Latent class analysis reveals clinically relevant atopy phenotypes in 2 birth cohorts

Background: Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear. Objective: We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE). Methods: Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort. Results: The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-gamma ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk. Conclusions: LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function.Peer reviewe

N. Quellien, Chansons et danses des Bretons.

Kaulek Jean. N. Quellien, Chansons et danses des Bretons.. In: Bibliothèque de l'école des chartes. 1889, tome 50. pp. 463-464

Disagreement between skin prick tests and specific IgE in early childhood

BACKGROUND: Accurate diagnosis of allergic sensitization is essential in clinical practice and allergy research, and the choice of assessment method may have an important impact. The PASTURE study (Protection against Allergy: Study of Rural Environment) examines the influence of exposure to a dairy farm environment on the occurrence of allergy in a cohort of rural European children from birth to 10 years. The aim of our study was to analyze agreement between skin prick tests (SPTs), to aeroallergens and food allergens, and specific IgE and to evaluate the association of SPT with atopic dermatitis in the 204 French children of the PASTURE study. METHODS: SPT, atopic dermatitis assessment, and specific IgE measurements were performed at 1, 4.5, and 6 years. RESULTS: A total of 137 children attended all three visits. The agreement between SPTs and specific IgE was poor except for perennial aeroallergens at 6 years and for an IgE cutoff greater than 0.7 IU/ml (κ = 0.69, 0.5202 - 0.8621). The prevalence of positive SPTs increased with age. Positive SPTs were transient at 1 year, whereas they were persistent between 4.5 and 6 years. Positive SPTs at 1 year were predictive of the occurrence of atopic dermatitis during follow-up. CONCLUSION: SPTs did not have good agreement with serum-specific IgE in early childhood. Both tests (SPT and specific IgE) should be used. Skin allergenic reactivity increased with age and was transient at 1 year but associated with the occurrence of atopic dermatitis

Comparative phenotype and immunogenicity of freshly isolated and immortalized rat hepatocytes

Immortalized hepatocytes are an attractive cell source for hepatocyte transplantation and gene transfer. We compared the phenotype and immunogenicity of freshly isolated (FIH) and immortalized (IMH) rat hepatocytes. Effect of culture and proinflammatory cytokines (TNF-agr, IFN-ggr) was studied on phenotype. FIH were isolated by collagenase digestion. Two SV40 immortalized hepatocyte cell lines were tested (RH1 and P9). Immunophenotyping was performed by FACS analysis using anti-rat-specific antibodies. Immunogenicity was evaluated by a mixed lymphocyte hepatocyte reaction (MLHR). FIH suspension was an almost homogeneous parenchymal cell population with few (1-2%) CD8+ cells. FIH showed a positive staining for ICAM-1 (20-35%) and for Class I (RT1A, 30-60%) but no staining for Class II (RT1B). After 48 h of culture, the already ICAM-1-positive cells were more strongly stained and additionally 3.6% of the cells (possibly endothelial cells) were Class II positive. IMH showed a consistent expression of Class I (93-97%) and ICAM-1 (95-97%) but no expression of Class II. Culture of IMH for 48 h had no effect on Class II expression but increased ICAM-1 expression. Addition of TNF-agr at 1000 UI/ml to cultures of FIH or IMH increased Class I and ICAM-1 expression whereas IFN-ggr (50 or 1000 UI/ml) had no evident effect. Hepatocyte immunogenicity, assessed in MLHR and appreciated by the stimulation index (SI) test/SI syngeneic control, was similar for IMH (RH1: 2.68 ± 0.89; P9: 2.37 ± 0.78) and FIH (2.52 ± 0.18). In conclusion, despite some quantitative immunophenotypic differences, FIH and IMH induced the same proliferation rate of allogeneic T lymphocytes. Thus, immortalized hepatocytes may constitute an appropriate cellular model to study the prevention of hepatocyte rejection by gene transfer

La diversité de consommation de fromages dans la petite enfance : un facteur protecteur des maladies allergiques ?

National audienc

Protective effect of diversity of cheese consumption in early life against allergic diseases

absen

Prognostic value of CD4+ T lymphopenia in non-small cell lung Cancer

International audienceBackground: There is a paucity of data regarding the prognostic influence of peripheral blood CD4+ T lymphopenia in non-small cell lung cancer (NSCLC). Therefore, we investigated the prognostic value of T lymphopenia in NSCLC. Materials: Treatment-naive patients with a pathological diagnosis of NSCLC, at clinical stage I to IV were included in the prospective TELOCAP1 study. Lymphocytes count was evaluated in peripheral blood by flow cytometry. CD4+ and CD8+ T lymphopenia were defined as an absolute count of 500/ μL (median overall survival (OS) 16.1 versus 21.7 months, hazard ratio (HR): 1.616 [95% CI: 1.1-2.36], p = 0.012). This association with OS was especially marked in local/loco-regional NSCLC stages (median OS, 21.8 versus 72 months, respectively, HR: 1.88 [95% CI: 0.9-3.8], p = 0.035). Multivariate analysis confirmed the worse prognosis associated with CD4+ T lymphopenia in local/loco-regional NSCLC, but not in metastatic patients (HR 2.028 [95% CI = 1.065-3.817] p = 0.02). Restricted cubic spline analysis showed that patients with CD4+ T lymphocytes count ≤500/μL displayed a high risk of death regardless of NSCLC clinical stage. There was no obvious relationship between CD8+ T lymphopenia and clinical outcome. Conclusion: We identified CD4+ T lymphopenia as an independent prognostic factor in local/loco-regional stages of NSCLC and CD4+ T lymphopenia is also associated with a high risk of death, regardless of NSCLC clinical stage