Impaired post-sleep apnea autonomic arousals in patients with drug-resistant epilepsy

OBJECTIVE

Sudden and unexpected deaths in epilepsy (SUDEP) pathophysiology may involve an interaction between respiratory dysfunction and sleep/wake state regulation. We investigated whether patients with epilepsy exhibit impaired sleep apnea-related arousals.

METHODS

Patients with drug-resistant (N = 20) or drug-sensitive (N = 20) epilepsy and obstructive sleep apnea, as well as patients with sleep apnea but without epilepsy (controls, N = 20) were included. We explored (1) the respiratory arousal threshold based on nadir oxygen saturation, apnea-hypopnea index, and fraction of hypopnea among respiratory events; (2) the cardiac autonomic response to apnea/hypopnea quantified as percentages of changes from the baseline in RR intervals (RRI), high (HF) and low (LF) frequency powers, and LF/HF.

RESULTS

The respiratory arousal threshold did not differ between groups. At arousal onset, RRI decreased (-9.42%) and LF power (179%) and LF/HF ratio (190%) increased. This was followed by an increase in HF power (118%), p < 0.05. The RRI decrease was lower in drug-resistant (-7.40%) than in drug-sensitive patients (-9.94%) and controls (-10.91%), p < 0.05. LF and HF power increases were higher in drug-resistant (188%/126%) than in drug-sensitive patients (172%/126%) and controls (177%/115%), p < 0.05.

CONCLUSIONS

Cardiac reactivity following sleep apnea is impaired in drug-resistant epilepsy.

SIGNIFICANCE

This autonomic dysfunction might contribute to SUDEP pathophysiology.

Data-driven adult asthma phenotypes based on clinical characteristics are associated with asthma outcomes twenty years later

BACKGROUND

Research based on cluster analyses led to the identification of particular phenotypes confirming phenotypic heterogeneity of asthma. The long-term clinical course of asthma phenotypes defined by clustering analysis remains unknown, although it is a key aspect to underpin their clinical relevance. We aimed to estimate risk of poor asthma events between asthma clusters identified 20 years earlier.

METHODS

The study relied on two cohorts of adults with asthma with 20-year follow-up, ECRHS (European Community Respiratory Health Survey) and EGEA (Epidemiological study on Genetics and Environment of Asthma). Regression models were used to compare asthma characteristics (current asthma, asthma exacerbations, asthma control, quality of life, and FEV₁ ) at follow-up and the course of FEV₁  between seven cluster-based asthma phenotypes identified 20 years earlier.

RESULTS

The analysis included 1325 adults with ever asthma. For each asthma characteristic assessed at follow-up, the risk for adverse outcomes differed significantly between the seven asthma clusters identified at baseline. As compared with the mildest asthma phenotype, ORs (95% CI) for asthma exacerbations varied from 0.9 (0.4 to 2.0) to 4.0 (2.0 to 7.8) and the regression estimates (95% CI) for FEV₁ % predicted varied from 0.6 (-3.5 to 4.6) to -9.9 (-14.2 to -5.5) between clusters. Change in FEV₁ over time did not differ significantly across clusters.

CONCLUSION

Our findings show that the long-term risk for poor asthma outcomes differed between comprehensive adult asthma phenotypes identified 20 years earlier, and suggest a strong tracking of asthma activity and impaired lung function over time.

Benefit of continuous positive airway pressure on work quality in patients with severe obstructive sleep apnea

BACKGROUND

The objective of this prospective study was to assess the effect of CPAP therapy on job productivity and work quality for patients with severe obstructive sleep apnea (OSA).

METHODS

A convenience sample of patients diagnosed with severe OSA using polysomnography or polygraphy and with a therapeutic indication for CPAP was enrolled in our study. Patients completed two self-administered questionnaires: the first before CPAP therapy and the second during the first 6 months after CPAP treatment. OSA symptoms were evaluated through self-administered questionnaires assessing potential effects on occupational activity: excessive daytime sleepiness was rated by the Epworth Sleepiness Scale (ESS), emotional status was rated by the Hospital Anxiety and Depression (HAD) scale, work quality was rated by the Work Role Functioning Questionnaire (WRFQ).

RESULTS

Forty patients (30 men, mean age 47.3 ± 8.3, mean BMI 31.6 ± 7.4, mean apnea-hypopnea index 51.8 ± 16.3) showed a beneficial effect of CPAP therapy on ESS score (mean 11.6 to 8.2, p < 0.0001), the anxiety dimension (mean 57.5% to 20%, p = 0.0002), and the overall anxiety-depressive score (mean 50% to 22.5%, p = 0.0006). Mean WRFQ scores were significantly improved in the second questionnaire for the dimensions of timetable requirements (69.3% to 83.5%, p < 0.0001), productivity requirements (71.4% to 82.2%, p < 0.0001), mental requirements (72.0% to 84.3%, p < 0.0001), and social requirements (82.6% to 91.4%, p < 0.003).

CONCLUSIONS

We observed that adherence to CPAP therapy for patients with severe OSA mitigates the impact of symptoms on work including excessive daytime sleepiness, impairment of work ability, and anxiety and depressive disorders.

Association between air pollution and rhinitis incidence in two European cohorts

BACKGROUND

The association between air pollution and rhinitis is not well established.

AIM

The aim of this longitudinal analysis was to study the association between modeled air pollution at the subjects' home addresses and self-reported incidence of rhinitis.

METHODS

We used data from 1533 adults from two multicentre cohorts' studies (EGEA and ECRHS). Rhinitis incidence was defined as reporting rhinitis at the second follow-up (2011 to 2013) but not at the first follow-up (2000 to 2007). Annual exposure to NO₂, PM₁₀ and PM_2.5 at the participants' home addresses was estimated using land-use regression models developed by the ESCAPE project for the 2009-2010 period. Incidence rate ratios (IRR) were computed using Poisson regression. Pooled analysis, analyses by city and meta-regression testing for heterogeneity were carried out.

RESULTS

No association between long-term air pollution exposure and incidence of rhinitis was found (adjusted IRR (aIRR) for an increase of 10 μg·m^-3 of NO_2: 1.00 [0.91-1.09], for an increase of 5 μg·m^-3 of PM_2.5: 0.88 [0.73-1.04]). Similar results were found in the two-pollutant model (aIRR for an increase of 10 μg·m^-3 of NO_2: 1.01 [0.87-1.17], for an increase of 5 μg·m^-3 of PM_2.5: 0.87 [0.68-1.08]). Results differed depending on the city, but no regional pattern emerged for any of the pollutants.

CONCLUSIONS

This study did not find any consistent evidence of an association between long-term air pollution and incident rhinitis.

Characterization of Rhinitis According to the Asthma Status in Adults Using an Unsupervised Approach in the EGEA Study

Background

The classification of rhinitis in adults is missing in epidemiological studies.

Objective

To identify phenotypes of adult rhinitis using an unsupervised approach (data-driven) compared with a classical hypothesis-driven approach.

Methods

983 adults of the French Epidemiological Study on the Genetics and Environment of Asthma (EGEA) were studied. Self-reported symptoms related to rhinitis such as nasal symptoms, hay fever, sinusitis, conjunctivitis, and sensitivities to different triggers (dust, animals, hay/flowers, cold air…) were used. Allergic sensitization was defined by at least one positive skin prick test to 12 aeroallergens. Mixture model was used to cluster participants, independently in those without (Asthma-, n = 582) and with asthma (Asthma+, n = 401).

Results

Three clusters were identified in both groups: 1) Cluster A (55% in Asthma-, and 22% in Asthma+) mainly characterized by the absence of nasal symptoms, 2) Cluster B (23% in Asthma-, 36% in Asthma+) mainly characterized by nasal symptoms all over the year, sinusitis and a low prevalence of positive skin prick tests, and 3) Cluster C (22% in Asthma-, 42% in Asthma+) mainly characterized by a peak of nasal symptoms during spring, a high prevalence of positive skin prick tests and a high report of hay fever, allergic rhinitis and conjunctivitis. The highest rate of polysensitization (80%) was found in participants with comorbid asthma and allergic rhinitis.

Conclusion

This cluster analysis highlighted three clusters of rhinitis with similar characteristics than those known by clinicians but differing according to allergic sensitization, and this whatever the asthma status. These clusters could be easily rebuilt using a small number of variables.

Long-term benefits of inhaled corticosteroids in asthma: the propensity score method

PURPOSE

The aim of this study was to apply a propensity score approach to assess the long-term benefits of inhaled corticosteroids (ICS) on respiratory health in asthma.

METHODS

This analysis was conducted on adults with persistent asthma from the Epidemiological study on the Genetics and Environment of Asthma, a 12-year follow-up study. ICS exposure was assessed by questionnaire. Change in lung function over the follow-up period, asthma control, and health-related quality of life (asthma quality of life questionnaire) were assessed by standardized and validated methods.

RESULTS

Among 245 adults with persistent asthma, 78 (31.8%) were regularly/continuously exposed to ICS (≥6 months/year, ICS++ ) and 167 never/irregularly exposed to ICS (<6 months/year, ICS+/- ) over the follow-up period. Compared with ICS+/- subjects, a nonsignificant trend for a slower lung function decline (mL/year) was observed in ICS++ subjects (β [95%CI] = -11.4 [-24.9; 2.0]). The ICS++ subjects did not have better controlled asthma and higher health-related quality of life as compared with ICS+/- subjects.

CONCLUSIONS

Applying a propensity score method did not offer evidence of a statistical significant long-term benefit of ICS on respiratory health in adults with persistent asthma regularly or continuously exposed to ICS over a long period.

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.

A new animal model of obstructive sleep apnea responding to continuous positive airway pressure

STUDY OBJECTIVES

An improved animal model of obstructive sleep apnea (OSA) is needed for the development of effective pharmacotherapies. In humans, flexion of the neck and a supine position, two main pathogenic factors during human sleep, are associated with substantially greater OSA severity. We postulated that these two factors might generate OSA in animals.

DESIGN

We developed a restraining device for conditioning to investigate the effect of the combination of 2 body positions-prone (P) or supine (S)-and 2 head positions-with the neck flexed at right angles to the body (90°) or in extension in line with the body (180°)-during sleep in 6 cats. Polysomnography was performed twice on each cat in each of the 4 sleeping positions-P180, S180, P90, or S90. The effect of continuous positive airway pressure (CPAP) treatment was then investigated in 2 cats under the most pathogenic condition.

SETTING

NA.

PATIENTS OR PARTICIPANTS

NA.

INTERVENTIONS

NA.

MEASUREMENTS AND RESULTS

Positions P180 and, S90 resulted, respectively, in the lowest and highest apnea-hypopnea index (AHI) (3 ± 1 vs 25 ± 2, P < 0.001), while P90 (18 ± 3, P<0.001) and S180 (13 ± 5, P<0.01) gave intermediate values. In position S90, an increase in slow wave sleep stage 1 (28% ± 3% vs 22% ± 3%, P<0.05) and a decrease in REM sleep (10% ± 2% vs 18% ± 2%, P<0.001) were also observed. CPAP resulted in a reduction in the AHI (8 ± 1 vs 27 ± 3, P<0.01), with the added benefit of sleep consolidation.

CONCLUSION

By mimicking human pathogenic sleep conditions, we have developed a new reversible animal model of OSA.

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).

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.

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.

[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.

[Sweet's syndrome associated with squamous cell bronchial carcinoma. Neutrophilic dermatosis and non-small cell lung cancer]

INTRODUCTION

Sweet's syndrome, one of the neutrophilic dermatoses, is idiopathic in most cases. In 10-20% of cases it is paraneoplastic, associated with a solid tumour or haematological malignancy. An association with carcinoma of the bronchus has been only rarely described.

CASE REPORT

We report the case of a 56 year old man who presented with Sweet's syndrome two months before the diagnosis of a squamous cell carcinoma of the bronchus. The dermatosis responded well to corticosteroids. The progress of the tumour was favourable, with stabilisation following 3 courses of chemotherapy and local radiotherapy.

DISCUSSION

This case report updates this rare association and underlines the importance of undertaking appropriate thoracic investigations in the presence of this dermatosis. A paraneoplastic secretion of interleukin-8, GM-CSF and/or G-CSF by the bronchial tumour cells facilitating the recruitment of neutrophils, particularly in the skin, may account for the pathophysiology of this condition.

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.

Association between asthma control in children and loss of workdays by caregivers

BACKGROUND

Although the economic burden of pediatric asthma is a significant public health issue, the loss of workdays by caregivers because of their children's asthma remains scarcely investigated.

OBJECTIVES

To evaluate asthma-related loss of workdays incurred by caregivers of asthmatic children and its association with the level of asthma control.

METHODS

A retrospective observational study was conducted based on a French computerized general practitioners' database and a survey questionnaire. Children aged 6 to 16 years with persistent asthma (Global Initiative for Asthma grade > or = 2) were included in the study. Level of children's asthma control was evaluated from recent asthma symptoms. Caregivers reported the number of workdays lost because of their child's asthma during the 12-month study.

RESULTS

Nearly 30% of caregivers lost workdays during the study because of their children's asthma. More than 13% of caregivers lost more than 5 days. Caregiver absenteeism significantly correlated with all components of asthma control (use of relievers, nocturnal symptoms, impairment of activities, and asthma crises). A significant 8-fold risk of losing more than 5 workdays by caregivers was observed when the child's asthma was poorly controlled (odds ratio, 8.6; 95% confidence interval, 2.4-30.5); caregivers' absenteeism also increased significantly with the number of episodes of oral corticosteroid use during the study.

CONCLUSIONS

Caregivers' loss of workdays owing to their children's asthma is substantial and is highly correlated with the level of asthma control. These findings highlight the necessity of educational programs for children with poor asthma control and their caregivers to prevent severe asthma attacks that lead to caregiver absenteeism.

Clustering patterns of LOD scores for asthma-related phenotypes revealed by a genome-wide screen in 295 French EGEA families

A genome-wide scan for asthma phenotypes was conducted in the whole sample of 295 EGEA families selected through at least one asthmatic subject. In addition to asthma, seven phenotypes involved in the main asthma physiopathological pathways were considered: SPT (positive skin prick test response to at least one of 11 allergens), SPTQ score being the number of positive skin test responses to 11 allergens, Phadiatop (positive specific IgE response to a mixture of allergens), total IgE levels, eosinophils, bronchial responsiveness (BR) to methacholine challenge and %predicted FEV(1). Four regions showed evidence for linkage (P</=0.001): 6q14 for %FEV(1), 12p13 for IgE, 17q22-q24 for SPT and 21q21 for both SPTQ and %FEV(1). Nine other regions indicated smaller linkage signals (0.001<P</=0.005). While most of these regions have been reported by previous asthma and lung function screens, 6q14 appears to be a new region potentially linked to %FEV(1). To determine which of these various asthma phenotypes are more likely to share common genetic determinants, a principal component analysis was applied to the genome-wide LOD scores. This analysis revealed clustering of LODs for asthma, SPT and Phadiatop on one axis and clustering of LODs for %FEV(1), BR and SPTQ on the other, while LODs for IgE and eosinophils appeared to be independent from all other LODs. These results provide new insights into the potential sharing of genetic determinants by asthma-related phenotypes.

Persistent asthma: disease control, resource utilisation and direct costs

Despite evidence that adverse outcomes are less frequent when asthma management is optimised, the link between the level of control, disease severity and medical resource utilisation (MRU) is poorly documented. This relationship was investigated in a group of patients suffering from persistent asthma (Global Initiative for Asthma (GINA) > or = 2) in France. In 1998 a computerised family practice database was used to identify asthma patients aged 17-50 yrs. Information from the database was complemented by a patient survey to retrospectively assess the level of asthma control and hospital contacts. Costs of MRU over a 12-month study period were related to demographics, medical history, asthma control, and doses of inhaled corticosteroids prescribed during the prestudy period. A review of the computerised medical database identified 1,038 adult patients with persistent asthma, who completed the survey questionnaire. Over a 12-month period, the mean cost of MRU was 549.8 euros for well-controlled patients, 746.3 euros per patient with moderate control, and 1,451.3 euros per patient with poor control. Costs also increased significantly with age, access to free asthma care, comorbid conditions, asthma symptoms in the past year and whether inhaled corticosteroids had been prescribed before the study period. In patients with persistent asthma, large differences were observed in the use of medical resources according to control and severity. Therefore, if patients appropriately use prescribed control therapy, their use of medical resources may be reduced.

[Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA) - First results of a multi-disciplinary study]

The French co-operative epidemiological study EGEA realised in 1991/95 combines a case control study and a study of the families of asthmatic cases. A synthesis of the results already obtained is presented. Smoking was related to IgE, even in asthmatics and was clearly related to the clinical severity of asthma, an aspect insufficiently taken into account. The relationships of occupational exposures to asthma have been assessed using a job exposure matrix. Segregation analyses on IgE have shown, after correction for the mode of ascertainment, the existence of a dominant major gene and familial residual correlation. A systematic genome screen realised in families with 2 asthmatic siblings showed linkage of various regions in the genome implicated to asthma or related phenotypes (1p, 11p, 11q, 12q, 13q, 17q, 19q), coherent with genome screens realised in other studies. Regarding candidate genes, no association was evidenced between asthma and the AF508 mutation of the cystic fibrosis gene. The analysis is still in progress by studies on the heterogeneity of asthma with refined genetic studies and by searching to integrate results regarding environmental and genetic factors and studying their interactions.

Level of control and hospital contacts in persistent asthma

The purpose of this study was to estimate relationships between asthma control and hospital contacts (visits to emergency rooms and hospitalizations) in a group of patients suffering from persistent asthma, after adjustment for prior use of inhaled corticosteroids. A computerized family practice database was used to identify patients (aged 6-50 years) with persistent asthma who received asthma therapy from January 1995. The database provided information on patient demographics and drug therapy. Asthma control was estimated by a survey of patients at the end of a 12-month study period. Frequency of hospital contacts during the study period was related to demographics, asthma control, and prescribed doses of inhaled corticosteroids during a prestudy period. Review of computerized medical files of 497 family practice physicians identified 1,966 patients with persistent asthma who met the study criteria. Of these patients, 1,251 completed the survey (63.6%). Asthma control was assessed in 1,130 patients; it was moderate or poor in 42% of the cases. During the 12-month study period, 14.8% of patients reported at least one hospital contact. The level of asthma control was significantly (p < 0.001) associated with hospital contacts. The odds ratio (OR) for hospital contact for good and poor asthma control was 0.5 (95% confidence interval [CI] 0.2-0.7) and 2.2 (95% CI 1.2-4.4), respectively. Asthma control was related to hospital contacts independently of use of inhaled corticosteroids before the study period. Overall, control of asthma was not optimal in this population. The occurrence of hospital contacts was closely related with the level of control. This association was independent of the dose of inhaled corticosteroids prescribed before the study, suggesting that in asthma, hospital contacts are primarily related to the level of control experienced by the patients.

[Neoadjuvant chemoradiotherapy and peroperative radiotherapy for non-small-cell lung cancer of the apex. A study of 5 cases]

The management of superior sulcus tumors with Pancoast 's syndrome is not well defined, especially in view of their low frequency. Even if surgery performed by "en bloc" resection of the tumor and the chest wall is recommended, neoadjuvant treatment could have a potential benefit on the resecability and pain control. We report five cases of Pancoast tumors (NSCLC), treated by radiotherapy and chemotherapy before surgery. Four tumors was on stage IIIb. A regimen with radiotherapy (50 Gy) and chemotherapy (cisplatinum + etoposide) was initially performed. Four tumors were resected, with 2 complete pathologic responses and good control on pain. Three patients received radiotherapy during surgery. No toxic reaction was observed. This regimen may be discussed with locally advanced tumors and poor prognosis.

[Epidemiological study of genetic and environmental factors in asthma, bronchial hyperresponsiveness and atopy. Protocol and potential selection bias]

BACKGROUND

The EGEA study combines a case-control study and a family study to assess genetic and environmental risk factors and their interactions for asthma, bronchial hyperresponsiveness and atopy. Information is scanty regarding potential selection biases, in particular regarding familial ressemblance in epidemiological surveys of this kind.

METHODS

Asthmatic probands (adult and paediatric) were recruited in chest clinics of six clinical centres. Controls were mostly population-based (electoral rolls) for adults and recruited in surgery departments for children.

RESULTS

The population examined includes 348 nuclear families ascertained by one asthmatic and 416 controls, totalling 1847 subjects (EGEA I) and an additional sample of 40 families ascertained by two asthmatic siblings (EGEA II). Potential biases for the various types of analyses have been studied. Quantification of the consequences of the greater participation of probands with a parental history of asthma shows it does not introduce a major bias in the estimates of familial resemblance. Cases and controls showed a good comparability regarding sex, age, area of residence and familial geographical origin, allowing proper associations studies for environmental and candidate genetic factors.

CONCLUSIONS

The case-control component of the study will allow to perform studies on environmental factors and association studies for various genetic polymorphisms. Using the family base collected, segregation and genetic linkage/association analyses with DNA markers may be performed.

Genome screen for asthma and related phenotypes in the French EGEA study

A genome-wide search was conducted in 107 nuclear families with at least two siblings with asthma, as part of the French EGEA study. A two-stage analysis strategy was applied to the 107 families divided into two independent subsets of 46 and 61 families, where all regions detected in the first set of families were tested for replication in the second set. In addition, all regions reported by published genome scans in different populations were examined in the total sample. A total of 254 markers were typed in the first set of families and 70% of them in the second set. Linkage was investigated by model-free methods for asthma and four asthma-related phenotypes: bronchial responsiveness (BR), skin test response, total immunoglobulin E (IgE) levels, and eosinophil count. The two-stage analysis led to the detection of three regions: 11p13 for IgE, 12q24 for eosinophils, and 17q12-21 for asthma and skin tests. Among the regions reported by published genome screens, seven were found in the 107 French EGEA families: three being already detected by the two-stage analysis, 11p13 (p = 0.005), 12q24 (p = 0.0008), and 17q12-21 (p = 0.001), and four additional ones, 1p31 (p = 0.005) for asthma, 11q13 (p = 0.006) for IgE, 13q31 (p = 0.001) for eosinophils, and 19q13 (p = 0.02) for BR.

EGEA (Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy)-- descriptive characteristics

The Epidemiological study on the Genetics and Environment of Asthma (EGEA) was planned to assess genetic, environmental risk factors and their interactions for asthma and for the two related traits of bronchial hyperresponsiveness and atopy. The population examined includes 348 nuclear families ascertained by one asthmatic (213 adult and 135 paediatric probands) and 416 controls, totalling 1,847 subjects (EGEA I). Prevalences of asthma, skin prick test response, high IgE and bronchial hyperresponsiveness were for parents, siblings, and offspring of cases intermediate between cases and spouses or controls, both in adults and children, confirming the familial resemblance for asthma and related traits. With an additional sample of 40 families ascertained by two asthmatic siblings (EGEA II), a total of 119 families with two asthmatic siblings has been ascertained for a genome screening.

CD40 expression by human bronchial epithelial cells

CD40 is a 50-kDa protein expressed on B cells, dendritic cells, monocytes and epithelial cells, but the distribution of CD40 expression in humans is not completely known. It binds to a ligand (CD40L) which is expressed essentially on activated T cells. The interaction between CD40 and CD40L plays important roles in immune responses. CD40 expression was investigated on bronchial tissues and human bronchial cell lines using immunohistochemistry, immunofluorescence staining and analysis with a cytometer, respectively. Constitutive CD40 expression, but not that of CD40L, was slightly detectable on normal human bronchial epithelial cells (HBEC) in situ and on an adult lung adenocarcinoma (SKLU1) cell line, while another cell line, a bronchial transformed SV40 cell line (WI26VA4), was negative for CD40. Among the various cytokines tested, only interferon (IFN)-gamma was found to induce CD40 expression on WI26VA4. Tumour necrosis factor (TNF)-alpha was the best cytokine able to up-regulate CD40 in SKLU1 cells. A combination of IFN-gamma and TNF-alpha was slightly more effective than the cytokine alone at up-regulating CD40 expression on both cell lines. We further investigated the functional consequences of CD40 ligation on both cell lines. These bronchial cells expressed CD40, HLADR and CD54 under basal conditions or when stimulated by cytokines. Stimulation through CD40 did not affect cell-surface-antigen expression on either cell line. The production of cytokines such as interleukin (IL)-6 and granulocyte macrophage-colony stimulating factor (GM-CSF) by HBEC has been described. SKLU1 and WI26VA4 cells released IL-6 and GM-CSF spontaneously. Whatever the case, CD40 engagement did not modulate spontaneous or TNF-alpha-induced production of these two cytokines. These data indicate for the first time that normal HBEC express CD40 in situ. Further investigations are required in order to determine the role of CD40 on normal HBEC.

Epidemiological study of the genetics and environment of asthma, bronchial hyperresponsiveness, and atopy: phenotype issues

The Epidemiological Study of the Genetics and Environment of Asthma (EGEA) combined a case-control study and a family study. The total sample of 1,854 consisted of 348 patients with asthma selected through chest clinics and 416 control subjects and nuclear families ascertained through the cases. The protocol included standardized questionnaires, bronchial responsiveness, allergen skin-prick tests according to international protocols, total serum immunoglobulin E (IgE) level measurements, and blood eosinophilia. Criteria used to select subjects with asthma and determine asthma status of relatives for affected sibling pair linkage analysis are described. Based on figures from the 348 asthma cases of the EGEA study, issues relative to the definition of severe asthma and intermediate phenotypes such as bronchial responsiveness and allergic markers are discussed. Given the phenotypic heterogeneity involved, relevant phenotypes that may lead to the detection of genetic factors will depend on the hypothesis tested. Standardization of primary data and subphenotypes is a prerequisite for pooling data, which will be needed in the future to better understand the genetics and environmental factors of asthma.

RU 41740 (Biostim) stimulates the production of granulocyte macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro

1. In this study, we observed the effects of RU 41740 (Biostim) on the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) in human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by enzyme-linked immunosorbent assay. 3. We report that epithelial cells spontaneously released both cytokines and that RU 41740 induced a significant increase in production of IL-8 and GM-CSF. 4. This is the first observation of a stimulatory effect of an immunostimulating compound used in humans on cytokine production by epithelial cells.

Uptake of 12-HETE by human bronchial epithelial cells (HBEC): effects on HBEC cytokine production

12-HETE, the major lipoxygenase end-product of platelets and macrophages, may be released in contact of bronchial epithelium in inflammatory diseases of the lung. We have studied the outcome of 12-HETE in presence of human bronchial epithelial cells (HBEC). When HBEC were incubated with [3H]12-HETE for 30 minutes, 27.5% of total radioactivity was found in HBEC and 72.5% in supernatants. Unesterified 12-HETE accounted for 22.4% of total radioactivity, 4.5% being recovered in phospholipids, preferentially in phosphatidylcholine and phosphatidylethanolamine. No incorporation in neutral lipids was detected. 72.9% of the incubated radioactivity was recovered in un identified metabolites. As 12-HETE has been shown to modulate the expression and production of various proteins, the consequence of the 12-HETE uptake on the release of GM-CSF and IL8 by HBEC was assessed. HBEC from control subjects were cultured for 24 hours with 12-HETE (10(-9) to 10(-7)M) in the presence or absence of TNF alpha. Detectable amounts of both cytokines were released in the supernatant in basal conditions at 24hr, and TNF alpha increased significantly the release of GM-CSF. 12-HETE at 10(-7)M weakly but significantly decreased the TNF-induced release of GM-CSF from HBEC. Thus the uptake of 12-HETE could affect the epithelial cell function in some situations.

Antihistamines and production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro: evaluation of the effects of loratadine and cetirizine

1. In this study, we compared the effects of two antihistamine drugs on the production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by the use of an enzyme-linked immunosorbent assay. 3. Epithelial cells spontaneously released both cytokines and tumor necrosis factor alone induced a significant increase in this production but loratadine and cetirizine had no effect at the various concentrations studied. 4. The antihistamines have no effect and this suggests that histamine plays no role in cytokine production under these conditions.

Increased respiratory burst and phosphodiesterase activity in alveolar eosinophils in chronic eosinophilic pneumonia

A 43 year old woman presented with chronic eosinophilic pneumonia characterised by a high alveolar eosinophilic count, which allowed biochemical study of these cells. Alveolar eosinophils spontaneously produced high amounts of oxygen free radicals and exhibited an increased level of cyclic adenosine monophosphate (cAMP) phosphodiesterase (PDE) activity compared to blood eosinophils from control or allergic subjects. This activity was preferentially located in the plasma membrane, whilst the PDE activity of blood eosinophils from asthmatics or controls predominated in the cytosol. Because of the potential role of phosphodiesterase during eosinophil activation and recruitment, phosphodiesterase inhibitors may be useful in the treatment of eosinophilic pneumonia.

[Corticoid resistance in asthma]

Incorrect application of corticosteroid treatment, whether due to non-compliance, misinterpretation of etiological factors, or inadapted treatment, can lead to the difficult problem of corticoresistance. The expression of the phenomenon are varied and may concern all or part of the effector cells responsible for the inflammatory reaction. The underlying mechanism is still poorly understood but appears to involve a generally acquired, though sometimes inborn or genetically induced, desensitization of the receptor cells. Several substitute treatments have been proposed including methotrexate, gold salts, cyclosporin A, but the results have not been very promising.

Leukotriene B4 production by blood neutrophils in allergic rhinitis--effects of cetirizine

BACKGROUND

Mucosal inflammatory processes in late phase of allergic diseases involve cytokine production, cell adhesion molecule overexpression and release of inflammatory mediators with chemotactic activity, such as leukotriene B4 (LTB4). We had previously observed increased production of LTB4 by neutrophils in patients with allergic rhinitis and discussed the role of granulocyte macrophage-colony stimulating factor (GM-CSF) priming. Some antihistaminic compounds were shown to diminish the production of leukotrienes by neutrophils.

OBJECTIVES

In a first step, we evaluated in ex vivo and in vitro studies, the effects of cetirizine on LTB4 production by blood neutrophils from allergic and healthy subjects. In a second step, we studied the in vitro effect of cetirizine on LTB4 production by neutrophils from healthy subjects during GM-CSF priming of these cells.

METHODS

Neutrophils from both populations were purified from venous blood and LTB4 production was measured using high performance liquid cromatography (HPLC) method.

RESULTS

In ex vivo studies, cetirizine treatment induced a decreased LTB4 production by neutrophils in allergic rhinitis. This effect of decreased LTB4 production was reproduced in vitro with 10(-8)-10(-6)M cetirizine. Nevertheless, this anti-H1 compound had no effect on neutrophil priming with GM-CSF.

CONCLUSION

As LTB4 is an important chemotactic factor, Cetirizine could act on inflammatory cell recruitment by inhibiting LTB4 production by neutrophils.

Granulocyte-macrophage colony stimulating factors (GM-CSF) and interleukin 8 (IL-8) production by human bronchial epithelial cells (HBEC) in asthmatics and controls. Lack of in vitro effect of salbutamol compared to sodium nedocromil

The bronchial epithelium produces cytokines that could contribute to inflammatory events in airways. In this study we determined the basal and TNFalpha stimulated productions of GM-CSF and IL-8 by human bronchial epithelial cells (HBEC) collected from 12 control and six asthmatic patients. Spontaneous and TNFalpha-induced GM-CSF or IL-8 released levels increased significantly with time. Epithelial cells from asthmatic patients spontaneously released high levels of GM-CSF (24 h). TNFalpha potentiated GM-CSF and IL-8 release in control subjects and only the IL-8 production in asthmatics. Nedocromil sodium, an antiinflammatory drug, and salbutamol, a beta2-agonist, are commonly used in asthma. They were evaluated on the spontaneous and TNF-induced expression of GM-CSF and IL-8 in cultured bronchial epithelial cells. Nedocromil sodium, at the concentration of 10(-6) M, reduced the TNF-induced increase in GM-CSF but not the IL-8 release. Salbutamol, at the concentration of 10(-6) or 10(-5) M, did not affect the constitutive or stimulated production of both cytokines.

Antibiotics and production of granulocyte-macrophage colony-stimulating factor by human bronchial epithelial cells in vitro. A comparison of cefodizime and ceftriaxone

Cultured human bronchial epithelial cells (HBEC) produce both granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 8 (IL-8). The influence of cefodizime (CAS 69739-16-8), a new broad spectrum cephalosporin with immunostimulatory effects, and ceftriaxone on the production of GM-CSF and IL-8 in HBEC primary cultures was investigated. HBEC were isolated from biopsy specimens obtained during fibreoptic bronchoscopy in 12 patients (most frequent diagnosis: chronic bronchitis). Confluent monolayers of HBEC cultured on collagen were incubated for 24 h in a medium without study drugs (spontaneous production) or containing cefodizime or ceftriaxone at the clinically relevant concentrations of 1, 10 and 100 mg/l, with or without tumor necrosis factor alpha (TNF alpha, 100 U/ml). GM-CSF and IL-8 were measured in supernatant by ELISA technique. TNF alpha alone led to a significant (p < 0.005) increase in both GM-CSF and IL-8 production. Cefodizime induced a significant (p < 0.05), dose-dependent increase in GM-CSF release. No additive effect of cefodizime with TNF alpha was observed. Cefodizime did not affect IL-8 production and ceftriaxone had no influence on cytokine production. This is the first report of a stimulatory effect of a beta-lactam antibiotic on cytokine production by epithelial cells. GM-CSF production by epithelial cells is an important immunological step for neutrophil and monocyte recruitment and cell priming during lung defence. Previous studies with cefodizime in immunodepressed subjects have shown activation of phagocytosis and phagocytosis-related functions in non-lung phagocytes. An indirect mechanism of action, similar to that indicated by our results, may have been responsible for these stimulatory effects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Sleep apnea syndrome in obese patients: are there any predictive factors ?]

The aim of this study was to determine whether clinical, spirometric, or arterial blood gas data could predict sleep apnea syndrome (SAS) among obese patients with at least one functional complaint. Eighty three obese patients, 46 males and 37 females, aged 53.2 +/- 13.7 years, with a body mass index (BMI) above 30 kg/m2 were investigated with: clinical questionnaire; pulmonary function tests; arterial blood gas measurements; nocturnal monitoring of oronasal airflow, thoracic and abdominal movements, and arterial oxygen saturation. Thirty five patients (42.2%) had a SAS, 18 (26.7%) had nocturnal oxygen desaturations, and 30 (36.1%) had a normal nocturnal monitoring. There were 63% males in the SAS group and 32% in the group without SAS (P < 0.01). Age, weight, frequency of systemic hypertension, frequency of each clinical symptom, spirometric and arterial blood gas data were identical in the two groups. In conclusion, rate of SAS is very high in obese patients presenting a BMI above 30 and at least one functional complaint. No predictive test is identified.

Impaired G-proteins and cyclic nucleotide phosphodiesterase activity in T-lymphocytes from patients with sarcoidosis

Among the various immune abnormalities which characterize active sarcoidosis, a low proliferative response of peripheral blood lymphocytes to mitogenic lectins has long been observed. Since membrane-associated G-proteins are very likely to be crucial elements in lectin signal transduction, we investigated the binding of 5'-guanylylimidodiphosphate (GppNHp), a non hydrolyzable GTP analogue, to blood total lymphocyte membranes and to blood T-lymphocyte membranes from patients with active sarcoidosis, and from healthy control subjects. GppNHp binding was markedly decreased in peripheral cells from patients with sarcoidosis as compared to controls, suggesting the occurrence of a defect at the level of G-protein(s). A further characterization of G-proteins in these cells by means of ADP-ribose-labelling in the presence of bacterial toxins brought forward a significant decrease in the labelling of a 40 kDa protein, the major pertussis toxin substrate, in membranes from sarcoid patients, while the labelling of the major 44 kDa cholera toxin substrate proved to be unchanged with respect to control membranes. It is hypothesized that, in sarcoid lymphocytes, a defect in the negative control of adenylate cyclase mediated by the inhibitory G-protein Gi, prevents the lowering of cAMP necessary to normal mitogenic response of blood lymphocytes to stimulation. cAMP degradation by the specialized enzyme phosphodiesterase constitutes another critical step in the control of cAMP levels. Both cAMP and cGMP phosphodiesterase activities were found decreased in blood total lymphocyte preparations from sarcoid patients. With purified T-cells, although the mean cAMP and cGMP phosphodiesterase activities from sarcoid patients were found more markedly decreased with respect to healthy donors, only the decrease in cGMP phosphodiesterase was found statistically significant. The role these defects in cyclic nucleotide degradation potentially play in the disturbance of blood lymphocytes response associated with sarcoidosis is discussed.

Leukotriene B4 level in stimulated blood neutrophils and alveolar macrophages from healthy and asthmatic subjects. Effect of beta-2 agonist therapy

Leukotriene B4 levels were measured after stimulation by calcium ionophore A23187: (i) in peripheral, neutrophils (PMN) from allergic asthmatics, rhinitis and healthy subjects; (ii) in macrophages collected by bronchoalveolar lavage. LTB4 levels in PMNs were significantly higher in non-treated allergic asthmatics and non-treated subjects with rhinitis compared to controls. Beta-2 agonist-treated asthmatics showed a significantly decreased LTB4 production which was not different from those of controls. In vitro, LTB4 production decreased significantly after PMN incubation with Salbutamol (10(-6) mol l-1). LTB4 produced by AM collected by BAL was measured in non-treated (n = 5) and treated (n = 11) asthmatics with inhaled beta-2 agonist. AM collected from all controls and non-treated asthmatics produced LTB4. By contrast, no production of LTB4 was observed in the treated group. LTB4 production decreased when normal AM were incubated in vitro with Salbutamol (10(-8) mol l-1). These results suggest that biochemical differences occur in PMN and macrophages from subjects treated with beta-2 agonist, presumably in changing the 5-lipoxygenase pathway.

Pretreatment staging evaluation in small cell lung carcinoma. A new approach to medical decision making

The real need for extensive staging at the time of diagnosis is discussed in regard to small cell lung carcinoma. We performed a decisional retrospective analysis on a series of 182 patients, based on three staging steps: the first step included physical examination and routine biologic tests. The second step consisted of liver ultrasonography and needle aspiration of any clinically detectable tumor mass, and the third step included bone marrow examination, radionuclide bone scan, thoracic, abdominal, and brain CT scan. A stepwise multivariate logistic regression performed on 11 variables considered in the first step shows that a four-parameter model can predict the spread of the disease (limited or extensive): weight loss, performance status, and elevated LDH or alkaline phosphatase levels. Limited disease can be predicted in two ways: (1) elevated LDH with normal alkaline phosphatases, no weight loss, and good performance status, or (2) normal LDH and alkaline phosphatases. In this series, 28 percent of patients can be predicted as having extensive disease and can be treated with chemotherapy alone without chest irradiation. After the second step, the probability of disease being extensive is only 25 percent, and only 84 (46.15 percent) patients would need to undergo the third step of staging procedures (brain CT scan, bone marrow aspiration and biopsy, radionuclide bone scan) with this method. We conclude that a multistep approach represents a simple staging method and offers the advantage of harmlessness and lower costs for patients not to be evaluated in prospective clinical trials.

Increased membrane fluidity in blood leukocytes from allergic subjects. A possible role for leukotriene B4

Modifications of lipid metabolism and increased plasma membrane fluidity may occur during cell activation and occur in leukocytes of patients with allergic disease. Using a fluorescent probe (TMA-DPH) and a polarization technique, we studied the variations of membrane fluidity in blood leukocytes from allergic and normal subjects. The anisotropic coefficient, which is inversely related to the rotational motion of the probe in membrane phospholipids, was significantly higher in normal subjects than in allergic ones. This result implies an increased membrane fluidity in leukocytes from allergic patients. No correlation could be observed with the etiology or the severity of allergic disease, nor with cell preparation composition or serum IgE level. Such a modification of membrane fluidity has been reproduced after incubation of leukocytes from normal subjects with leukotriene B4, but not with cells from allergic patients. Establishing the mechanism of these differences requires further investigations.