Low eosinophils during bronchiolitis in infancy are associated with lower risk of adulthood asthma

Characteristic features of infants with pneumonia testing positive for specific immunoglobulin E

OBJECTIVE

To analyse the characteristic features of infants with pneumonia who test positive for serum milk-specific immunoglobulin E (sIgE) and to provide a reference for the diagnosis, management and prevention of the condition.

METHODS

We retrospectively analysed data from 284 infants admitted to our hospital with pneumonia between January 2017 and December 2020 who underwent serum allergen testing. Based on the results, patients were categorised into three groups: pure milk sIgE-positive; mixed milk sIgE-positive; and allergen sIgE-negative. We then compared the general conditions, clinical characteristics, laboratory tests, imaging results and pathogenic data across these groups.

RESULTS

Among the patient population, 16.20% (46/284) tested positive for pure milk sIgE, 32.75% (93/284) tested positive for mixed milk sIgE and 51.06% (145/284) were negative for any allergen sIgE. Statistically significant differences were observed among the three groups in terms of general conditions, breastfeeding status, pre-existing respiratory infections and history of respiratory infections (>3 times) (p < 0.05 for each). The median length of hospital stay was longer in the pure milk sIgE-positive group and the mixed milk sIgE-positive group (8 [range 7-10] days) compared with the allergen sIgE-negative group (8 [range 6-9] days) (p < 0.05). The eosinophil counts of the mixed milk sIgE-positive group were significantly higher than in the other two groups (p < 0.05). Haemophilus influenzae of the pure milk sIgE-positive group was significantly higher than in the other two groups (p < 0.05).

CONCLUSION

The presence of mixed milk sIgE allergens does not exacerbate clinical symptoms. However, infants who test positive solely for milk sIgE and have pneumonia require longer hospitalisation. This suggests that extra attention is necessary for infants with milk allergies when they develop pneumonia.

Cord blood granulocyte levels are associated with severe bronchiolitis in the first year of life

Objectives

Bronchiolitis is a leading cause of infant hospitalisation in the first year of life, and it preferentially affects infants born to mothers with asthma. Here, we evaluate cord blood granulocytes in infants born to mothers with asthma participating in the Breathing for Life Trial (BLT), to investigate early life determinants of bronchiolitis hospitalisation within the first year of life.

Methods

Cord blood from 89 participants was collected into EDTA tubes and processed within 6 h of birth. Cells were stained in whole cord blood for eosinophils (CD45+, CD193+, CD16-), and neutrophils (CD45+, CD193-, CD16+). Medical records were reviewed for bronchiolitis hospitalisation in the first 12 months of life. Statistical analyses were conducted using Stata IC16.1.

Results

Logistic regression adjusted for caesarean section, gestational age, maternal smoking during pregnancy, foetal heart deceleration during labour, and season of birth revealed an association between cord blood eosinophil levels and bronchiolitis hospitalisation in the first 12 months of life with an Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC) curve of 0.943 (aOR = 1.35, P = 0.011). Neutrophils were associated with the risk of bronchiolitis hospitalisation in a univariable logistic regression (OR = 0.93, P = 0.029); however, there was no statistical significance in the adjusted model.

Conclusions

Higher eosinophil numbers in cord blood were associated with bronchiolitis hospitalisation in the first 12 months in a cohort of infants born to asthmatic mothers. This suggests that susceptibility to bronchiolitis in later life is influenced by the immune cell profile prior to viral infection.

Blood eosinophils during bronchiolitis: Associations with atopy, asthma and lung function in young adults

AIM

To study if blood eosinophils during bronchiolitis were associated with atopy, asthma and lung function in young adults and if these associations differed between respiratory syncytial virus (RSV) bronchiolitis and non-RSV bronchiolitis.

METHODS

This historical cohort enrolled 225 subjects. Blood eosinophils were measured during bronchiolitis in infancy, and the subjects were invited to a follow-up at 17-20 years of age including questionnaires for asthma and examinations of lung function and atopy.

RESULTS

The level of eosinophils was positively associated with subsequent atopy in the unadjusted analysis, but not in the adjusted analysis, and not with asthma. There was a negative association between the level of eosinophils and forced vital capacity (FVC) (-0.11; -0.19, -0.02) and forced expiratory volume in first second (FEV₁ ) (-0.12; -0.21, -0.03) (regression coefficient; 95% confidence interval). The non-RSV group had higher levels of eosinophils during bronchiolitis, but there was no interaction between the level of eosinophils and RSV status for any outcome.

CONCLUSIONS

The level of eosinophils during bronchiolitis was negatively associated with lung function in young adult age, but we found no associations with atopy or asthma. These associations were not different after RSV bronchiolitis compared to non-RSV bronchiolitis.

Risk factors associated with comorbid asthma in patients with chronic rhinosinusitis with nasal polyps: a cross-sectional study

Background

Although 20–60% of patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have asthma, the risk factors associated with comorbid asthma are not clear. The aim of the study was to investigate the factors associated with asthma, and develop a practical scoring system to screen asthma comorbidity in CRSwNP patients.

Methods

This report describes a cross-sectional study with consecutive CRSwNP patients. Two cohorts of CRSwNP patients named “modelling” group and “validation” group were investigated respectively. Logistic regression analysis was performed based on demographic and clinical data collected from patients in the modelling group to determine the risk factors associated with asthma, and establish a scoring system for screening comorbid asthma. Receiver operating characteristic curve was constructed to evaluate the screening system; the optimal cut-off point was established by means of the Yoden Index. The consistency between the diagnosis of asthma by the Global Initiative for Asthma (GINA) criteria and by the screening system was assessed by Kappa value in the validation group.

Results

Totally 150 patients in modelling group and 78 patients in validation group were enrolled. Female gender (odds ratio [OR] = 6.4; P < 0.001), allergic rhinitis (OR = 2.9; P = 0.021), serum total (T)-immunoglobulin (Ig) E ≥ 69.0kU/L (OR = 12.0; P < 0.001), and blood eosinophil count  ≥ 0.35 × 10⁹/L (OR = 4.0; P = 0.001) were shown to be independent risk factors for asthma in patients with CRSwNP. Based on these variables, a scoring system (FAIE) ranging from 0(no risk) to 6(high risk); was developed. The area under the receiver operating characteristic curve of the system was 0.823, and the optimal cut-off value was 3 points, with sensitivity 83.8% and specificity 68.6% for screening asthma. The asthma comorbidity determined with FAIE score ≥ 3 points in the validation group, was moderately consistent with that defined by GINA (Kappa = 0.513, P < 0.001), with sensitivity 76.9% and specificity 74.4%.

Conclusions

Female gender, allergic rhinitis, serum T-IgE level, and blood eosinophil count are independent risk factors for asthma comorbidity in patients with CRSwNP, and the FAIE system may be practical for screening comorbid asthma in these patients.

Blood eosinophils, specific immunoglobulin E, and bronchiolitis severity

BACKGROUND

Bronchiolitis is the leading cause of hospitalization for United States infants. Blood eosinophil and serum specific IgE (sIgE) levels are separately linked to clinical severity but few studies have examined these biomarkers together.

OBJECTIVE

Among infants hospitalized for bronchiolitis, we investigated the association between (1) blood eosinophilia and severity, (2) sIgE sensitization and severity, and (3) interaction between the two biomarkers on severity.

METHODS

We enrolled 1016 infants hospitalized for bronchiolitis between 2011 and 2014 across 17 U.S. hospitals into a prospective cohort study. Of those, 873 (86%) had eosinophils measured and all had sIgE levels from blood collected at hospitalization. We investigated higher bronchiolitis severity using intensive care therapy as the outcome (i.e., intensive care unit admission, intubation, and/or receipt of continuous positive pressure ventilation).

RESULTS

Among 873 infants in the analytic cohort, 18% had blood eosinophilia of ≥3%, and 20% were positive for sIgE. With regard to bronchiolitis severity, 15% received intensive care therapy. In unadjusted analyses, eosinophils ≥3% was not associated with intensive care therapy, while sIgE was associated with a significantly higher risk (odds ratio [OR]: 1.44, 95% confidence interval [CI]: 1.08-1.92; p = .01). In a multivariable model for intensive care therapy, eosinophilia remained unassociated with severity, and sIgE remained associated (OR: 1.60, 95% CI: 1.05-2.45; p = .03). Also, sIgE did not modify the association between eosinophil level and intensive care therapy (pinteraction  = .14).

CONCLUSION

Blood eosinophilia of ≥3% was not associated with bronchiolitis severity. By contrast, sIgE was independently associated with bronchiolitis severity and did not modify the association between eosinophil level and severity.

Severe bronchiolitis profiles and risk of recurrent wheeze by age 3 years

BACKGROUND

A better understanding of bronchiolitis heterogeneity might help clarify its relationship with the development of recurrent wheezing and asthma.

OBJECTIVES

We sought to identify severe bronchiolitis profiles using a clustering approach and to investigate for the first time their association with allergy/inflammatory biomarkers, nasopharyngeal microbiota, and development of recurrent wheezing by age 3 years.

METHODS

We analyzed data from a prospective, 17-center US cohort study of 921 infants (age <1 year) hospitalized with bronchiolitis (2011-2014 winters) with posthospitalization follow-up. Severe bronchiolitis profiles at baseline (hospitalization) were determined by using latent class analysis based on clinical factors and viral etiology. Blood biomarkers and nasopharyngeal microbiota profiles were determined by using samples collected within 24 hours of hospitalization. Recurrent wheezing by age 3 years was defined based on parental report of breathing problem episodes after discharge.

RESULTS

Three severe bronchiolitis profiles were identified: profile A (15%), which was characterized by a history of breathing problems/eczema during infancy and non-respiratory syncytial virus (mostly rhinovirus) infection; profile B (49%), which has the largest probability of respiratory syncytial virus infection and resembled classic respiratory syncytial virus-induced bronchiolitis; and profile C (36%), which was composed of the most severely ill group. Profile A infants had higher eosinophil counts, higher cathelicidin levels, and increased proportions of Haemophilus-dominant or Moraxella-dominant microbiota profiles. Compared with profile B, we observed significantly increased risk of recurrent wheezing in children with profile A (hazard ratio, 2.64; 95% CI, 1.90-3.68) and, to a lesser extent, with profile C (hazard ratio, 1.51; 95% CI, 1.14-2.01).

CONCLUSION

Although longer follow-up is needed, our results might help identify, among children hospitalized for bronchiolitis, subgroups with particularly increased risk of asthma.

RSV-hRV co-infection is a risk factor for recurrent bronchial obstruction and early sensitization 3 years after bronchiolitis

To assess risk factors of recurrent bronchial obstruction and allergic sensitization 3 years after an episode of acute bronchiolitis, whether after ambulatory care treatment or hospitalization. A monocentric prospective longitudinal study including infants aged under 1 year with acute bronchiolitis was performed, with clinical (severity score), biological (serum Krebs von den Lungen 6 antigen), and viral (14 virus by naso-pharyngeal suction detection) assessments. Follow-up included a quaterly telephone interview, and a final clinical examination at 3 years. Biological markers of atopy were also measured in peripheral blood, including specific IgEs towards aero- and food allergens. Complete data were available for 154 children. 46.8% of them had recurrent wheezing (RW). No difference was found according to initial severity, care at home or in the hospital, respiratory virus involved, or existence of co-infection. A familial history of atopy was identified as a risk factor for recurrent bronchial obstruction (60% for RW infants versus 39%, P = 0.02), as living in an apartment (35% versus 15%, P = 0.002). 18.6% of the infants were sensitized, with 48.1% of them sensitized to aeroallergens and 81.5% to food allergens. Multivariate analysis confirmed that a familial history of atopy (P = 0.02) and initial co-infection RSV-hRV (P = 0.02) were correlated with the risk of sensitization to aeroallergens at 3 years. Familial history of atopy and RSV-hRV co-infection are risk factors for recurrent bronchial obstruction and sensitization.

Relationships among aeroallergen sensitization, peripheral blood eosinophils, and periostin in pediatric asthma development

BACKGROUND

Biomarkers, preferably noninvasive, that predict asthma inception in children are lacking.

OBJECTIVE

Little is known about biomarkers of type 2 inflammation in early life in relation to asthma inception. We evaluated aeroallergen sensitization, peripheral blood eosinophils, and serum periostin as potential biomarkers of asthma in children.

METHODS

Children enrolled in the Childhood Origins of ASThma study were followed prospectively from birth. Blood samples were collected at ages 2, 4, 6, and 11 years, and serum-specific IgE levels, blood eosionophil counts, and periostin levels were measured in 244 children. Relationships among these biomarkers, age, and asthma were assessed.

RESULTS

Serum periostin levels were approximately 2- to 3-fold higher in children than previously observed adult levels. Levels were highest at 2 years (145 ng/mL), and did not change significantly between 4 and 11 years (128 and 130 ng/mL). Age 2 year periostin level of 150 ng/mL or more predicted asthma at age 6 years (odds ratio [OR], 2.3; 95% CI, 1.3-4.4). Eosinophil count of 300 cells/μL or more and aeroallergen sensitization at age 2 years were each associated with increased risk of asthma at age 6 years (OR, 3.1; 95% CI, 1.7-6.0 and OR, 3.3; 95% CI, 1.7-6.3). Children with any 2 of the biomarkers had a significantly increased risk of developing asthma by school age (≥2 biomarkers vs none: OR, 6.6; 95% CI, 2.7-16.0).

CONCLUSIONS

Serum periostin levels are significantly higher in children than in adults, likely due to bone turnover, which impairs clinical utility in children. Early life aeroallergen sensitization and elevated blood eosinophils are robust predictors of asthma development. Children with evidence of activation of multiple pathways of type 2 inflammation in early life are at greatest risk for asthma development.