Clinical implications of isolated troponinemia following immune checkpoint inhibitor therapy

Cardiovascular adverse events induced by immune checkpoint inhibitors (ICIs) have gained significant interest over the past decade due to their impact on short- and long-term outcomes. They were initially thought to be rare, but the increasing use of ICIs in the treatment of both advanced and early stages of various malignancies has resulted in a substantial increase in their incidence. Different guidelines have proposed screening measures for ICI-induced myocarditis by incorporating troponin measurements at baseline and during the first few weeks of treatment. However, no specific guidelines have been developed yet regarding the interpretation of an asymptomatic rise in troponins. This state-of-the art review aims to provide an overview of the clinical relevance of elevated troponins during checkpoint inhibition and recommendations on how to manage elevated troponin levels during ICI therapy.

Intranasal Fluticasone Once Daily Compared with Once-Daily Cetirizine in the Treatment of Seasonal Allergic Rhinitis : Results of a Multicentre, Double-Blind Study

The efficacy and tolerability of fluticasone aqueous nasal spray, 200µg once daily for 21 days, was compared with cetirizine, 10mg once daily for 21 days, in a multicentre, randomised, double-blind, double-dummy, parallel group study. 237 evaluable patients aged 12 years and above, with seasonal allergic rhinitis (defined as having a positive skin test and a total symptom score of ≥ 6/15), received either fluticasone aqueous nasal spray (n = 119) or cetirizine (n = 118). Improvement in total symptom score was observed in patients from both treatment groups, with the improvement in the fluticasone treatment group being significantly greater (decrease in total symptom score from 9.23 to 2.13) than in the cetirizine treatment group (decrease in total symptom score from 9.36 to 4.31; p < 0.001). There was also a significantly greater improvement in the number of symptom-free days for all symptoms in favour of fluticasone aqueous nasal spray compared with cetirizine (p < 0.001). Furthermore, the percentage of days when patients did not require terfenadine as rescue therapy was significantly greater in the fluticasone group (87%) than in the cetirizine group (80%; p < 0.05). Five adverse events were reported during intranasal fluticasone treatment and 10 adverse events were reported during cetirizine therapy. There were no treatment-related withdrawals from therapy in the fluticasone group, but 5 treatment-related withdrawals were reported in the cetirizine group.This study demonstrated that fluticasone aqueous nasal spray, 200µg once daily, was significantly more effective than cetirizine, 10mg once daily, and had comparable (if not better) tolerability, in the treatment of seasonal allergic rhinitis.

Air pollution and asthma control in the Epidemiological study on the Genetics and Environment of Asthma

BACKGROUND

The associations between exposure to air pollution and asthma control are not well known. The objective of this study was to assess the association between long-term exposure to NO(2), O(3) and PM(10) and asthma control in the follow-up of the Epidemiological study on the Genetics and Environment of Asthma (EGEA2) (2003-2007).

METHODS

Modelled outdoor NO(2), O(3) and PM(10) estimates were linked to each residential address using the 4 km grid air pollutant surface developed by the French Institute of Environment in 2004. Asthma control was assessed in 481 subjects with current asthma using a multidimensional approach following the 2006-2009 Global Initiative for Asthma guidelines. Multinomial and ordinal logistic regressions were conducted adjusted for sex, age, body mass index, education, smoking and use of inhaled corticosteroids. The association between air pollution and the three domains of asthma control (symptoms, exacerbations and lung function) was assessed. ORs are reported per IQR.

RESULTS

Median concentrations (in micrograms per cubic metre) were 32 (IQR 25-38) for NO(2) (n=465), 46 (41-52) for O(3) and 21 (18-21) for PM(10) (n=481). In total, 44%, 29% and 27% had controlled, partly controlled and uncontrolled asthma, respectively. The ordinal ORs for O(3) and PM(10) with asthma control were 1.69 (95% CI 1.22 to 2.34) and 1.35 (95% CI 1.13 to 1.64), respectively. When including both pollutants in the same model, both associations persisted. Associations were not modified by sex, smoking status, use of inhaled corticosteroids, atopy, season of examination or body mass index. Both pollutants were associated with each of the three main domains of control.

CONCLUSIONS

The results suggest that long-term exposure to PM(10) and O(3) is associated with uncontrolled asthma in adults, defined by symptoms, exacerbations and lung function.

Asthma control assessed in the EGEA epidemiological survey and health-related quality of life

BACKGROUND

The aims were to assess 1) the relationship of asthma control assessed by combining epidemiological survey questions and lung function to Health-Related Quality of Life (HRQL) and 2) whether individuals with controlled asthma reach similar generic HRQL levels as individuals without asthma.

METHODS

The analysis included 584 individuals without asthma and 498 with asthma who participated in the follow-up of the Epidemiological study on Genetics and Environment of Asthma (EGEA). Asthma control was assessed from survey questions and lung function, closely adapted from the 2006-2009 Global Initiative for Asthma guidelines. The Asthma Quality of Life Questionnaire (AQLQ, scores range:1-7) and the generic SF-36 (scores range: 0-100) were used.

RESULTS

Adjusted mean total AQLQ score decreased by 0.5 points for each asthma control steps (6.4, 5.9 and 5.4 for controlled, partly-controlled and uncontrolled asthma respectively, p < 0.0001). The differences in SF-36 scores between individuals with controlled asthma and those without asthma were minor and not significant for the PCS (-1, p = 0.09), borderline significant for the MCS (-1.6, p = 0.05) and small for the 8 domains (<5.1) although statistically significant for 4 domains.

CONCLUSION

These results support the discriminative properties of the proposed asthma control grading system and its use in epidemiology.

Variable content of Fel d 1 variants in house dust and cat extracts may have an impact on allergen measurement

BACKGROUND

The major cat allergen, Fel d 1, is a tetrameric glycoprotein composed of 2 heterodimers. Polymorphisms in this allergen are well documented. Recent work shows that Fel d 1 samples can contain core fragments of variable immunoreactivity.

OBJECTIVES

Our objective was to compare Fel d 1 polymorphism in cat extracts and house dust, which is used as an indicator of allergen exposure and to understand how the combination of individual Fel d 1 variants can affect cat allergen measurement.

METHODS

Natural Fel d 1 allergens were water-extracted from house dust and from the chest area and anal sacs of a cat. Recombinant Fel d 1 was provided commercially. The samples were analyzed by immunoblotting; variants were isolated using gel electrophoresis and tested using enzyme-linked immunosorbent assay.

RESULTS

Four Fel d 1 variants of 40, 30, 19-21, and 14-16 kDa were consistently identified in Fel d 1 samples. Fel d 1 patterns found in house dust and the chest area wash were similar. Dimers were shown to be the major variant, while intact or truncated tetramers and core fragments were found in variable amounts. Intact and truncated dimers of Fel d 1 displayed similar antibody binding. Conversely, the intact tetramer-but not the core tetramer-was found to bind twice the antibody amount as the dimers and core fragments.

CONCLUSIONS

Despite a common pattern of Fel d 1 variants in cat extracts and house dust, variations in the tetramer-to-dimer ratio among samples may introduce major discordances in cat allergen measurements using immunoassays. Our findings indicate the need for further harmonization of allergen immunoassays.

Immunological differences in the global release of the major cat allergen Fel d 1 are influenced by sex and behaviour

The biological function of Fel d 1, the major cat allergen released in the environment, is still unclear despite studies suggesting a putative role in chemical communication. Structural and immunological polymorphisms of Fel d 1 have been described. This study examined how Fel d 1 immunological polymorphism may have a physiological origin by estimating a potential relationship with the sex of cats and cat-human interactions. Samples from bath washes of 21 cats were screened to study antibody binding to Fel d 1 using an ELISA. Personality and Tolerance Handling scores were used to assess the behaviour of the cats. In the washes, Fel d 1 concentrations were significantly lower in females than in males (P<0.05). Slopes from the ELISA dose-dependent curves varied among the cats: males secreted Fel d 1 variants with higher antibody recognition than females (P<0.01). Females that were aggressive and difficult to handle displayed a diminished slope value, and therefore a weaker Fel d 1 immunoreactivity in global washes, compared to females that were sociable (P=0.09) and easy to handle (P=0.07). This study shows a variable immunological polymorphism of Fel d 1 within a cat population, particularly between males and females, and this polymorphism appears to be related to cat-human interactions.

Differences in allergen-induced T cell activation between allergic asthma and rhinitis: Role of CD28, ICOS and CTLA-4

Background

Th2 cell activation and T regulatory cell (Treg) deficiency are key features of allergy. This applies for asthma and rhinitis. However with a same atopic background, some patients will develop rhinitis and asthma, whereas others will display rhinitis only. Co-receptors are pivotal in determining the type of T cell activation, but their role in allergic asthma and rhinitis has not been explored. Our objective was to assess whether allergen-induced T cell activation differs from allergic rhinitis to allergic rhinitis with asthma, and explore the role of ICOS, CD28 and CTLA-4.

Methods

T cell co-receptor and cytokine expressions were assessed by flow cytometry in PBMC from 18 house dust mite (HDM) allergic rhinitics (R), 18 HDM allergic rhinitics and asthmatics (AR), 13 non allergic asthmatics (A) and 20 controls, with or without anti-co-receptors antibodies.

Results

In asthmatics (A+AR), a constitutive decrease of CTLA-4+ and of CD4+CD25+Foxp3+ cells was found, with an increase of IFN-γ+ cells. In allergic subjects (R + AR), allergen stimulation induced CD28 together with IL-4 and IL-13, and decreased the proportion of CTLA-4+, IL-10+ and CD4+CD25+Foxp3+ cells. Anti-ICOS and anti-CD28 antibodies blocked allergen-induced IL-4 and IL-13. IL-13 production also involved CTLA-4.

Conclusions

T cell activation differs between allergic rhinitis and asthma. In asthma, a constitutive, co-receptor independent, Th1 activation and Treg deficiency is found. In allergic rhinitis, an allergen-induced Treg cell deficiency is seen, as well as an ICOS-, CD28- and CTLA-4-dependent Th2 activation. Allergic asthmatics display both characteristics.

Insights into severe asthma control as assessed by guidelines, pulmonologist, patient, and partner

INTRODUCTION

The most recent guidelines on asthma management advocate a treatment strategy based on control of the disease rather than severity, a switch based on reported evidence.

AIMS

This observational, questionnaire-based study set out to investigate how control of the disease is assessed by the physician as well as the patient and his/her live-in partner and to compare these assessments with an assessment made according to the guidelines.

METHODS

In 169 patients with severe, persistent asthma on at least a high-dose inhaled corticosteroid plus an inhaled long-acting β2-agonist, control of the disease was assessed by the pulmonologist, the patient, and the patient's live-in partner. These assessments were compared with an assessment based on the guidelines. Results. Both patients and partners tended to judge disease control as better than their pulmonologists who, in turn, estimated control as acceptable in 58% of their patients in whom the guidelines would advocate more aggressive treatment. The most common guidelines criteria defining inadequate control in the "uncontrolled" 87.4% of this population were "limitation of physical activity" (72.3%) and "FEV₁" ≤ 85% of personal best" (63.3%).

CONCLUSIONS

To assess control in severe asthma, the patient's opinion is of limited value, as is that of their partners. Although a guidelines-based strategy has been shown to be effective in clinical trials conducted on large-scale populations in which mild or moderate disease is predominant, more aggressive treatment to achieve definitive control may not be appropriate in the 10% of asthma sufferers with severe disease; in everyday practice, lung specialists appear to implement such a strategy.

Histamine induces Th2 activation through the histamine receptor 1 in house dust mite rhinitic but not asthmatic patients

BACKGROUND

Effects of mast cell-released histamine on smooth muscle and endothelial cells are considered as responsible of immediate symptoms of anaphylaxis. However, little is known about histamine effects on Th2 lymphocytes, which orchestrate the allergic reaction upstream of mast cells.

OBJECTIVE

We addressed this question in house dust mite (HDM) allergics, according to the presence of rhinitis or asthma and allergen stimulation.

METHODS

Peripheral blood mononuclear cell from 15 rhinitic and 14 asthmatic HDM-allergic subjects and 16 controls were cultured with Der p 1 or histamine. The effect of Der p 1 on histamine receptor (H1R and H2R) expression was studied. T-cell cytokine production was studied upon Der p 1 or histamine stimulation. The role of H1R in histamine effects was assessed with levocetirizine.

RESULTS

H1R and H2R are overexpressed on T cells from asthmatic but not from rhinitic subjects. Der p 1 increases H1R expression on CD4(+) cells from both allergic groups, and decreases it in controls, on CD4(+) and CD8(+) subsets. Der p 1 decreases T-cell H2R expression in asthmatics. Allergen increases IL-4 and IL-13 in both allergic groups. Histamine increases Th2 cytokines in rhinitics only, and levocetirizine abolishes this effect. In asthmatics and controls, histamine decreases T-cell cytokines through a non-H1R dependent pathway.

CONCLUSION

In rhinitis but not in asthma, histamine is able to increase allergic inflammation by increasing Th2 cytokine production in a positive feedback dependent on H1R. This result could explain in part why H1R antagonists, are very efficient in rhinitis, but not in asthma.

Distribution of core fragments from the major cat allergen Fel d 1 is maintained among the main anatomical sites of production

BACKGROUND

Polymorphism of Fel d 1 has long been observed, but structural characterization of Fel d 1 variants among the various sites of production and animals is still missing. This study was aimed at elucidating the structural polymorphism of this protein as a function of the site of production and the resulting influence on the immunological behavior of the allergen.

METHODS

Fel d 1 was water-extracted from the 4 main sites of production, i.e. cheek zone, interdigital zone, anal sac (AS), and chest area and a panel of 10 cats. Fel d 1-like materials were immunoblotted, immunopurified and characterized by MALDI-TOF MS. Immunoreactivity was studied using ELISA dose-dependent curves at equilibrium.

RESULTS

In all areas, 4-10 isoforms ranging from 7 to 40 kDa were detected by MS. Essentially two truncated heterodimers of 13-14 and 16-17 kDa were identified together with intact Fel d 1 in all compartments and they were largely predominant in AS. These core fragments were found to contribute to a variable recognition by antibodies in a panel of ELISA.

CONCLUSIONS

Our study identified truncated dimers of Fel d 1, probably resulting from proteolytic degradation of both chains and present in all cats. Core fragments are largely distributed among anatomical sites of production and especially well represented in AS. They are recognized as intact allergens by antibodies and may therefore introduce discrepancies in allergen measurement depending on the variable amount of intact and degraded Fel d 1 produced by the cat.

17q21 variants modify the association between early respiratory infections and asthma

Single nucleotide polymorphisms (SNPs) at chromosome 17q21 confer an increased risk of early-onset asthma. The objective was to study whether 17q21 SNPs modify associations between early respiratory infections and asthma. Association analysis was conducted in 499 children (268 with asthma, median age 11 yrs) from the Epidemiological Study on the Genetics and Environment of Asthma (EGEA). The 12-yr follow-up data were used to assess persistent or remittent asthma in young adulthood. Respiratory infection before 2 yrs of age was assessed retrospectively. For the 12 17q21 SNPs studied, the odds ratios (OR) for association between infection and early-onset asthma (age at onset <or=4 yrs) were higher in carriers of risk genotypes (OR 3.42-6.36) than in noncarriers (OR 1.84-2.44; p-value for interaction 0.02-0.04 for five SNPs). Risk genotypes also increased the association between infection and childhood asthma that remits in adulthood (OR 4.84-7.16 in carriers and 1.74-2.25 in noncarriers; p-value for interaction 0.008-0.05 for 10 SNPs). In children with 17q21 risk genotypes and early-life environmental tobacco smoke (ETS) exposure, associations between infection and asthma were further enhanced. 17q21 genetic variants and early ETS exposure enhance the association between early respiratory infections and early-onset asthma and childhood asthma that remits in adulthood.

Phenotypic determinants of uncontrolled asthma

BACKGROUND

Although uncontrolled asthma remains frequent, determinants of asthma control are poorly studied.

OBJECTIVES

The aim was to estimate the distribution and the phenotypic characteristics of asthma control in 2 groups of subjects defined by the use of inhaled corticosteroids (ICS) in the past 12 months, in the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA).

METHODS

Five hundred one adult current patients with asthma who participated in the follow-up of the EGEA study were included. Asthma control was assessed from survey questions reflecting asthma control, as defined in the 2006 Global Initiative for Asthma guidelines. The factors analyzed were age, sex, educational level, body mass index, active and passive smoking, sensitization to aeroallergens, total IgE, rhinitis, chronic cough/phlegm, and age at asthma onset. Analyses were stratified according to ICS use.

RESULTS

Uncontrolled asthma was more frequent in ICS users (27.6%, 35.0%, and 37.4% with controlled, partly-controlled, and uncontrolled asthma respectively) compared with non-ICS users (60.0%, 23.9%, and 16.1%, respectively). In ICS users, chronic cough or phlegm and female sex were independently and significantly related to uncontrolled asthma. In non-ICS users, high total IgE and sensitization to molds were associated with uncontrolled asthma. Smoking and rhinitis were not associated with asthma control.

CONCLUSION

Optimal asthma control remained unachieved in the majority of patients with asthma in this study. Factors associated with uncontrolled asthma were different in ICS users (chronic cough/phlegm, female sex) and non-ICS users (high total IgE and sensitization to molds).

Allergen-specific immunotherapy in allergic rhinitis and asthma. Mechanisms and proof of efficacy

Appeared at the beginning of the 20th century, allergen-specific immunotherapy (SIT) has long been used in allergic rhinitis and asthma without any knowledge of its mechanisms of action or any tangible proof of its efficacy. However, from the beginning of the era of evidence-based medicine, a number of placebo-controlled studies have been published and reached a sufficient number to assess the cellular events induced by SIT and allow meta-analysis to provide guidelines based on proofs. Controlled studies and meta-analysis concerned not only subcutaneous immunotherapy but also the sublingual route, demonstrating an effect of SIT on symptoms and medication use. Most recently sublingual tablets were proposed in allergic rhinitis. This paper reviews the mechanisms of SIT, the evidence of efficacy of SIT from the injective to the sublingual route and reminds the current guidelines.

Effect of 17q21 variants and smoking exposure in early-onset asthma

BACKGROUND

A genomewide association study has shown an association between variants at chromosome 17q21 and an increased risk of asthma. To elucidate the relationship between this locus and disease, we examined a large, family-based data set that included extensive phenotypic and environmental data from the Epidemiological Study on the Genetics and Environment of Asthma.

METHODS

We tested 36 single-nucleotide polymorphisms (SNPs) in the 17q21 region in 1511 subjects from 372 families for an association with asthma. We also tested for genetic heterogeneity according to the age at the onset of asthma and exposure to environmental tobacco smoke in early life.

RESULTS

Eleven SNPs were significantly associated with asthma (P<0.01), of which three (rs8069176, rs2305480, and rs4795400) were strongly associated (P<0.001). Ordered-subset regression analysis led us to select an onset at 4 years of age or younger to classify patients as having early-onset asthma. Association with early-onset asthma was highly significant (P<10(-5) for four SNPs), whereas no association was found with late-onset asthma. With respect to exposure to environmental tobacco smoke in early life, we observed a significant association with early-onset asthma only in exposed subjects (P<5x10(-5) for six SNPs). Under the best-fitting recessive model, homozygous status (GG) at the most strongly associated SNP (rs8069176) conferred an increase in risk by a factor of 2.9, as compared with other genotypes (AG and AA) in the group exposed to environmental tobacco smoke (P=2.8x10(-6); P=0.006 for the test for heterogeneity of the SNP effect on early-onset asthma between groups with tobacco exposure and those without such exposure).

CONCLUSIONS

This study shows that the increased risk of asthma conferred by 17q21 genetic variants is restricted to early-onset asthma and that the risk is further increased by early-life exposure to environmental tobacco smoke. These findings provide a greater understanding of the functional role of the 17q21 variants in the pathophysiology of asthma.

T-cell activation during exacerbations: a longitudinal study in refractory asthma

BACKGROUND

Asthma exacerbations represent the main source of costs and morbidity in asthma care, and drugs specifically designed to prevent exacerbations are needed. A prerequisite is to dispose of a precise knowledge of inflammatory events leading to exacerbations.

OBJECTIVE

To study T-cell activation during exacerbations from severe refractory asthmatics.

METHODS

Proportions of blood T-cell interleukin (IL)-13, interferon-gamma, IL-4, IL-5, IL-10 production and of CD4+CD25+(high)CD62L+CD45RO+ [T regulatory (Treg)] cells were determined by flow cytometry. Blood cytokine mRNA was studied by reverse transcription-polymerase chain reaction and the respective protein levels were determined by cytokine beads array. Depletion of Treg cells was performed to study their activation. T-cell cytokines were detected in parallel in induced sputum.

RESULTS

At baseline, T helper 2 (Th2) cells were increased in asthmatics, whereas T helper 1 (Th1) and Treg T cells were decreased. T helper 2 cells increased before exacerbations, followed by Th1 cells, in blood and induced sputum, albeit Treg cells decreased in parallel with IL-10-producing T cells. Concordant results were found at the mRNA level. The suppressive activity of Treg cells was impaired during exacerbations compared to baseline.

CONCLUSIONS

New insights are given into pathophysiology of asthma exacerbations: Although at baseline T-cell activation is Th2-biased, a mixed Th1/Th2 activation occurs during exacerbations. The Treg cell deficiency found at baseline in SRA increases during exacerbations.

Evidence for linkage of a new region (11p14) to eczema and allergic diseases

Asthma, allergic rhinitis (AR) and atopic dermatitis also called eczema are allergic co-morbidites, which are likely to depend on pleiotropic genetic effects as well as on specific genetic factors. After a previous genome-wide linkage screen conducted for asthma and AR in a sample of 295 French EGEA families ascertained through asthmatic subjects, the aim here was to search for genetic factors involved in eczema and more particularly the ones shared by the three allergic diseases using the same EGEA data. In this sake, eczema and phenotypes of "allergic disease" accounting for the joint information on the presence/absence of the three diseases were examined by linkage analyses using the maximum likelihood binomial method. A fine mapping was carried out in regions detected for potential linkage, followed by association studies using the family-based association test (FBAT). Evidence for linkage to 11p14 region was shown for "allergic disease" and eczema. Linkage was also indicated between eczema and 5q13 and between "allergic disease" and both 5p15 and 17q21 regions. Fine mapping supported the evidence of linkage to 11p14 and FBAT analyses showed the association between "allergic disease" and a marker located at the linkage peak on 11p14. Further investigations in this region will allow identifying genetic factor(s) which could have pleiotropic effect in the three allergic diseases.

[Exacerbation in asthma: definitions and immunopathology]

There is no unequivocal definition of exacerbation in asthma. These are defined as episodes of increased or aggravated respiratory symptoms or as use of oral corticosteroid therapy. Viral infection is the most frequent cause of exacerbations. Inflammation during exacerbations is heterogeneous. It may be associated with bronchial hypereosinophilia, which is used as a predictive marker for exacerbation, and with neutrophilia, which is more resistant to corticosteroids. During viral infection, an inappropriate Th1 antiviral inflammation develops, associated with the intrinsic Th2 activity that leads to an aberrant immune response. Exacerbations secondary to allergen exposure are classically described as due to a Th2-type inflammation; but Th1 response also seems to play a role. Exposure to air pollutants appears able not only to induce bronchial inflammation but also to potentiate the inflammatory reactions of patients with exacerbations.

[Environmental factors for asthma severity and allergy: results from the EGEA study]

INTRODUCTION

EGEA (Epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), a case control and family study including 2048 individuals, was initiated to look for environmental and genetic risk factors for asthma. A synthesis of the results obtained since 2002 on phenotypic and environmental aspects of asthma severity and allergy are presented in this article.

METHODS AND RESULTS

The results support a role for hormonal factors in asthma severity and in various allergic markers of asthma. A greater body mass index was related to a more severe asthma in women with early menarche. Associations between markers of allergy (eosinophils, IgE and atopy) and hormonal dependent events in women (premenstrual asthma, menopause and oral contraceptive use) have been found. In asthmatics, exposure to agents known to be associated with occupational asthma, active and passive smoking were associated with an increased clinical asthma severity score. The study underlines the protective role of country living and exposure to pets in early life on allergy markers in adulthood, supporting the hygiene hypothesis.

CONCLUSIONS

New hypothesis will be tested in the near future from the second stage of this survey.

T-cell activation in occupational asthma and rhinitis

BACKGROUND

Allergic asthma and rhinitis are described as associated with a Th2 activation. However, recent works indicate that a Th1 activation can also be associated with these diseases, concomitantly to a defect in regulatory T (Treg) cell activation. Occupational asthma (OA) and occupational rhinitis (OR) are peculiar cases of these diseases in which the T-cell activation profile is largely unknown.

OBJECTIVE

To characterize T-cell activation induced after a specific inhalation test (SIT) in OA and OR.

MATERIAL AND METHODS

A total of 21 subjects with OA, 10 subjects with OR, 10 exposed nonallergic (ENA) subjects, and 14 healthy volunteers were included. The SIT with the incriminated substance was performed in patients and ENA subjects. Blood and induced sputum were obtained before and after SIT. T cells were analysed for CD69, CD25, IL-13, and IFN-gamma expression by flow cytometry. IL-4 and IFN-gamma were assayed by enzyme-linked immunosorbent assay (ELISA) in cell culture supernatants. Treg cells were identified as CD4(+)CD25(+high)CD45RO(+)CD69(-) T cells in peripheral blood.

RESULTS

Baseline IFN-gamma production was decreased in OA and OR compared with controls. The SIT induced an increase in both Th1 and Th2 cells in blood and sputum from OA. In this group, the proportion of peripheral Treg cells decreased after SIT. Similar results were found in the CD8(+) population. ELISA assays were concordant with flow cytometry. In OR, an attenuated activation profile was found, with an increase in the proportion of IL-13-producing T cells after SIT. By contrast, in ENA subjects, SIT induced Th2 activation, with an increase in Treg cells and a decrease in Th1 cells.

CONCLUSIONS

Our results demonstrate a gradient of T-cell activation from a tolerating profile in ENA subjects to an inflammatory profile in OA, with an intermediate stage in OR.

Safety and efficacy of Juniperus ashei sublingual-swallow ultra-rush pollen immunotherapy in cypress rhinoconjunctivitis. A double-blind, placebo-controlled study

BACKGROUND

The safety and efficacy of high-dose sublingual-swallow immunotherapy (SLIT) has been established in pollen rhinoconjunctivitis. This treatment has now been evaluated using an ultra-rush incremental dose regimen with a Juniperus ashei allergen extract in patients allergic to Cupressus sempervirens and Cupressus arizonica.

METHODS

Patients received either placebo or SLIT. Evaluation of safety was based on the frequency of adverse events during the incremental dose period (half a day) and during maintenance therapy (4 months). Evaluation of efficacy was based on symptom and medication scores at the pollen peak.

RESULTS

Seventy of the 76 patients included completed the study. There were no drop-outs during the rush procedure. One patient in the active group dropped out during the maintenance therapy due to adverse events: gastric pain and vomiting. There was also 1 drop-out in the placebo group due to pregnancy. Adverse events were infrequent, local and mild. Symptom scores for rhinitis and conjunctivitis were not statistically different between groups, but there was a marked and significant (p < 0.03) decrease of the medication score (about 50%) and nasal steroid consumption (about 75%) in the active treatment group. An increase from baseline of serum IgE and IgG4 J. ashei-specific antibodies was only observed in actively treated patients (p < 0.04 and p < 0.01, respectively).

CONCLUSIONS

The tolerability and safety of high-dose ultra-rush SLIT were comparable to those reported in previous SLIT studies. SLIT with J. ashei extract, due to its high Jun a 1 content, significantly reduced nasal steroid consumption in patients allergic to European cypress.

Ultra-rush venom immunotherapy induces differential T cell activation and regulatory patterns according to the severity of allergy

BACKGROUND

Venom immunotherapy (VIT) induces immune tolerance to hymenoptera venom antigens in allergic patients and is therefore a helpful model for studying modulation of allergic immune response. The objectives were to assess the early effects of ultra-rush VIT on T lymphocyte activation and regulatory profile induction, in all subjects combined and according to the four severity grades of the Mueller classification.

MATERIALS AND METHODS

Blood samples from 30 vespid-allergic patients were taken before and after the first day of treatment, and before day 15 and day 45 booster injections. IFN-gamma and IL-4 levels were assayed by ELISA, in whole-blood supernatants. IFN-gamma and IL-13-producing T cells, but also natural CD4+CD25+high regulatory T cells and acquired regulatory T cell proportions were assessed by flow cytometry. Results were analysed in the whole population and compared between patients with I-II or III-IV allergic reactions.

RESULTS

During VIT, IFN-gamma increased in whole blood when IL-4 decreased. Among T cells, the percentage of CD3+IFN-gamma+ cells increased while IL-13-producing T cells decreased. Proportions of CD4+CD25+high cells and IL-10-producing T cells increased with VIT. In I-II subjects, IFN-gamma increased gradually, whereas it remained at low levels in III-IV patients. By contrast, IL-4 decrease was more pronounced in III-IV patients. Increase in CD4+CD25+high T cells occurred early in I-II patients but was delayed in III-IV patients. IL-10-producing T cells increased gradually in both groups but were in a lower proportion in III-IV patients.

CONCLUSION

A T helper type 2 (Th2)-to-Th1 switch occurs during ultra-rush VIT, in parallel with natural and acquired regulatory T cell increase. These events occur earlier and at a higher level in less severe subjects, suggesting that VIT tolerance induction is easier to achieve in these patients.

Do patients with skin allergies have higher levels of anxiety than patients with allergic respiratory diseases? Results of a large-scale cross-sectional study in a French population

BACKGROUND

Psychological comorbidity is a known aspect of allergic disease. However, there is recent evidence that a large proportion of allergic patients remains undiagnosed and untreated for psychological disease. In addition, the complexities of the anxiety-allergy relationship, i.e. differences for current and past disease, or differences among allergic disease types, are not well understood.

OBJECTIVES

To measure the level of anxiety in a large allergic population in France using a standardized measure, the State/Trait Anxiety Inventory (STAI).

METHODS

Allergy patients in France (n = 3939) who visited their allergy specialists participated in the study. The patients completed a questionnaire which was then linked to the questionnaire completed by their physician. Only patients with both subject and physician questionnaire were kept in the analyses. Mean STAI scores for the State (S) and Trait (T) scales were obtained for each allergic disease. ANCOVA models testing group differences on the mean scores, using the categories "current disease", "past disease" and "allergic disease ever", were assessed along with relevant confounders.

RESULTS

Allergic rhinitis (AR), asthma and atopic dermatitis (AD) were the most prevalent conditions of the 12 allergic diseases assessed in the study. Women had higher mean STAI S/T scores than men and age was also found to be associated with higher S scores; therefore, both age and gender were included as covariates where relevant. A single ANCOVA model for each STAI scale showed a statistical difference among the various allergic diseases. Using the category "current disease" each allergic disease was assessed separately regarding the presence or absence of that disease. Higher, statistically significant mean STAI scores were found for AD and allergic urticaria on the S scale and for AD on the T scale. Similarly, for the category "allergic disease ever", AD and allergic urticaria reached statistical significance on the S scale, while on the T scale only AD was statistically significant. When patients were assessed for anxiety based on their past disease, asthma, AR and sinusitis were significant on the S scale while asthma and nasal polyps were statistically significant on the T scale. When asthma and AD were tested simultaneously, only the latter was significant.

CONCLUSIONS

High mean scores for State and Trait anxiety were mostly associated with AD.

Diesel exhaust particles enhance T-cell activation in severe asthmatics

Prevalence of asthma is increasing in westernized countries. Epidemiological studies showed the impact of traffic pollution on the triggering of asthma symptoms and exacerbations, and this effect is mainly attributed to the polycyclic aromatic hydrocarbon core of diesel exhaust particles (DEP). However, although DEP induce IgE synthesis, little is known of their role on T-cell activation, the main cells orchestrating asthma inflammation. We assessed the effect of DEP on T-cell activation in severe uncontrolled asthmatics during (n = 13) and outside (n = 19) exacerbations. Results were compared with data obtained in healthy controls (n = 14). Peripheral blood mononuclear cells were cultured in the presence of low-dose DEP. T-cell activation markers, CD69 and CD25, interleukin-4 (IL-4) and interferon (IFN)-gamma production and T-cell proliferation were assessed by flow cytometry. DEP exposure increased the proportion of CD3+CD69+ T cells in all subjects. The proportion of CD25+ T cells increased under DEP stimulation in the exacerbation group only. IFN-gamma- and IL-4-producing T cells increased in both asthmatic groups, especially during exacerbations, but not in controls. This effect was more pronounced for IL-4. In response to DEP stimulation, T-cell proliferation increased in higher proportion in asthmatics compared with controls. These results show that DEP activate T cells in asthmatics only, with a higher effect during exacerbations. This is in keeping with epidemiological data which demonstrated that DEP trigger respiratory symptoms in asthmatics but not in controls. The higher effect of DEP in exacerbated asthmatics suggests that uncontrolled asthma is a risk factor for aggravation under exposure to traffic pollutants.

[T regulatory lymphocytes, atopy and asthma: a new concept in three dimensions]

BACKGROUND

Allergic inflammation is considered to be the result of a pattern of Th2 lymphocyte activation. However this inflammation, relevant for atopy and infiltration of affected tissues by eosinophils, is insufficient by itself to explain the clinical features of asthma. Several studies have demonstrated that Th2 type inflammation was also associated in asthma with a Th1 response, with production of gamma interferon. It has recently been shown that the regulatory T lymphocytes (Treg) which produce IL-10 and/or TGF-beta and induce tolerance are defective in allergic patients. In addition, these lymphocytes increase during specific immunotherapy. Their decrease could explain the Th2 activation found in atopic patients.

PERSPECTIVE

We review the potential importance of Treg cells in atopy and also asthma, and propose a concept whereby the allergic inflammatory response would not be due to a Th1/Th2 imbalance, but rather to a Treg deficiency progressively rising from normal to atopic, from atopy to asthma and from asthma to acute exacerbations.

CONCLUSION

Three dimensions of inflammation need therefore to be taken into account: Th1, Th2 and Treg.

Variation of T-cell activation in allergic subjects during natural pollen exposure

BACKGROUND

Allergic inflammation is characterized by a Th2 activation. However, little is known about dynamics of T-cell cytokine production during natural allergen exposure. The aim of this study was to assess the Th1/Th2 balance in cypress allergic patients compared with controls, and variations of this balance over the pollen season.

METHODS

Twenty cypress allergic patients and 10 controls were studied, distributed during two consecutive pollen seasons. Cytokine production was assessed by flow cytometry and ELISA. The variation of cytokine production during the pollen season was analyzed among patients in four occasions, and the preseason values were compared with controls. IL-13 and IFN-gamma-containing T cells were assessed among whole blood cells and PBMC. In addition the effect of specific stimulation by Juniperus ashei pollen extract was studied.

RESULTS

Compared with controls, IL-13-producing T cells were increased in allergics in any case. By contrast, compared with controls, allergic IFN-gamma-producing T cells were decreased in whole blood, but not in PBMC, and were increased after specific stimulation. During the season, an increase in IFN-gamma- and a decrease in IL-13-producing T cells occurred in patients, whatever the culture conditions.

CONCLUSION

These results show that the allergic T-cell activation is not limited to a Th2 profile: allergen-stimulated T cells are able to produce IFN-gamma at baseline, and the Th1/Th2 ratio increases during the pollen season.

[Pathophysiological mechanisms of asthma and atopy: old and new concepts]

After the discovery of IgE, fundamental immunology studies done during the 1980s and 1990s established that allergic reactions were a particular form of inflammatory reaction governed by Th2 lymphocytes. However, this model, while relevant to atopy, is insufficient to explain allergies, and notably asthma, in which Th1 inflammation is associated. The recent concept that natural tolerance is deficient in atopic subjects, increased in allergic subjects, and maximal in symptomatic allergic subjects, reconciles these conflicting findings by proposing a model in which three axes of T cell activation are involved, namely Th2, Th1 and regulatory T cells.

Dog factor differences in Can f 1 allergen production

BACKGROUND

The clinical importance of dog allergy is well known, but it is unknown if all types of dogs represent the same risk for allergic patients. The purpose of this work was to evaluate among 288 healthy dogs if the levels of Can f 1 on fur vary between breeds (German Shepherd, Pyrenean Shepherd, Poodle, Cocker spaniel, Spaniel, Griffon, Labrador retriever and Yorkshire terrier), gender, hormonal status, hair length, and according to the presence of seborrhea.

METHODS

Each dog was shaved in a limited area and Can f 1 concentrations were measured in mug/g fur by ELISA. The results (geometric mean values and 95% confidence intervals) were analyzed using analysis of variance and with nonparametric tests.

RESULTS

A wide variability in Can f 1 levels was found between dog breeds, from Labradors [1.99 (0.03-129.91)] to Yorkshires [16.72 (3.67-76.16)] and Poodles [17.04 (2.79-103.94)] but only the Labrador levels were significantly different from each other breed. Males produced more Can f 1 than females, 11.75 (1.27-108.40) vs 8.89 (0.91-86.39). No difference was found according to hair length or hormonal status. The seborrheic status highly (P = 0.0019) influenced the presence of Can f 1 on hair: 16.66 (1.59-173.96) vs 9.40 (1.03-85.70).

CONCLUSION

Breeds (Labrador retriever), sex and seborrhea seem to influence the levels of Can f 1 on fur.

Twenty five year mortality and air pollution: results from the French PAARC survey

AIMS AND METHODS

Long term effects of air pollution on mortality were studied in 14,284 adults who resided in 24 areas from seven French cities when enrolled in the PAARC survey (air pollution and chronic respiratory diseases) in 1974. Daily measurements of sulphur dioxide, total suspended particles, black smoke, nitrogen dioxide, and nitric oxide were made in 24 areas for three years (1974-76). Cox proportional hazards models controlling for individual confounders (smoking, educational level, body mass index, occupational exposure) were applied, and frailty models used to take into account spatial correlation. Indicators of air pollution were the mean concentration.

RESULTS

Models were run before and after exclusion of six area monitors influenced by local traffic (NO/NO2 >3 in ppb). After exclusion of these areas, analyses showed that adjusted risk ratios (95% CI) for TSP, BS, NO2, and NO for non-accidental mortality were 1.05 (1.02 to 1.08), 1.07 (1.03 to 1.10), 1.14 (1.03 to 1.25), and 1.11 (1.05 to 1.17) for 10 microg/m3 respectively. Consistent patterns for lung cancer and cardiopulmonary causes were observed.

CONCLUSIONS

Urban air pollution assessed in the 1970s was associated with increased mortality over 25 years in France.

Assessment of a therapeutic education programme for asthma patients: "un souffle nouveau"

The aim of this study was to evaluate the impact of a new patient education programme on adults with asthma. This self-management programme included an individual assessment of patient's needs and two educational group sessions. Teaching methods and session content are described as well as caregivers training programme. The training sessions included a written asthma action plan based on symptoms and personal peak expiratory flow. Patients (n = 238) aged from 18 to 60 years were allocated to the intervention (group A) or control group (group B). Patients filled during 1 year a daily diary and questionnaire and they were administered telephone interviews. 127 patients were included in the treatment program and 111 in the control group. There was a significant improvement in the educated group with regard to symptoms free days (P = 0.03), number of awakenings (P = 0.04), consumption of corticosteroids (P = 0.03), consumption of beta2-agonists (P = 0.03), and quality of life score (P = 0.01). In conclusion, this study validates a specific educational approach named "un souffle nouveau".

Genome screen in the French EGEA study: detection of linked regions shared or not shared by allergic rhinitis and asthma

In the sample of 295 French EGEA families with at least one asthmatic subject, a genome screen was conducted to identify potential linkage regions specific either to allergic rhinitis (AR) or to asthma as well as those shared by the two diseases. Two binary rhinitis phenotypes based on (1) diagnosis (ARbin1) and (2) symptoms (ARbin2) and a categorical ordered trait (ARcat) were considered. Asthma phenotype was based on answers to a standardized questionnaire plus the presence of bronchial hyper-responsiveness. Linkage analyses were conducted using the maximum likelihood binomial (MLB) method. These analyses provided potential evidence for linkage to three regions in the whole sample: 1p31 for the phenotype defined by ARbin2 plus asthma (P=0.00016), 2q32 for ARbin2 (P=0.00016) and 3p24-p14 for ARcat (P=0.001). Two other regions were detected in the subset of 185 families with at most one asthmatic sib: 9p22 and 9q22-q34 for ARbin1 (P=0.001 and 0.0007, respectively). No region showed evidence for linkage to asthma without being also linked to AR. While 1p31 may contain a genetic determinant common to asthma and AR, 2q32, 3p24-p14, 9p22 and 9q22-q34 are more likely to harbor genetic factors specific to AR.

[Epidemiology of seasonal spring-time allergic rhinitis in adults in France]

OBJECTIVE

Describe the profile of patients consulting a general practitioner or allergologist for seasonal spring-time allergic rhinitis (SAR) in France.

METHODS

3.348 physicians (3.284 general practitioners and 64 allergologists) recruited in 4 monthly episodes from March to June 1998, 34.851 patients consulting for SAR. Using a questionnaire, demographical data concerning the practitioners consulted and all the patients were collected. For 12,420 patients the symptomatology, history of asthma and ongoing treatment for SAR were analysed by comparing the population consulting a general practitioner (A) or an allergologist (B).

RESULTS

Mean age for all patients with suspected SAR was of 37.1 +/- 15.7 years with a majority of women (54.90%). For 1,441 patients, it was the first consultation for this disorder, notably with a general practitioner, (11.1 vs. 2.4%). Aqueous rhinorrhea, sneezing and nasal obstruction were the most frequent symptoms noted, without significant difference between the type of practitioner consulted. 5.711 patients had undergone previous allergy tests, with more skin tests in the group consulting an allergologist (78 vs. 44.9%). Association with history of asthma was similar in both groups (30%). Impact on daily life was almost identical, whether isolated or associated with past history of asthma (56 vs. 51.6%), but differed with regard to sleep (56.7 vs. 21.1%). During the consultation, 5.889 patients were already treated with antihistamines (83.2%), whatever the type of practitioner consulted.

CONCLUSION

Seasonal spring-time allergic rhinitis is a frequent pathology, which significantly impairs quality of life. There is little difference in patients' profile whether they consult a general practitioner or an allergologist.

Phenotypes of asthma revisited upon the presence of atopy

Immunological studies claimed that atopic and non-atopic asthma share more similarities than differences. However, these two phenotypes of asthma are considered to be distinguishable upon distinct clinical patterns, which were not systematically assessed before in a large population. We studied characteristics discriminating atopic from non-atopic asthma among 751 asthmatic patients and 80 factors were analysed in univariate and multivariate analysis. Age, age of onset of asthma, female/male ratio were higher in non-atopic (n=200) than in atopic (n=551) asthmatics. Familial asthma, seasonal symptoms, rhinitis, conjunctivitis, allergen-triggered symptoms, improvement in altitude, exercise-induced asthma were associated with atopy. Non-atopic asthmatics displayed lower FEV(1) and FVC. Smoking was more frequent and asthma was more severe in these patients. Younger age, early onset, male sex, rhinitis and smoking were independent factors discriminating atopic from non-atopic asthma. This study establishes in a large population of asthmatics that although similarities exist between atopic and non-atopic asthma, two clinical phenotypes can still distinguish both kinds of asthma.