (5, 11 and 19 Hz) FOT, and asthma diagnosis and control.

METHODS

Spirometry measures, resistance at 5 (R5) and 19 Hz (R19), reactance at 5 Hz (X5), resonant frequency (f_res ), resistance difference between 5-19 Hz (R5-R19) and Asthma Control Test scores were determined in 234 asthmatic and 60 healthy subjects (aged 13-39 years). We used standardized lung function variables in logistic regression analyses, unadjusted and adjusted for age, height, gender and weight.

RESULTS

Lower FEV₁ /FVC (OR [95% CI] 0.47 [0.32, 0.69]) and FEF₅₀ (0.62 [0.46, 0.85]) per standard deviation increase, and higher R5 (3.31 [1.95, 5.62]) and R19 (2.54 [1.65, 3.91]) were associated with asthma diagnosis. Independent predictive effects of FEV₁ /FVC and R5 or R19, respectively, were found for asthma diagnosis. Lower FEV₁ /FVC and altered peripheral FOT measures (X5, f_res and R5-R19) were associated with uncontrolled asthma (P-values < .05).

CONCLUSIONS

Resistance FOT measures were equally informative as spirometry, related to asthma diagnosis, and, furthermore, offered additive information to FEV₁ /FVC, supporting a complementary role for FOT. Asthma control was related to FOT measures of peripheral airways, suggesting a potential use in identifying such involvement. Further studies are needed to determine a clinical value and relevant reference values in children, for the multifrequency FOT measurements.

Conjunctival provocation test in diagnosis of peanut allergy in children

BACKGROUND

Peanut allergy frequently causes severe allergic reactions. Diagnosis includes detection of IgE to peanuts in serum or by skin prick tests. While children may have allergic sensitization without having clinical peanut allergy, oral peanut challenge is often required for accurate diagnosis. The conjunctival provocation test is used for diagnosis and evaluation of treatment effect in inhalant allergies, but it has not been evaluated as a tool for diagnosing peanut allergy.

OBJECTIVE

To investigate whether the conjunctival provocation tests may be feasible, accurate and safe in diagnosing clinically relevant peanut allergy in patients with suspected peanut allergy.

METHODS

This cross-sectional case-control study in children with clinical or laboratory suspected peanut allergy included 102 children recruited from the regional paediatric departments and specialist practices during one year from April 2011. A peanut-tolerant control group of 28 children of similar age was recruited locally. A double-blind placebo-controlled conjunctival provocation test with peanut extract was performed in all children, while oral peanut provocation was performed as double-blind placebo-controlled challenge in children with suspected peanut allergy and as an open challenge in the control children.

RESULTS

All 81 children with a positive double-blind placebo-controlled oral food challenge (OFC) also had a positive conjunctival provocation test. None of the children with negative conjunctival provocation test had a positive OFC. The sensitivity and the specificity of the conjunctival provocation test were 0.96 and 0.83, respectively. No children had severe adverse reaction caused by the conjunctival provocation test, whereas 23 children suffered an anaphylactic reaction to the OFC.

CONCLUSION AND CLINICAL RELEVANCE

Conjunctival allergen challenge appears to be feasible, accurate and safe in diagnosing children referred for suspected peanut allergy.

Measurement of specific IgE antibodies to Ses i 1 improves the diagnosis of sesame allergy

BACKGROUND

The number of reported cases of allergic reactions to sesame seeds (Sesamum indicum) has increased significantly. The specific IgE tests and skin prick tests presently available for diagnosis of sesame allergy are all based on crude sesame extract and are limited by their low clinical specificity. Thus, oral food challenge (OFC) is still the gold standard in the diagnosis.

OBJECTIVE

The aim was to identify the allergen components useful to diagnose sesame-allergic children with the goal to reduce the number of OFCs needed.

METHODS

Ninety-two sesame-sensitized children were consecutively enrolled and diagnosed based on OFC or convincing history. Specific IgE to purified native 11S globulin (nSes i 11S), 7S globulin (nSes i 7S), 2S albumin (nSes i 2S), and two recombinant 2S albumins (rSes i 1 and rSes i 2) was measured by ELISA and/or ImmunoCAP (rSes i 1/streptavidin application).

RESULTS

Based on area under curve (AUC) values from receiver operating characteristic (ROC) analysis, rSes i 1 was shown to have the best diagnostic performance of the allergen components in ELISA. The experimental rSes i 1 ImmunoCAP test had larger AUC (0.891; 95% CI, 0.826-0.955) compared to the commercially available sesame ImmunoCAP (0.697; 95% CI, 0.589-0.805). The clinical sensitivity and specificity for the rSes i 1 ImmunoCAP test at optimal cut-off (3.96 kUA /L) were 86.1% and 85.7%, respectively.

CONCLUSION AND CLINICAL RELEVANCE

Sensitization to Ses i 1 is strongly associated with clinical sesame allergy. Measurement of specific IgE to rSes i 1 could reduce the numbers of OFCs needed.

Simultaneously elevated exhaled nitric oxide and serum-eosinophil cationic protein relate to recent asthma events in asthmatics in a cross-sectional population-based study

BACKGROUND

We have reported that increased fraction of exhaled nitric oxide (FeNO), a measure of TH₂ -driven airway inflammation, and blood eosinophil count, a marker of systemic eosinophil inflammation, correlated with asthma attacks in a population-based study.

OBJECTIVE

To investigate the relation between simultaneously elevated FeNO and serum eosinophil cationic protein (S-ECP) levels and asthma events among asthmatics.

METHODS

Measurements of FeNO (elevated ≥ 25 ppb) and S-ECP (elevated ≥ 20 ng/mL) were performed in 339 adult asthmatics. Asthma events (attacks and symptoms) were self-reported.

RESULTS

Simultaneously normal S-ECP and FeNO levels were found in 48% of the subjects. Subjects with simultaneously elevated S-ECP and FeNO (13% of the population) had a higher prevalence of asthma attacks in the preceding 3 months than subjects with normal S-ECP and FeNO (51% vs. 25%, P = 0.001). This was not found for subjects with singly elevated S-ECP (P = 0.14) or FeNO (P = 0.34) levels. Elevated S-ECP and FeNO levels were independently associated with asthma attacks in the preceding 3 months after adjusting for potential confounders (OR (95% CI) 4.2 (2.0-8.8).

CONCLUSIONS

Simultaneously elevated FeNO and S-ECP levels were related to a higher likelihood of asthma attacks in the preceding 3 months. This indicates that there is a value in measuring both FeNO and systemic eosinophilic inflammation in patients with asthma to identify individuals at high risk of exacerbations.

CLINICAL RELEVANCE

FeNO and S-ECP are markers for inflammation in asthma, but are dependent on different inflammatory pathways and weakly correlated. Simultaneous measurements of both offer better risk characterization of adult asthmatics.

Multiplex component-based allergen microarray in recent clinical studies

During the last decades component-resolved diagnostics either as singleplex or multiplex measurements has been introduced into the field of clinical allergology, providing important information that cannot be obtained from extract-based tests. Here we review recent studies that demonstrate clinical applications of the multiplex microarray technique in the diagnosis and risk assessment of allergic patients, and its usefulness in studies of allergic diseases. The usefulness of ImmunoCAP ISAC has been validated in a wide spectrum of allergic diseases like asthma, allergic rhinoconjunctivitis, atopic dermatitis, eosinophilic esophagitis, food allergy and anaphylaxis. ISAC provides a broad picture of a patient's sensitization profile from a single test, and provides information on specific and cross-reactive sensitizations that facilitate diagnosis, risk assessment, and disease management. Furthermore, it can reveal unexpected sensitizations which may explain anaphylaxis previously categorized as idiopathic and also display for the moment clinically non-relevant sensitizations. ISAC can facilitate a better selection of relevant allergens for immunotherapy compared with extract testing. Microarray technique can visualize the allergic march and molecular spreading in the preclinical stages of allergic diseases, and may indicate that the likelihood of developing symptomatic allergy is associated with specific profiles of sensitization to allergen components. ISAC is shown to be a useful tool in routine allergy diagnostics due to its ability to improve risk assessment, to better select relevant allergens for immunotherapy as well as detecting unknown sensitization. Multiplex component testing is especially suitable for patients with complex symptomatology.

Increase in pollen sensitization in Swedish adults and protective effect of keeping animals in childhood

BACKGROUND

To date, most studies of the 'allergy epidemic' have been based on self-reported data. There is still limited knowledge on time trends in allergic sensitization, especially among adults.

OBJECTIVE

To study allergic sensitization, its risk factors and time trends in prevalence.

METHODS

Within West Sweden Asthma Study (WSAS), a population-based sample of 788 adults (17-60 years) underwent skin prick tests (SPTs) for 11 aeroallergens 2009-2012. Specific IgE was analysed in 750 of the participants. Those aged 20-46 years (n = 379) were compared with the European Community Respiratory Health Survey sample aged 20-46 year from the same area (n = 591) in 1991-1992.

RESULTS

Among those aged 20-46 years, the prevalence of positive SPT to pollen increased, timothy from 17.1% to 29.0% (P < 0.001) and birch from 15.6% to 23.7% (P = 0.002) between 1991-1992 and 2009-2012. Measurements of specific IgE confirmed these increases. Prevalence of sensitization to all other tested allergens was unchanged. In the full WSAS sample aged 17-60 years, any positive SPT was seen in 41.9%, and the dominating sensitizers were pollen (34.3%), animals (22.8%) and mites (12.6%). Pollen sensitization was strongly associated with rhinitis, whereas indoor allergens were more associated with asthma. Growing up with livestock or furred pets decreased the risk of sensitization, adjusted odds ratio 0.53 (0.28-0.995) and 0.68 (0.47-0.98), respectively.

CONCLUSION

Pollen sensitization has increased in Swedish adults since the early 1990s, while the prevalence of sensitization to other allergens has remained unchanged. This is one plausible explanation for the increase in rhinitis 1990-2008 in Swedish adults, during which time the prevalence of asthma, which is more associated with perennial allergens, was stable. Contact with animals in childhood seems to reduce the risk of sensitization well into adulthood. One major factor contributing to the rise in pollen allergy is a significant increase in levels of birch and grass pollen over the past three decades.

High IgE levels to α-lactalbumin, β-lactoglobulin and casein predict less successful cow's milk oral immunotherapy

BACKGROUND

A new treatment option for persistent cow's milk allergy (CMA) is oral immunotherapy (OIT). Not all patients develop tolerance during therapy, and markers to identify those who will benefit from it are needed. The objective was to study the IgE and IgG4 antibody profiles to milk and milk proteins before and after OIT in relation to clinical outcome.

METHODS

Seventy-six children (5-17 years) with challenge-verified CMA were subjected to a 6-month OIT protocol. The treatment aimed at reaching a maintenance dose of 200 ml CM (high dose = HD). Those who did not reach target were analysed as a low-dose (LD) group. Sera were characterized before and after OIT regarding serum levels of IgE and IgG4 to milk and five milk allergen components evaluated together with clinical CMA symptoms and outcome of OIT.

RESULTS

Fifty-five (72%) patients reached the maintenance dose (HD) during therapy. High specific IgE levels towards the milk allergens α-lactalbumin (P = 0.048), β-lactoglobulin (P = 0.006) and casein (P = 0.015) before OIT start were associated with lower maintenance dose reached. Patients who developed desensitization had a larger increase in IgG4 levels to α-lactalbumin (P = 0.034), β-lactoglobulin (P = 0.010), casein (P = 0.047) and lactoferrin (P = 0.030) during treatment than those who failed.

CONCLUSIONS

Component-resolved diagnostics before OIT can help to identify children with lower probability of a successful OIT outcome, as high IgE levels to α-lactalbumin, β-lactoglobulin and casein are associated with lower maintenance dose reached. An increase in the IgG4 concentration to milk components during treatment indicated effective desensitization.

Comparison of Molecular Multiplex and Singleplex Analysis of IgE to Grass Pollen Allergens in Untreated German Grass Pollen-Allergic Patients

BACKGROUND

The ImmunoCAP ISAC 112 platform is the only commercially available molecular allergy IgE multiplex test. Data on the comparison of this rather novel test with the molecular singleplex ImmunoCAP IgE platform are lacking.

OBJECTIVE

To compare the multiplex ISAC 112 platform and the singleplex ImmunoCAP platform in regard to IgE to grass pollen allergens in untreated grass pollen-allergic patients in Germany.

METHODS

Serum samples from 101 adults with grass pollen allergy were analyzed for specific IgE (sIgE) to 8 allergenic molecules from timothy grass pollen and to the 112 allergenic molecules included in the ISAC panel. The results for the multiplex and singleplex tests were subsequently analyzed statistically.

RESULTS

Comparison of sIgE to grass pollen allergens detected by ISAC 112 and the singleplex ImmunoCAP assay revealed the following correlation coefficients: 0.88 (rPhl p 1), 0.96 (rPhl p 2), 0.70 (nPhl p 4), 0.94 (rPhl p 5b), 0.92 (rPhl p 6), 0.85 (rPhl p 11), and 0.78 (rPhl p 12).

CONCLUSION

Molecular testing with ISAC 112 correlates well with the ImmunoCAP platform for respective molecular timothy grass pollen allergens.

Alveolar and exhaled NO in relation to asthma characteristics--effects of correction for axial diffusion

BACKGROUND

Inflammation in the small airways might contribute to incomplete asthma disease control despite intensive treatment in some subgroups of patients. Exhaled NO (FeNO) is a marker of inflammation in asthma and the estimated NO contribution from small airways (CalvNO ) is believed to reflect distal inflammation. Recent studies recommend adjustments of CalvNO for trumpet model and axial diffusion (TMAD-adj). This study aimed to investigate the clinical correlates of CalvNO , both TMAD-adjusted and unadjusted.

METHODS

Asthma symptoms, asthma control, lung function, bronchial responsiveness, blood eosinophils, atopy and treatment level were assessed in 410 subjects, aged 10-35 years. Exhaled NO was measured at different flow-rates and CalvNO calculated, with TMAD-adjustment according to Condorelli.

RESULTS

Trumpet model and axial diffusion-adjusted CalvNO was not related to daytime wheeze (P = 0.27), FEF50 (P = 0.23) or bronchial responsiveness (P = 0.52). On the other hand, unadjusted CalvNO was increased in subjects with daytime wheeze (P < 0.001), decreased FEF50 (P = 0.02) and with moderate-to-severe compared to normal bronchial responsiveness (P < 0.001). All these characteristics correlated with increased FeNO (all P < 0.05). Unadjusted CalvNO was positively related to bronchial NO flux (J'awNO ) (r = 0.22, P < 0.001) while TMAD-adjCalvNO was negatively related to J'awNO (r = -0.38, P < 0.001).

CONCLUSIONS

Adjusted CalvNO was not associated with any asthma characteristics studied in this large asthma cohort. However, both FeNO and unadjusted CalvNO related to asthma symptoms, lung function and bronchial responsiveness. We suggest a potential overadjustment by current TMAD-corrections, validated in healthy or unobstructed asthmatics. Further studies assessing axial diffusion in asthmatics with different degrees of airway obstruction and the validity of proposed TMAD-corrections are warranted.

The effects of physical exercise and smoking habits on the expression of SPLUNC1 in nasal lavage fluids from allergic rhinitis subjects

OBJECTIVE

Palate lung nasal epithelial clone (PLUNC) is a family of proteins, which are proposed to participate in the innate immune defense against infections in the upper aero-digestive tract. The aim of this study was to investigate the expression of SPLUNC1 in allergic rhinitis subjects with considerations taken to the mucosal function and smoking habits.

METHODS

The participants, recruited from a cohort followed from infancy, were re-examined at the age of 18 years regarding allergy development. Based on medical histories and skin prick tests the participants were classified into groups with persistent allergic rhinitis (n=18), intermittent allergic rhinitis (n = 8) and healthy controls (n = 13). Seven subjects (3, 2 and 2 in each group, respectively) reported smoking habits. The SPLUNC1 levels in nasal lavage fluids were analyzed by Western blot. Changes in the volume of the proper nasal cavity before and after physical exercise (Vol2(increase)) were analyzed by acoustic rhinometry.

RESULTS

Compared to the control group the SPLUNC1 level was significantly lower in the persistent allergy group (3.8 ± 3.4 OD vs. 1.3 ± 1.5 OD; p = 0.02), but not in the intermittent allergy group without current exposure to allergens (3.6 ± 4.7 OD). No differences were found in Vol2(increase) between any of the allergy groups and controls. In smokers Vol2(increase) was significantly reduced (p < 0.01) and the SPLUNC1 levels were lower compared to non-smokers. A significant correlation was found between SPLUNC1 and Vol2(increase) (p < 0.01; r = 0.53) in non-smokers.

CONCLUSIONS

Current allergen exposure has an impact on SPLUNC1 expression in nasal lavage fluid, why allergy ought to be considered in study populations where analyses of SPLUNC1 levels are included in the reports. The normal nasal decongestion after exercise was not affected by allergy in contrast to smoking habits. The correlation between SPLUNC1 levels and Vol2(increase) in non-smokers may indicate involvement of SPLUNC1in the regulation of the normal function of the nasal mucosa. Complementary studies are needed to confirm the smoke-related reduction of SPLUNC1 expression and to analyze the possible participation of SPLUNC1 in the nasal mucosa regulation.

Nasal nitric oxide is associated with exhaled NO, bronchial responsiveness and poor asthma control

The fraction of exhaled nitric oxide (FeNO) is an established marker of airway inflammation in asthma. Nasal nitric oxide (nNO) has initially been regarded as a promising marker of inflammation of nasal mucosa. However, due to its dual origins, paranasal sinuses and nasal mucosa, the clinical use of nNO is controversial. There is an inflammatory link between inflammation in the upper and lower airways within the united airways' paradigm, but the study of the clinical value of nNO in asthma has been limited. The objective of this study is to analyse nNO in asthmatics and its relationship to FeNO, bronchial hyperresponsiveness, allergic sensitization and asthma control. A total of 371 children and young adults from an asthma cohort were included in this study, which performed measurements of nNO (through aspiration at 5 mL s(-1)), FeNO, bronchial responsiveness to methacholine, blood eosinophil count (B-Eos) and IgE sensitization. The asthma control test (ACT) and a questionnaire regarding medical treatment, symptoms of asthma, rhinitis and chronic rhinosinusitis were completed by all subjects. An association was found between higher nNO levels and increased bronchial responsiveness (p < 0.001), FeNO (p < 0.001) and B-Eos (p = 0.002). Sensitization to furry animals related to higher levels of nNO (p < 0.001). Subjects with poorly controlled asthma (ACT < 15) had lower levels of nNO than subjects with a higher ACT score (619 ± 278 ppb, versus 807 ± 274 ppb, p = 0.002). Loss of smell showed the strongest association with lower nNO levels among the upper airway symptoms recorded. In patients with asthma, nNO was positively correlated with exhaled NO, bronchial responsiveness and asthma control. This study suggests clinical utility of nNO in subjects with asthma, but in order to get better understanding of the nNO determinants, simultaneous mapping of upper airway comorbidities by clinical examination is appropriate.

Aeroallergen and food IgE sensitization and local and systemic inflammation in asthma

BACKGROUND

We recently reported an independent association between IgE sensitization to food allergens and increased airway inflammation, assessed by fraction of exhaled nitric oxide (FeNO), in a population-based study (J Allergy Clin Immunol, 130, 2012, 397). Similar studies have not been performed in populations with asthma. The aim of the present study was to investigate the allergic sensitization profile in asthmatics and examine FeNO, airway responsiveness and blood eosinophilia in relation to type and degree of IgE sensitization.

METHOD

FeNO, airway responsiveness, blood eosinophil count (B-Eos) and IgE sensitization to food allergens and aeroallergens were determined in 408 subjects with asthma, aged 10-34 years.

RESULTS

Asthmatics had higher prevalence of IgE sensitization against all allergens than controls (P < 0.001). Mite, pollen, furry animal, mould and food sensitizations were each associated with increased FeNO, airway responsiveness and B-Eos in asthmatics. IgE sensitization to mould, furry animals and food allergens was independently related to FeNO (all P < 0.05) after adjustment for age, sex, height, smoking history and medication. IgE sensitization to mould (P < 0.001) and furry animals (P = 0.02) was related to airway responsiveness in a similar model. Finally, IgE sensitization to mould (P = 0.001), furry animals (P < 0.001) and food allergens (P < 0.001) was independently related to B-Eos.

CONCLUSION

Independent effects of IgE sensitization to aeroallergens (furry animals and mould) and food allergens were found on both local and systemic markers of inflammation in asthma. The finding regarding food IgE sensitization is novel, and a clinical implication might be that even food sensitization must be assessed to fully understand inflammation patterns in asthma.

IgE antibodies to animal-derived lipocalin, kallikrein and secretoglobin are markers of bronchial inflammation in severe childhood asthma

BACKGROUND

Component-resolved allergy diagnostics enables the detection of crossreactive or species-specific allergen components. This study analysed Immunoglobulin E (IgE) profiles to single allergen components in relation to bronchial inflammation in severe childhood asthma.

METHODS

Ninety-five schoolchildren were assessed, 39 with controlled mild-to-moderate asthma and 56 uncontrolled severe asthmatics. Allergen components (n = 111) of food allergens, pollen and perennial aeroallergens were analysed using an immunosolid-phase allergen chip. Blood eosinophils (10(9) × l(-1)), bronchial inflammation (FeNO, ppb), lung function (FEV(1)%) and bronchial hyper-responsiveness (BHR) (dose-response slope of methacholine challenge) were measured.

RESULTS

A specific IgE response to more than three animal-derived components--lipocalin (nMus m 1, rEqu c 1, Fel d 4, rCan f 1, 2), kallikrein (rCan f 5) and secretoglobin (rFel d 1)--was more common among severe asthmatics compared to children with controlled asthma (n = 14 vs n = 3, P = 0.030). These subjects also displayed higher blood eosinophils (0.65 vs 0.39, P = 0.021), higher Fractional exhaled nitric oxide (38 ppb vs 25 ppb, P = 0.021) and increased BHR (112 vs 28, P = 0.002) compared to other severe asthmatics positive to fewer lipocalin/kallikrein/secretoglobin components. Among all sensitized subjects, there were correlations between specific IgE levels for rFel d 4 and nMus m 1 (r = 0.751, P ≤ 0.001) and for rFel d 4 and rEqu c 1 (r = 0.850, P ≤ 0.001).

CONCLUSION

Multi-sensitization towards lipocalin, kallikrein and secretoglobin components is associated with increased bronchial inflammation in severe asthmatics. In addition, crossreactive patterns were observed between different lipocalin components.

Peanut sensitization during the first 5 yr of life is associated with elevated levels of peanut-specific IgG

BACKGROUND

  Allergen-specific IgE antibodies are implicated in allergic diseases while allergen-specific IgG antibodies have been proposed to prevent allergic reactions. The objective for this study was to study whether the immune response (IgG and IgG4) to peanut differs in IgE-sensitized and non-sensitized young children.

METHODS

  A total of 239 children have been followed prospectively from birth to 5 yr of age. The levels of IgG and IgG4 to peanut, Ara h 2, and Ara h 8 were analyzed at 2 and 5 yr of age and related to IgE sensitization and peanut consumption.

RESULTS

  The levels of peanut-specific IgG and IgG4 were significantly higher in peanut-sensitized children at 2 and 5 yr of age when compared with non-sensitized children and children sensitized to other food/inhalant allergens. A strong correlation was seen between levels of peanut-specific IgG/IgG4-ratios and peanut-specific IgE at 5 yr of age. Children avoiding peanuts, a subgroup of the peanut sensitized, had statistically significant higher levels of IgE to peanut and a tendency of higher IgG and IgG4 levels to peanut. In the avoidance group, significant correlations between IgE and IgG/IgG4 to peanut were found compared with children eating peanuts.

CONCLUSION

  Peanut-specific IgG or IgG4 levels were elevated in peanut-sensitized children especially those avoiding peanuts. In our study, IgG and IgG4 do not seem to indicate tolerance or protection from sensitization.

Basophil allergen threshold sensitivity, CD-sens, IgE-sensitization and DBPCFC in peanut-sensitized children

BACKGROUND

Immunoglobulin E (IgE)-sensitization to peanut is common and can indicate an allergy. A positive test needs to be confirmed by a double-blind, placebo-controlled food challenge (DBPCFC), which is regarded as 'the gold standard'. The aim of the study was to evaluate the basophil allergen threshold sensitivity (CD-sens) and antibodies to peanut allergen components in relation to DBPCFC in the diagnoses of peanut allergy in children.

METHODS

Thirty-eight children with suspected peanut allergy underwent a DBPCFC. CD-sens to peanut and Ara h 2 were analysed as well as IgE-antibody to peanut and some of its allergen components (Ara h 1, 2, 3, 8 and 9).

RESULTS

Twenty-five children had a positive DBPCFC, and 92% of these were positive in CD-sens to peanut and Ara h 2. Two children with a positive DBPCFC were classified as 'low-responders' and were not further evaluated. Children positive in DBPCFC had higher CD-sens values to peanut (median 1.3; range 0.4-29, n = 21) compared with children negative in DBPCFC (median 0; range 0-0.5, n = 13) (P < 0.0001). A positive DBPCFC correspond with increased levels of IgE-antibody to Ara h 1, 2 and 3 compared with those with a negative challenge (P < 0.0001 for all). All children with a negative CD-sens were negative in DBPCFC.

CONCLUSION

In this study, a negative CD-sens to peanut excluded peanut allergy. Both tests, CD-sens to peanut and immunoassay for IgE-antibody to the peanut components, appear to be safe, time saving and cost-effective complements to DBPCFC.

An explorative study of low levels of allergen-specific IgE and clinical allergy symptoms during early childhood

BACKGROUND

Early identification of children at risk for later development of allergic disease is essential for early intervention and initiation of proper treatment and management.

OBJECTIVE

To investigate the relationship between low levels (0.1-0.7 kU(A) /l) of IgE sensitization to food and inhalant allergens and symptoms of eczema, rhinitis, and asthma from birth to 5 years of age.

METHODS

Children (268) were followed prospectively from birth to 5 years of age with physical examinations and measurements of s-IgE at 6, 12, 24, and 60 months of age.

RESULTS

Seventy-four percent of the children with low levels of s-IgE to egg and/or milk at the age of 6 months were still sensitized to one or more allergens at age 2 years. Eighty-four percent of the children with low levels of s-IgE to any of the studied allergens at 12 months of age were still sensitized at age 5. The low levels of egg and milk s-IgE also significantly increased the risk for eczema at the same age and also increased the risk for eczema at 2 years of age.

CONCLUSION

Low levels of s-IgE can be detected from the age of 6 months and are related to further IgE sensitization. The low levels seem to be of importance for both the association to present symptoms and for prediction of future allergic symptoms, especially eczema during early infancy. A detectable s-IgE level, albeit low, could be a clear signal that the immune system is alerted and should be followed.

Can immunoglobulin E-measurement replace challenge tests in allergic rhinoconjunctivits to grass pollen?

BACKGROUND

There is minimal data available concerning the dose-response relationship between allergen exposure and clinical reactivity for outdoor aeroallergens, such as timothy grass pollen. Timothy pollen-specific IgE (sIgE) determinations might assist in predicting the clinical reactivity in patients with allergic rhinoconjunctivitis (ARC).

METHODS

Allergen-sIgE antibody levels of timothy grass pollen were correlated with individual threshold doses eliciting allergic reactions in skin prick test (SPT), conjunctival (CPT) and nasal (NPT) provocation tests in patients suffering from pollen-induced rhinoconjunctivitis and healthy controls.

RESULTS

One hundred and four patients with ARC (median age: 27 years; range: 18-64; females: 58%) and 36 controls (25 years (22-77); females: 70%) were included in the study. Ninety-six percent of the patients showed a positive reaction in the nasal and 57% showed a positive reaction in the conjunctival provocation. With regarding to titrated SPT, 98% of the patients showed a positive skin test reaction; correlating with the level of sIgE for timothy (P < 0.001). For both provocation protocols, there was no correlation between the provocation concentration at the reaction and the level of sIgE for timothy. The ratio of sIgE/total IgE correlated with the dilution level of SPT (P < 0.002) and CPT (P < 0.01), respectively.

CONCLUSION AND CLINICAL RELEVANCE

A dose-response relationship between the levels of sIgE and clinical outcome of timothy allergen exposure could not be established. Although IgE-determination remains an important key element in allergy diagnosis, provocation tests are procedures of choice if the clinical relevance of an allergen has to be confirmed.

The role of hen's egg-specific IgE, IgG and IgG4 in the diagnostic procedure of hen's egg allergy

BACKGROUND

Hen's egg (HE) allergy is a common disease in childhood. HE-specific serum IgE has been correlated with the outcome of oral food challenge tests, and diagnostic decision points have been described as helpful but still not sufficient to reduce the requirement for oral food challenges. The aim of the study was to correlate HE-specific IgE, IgG and IgG4 levels with the outcome of double-blind, placebo-controlled food challenges (DBPCFC) in patients with suspected HE allergy to improve diagnostic procedures.

METHODS

HE-specific IgE, IgG, and IgG4 levels were compared between 150 children with suspected HE allergy based on sensitization and/or patient's history who underwent DBPCFC. Sixty-six patients were HE-allergic (HE-sensitized with a positive DBPCFC), 48 HE-sensitized but tolerant (negative DBPCFC), and 36 patients were nonsensitized and tolerant (negative DBPCFC). Prior to food challenge HE-specific serum IgE, IgG, and IgG4 were measured with the Phadia CAP-system.

RESULTS

HE-specific IgE was significantly higher in HE-allergic patients than in clinically tolerant ones. However, there was no difference in HE-specific IgG and IgG4 concentrations between the patient groups.

CONCLUSION

A proposed cut-off level of 12 kU/l IgE would identify children above this level correctly as HE-allergic. The level of HE-specific IgG or IgG4 in serum of children with suspected HE allergy does not add any additional information in the diagnostic procedure of HE allergy. For diagnostic purposes, specific IgG or IgG4 should not routinely be tested.

IgE antibodies to omega-5 gliadin associate with immediate symptoms on oral wheat challenge in Japanese children

BACKGROUND

Gliadins have been implicated in immunoglobulin E (IgE)-mediated allergy to ingested wheat and omega-5-gliadin is known to represent a major allergen in wheat-dependent exercise-induced anaphylaxis. Less known is whether omega-5-gliadin is a clinically relevant allergen in children with immediate allergy to ingested wheat. This study investigates whether specific IgE antibodies to omega-5-gliadin (sIgE-omega-5-gliadin-ab) could be used as a marker for oral wheat challenge outcome in wheat-sensitized children. A secondary objective was to study whether the level of sIgE-omega-5-gliadin was related to symptom severity in children with a positive challenge test.

METHODS

Serum samples from 88 children sensitized to wheat, of whom 35 underwent wheat challenge, were collected consecutively. sIgE-omega-5-gliadin-ab was related to a physician's diagnosis of wheat allergy and challenge symptoms.

RESULTS

The mean concentration of sIgE-omega-5-gliadin-ab was 7.25 kU(A)/l in patients with wheat allergy and 1.08 kU(A)/l in patients with no wheat allergy (P < 0.01). sIgE-omega-5-gliadin-ab was only detected in 12 of the non-wheat allergic children and 11 of them had a specific IgE to wheat below 1.30 kU(A)/l. Children reacting with severe symptoms upon challenge (n = 8) had increased levels of sIgE-omega-5-gliadin-ab compared to children with moderate, mild or no symptoms (P < 0.001).

CONCLUSIONS

The presence of sIgE-omega-5-gliadin-ab is related to the reaction level to wheat challenge outcome in wheat-sensitized children. The sIgE-omega-5-gliadin-ab was found to be associated with a strong convincing history of wheat allergy also in those cases when oral food challenge was avoided. The sIgE-omega-5-gliadin-ab level may serve as a marker for clinical reactivity in wheat-sensitized individuals.

Measurements of eosinophil activation before and after food challenges in adults with food hypersensitivity

BACKGROUND

Objective assessment of inflammatory reactions in the gastrointestinal tract could be useful in the diagnosis of food hypersensitivity. The aim of the present study was to investigate the involvement of eosinophils and mast cells in the inflammatory response of patients with food hypersensitivity before and after food challenges.

METHODS

Eleven patients (4 with IgE-mediated allergy and 7 without) with food hypersensitivity and positive double-blind, placebo-controlled food challenge were subjected to food challenge in a single-blinded fashion. Four subjects with no known food hypersensitivity were recruited as controls. Placebo was given after a 1-week washout period followed by an active dose. Stool, urinary and serum samples were collected and symptoms were recorded in a diary. Fecal samples were analyzed for eosinophil protein X (F-EPX) and tryptase; urinary samples for EPX (U-EPX) and leukotriene E4 (U-LTE4) and serum samples were analyzed for eotaxin and food-specific IgE antibodies.

RESULTS

Patients with IgE-mediated food allergy had increased levels of F-EPX compared to controls and tended to have lower serum levels of eotaxin compared to non-allergic patients and controls. U-LTE4 was significantly higher in allergic patients compared to non-allergic patients after challenge. Moreover, F-EPX correlated to U-LTE4 (p = 0.011). Reported symptoms, abdominal pain, distension, flatulence and nausea were similar in the allergic and non-allergic patients.

CONCLUSION

The results strongly indicate that eosinophils are activated in the gastrointestinal tract of food-allergic patients but not in patients with non-allergic food hypersensitivity. Due to the inconsistent pattern of symptoms after placebo and active food challenge, it was not possible to relate the levels of inflammation markers to the recorded symptoms.

Double-blind placebo-controlled challenges for peanut allergy the efficiency of blinding procedures and the allergenic activity of peanut availability in the recipes

BACKGROUND

A firm diagnosis of double-blind placebo-controlled food challenge (DBPCFC) would facilitate the diagnosis in patients with uncertain history of reaction. Guidelines are lacking for an upper provoking dose and how to hide high concentrations of peanuts.

AIM

To develop and evaluate a double-blind recipe with minimum 10% of peanut. To compare the recipe with published recipes regarding blindness, taste, texture and immunoglobulin (Ig)E antibody binding to peanut.

METHODS

A recipe (I) with 10% of peanut was developed evaluated and used in DBPCFC. The challenges were followed by development of a concentrated recipe (II) (15% peanut, 25% fat). Recipe II was compared with the only published recipe (III) (11% peanut, 7% fat) regarding taste, texture and availability of peanut. Recipe IV (12% peanut, 10% fat) was developed using the same methods. The binding of IgE in the recipes was measured using an inhibition method.

RESULTS

During challenges, one patient reacted after 4 g, emphasizing the need for blinding recipes containing high doses of peanut. Evaluation between recipes II and III, only recipe II was regarded as blind by the taste panels. A tenfold lower availability of peanut protein in the recipe II was found at 50% of inhibition. Recipe IV had a better IgE binding that did not differ from the original peanut extract.

CONCLUSION

The peanut taste and texture can be hidden in a challenge medium. The fat content was important for the availability of the allergenic protein in challenges. The availability of allergens must be taken into consideration when used for DBPCFC.

Prophylactic management of children at risk for recurrent upper respiratory infections: the Preventia I Study

BACKGROUND

Given the morbidity and mortality of asthma and the recent dramatic increase in its prevalence, pharmacologic prophylaxis of this disease in children at risk would represent a major medical advance.

OBJECTIVES

The Preventia I Study was designed to evaluate the efficacy and long-term safety of loratadine in reducing the number of respiratory infections in children at 24 months. A secondary objective was to investigate the benefit of loratadine treatment in preventing the onset of respiratory exacerbations.

METHODS

Preventia I was a randomized placebo-controlled study involving 22 countries worldwide. The children were 12-30 months of age at enrollment and had experienced at least five episodes of ENT infections, and no more than two episodes of wheezing during the previous 12 months. Phase I was a 12-month double-blind period during which the children were treated with loratadine 5 mg/day (2.5 mg/day for children</=24 months of age) or placebo. Phase II was a double-blind follow-up period without study medication.

RESULTS

Of the 412 children enrolled, 342 and 310 completed Phase I and Phase II, respectively. The results showed a significant decrease in the number of infections in the whole population of children. However, no difference was observed between the loratadine and placebo group. When considering secondary end-points, loratadine was shown to reduce the number of respiratory exacerbations during the treatment phase. None of the 204 children who received loratadine discontinued the study because of drug-related events. Loratadine treatment was not more sedative than placebo and was not associated with cardiovascular events.

CONCLUSION

The strong decrease in the rate of infections in the children at risk of recurrent infections, while not being influenced by loratadine treatment, should encourage future reflection in terms of prophylactic management. This study also confirms the long-term safety of loratadine and its metabolites in young children.

Specific immunoglobulin E antibodies to peanut over time in relation to peanut intake, symptoms and age

The clinical outcome of peanut allergy and some factors associated with development of peanut allergy remain unsolved. It has not been clarified to what extent peanut intake affects immunoglobulin (IgE) antibody formation in peanut sensitized individuals. The aim of the study was to investigate the development of peanut hypersensitivity in children and adolescents with specific IgE antibodies to peanut, using questionnaires and current serum tests and comparing it to information obtained 5-6 yr earlier, to investigate how peanut intake during this period related to subject age, IgE antibody levels and symptoms and to investigate what information this patient group was given at the time of diagnosis regarding avoidance of peanut related food. All patients with detectable peanut-specific IgE antibodies investigated during 1994-1996 deriving from two allergy laboratories in the western region of Sweden were traced and reinvestigated (n=132). A total of 111 subjects (63 with peanut allergy and 48 peanut sensitized) participated in the questionnaire. Eighty-six of them consented to be enrolled in a further interview and renewed testing of specific IgE antibody to peanut 5 yr later. All tests were done using the Pharmacia CAP system. Increased IgE antibody levels during follow-up was related to age; subjects 0-6 yr at initial test occasion were more likely to have higher IgE antibody class than the older individuals (p=0.018). Exposure to peanut during the study, i.e. 5-6 yr since diagnosis, did not seem to affect the result. During the follow-up period, 29 out of 86 (34%) increased their IgE antibody class. At the second test occasion the remaining subjects had similar (28%) or lowered (38%) levels of IgE antibodies. Exposure to peanut during follow-up was more common in subjects with IgE antibody class 1-3 compared to subjects with high value (> 3) at the initial test (p=0.003). Reported symptoms during follow-up were also more common in subjects with initially high IgE antibody value. Individuals with initially high IgE antibodies to peanut had been given more information about peanut allergy and cross-reacting allergens than other individuals. The subjects over 6 yr of age showed a decrease in peanut-specific IgE class over a 5-yr period. Together with the literature, our result suggest that follow-up and renewed testing is recommended, since there may be a change in IgE antibody classes and clinical sensitivity over time. Even in Sweden, with a low consumption of peanuts, the youngest individuals with peanut sensitization experienced a similar course of events that has been reported in other countries.

Why do parents hesitate to vaccinate their children against measles, mumps and rubella?

BACKGROUND

Thanks to a successful voluntary vaccination programme, measles, mumps and rubella are rare diseases in Sweden. Coverage among children 18 mo of age has been 99%, but the measles, mumps and rubella vaccination (MMR) has increasingly been questioned among parents.

AIM

To study reasons why parents choose not to vaccinate their child against measles, mumps and rubella, and their opinions on vaccines and the diseases themselves. A secondary objective was to compare coverage at 18 mo of age based on parental report with the national statistics based on patient charts.

METHODS

The official statistics were compared with patient charts for two birth cohorts in the city of Göteborg, Sweden. Out of these children born in 1995 and 1996, 300 unvaccinated and vaccinated children were identified. Their parents received a postal questionnaire assessing the parent's views on vaccines and childhood diseases.

RESULTS

The documented vaccine coverage in this study was higher in 1995 and 1996 than official statistics indicated. The major reason, for both groups, for accepting respectively declining vaccination was strengthening the child's immune system. Parents with children unvaccinated against MMR were also more likely to have declined vaccination against diphtheria, polio, tetanus, Haemophilus influenzae and pertussis. One-third of the parents with a child unvaccinated against MMR had not yet made their final decision 3 y after the vaccine offer. Few parents, both with vaccinated and unvaccinated children, had acquired vaccine information from the Internet. Both groups believed that insufficient time was allocated for vaccine information and discussion at the Child Health Centre.

CONCLUSION

Our study indicates that official statistics on MMR vaccination uptake underestimate the number of vaccinated children. Vaccine safety is a major concern for many parents and needs to be addressed by healthcare professionals at institutions offering paediatric vaccinations.

Peripheral blood eosinophils and IL-4 in infancy in relation to the appearance of allergic disease during the first 6 years of life

Eosinophils in peripheral blood and serum levels of interleukin (IL)-4 were analysed at 3 and 18 months and at 6 years in a prospective study comprising 67 children, of whom the majority had atopic heredity. The children were monitored from birth up to 6 years of age and the findings were related to family history of allergy and development of allergic disease. Twenty-nine children (43%) of the original group of 67 children were diagnosed as allergic at the age of six. Fifteen of 23 children with eosinophilia (>4 x 10(8) eosinophils/l) at 3 months of age were regarded as allergic at 6 years, when compared with 12 out of 38 children with normal eosinophil counts at 3 months (chi2 = 6.7, p < 0.01). Children with detectable IL-4 in serum at 18 months were more often allergic at 6 years, when compared with those children with no detectable IL-4 (chi2 = 8.6, p < 0.01). Furthermore, the allergic children had a mean IL-4 value of 0.35 microg/l (95% CI: 0.10-1.48) at 18 months, when compared with 0.17 microg/l (95% CI: 0.10-0.72, p < 0.001) in the non-allergic children. At 6 years of age, only nine children had detectable levels of IL-4 and five of them were classified as allergic. Eosinophilia at this age was also associated with allergic disease. We conclude that eosinophilia during infancy and increased levels of IL-4 at 18 month of age are associated with allergic disease during the first 6 years of life. This might indicate that the first 2 years of life are particularly important for the development of allergy.

Introduction of food during the infant's first year: a study with emphasis on introduction of gluten and of egg, fish and peanut in allergy-risk families

AIM

The aim of the current study was to retrospectively examine introduction of food during the first year in a representative sample of Swedish children. A secondary aim was to study how parents with history of atopy introduced food to their infants.

METHODS

Data derive from 467 infants who visited child health centres in three different counties in Sweden for health check-up at 12 mo of age. The parents were asked to fill in a questionnaire about breastfeeding and/or formula feeding, time of introduction of weaning food focusing on cow's milk, follow-on formula, porridge, fish and egg. Questions regarding hypersensitivity in the family, peanut consumption of mother as well as in the child, and questions about number of siblings, ethnic background and parental education were included.

RESULTS

Compliance with suggested introduction of gluten-containing food was low; as many as 45% had avoided gluten until 6 mo of age, instead of introducing gluten between 4 and 6 mo. Only 33% of parents with stated family hypersensitivity avoided giving their child fish and 23% avoided egg during the first year, even though this recommendation was present at the time of the study. Almost 50% of all mothers had avoided peanuts during pregnancy even though there was no such advice. The avoidance of peanut was not connected to hypersensitivity in the family.

CONCLUSION

These results suggest that time of introduction of gluten was not in accordance with the current recommendation. The results imply that there is a need to follow up if and how this feeding information is distributed to parents with infants and also to sharpen the information to the right target groups, otherwise implementation of preventive strategies will be less useful.

Evaluation of screening procedures for congenital cataracts

AIM

To evaluate the efficacy of two different Swedish screening procedures for early detection of congenital cataracts in comparison with no screening.

METHODS

Children born between January 1992 and December 1998 in Swedish regions with an established eye-screening routine procedure, diagnosed with congenital cataract, and operated on before 1 y of age, were included in a retrospective study. Age at referral and age at time of the operation were compared between regions using different screening procedures: screening in the maternity wards (Region 1), at the well-baby clinics (Region 2) and one region without any screening (Region 3).

RESULTS

Seventy-two children were included in the study. Concerning early diagnosis and surgery, Region 1 differed significantly from Regions 2 and 3, which were more similar and were combined for further analysis. The difference in detected cases was greatest at 21 d of age (55% vs 18%; p < 0.001), but persisted even at 100 d of age (78% vs 64%; p < 0.02). Region 1 screening resulted in more and earlier cases detected than the other two regions (22 vs 15 per 100,000 births). In 72% of all cases, surgery was performed in response to referrals from either the maternity wards (36%), or the well-baby clinics (36%). However, half of the cases from the well-baby clinics were detected too late, i.e. at > 100 d.

CONCLUSION

Eye screening in the maternity ward is preferable to well-baby clinic screening and to no screening at all, since it leads to early detection. Screening should also be performed routinely at well-baby clinics within the period when successful treatment is possible.

Breastfeeding and allergic disease: a multidisciplinary review of the literature (1966-2001) on the mode of early feeding in infancy and its impact on later atopic manifestations

BACKGROUND

Strategies to prevent children from developing allergy have been elaborated on the basis of state-of-the-art reviews of the scientific literature regarding pets and allergies, building dampness and health, and building ventilation and health. A similar multidisciplinary review of infant feeding mode in relation to allergy has not been published previously. Here, the objective is to review the scientific literature regarding the impact of early feeding (breast milk and/or cow's milk and/or formula) on development of atopic disease. The work was performed by a multidisciplinary group of Scandinavian researchers.

METHODS

The search in the literature identified 4323 articles that contained at least one of the exposure and health effect terms. A total of 4191 articles were excluded mainly because they did not contain information on both exposure and health effects. Consequently, 132 studies have been scrutinized by this review group.

RESULTS

Of the 132 studies selected, 56 were regarded as conclusive. Several factors contributed to the exclusions. The studies considered conclusive by the review group were categorized according to population and study design.

CONCLUSIONS

The review group concluded that breastfeeding seems to protect from the development of atopic disease. The effect appears even stronger in children with atopic heredity. If breast milk is unavailable or insufficient, extensively hydrolysed formulas are preferable to unhydrolysed or partially hydrolysed formulas in terms of the risk of some atopic manifestations.

Asthma and allergies at school--a Swedish national position paper

The marked rise in allergies during the past decade has been increasingly perceptible for school personnel. A quarter of Swedish parents of children with allergies are unsatisfied with the school environment and how the schools are organized around their children. The Association of School Physicians has, together with six other medical, teaching and patient organizations, developed written guidelines for the management of asthma and allergies in Swedish schools. The aim was to regulate the responsibility of the school and its personnel for students with asthma and allergies, and to strengthen safety arrangements within schools. A secondary aim was to describe how the curriculum, teaching equipment, excursions, and other school activities, could be arranged appropriately and safely for students with asthma and allergies. Five-hundred copies of the document were circulated to all of Sweden's municipalities, county councils and pediatric departments. There was general agreement regarding the schools' responsibility that no child should risk becoming ill or having exacerbation of symptoms due to conditions at school. Recommendations regarding smoking on school premises and the use of perfumes were criticised. The strength of this document is that all organizations actively involved with schools have agreed upon these recommendations. This document serves to suggest a minimum level of activities thus ensuring that even students with asthma and allergies will receive appropriate schooling.

Specific IgE antibodies to peanut in western Sweden--has the occurrence of peanut allergy increased without an increase in consumption?

BACKGROUND

Sensitization to peanut has seldom been investigated in Sweden. Therefore, all IgE-specific tests for peanut during a 5-year period were reviewed to study the relation between the levels of specific IgE antibody to peanut and age, sex, symptoms, and other atopic manifestations.

METHODS

All serum samples were analyzed for IgE antibodies to peanut in relation to sex, age, clinical reactions, and other food allergens. A subgroup was asked to answer a questionnaire about symptoms and atopic manifestations in relation to IgE antibody levels.

RESULTS

During the study period, 2417 tests were made for peanut. There was an increased prevalence of detectable IgE antibodies during the years studied. More than 80 individuals under 2 years of age were sensitized to peanut. In the subgroup, individuals with detectable IgE antibodies reported a shorter reaction time after eating peanuts than individuals with normal IgE antibody levels (P < 0.05).

CONCLUSION

The reaction pattern to peanuts in Sweden is similar to that in many other countries despite a reported steady and low consumption. The severity of symptoms was connected to age and IgE antibody level. Patients with normal or low IgE antibody levels were not always free of symptoms even though their risk of allergic symptoms was reduced.

[Increasing number of child abuse cases in Sweden--in accordance with reality?]

The number of police reports on child assault shows an increasing trend during the last two decades in Sweden. The purpose of this article is to present possible explanations. Increased awareness of child abuse, legislative reforms, changes in attitudes toward corporal punishment and violence in general, and changed routines within schools can explain the increasing trend in police reporting. An actual increase in the rate of child abuse is possible but less likely. Reports of increasingly violent behavior among young people must be taken seriously.

Atopic dermatitis in 5-6-year-old Swedish children: cumulative incidence, point prevalence, and severity scoring

BACKGROUND

This study aimed to evaluate the cumulative incidence, point prevalence, and severity of atopic dermatitis (AD) in a pediatric population. We also aimed to identify differential diagnoses relevant to AD in this population.

METHODS

Children scheduled for a health visit at 5.5 years of age were selected consecutively during the period October 1997-March 1998 from two cities in southern Sweden (Göteborg and Kristianstad). Schultz Larsen's questionnaire was used to evaluate the cumulative incidence of AD. Clinical examination was performed by dermatologists (A.B. and A.S.) for those children with active eczema. The UK working party's criteria were used for the clinical diagnosis of AD. The SCORAD index was used to evaluate the severity of eczema. This index includes evaluation of extent, intensity, and subjective symptoms to a maximum score of 103 points.

RESULTS

In Göteborg 1219 and in Kristianstad 742 questionnaires were answered regarding 1961 children, 1004 boys and 957 girls. The response rate was 89%. According to the answers to Schultz Larsen's questionnaire, the cumulative incidence of AD in the whole material was 20.7% (406/1961) (CI 95% 18.9-22.5). In Göteborg, 104 of the examined children fulfilled the UK working party's criteria, equivalent to a point prevalence of 8.5% (CI 95% 7.0-10.1). In Kristianstad, the corresponding point prevalence was 11.5% (CI 95% 9.2-13.8). The severity of AD was evaluated in all children with visible eczema. SCORAD evaluation was performed in 155 of the 157 children with visible eczema. The majority of children had mild or moderate eczema; mean value 20.5 (CI 95% 18.7-22.3), median 19.6. Of the 96 children who did not fulfil the criteria of AD, other skin disorders were diagnosed in 51 at the clinical examination. Dry skin was by far the most common differential diagnosis.

CONCLUSIONS

We have used validated protocols to evaluate the cumulative incidence, point prevalence, and severity of AD in a population-based study in southern Sweden The present study, involving a rural and urban pediatric population, shows that AD is common, usually classified as mild or moderate, and seems to increase over time.

Psychosomatic and psychosocial symptoms are associated with low blood pressure in Swedish schoolchildren

BACKGROUND

The relation between psychosomatic and psychosocial symptoms and blood pressure was studied in Swedish schoolchildren.

METHODS

Blood pressure was measured in 122 healthy Swedish schoolchildren, aged 6-16 years. Psychosomatic and psychosocial symptoms, delinquent behaviour, parental health and employment status were assessed.

RESULTS

Children with systolic blood pressure above + 1 SD of mean reported significantly less symptoms (x = 1.4) than children with blood pressure below -1 SD of the mean (x = 2.7; p < 0.05). Children with three or more self-reported symptoms had significantly lower blood pressure than children without symptoms both in the supine (110 +/- 12 vs. 120 +/- 18 mm Hg; p < 0.05) and in the standing position (117 +/- 17 vs. 127 +/- 18 mm Hg; p < 0.05).

CONCLUSIONS

We conclude that psychosomatic and psychosocial symptoms in children might be associated with low blood pressure.

Carriage of penicillin-susceptible and non-susceptible pneumococci in healthy young children in Göteborg, Sweden

OBJECTIVES

To study carriage of Streptococcus pneumoniae among healthy young children, determine the proportion of strains with decreased susceptibility to penicillin, and study possible risk factors for the carriage of penicillin-resistant strains.

METHODS

Between February 1996 and February 1997, 620 healthy, 18-month-old children in Goteborg, Sweden were screened for carriage of S. pneumoniae with decreased susceptibility to penicillin. Nasopharyngeal samples were obtained from children visiting child health centres for routine health control.

RESULTS

Streptococus pneumoniae was found in 322 samples and 18 strains (5.6%, CI95 3.4; 8.8) of all pneumococci showed decreased susceptibility to penicillin G with minimum inhibitory concentrations (MICs) ranging from 0.125 to 1.0 mg/l. The proportion of strains with decreased susceptibility was similar to that found in a laboratory-based material (6%), from the same geographical area and time period. A majority of the children with strains with decreased susceptibility to penicillin (n = 11) were not attending day-care centres.

CONCLUSIONS

The prevalence of S. pneumoniae with reduced susceptibility to penicillin is still low in unselected healthy Swedish children.

Postnatal growth and health in children born after cryopreservation as embryos

BACKGROUND

There is uncertainty about the health of children born from in-vitro fertilisation (IVF) with cryopreserved embryos. We investigated the postnatal growth and health (up to 18 months) of these children compared with those born after standard IVF with fresh embryos and those from spontaneous pregnancies.

METHODS

255 children from cryopreserved embryos were matched by maternal age, parity, single or twin pregnancy, and date of delivery with 255 children born after IVF with fresh embryos, and 252 children from spontaneous pregnancies. The main endpoint was growth; secondary endpoints were the prevalence of chronic illness, major malformations, cumulative incidence of common diseases, and development during the first 18 months. Growth was assessed by comparison with standard Swedish growth charts and by standard deviation scores.

FINDINGS

Growth features were similar for both singletons and twins in the three groups. There were 6 (2.4%) of 255, 9 (3.5%) of 255, and 8 (3.2%) of 252 major malformations in the cryopreserved group, standard IVF, and spontaneous groups, respectively (p=0.6 between the cryopreserved and standard IVF group). The prevalence of chronic diseases did not differ between the three groups, with 18.0%, 15.3%, and 16.7% of children with a chronic illness in the cryopreserved group, standard IVF, and spontaneous groups, respectively.

INTERPRETATION

The cryopreservation process does not adversely affect the growth and health of children during infancy and early childhood. Minor handicaps, behavioural disturbances, learning difficulties, and dysfunction of attention and perception cannot be ruled out at this age.

Nasal metachromatic cells in infancy in relation to the appearance of atopic disease during the first 6 years of life

The relationship between the appearance of nasal metachromatic cells (basophils and mast cells) during the first 18 months of life and the development of respiratory and other allergic diseases up to 6 years of age was studied prospectively in 67 children. Follow-up was done at 3, 6, 9, and 18 months and 6 years. Of the 31 children who had detectable metachromatic cells in the nasal mucosa during infancy, 18 had atopic manifestations at 6 years (58%), two were probably atopic (6%), and 11 (36%) were nonatopic. The corresponding numbers for the 33 children without detectable metachromatic cells during infancy were 10 atopic (30%), two probably atopic (6%), and 21 nonatopic (64%) at 6 years (P < 0.05). Children having detectable nasal metachromatic cells at every examination were more often allergic than children with no detectable cells at any time during the 6-year follow-up period (P < 0.05). In contrast, nasal metachromatic cells were equally commonly demonstrated at 6 years in children with and without current atopic manifestations. We conclude that metachromatic cells appear at an earlier age in the nasal mucosa of atopic than nonatopic infants. The observation further supports the existence of a primary immunologic abnormality in atopic patients as related to allergic inflammatory responses. The diagnostic efficacy of this marker was too low, however, to be clinically useful as a predictor of allergy.

How many teenagers think they have allergic rhinoconjunctivitis and what they do about it

OBJECTIVE

A study was made to assess the proportion of 17-year-old students who consider themselves to have allergic rhinoconjunctivitis and to find out how they treat themselves.

METHOD

The study was performed outside the pollen season in 1993 and 1994 and 5,938 first-year secondary school students in eight different cities were asked to answer a questionnaire during class.

RESULTS

A total of 1,458 students (24%) claimed that they suffered from allergic rhinoconjunctivitis after being given a description of the disease. Sixty-five percent had had symptoms for 3 or more years and most of the sufferers, 71%, had had symptoms during the spring and/or summer. In 32% of the sufferers the causative agent was unknown. Seventy-six percent (n = 1,103) of the sufferers treated themselves with drugs. The most commonly used drugs for a systemic effect were nonsedating antihistamines and for a local effect, sodium cromoglycate. Of those who used nasal drugs (sodium cromoglycate and/or steroids, n = 545), only 14% used them daily, 51% always when having symptoms, and 35% occasionally when having symptoms. The reasons for not using nasal sprays daily were inconvenience and embarrassment. Twenty-five percent had bought the drug over the counter in 1992, the first year when allergy drugs could be purchased without a prescription. The use of over-the-counter treatment increased in the following year to 33% (P < .05).

CONCLUSION

We conclude that many young people perceive themselves as having allergic rhinoconjunctivitis and that the treatment can be much improved for the group as a whole.

Serum levels of interleukin-4, soluble CD23 and IFN gamma in relation to the development of allergic disease during the first 18 months of life

Serum levels of Interleukin (IL)-4, Interferon (IFN)-gamma and soluble CD23 (sCD23) were analysed in a prospective study of 64 infants who were monitored from birth to 18 months of age. The findings were related to family history of atopy and the development of allergic disease in the infants. Low levels of IL-4 were detected in 10 of 63 cord blood samples (median 0.14 and range 0.32 micrograms/l). The levels then increased, both in health and atopic infants, reaching a peak at either 6 or 9 months and then decreased up to 18 months of age. The children who developed atopic disease during the first 18 months of life had significantly higher IL-4 median levels than those who did not, i.e. 0.24 (range 0.40) vs < 0.10 microgram/l at 3 months, (P < 0.001), 0.40 (range 0.95) vs 0.13 (0.19) microgram/l at 6 months (P < 0.01), 0.46 (range 0.78) vs 0.10 (0.24) microgram/l at 9 months (P < 0.001) and 0.30 (range 1.38) vs 0.10 (0.36) microgram/l at 18 months (P < 0.001). The IFN gamma levels were below the detection level, i.e. < 100 ng/l in all but 49 of the 196 serum samples that were analysed. There was no significant relationship with clinical outcome, nor with S-IgE levels. Soluble sCD23 levels increased in the infants with age. There was no association with either atopic disease, family history of allergic disease or IgE antibody levels. In conclusion, IL-4 levels in serum, but not sCD23 and IFN gamma are associated with allergic disease in infancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-4, soluble CD23 and interferon-gamma levels in serum during the first 18 months of life

Serum levels of interleukin (IL)-4, interferon (IFN)-gamma and soluble CD23 (sCD23) were analysed in a prospective study of 64 infants monitored from birth to 18 months of age. The levels were low at birth and then increased, reaching a peak at either 6 or 9 months and then decreased up to 18 months of age. The children who developed atopic disease during the first 18 months of life had significantly higher IL-4 median levels than those who did not. No relationship was seen between the levels of sCD23 and IFN-gamma and allergy. Thus, the IL-4 levels in serum, but not sCD23 and IFN-gamma, were associated with allergic disease in infancy. Elevated levels were recorded before the onset of clinical symptoms, indicating that atopic disease is associated with a primary deviation of T cell function.