Ethnic variability in persistent asthma after in utero tobacco exposure

BACKGROUND

The effects of in utero tobacco smoke exposure on childhood respiratory health have been investigated, and outcomes have been inconsistent.

OBJECTIVE

To determine if in utero tobacco smoke exposure is associated with childhood persistent asthma in Mexican, Puerto Rican, and black children.

PATIENTS AND METHODS

There were 295 Mexican, Puerto Rican, and black asthmatic children, aged 8 to 16 years, who underwent spirometry, and clinical data were collected from the parents during a standardized interview. The effect of in utero tobacco smoke exposure on the development of persistent asthma and related clinical outcomes was evaluated by logistic regression.

RESULTS

Children with persistent asthma had a higher odds of exposure to in utero tobacco smoke, but not current tobacco smoke, than did children with intermittent asthma (odds ratio [OR]: 3.57; P = .029). Tobacco smoke exposure from parents in the first 2 years of life did not alter this association. Furthermore, there were higher odds of in utero tobacco smoke exposure in children experiencing nocturnal symptoms (OR: 2.77; P = .048), daily asthma symptoms (OR: 2.73; P = .046), and emergency department visits (OR: 3.85; P = .015) within the year.

CONCLUSIONS

Exposure to tobacco smoke in utero was significantly associated with persistent asthma among Mexican, Puerto Rican, and black children compared with those with intermittent asthma. These results suggest that smoking cessation during pregnancy may lead to a decrease in the incidence of persistent asthma in these populations.

Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations

Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma.

Cosmopolitan and ethnic-specific replication of genetic risk factors for asthma in 2 Latino populations

BACKGROUND

Although Mexicans and Puerto Ricans are jointly classified as "Hispanic/Latino," there are significant differences in asthma prevalence, severity, and mortality between the 2 groups. We sought to examine the possibility that population-specific genetic risks contribute to this disparity.

OBJECTIVES

More than 100 candidate genes have been associated with asthma and replicated in an independent population, and 7 genome-wide association studies in asthma have been performed. We compared the pattern of replication of these associations in Puerto Ricans and Mexicans.

METHODS

We genotyped Mexican and Puerto Rican trios using an Affymetrix 6.0 GeneChip and used a family-based analysis to test for genetic associations in 124 genes previously associated with asthma.

RESULTS

We identified 32 single nucleotide polymorphisms (SNPs) in 17 genes associated with asthma in at least 1 of the 2 populations. Twenty-two of these SNPs in 11 genes were significantly associated with asthma in the combined population and showed no significant heterogeneity of association, whereas 5 SNPs were associated in only 1 population and showed statistically significant heterogeneity. In a gene-based approach 2 additional genes were associated with asthma in the combined population, and 3 additional genes displayed ethnic-specific associations with heterogeneity.

CONCLUSIONS

Our results show that only a minority of genetic association studies replicate in our population of Mexican and Puerto Rican asthmatic subjects. Among SNPs that were successfully replicated, most showed no significant heterogeneity across populations. However, we identified several population-specific genetic associations.

The impact of insurance on access to cancer clinical trials at a comprehensive cancer center

PURPOSE

Cancer patients at Johns Hopkins undergo insurance clearance to verify coverage for enrollment to interventional clinical trials. We sought to explore the impact of insurance clearance on disparities in access to cancer clinical trials at this urban comprehensive cancer center.

EXPERIMENTAL DESIGN

We evaluated the frequency of insurance-based denial of access to cancer clinical trials over a 5-year period after initiation of a formal insurance clearance process. We used a case-control design to compare demographic and clinical parameters of patients denied or approved for clinical trials participation by their insurance company in a 3-year interval.

RESULTS

From July 2003 to July 2008, insurance requests for clinical trial participation were submitted on 4,617 consented cancer patients at Johns Hopkins. A total of 628 patients (13.6%) with health insurance were denied therapeutic trial enrollment owing to lack of insurance coverage for participation. A total of 254 patients denied enrollment from 2005 to 2007 were selected for further analysis. Two-hundred sixty randomly selected patients approved for clinical trial participation served as controls. Patients approved were on average older (59.2 versus 54.9 years) than patients denied (P = 0.0001). Residents of Pennsylvania, which lacks a state law mandating cancer clinical trial coverage for residents, were overrepresented among the denied patients (P = 0.0009). No statistically significant variance in the likelihood of insurance denial was found on the basis of sex, race, stage of disease, or presence of comorbidities.

CONCLUSIONS

Denial of access to therapeutic clinical trials, even among insured patients, is a significant barrier to clinical cancer research. This barrier spans racial, ethnic, and gender categories.

Association of secondhand smoke exposure with nicotine dependence among Black smokers

INTRODUCTION

Exposure to secondhand smoke (SHS) is influenced by norms and regulations, socioeconomic status and immediate personal interactions. SHS exposure may occur in various settings, including the living space, workplace, and other social environments. This study examines the association between exposure to SHS and nicotine dependence among current smokers.

METHODS

A cross-sectional sample of 246 Black (60% male and 40% female) current smokers age 40 and older, from Baltimore, Maryland and Washington, D.C, responded to an interviewer-administered questionnaire. We examined nicotine dependence using clinical guidelines based on the Diagnostic and Statistical Manual of Mental Disorders, Text Revision (2000). We performed multivariate logistic regression to assess the association between SHS and nicotine dependence.

RESULTS

SHS exposure in the current home environment and exposure in settings outside the home, as well as difficulty to quit smoking and heaviness of smoking, were associated with nicotine dependence. After adjustment for age, gender, education, income, employment status, current alcohol consumption, history of marijuana use, and number of cigarettes smoked per day; exposure to SHS at home only, and in both current home environment and other settings, continued to be associated with clinically-defined nicotine dependence (OR=2.25; 95% CI 1.05, 4.86 vs. OR=2.31; 95% CI 1.03, 5.18), respectively.

DISCUSSION

These findings highlight the relative importance of examining SHS exposure in personal (residential and automobile) and public (workplace and outdoor) settings by current smokers. Promotion of smoke-free environments may reduce the prevalence of nicotine dependence among current smokers.

Abstract B15: Effect of patient navigation on mammography screening among African American female Medicare beneficiaries at risk for low health literacy

Context: African American older adult women are diagnosed with more advanced breast cancer and have lower survival rates than White women. While differences in health literacy may contribute to this disparity, there is limited information on intervention strategies to promote cancer screening among low-literate African American older adults.

Objective: To evaluate the effect of a patient navigator on adherence to mammography screening among African American female Medicare beneficiaries with low literacy scores. Design, Setting, and Participants: We analyzed data from the Cancer Prevention and Treatment Demonstration (CPTD) at Johns Hopkins, an ongoing community-based trial designed to determine whether patient navigation is an effective strategy for improving adherence to cancer screening among African American older adults. Participants are randomized to either a high intensity group (patient navigation = educational materials) or a low intensity group (educational materials only). This analysis included 272 women ages of 65 and older with low literacy scores, who were enrolled into the study between November 2006 and March 2010, and had at least one year of follow up data. Baseline and one year follow up interviews were conducted face to face by trained interviewers through standardized questionnaires. The REALM-R instrument was used to identify participants at risk for low health literacy, based on their score.

Main Outcome Measure: The outcome measure for this analysis was the between-group difference in the proportion of women receiving mammography screening during the follow up period. Multiple logistic regression was performed to control for potential confounders such as age, education, Medicaid coverage, and perceived health status.

Results: Compared to the educational materials only group (n=77), the patient navigation group (n=107) had a similar proportion of women who reported a mammogram at one year follow up (64% vs. 71 %, p-value = 0.32). However, after adjusting for baseline health and demographic characteristics, women in the patient navigation group were more likely to report a mammogram at one year follow up, compared to those in the educational materials group (OR 1.90 95% CI 1.01-3.54). Women who rated themselves as having excellent to good health at baseline were less likely to report a mammogram, than those who reported fair to poor health (OR 0.43 95% CI 0.21-0.87).

Conclusions: Use of a patient navigation-based intervention was positively associated with mammography screening adherence among African American older adult women with low literacy scores. In this study population, perception of health status may influence mammography screening adherence. Our findings underscore the need for tailored intervention strategies to reduce cancer screening disparities among low-literate African American older adults.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):B15.

Functional variants of the sphingosine-1-phosphate receptor 1 gene associate with asthma susceptibility

BACKGROUND

The genetic mechanisms underlying asthma remain unclear. Increased permeability of the microvasculature is a feature of asthma, and the sphingosine-1-phosphate receptor (S1PR1) is an essential participant regulating lung vascular integrity and responses to lung inflammation.

OBJECTIVE

We explored the contribution of polymorphisms in the S1PR1 gene to asthma susceptibility.

METHODS

A combination of gene resequencing for single nucleotide polymorphism (SNP) discovery, case-control association, functional evaluation of associated SNPs, and protein immunochemistry studies was used.

RESULTS

Immunohistochemistry studies demonstrated significantly decreased S1PR1 protein expression in pulmonary vessels in lungs of asthmatic patients compared with those of nonasthmatic subjects (P < .05). Direct DNA sequencing of 27 multiethnic samples identified 39 S1PR1 variants (18 novel SNPs). Association studies were performed based on genotyping results from cosmopolitan tagging SNPs in 3 case-control cohorts from Chicago and New York totaling 1,061 subjects (502 cases and 559 control subjects). The promoter SNP rs2038366 (-1557G/T) was found to be associated with asthma (P = .03) in European Americans. In African Americans an association was found for both asthma and severe asthma for intronic SNP rs3753194 (c.-164+170A/G; P = .006 and P = .040, respectively) and for promoter SNP rs59317557 (-532C/G) with severe asthma (P = .028). Consistent with predicted in silico functionality, alleles of the promoter SNPs rs2038366 (-1557G/T) and rs59317557 (-532C/G) influenced the activity of a luciferase S1PR1 reporter vector in transfected endothelial cells exposed to growth factors (epidermal growth factor, platelet-derived growth factor, and vascular endothelial growth factor) known to be increased in asthmatic airways.

CONCLUSION

These data provide strong support for a role for S1PR1 gene variants in asthma susceptibility and severity.

Abstract 979: Understanding the relationship between race and nicotine dependence

Background: Mounting evidence continues to demonstrate that nicotine dependence is a growing public health issue among current smokers. While duration of smoking, number of cigarettes smoked per day (CPD) and cessation attempts are common indicators of nicotine dependence, African Americans tend to smoke less cigarettes per day (CPD; 10 or less), initiate smoking at a later age and experience greater failed quit attempts, compared to whites, yet develop nicotine dependence. However, no previous study has examined the possibility that race differences in the social context which African Americans and non-Hispanic whites live may contribute to disparities and the persistence of nicotine dependence. Social class and immediate personal interactions occurs in various social contexts, including the living space, workplace, institutions or other physical environments. This project examines the contributions of demographic, behavioral and environmental factors as social contextual factors that contribute to smoking behavior and the persistence of nicotine dependence.

Objective: We examined race disparities in nicotine dependence among 761 African American and white current smokers living in similar social and environmental risk exposures and compared these estimates to 1461 black and white current smokers in a national sample of adults aged 20 and over.

Methods: Data was assessed from Exploring Health Disparities in Integrated Communities-Southwest Baltimore (EHDIC-SWB; 2003) and National Health and Nutritional Examination Survey (NHANES; 2001-2004) to determine if race disparities in nicotine dependence would be attenuated in EHDIC-SWB. Time to first cigarette was used to assess nicotine dependence. Logistic regression was used to assess the association between race and nicotine dependence, controlling for known confounders.

Results: In multivariate analysis, race differences in nicotine dependence were greater among African-Americans in a representative sample of US adults. African Americans in a national sample have a lower odds of nicotine dependence (OR = 0.8; 95% CI 0.46, 0.93) compared to whites. However, no race difference were detected among participants in the EHDIC-SWB study (0.87; 95% CI 0.62, 1.22).

Conclusions: Examination of social and environmental factors may reveal important insights into the nature of inequalities between black and white adults in health outcomes such as nicotine dependence. Our results highlight the importance of examining social contextual factors and suggest that the promotion of targeted interventions may reduce the prevalence of nicotine dependence among current smokers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 979.

Association between lifestyle factors and CpG island methylation in a cancer-free population

BACKGROUND

Many risk factors have been associated with cancer, such as age, family history, race, smoking, high-fat diet, and poor nutrition. It is important to reveal the molecular changes related to risk factors that could facilitate early detection, prevention, and overall control of cancer.

METHODS

We selected six cancer-specific methylated genes that have previously been reported in primary tumors and have also been detected in different bodily fluids of cancer patients. Here, we used quantitative fluorogenic real-time methylation-specific PCR in plasma DNA samples for the detection of methylation changes from an asymptomatic population who do not have any known cancer.

RESULTS

The promoter methylation frequencies of the studied genes were as follows: APC (7%), CCND2 (22%), GSTP1 (2%), MGMT (9%), RARbeta2 (29%), and P16 (3%). Promoter methylation of at least one of the genes analyzed was observed in approximately 46% (72 of 157) of the samples by binary dichotomization. Promoter hypermethylation of at least two genes was detected in 17% (26 of 157) of the samples. RARbeta2 methylation was observed in 45% of subjects who had a high-fat diet in contrast with those who had a low-fat diet (23%; P = 0.007).

DISCUSSION

Our findings may help to elucidate early methylation changes that may lead to cancer development. These methylation changes could be due to exposure to risk factors and may be useful for cancer prevention measures such as changes in lifestyle. Longitudinal follow-up of a high-risk population is needed to understand the association of methylation of candidate genes in cancer development.

Barriers to recruiting underrepresented populations to cancer clinical trials: a systematic review

Racial and ethnic minorities, older adults, rural residents, and individuals of low socioeconomic status are underrepresented among participants in cancer-related trials. The authors conducted a systematic review to determine the barriers to participation of underrepresented populations in cancer-related trials. Their search included English-language publications that reported original data on the recruitment of underrepresented groups to cancer treatment or prevention trials between 1966 and December 2005 in multiple electronic databases. They also hand-searched titles in 34 journals from January 2003 to December 2005 and they examined reference lists for eligible articles. Titles and abstracts were reviewed to identify relevant studies. Data on barriers to participation were synthesized both qualitatively and based on statistically significant associations with trial enrollment. Of 5257 studies that were cited, 65 studies were eligible for inclusion in the current analysis, including 46 studies on recruitment into cancer therapeutic trials, 15 studies on recruitment into prevention trials, and 4 studies on recruitment into both prevention and treatment trials. Numerous factors were reported as barriers to participation in cancer-related trials. However, only 20 of the studies reported statistically significant associations between hypothesized barriers and enrollment. The available evidence had limitations in quality regarding representativeness, justification of study methods, the reliability and validity of data-collection methods, potential for bias, and data analysis. The results indicated that underrepresented populations face numerous barriers to participation in cancer-related trials. The current systematic review highlighting the literature on recruitment of underrepresented populations to cancer trials and may be used as the evidence base toward developing an agenda for etiologic and intervention research to reduce the disparities in participation in cancer-related trials.

Epidemiology of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

BACKGROUND

The objective of this study was to summarize the published literature concerning the epidemiology of lung cancer.

METHODS

A narrative review of published evidence was conducted, identifying and summarizing key reports that describe the occurrence of lung cancer in populations and factors that affect lung cancer risk.

RESULTS

In the United States, lung cancer remains the leading cause of cancer death in both men and women, even though an extensive list of modifiable risk factors has long been identified. The predominant cause of lung cancer is exposure to tobacco smoke, with active smoking causing most cases but passive smoking also contributing to the lung cancer burden.

CONCLUSIONS

The reductions in smoking prevalence in men that occurred in the late 1960s through the 1980s will continue to drive lung cancer mortality rates downward in men during the first portion of this century, but rates in women have not yet begun to decrease. Fortunately, exposures to major occupational respiratory carcinogens have largely been controlled, but the population is still exposed to environmental causes of lung cancer, including radon, the second leading cause of lung cancer death.

Provider roles in the recruitment of underrepresented populations to cancer clinical trials

BACKGROUND

Providers play a vital role in the successful recruitment of underrepresented patients to cancer clinical trials because they often introduce the opportunity of clinical trials. The purpose of the current systematic review was to describe provider-related factors influencing recruitment of underrepresented populations to cancer clinical trials.

METHODS

To find original studies on the recruitment of underrepresented populations to cancer clinical trials, electronic databases from January 1966 to December 2005 were searched; hand-searched titles in 34 journals from January 2003 to January 2006; and reference lists were examined of eligible articles. Title and abstract reviews were conducted to identify relevant studies. Potential articles were then abstracted using a structured instrument and a serial review process by 2 investigators.

RESULTS

Eighteen studies were eligible for review: 13 targeted healthcare providers, 3 targeted patients/participants, and 2 targeted both providers and patients. The study designs included randomized controlled trial, concurrent controlled trial, case-control, descriptive, and qualitative. A lack of available protocols and/or a lack of provider awareness about clinical trials prevented providers from discussing the opportunity of clinical trials in 2 studies. In 14 studies, patient accrual was affected by provider attitudinal barriers relating to patient adherence to the study protocol, patient mistrust of research, patient costs, data collection costs, and/or patient eligibility. Providers' communication methods were barriers in 5 studies and promoters in 1 study.

CONCLUSIONS

A heterogeneous body of evidence suggests that several provider-related factors influence recruitment of underrepresented groups to clinical trials. Future recruitment efforts should address these factors.

Smoking affects response to inhaled corticosteroids or leukotriene receptor antagonists in asthma

RATIONALE

One-quarter to one-third of individuals with asthma smoke, which may affect response to therapy and contribute to poor asthma control.

OBJECTIVES

To determine if the response to an inhaled corticosteroid or a leukotriene receptor antagonist is attenuated in individuals with asthma who smoke.

METHODS

In a multicenter, placebo-controlled, double-blind, double-dummy, crossover trial, 44 nonsmokers and 39 light smokers with mild asthma were assigned randomly to treatment twice daily with inhaled beclomethasone and once daily with oral montelukast.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was change in prebronchodilator FEV(1) in smokers versus nonsmokers. Secondary outcomes included peak flow, PC(20) methacholine, symptoms, quality of life, and markers of airway inflammation. Despite similar FEV(1), bronchodilator response, and sensitivity to methacholine at baseline, subjects with asthma who smoked had significantly more symptoms, worse quality of life, and lower daily peak flow than nonsmokers. Adherence to therapy did not differ significantly between smokers and nonsmokers, or between treatment arms. Beclomethasone significantly reduced sputum eosinophils and eosinophil cationic protein (ECP) in both smokers and nonsmokers, but increased FEV(1) (170 ml, p = 0.0003) only in nonsmokers. Montelukast significantly increased a.m. peak flow in smokers (12.6 L/min, p = 0.002), but not in nonsmokers.

CONCLUSIONS

In subjects with mild asthma who smoke, the response to inhaled corticosteroids is attenuated, suggesting that adjustments to standard therapy may be required to attain asthma control. The greater improvement seen in some outcomes in smokers treated with montelukast suggests that leukotrienes may be important in this setting. Larger prospective studies are required to determine whether leukotriene modifiers can be recommended for managing asthma in patients who smoke.

Understanding disparities in asthma outcomes among African Americans

Racial disparities in asthma morbidity and mortality are greater than differences in asthma prevalence. This finding suggests that following the diagnosis of asthma, blacks receive substantially different care than non-Hispanic whites, through available health care systems and their social support networks, and racial differences in relevant environ-mental exposures contribute to differences in morbidity and mortality. An overview of factors that may contribute to disparities in asthma prevalence, morbidity, and mortality,including contextual factors, is provided.

A culturally targeted intervention to promote breast cancer screening among low-income women in East Baltimore, Maryland

In Maryland, outreach initiatives have been unsuccessful in engaging low-income African American women in mammography screening. This study aimed to identify factors influencing screening rates for low-income African American women. Based on the Health Belief Model, a modified time series design was used to implement a culturally targeted intervention to promote a no-cost mammography-screening program. Data were collected from women 40 years of age and older on their history of mammography use and their knowledge and beliefs about breast cancer. A 50% screening rate was achieved among 119 eligible participants. Significant predictors of screening behaviors were perceived barriers, lack of insurance, and limited knowledge. This culturally targeted intervention resulted in an unprecedented screening rate among low-income African American women in Baltimore, Maryland.

Beta2-agonists: friend or foe?

This review summarizes the effects of beta2-agonists on asthma severity. There has been a controversy as to whether the regularly scheduled use of beta2-adrenergic agonists increases the risk of adverse outcomes in asthma. A number of epidemiological and clinical studies have found an association between the regularly scheduled use of beta-agonist drugs and increased risk of asthma morbidity and mortality. However, this observation has not been consistent across studies. We discuss here the potential mechanisms to explain the relationship between the use of beta-agonists on a regularly scheduled basis and adverse outcomes of asthma therapy; and we provide a brief review of the effect of genetic diversity at the beta2-adrenergic receptor locus on asthma severity. Overall, the evidence suggests that the beta2-agonists in current use in the United States are generally safe and effective; friends, not foes.

CD14 tobacco gene-environment interaction modifies asthma severity and immunoglobulin E levels in Latinos with asthma

BACKGROUND

A recent family-based genomewide screen revealed linkage between the 5q31 region and the diagnosis of asthma, but only in those exposed to environmental tobacco smoke (ETS). Among the candidate genes in this region is CD14.

METHODS

To determine whether polymorphisms in the CD14 gene are related to this gene-by-environment interaction in Latinos, we used both family-based and cross-sectional cohort analysis to test for interactions between CD14 genotypes/haplotypes, exposure to ETS, and asthma-related phenotypes in 659 Mexican and Puerto Rican families.

RESULTS

We identified 21 single nucleotide polymorphisms (SNPs) in the CD14 gene by sequencing 72 Puerto Ricans, Mexicans, and African Americans with asthma. Three SNPs, -810, -159, and +1437, were further genotyped in families with asthma. Among all subjects with asthma exposed to ETS, without regard to ethnicity, CD14 +1437 genotypes were associated with asthma severity. SNP +1437 GG or GC genotypes were significantly associated with lower baseline FEV1 using both family-based (p = 0.0009) and cross-sectional cohort (p = 0.03) analyses. Subjects with asthma with the GG or GC genotypes who were exposed to ETS had mean baseline FEV1 (% predicted) values 8.6% lower than subjects not exposed to ETS (p = 0.03). As previously observed in whites, we found an interaction between plasma IgE levels, SNP -159 genotypes, and ETS exposure (p = 0.0002). The lowest IgE levels were in those subjects with the TT genotype and who were exposed to ETS regardless of ethnicity.

CONCLUSIONS

Our data suggest a gene-by-environment interaction between CD14 genotypes and ETS, which affects pulmonary function and IgE levels among Latinos with asthma.

Daily versus as-needed corticosteroids for mild persistent asthma

BACKGROUND

Although guidelines recommend daily therapy for patients with mild persistent asthma, prescription patterns suggest that most such patients use these so-called controller therapies intermittently. In patients with mild persistent asthma, we evaluated the efficacy of intermittent short-course corticosteroid treatment guided by a symptom-based action plan alone or in addition to daily treatment with either inhaled budesonide or oral zafirlukast over a one-year period.

METHODS

In a double-blind trial, 225 adults underwent randomization. The primary outcome was morning peak expiratory flow (PEF). Other outcomes included the forced expiratory volume in one second (FEV1) before and after bronchodilator treatment, the frequency of exacerbations, the degree of asthma control, the number of symptom-free days, and the quality of life.

RESULTS

The three treatments produced similar increases in morning PEF (7.1 to 8.3 percent; approximately 32 liters per minute; P=0.90) and similar rates of asthma exacerbations (P=0.24), even though the intermittent-treatment group took budesonide, on average, for only 0.5 week of the year. As compared with intermittent therapy or daily zafirlukast therapy, daily budesonide therapy produced greater improvements in pre-bronchodilator FEV1 (P=0.005), bronchial reactivity (P<0.001), the percentage of eosinophils in sputum (P=0.007), exhaled nitric oxide levels (P=0.006), scores for asthma control (P<0.001), and the number of symptom-free days (P=0.03), but not in post-bronchodilator FEV1 (P=0.29) or in the quality of life (P=0.18). Daily zafirlukast therapy did not differ significantly from intermittent treatment in any outcome measured.

CONCLUSIONS

It may be possible to treat mild persistent asthma with short, intermittent courses of inhaled or oral corticosteroids taken when symptoms worsen. Further studies are required to determine whether this novel approach to treatment should be recommended.

Measured diffusion capacity versus prediction equation estimates in blacks without lung disease

BACKGROUND

Lung volumes in African-Americans are on average 10-15% less than in Caucasians for the same height and are race corrected accordingly. Despite this fact, prediction equation estimates (PEE) of diffusion capacity of CO (DL(CO)) developed in Caucasians are not adjusted for lung volume in the black population. This could result in healthy blacks being labeled as abnormal.

OBJECTIVE

To test the hypothesis that healthy black subjects might be labeled as abnormal using three commonly used PEE of DL(CO) which are currently used in the United States.

METHODS

Forty-two nonsmoking black subjects with no history of any disease underwent DL(CO) testing. Controls consisted of 12 healthy Caucasian volunteers and the prediction equations themselves. The single breath diffusion capacity was used with a Collins system. The measured diffusing capacity was compared with the Miller, Knudson, and Crapo PEE by entering age, gender, height and weight for each subject into the appropriate equation. Abnormal was defined as a DL(CO) <80% predicted. Methane gas dilution and body plethysmography were used to determine alveolar volume. Values in parentheses in the results section are DLCO adjusted for alveolar volume proportions.

RESULTS

The average measured DL(CO) in blacks was 25.85 +/- 6.37 ml/min/mm Hg. This value was significantly different (p < 0.01) compared to the predicted DL(CO) of 29.80 +/- 4.77, 36.45 +/- 6.64, and 35.33 +/- 5.27 for the Miller, Knudson, and Crapo equations, respectively. This resulted in 14/42 (0/42), 33/42 (3/42), and 33/42 (9/42) DL(CO) (DL(CO)/VA) measurements being defined as abnormal using the Miller, Knudson, and Crapo prediction equations, respectively. In Caucasians, the average measured DL(CO) was not different from the Miller PEE. However, the measured DL(CO) was significantly lower than the Knudson and Crapo PEE, although less so than in blacks. This resulted in no Caucasian DL(CO) measurements defined as abnormal with the Miller PEE and some with the Knudson and Crapo PEE, but less so than in blacks. The measured alveolar volumes by methane dilution were slightly but not significantly decreased compared to those determined by plethysmography. Both measured values were significantly different (p < 0.01) compared to the predicted alveolar volumes of 6.19 +/- 0.91, 6.38 +/- 1.07, and 6.05 +/- 0.96 liters for the Miller, Knudson, and Crapo PEE in blacks, with no difference in predicted and measured lung volumes in Caucasians. The difference in predicted versus measured DL(CO) measurements in blacks was 13.2, 29.1, and 26.8%, respectively, for the Miller, Knudson, and Crapo prediction equations. These differences were similar to the reduction in predicted values of 22.5, 24.7, and 20.7% for the above-mentioned prediction equations, respectively, versus the measured alveolar volume by methane (in blacks). A race correction (reduction) of the Miller PEE for diffusion of 12% resulted in only 2/42 DL(CO) measurements being labeled as abnormal.

CONCLUSIONS

Current PEE for DLCO when used in healthy blacks can result in an abnormal reading in up to 50% or more of the time. This failure of the PEE is related to a reduction in lung volume in African-Americans that is not accounted for. One approach to overcome this problem, until separate PEE are developed in blacks, is to race correct the Miller PEE for diffusion by 12%. This reduces the DL(CO) error to less than 5% for this population.

Pharmacogenetic differences in response to albuterol between Puerto Ricans and Mexicans with asthma

BACKGROUND

In the United States, Puerto Ricans and Mexicans have the highest and lowest asthma prevalence, morbidity, and mortality, respectively. Ethnic-specific differences in the response to drug treatment may contribute to differences in disease outcomes. Genetic variants at the beta(2)-adrenergic receptor (beta(2)AR) may modify asthma severity and albuterol responsiveness. We tested the association of beta(2)AR genotypes with asthma severity and bronchodilator response to albuterol in Puerto Ricans and Mexicans with asthma.

METHODS

We used both family-based and cross-sectional tests of association with 8 beta(2)AR single nucleotide polymorphisms in 684 Puerto Rican and Mexican families. Regression analyses were used to determine the interaction between genotype, asthma severity, and bronchodilator drug responsiveness.

RESULTS

Among Puerto Ricans with asthma, the arginine (Arg) 16 allele was associated with greater bronchodilator response using both family-based and cross-sectional tests (p = 0.00001-0.01). We found a strong interaction of baseline FEV(1) with the Arg16Glycine (Gly) polymorphism in predicting bronchodilator response. Among Puerto Ricans with asthma with baseline FEV(1) < 80% of predicted, but not in those with FEV(1) > 80%, there was a very strong association between the Arg16 genotype and greater bronchodilator responsiveness. No association was observed between Arg16Gly genotypes and drug responsiveness among Mexicans with asthma.

CONCLUSIONS

Ethnic-specific pharmacogenetic differences exist between Arg16Gly genotypes, asthma severity, and bronchodilator response in Puerto Ricans and Mexicans with asthma. These findings underscore the need for additional research on racial/ethnic differences in asthma morbidity and drug responsiveness.

Use of regularly scheduled albuterol treatment in asthma: genotype-stratified, randomised, placebo-controlled cross-over trial

BACKGROUND

The issue of whether regular use of an inhaled beta2-adrenergic agonist worsens airflow and clinical outcomes in asthma is controversial. Retrospective studies have suggested that adverse effects occur in patients with a genetic polymorphism that results in homozygosity for arginine (Arg/Arg), rather than glycine (Gly/Gly), at aminoacid residue 16 of the beta2-adrenergic receptor. However, the existence of any genotype-dependent difference has not been tested in a prospective clinical trial.

METHODS

Patients with mild asthma, not using a controller medication, were enrolled in pairs matched for forced expiratory volume in 1 s (FEV1) according to whether they had the Arg/Arg (n=37; four of 41 matches withdrew before randomisation) or Gly/Gly (n=41) genotype. Regularly scheduled treatment with albuterol or placebo was given in a masked, cross-over design, for 16-week periods. During the study, as-needed albuterol use was discontinued and ipratropium bromide was used as needed. Morning peak expiratory flow rate (PEFR) was the primary outcome variable. The primary comparisons were between treatment period for each genotype; the secondary outcome was a treatment by genotype effect. Analyses were by intention to treat.

FINDINGS

During the run-in period, when albuterol use was kept to a minimum, patients with the Arg/Arg genotype had an increase in morning PEFR of 23 L/min (p=0.0162); the change in patients with the Gly/Gly genotype was not significant (2 L/min; p=0.8399). During randomised treatment, patients with the Gly/Gly genotype had an increase in morning PEFR during treatment with regularly scheduled albuterol compared with placebo (14 L/min [95% CI 3 to 25]; p=0.0175). By contrast, patients with the Arg/Arg genotype had lower morning PEFR during treatment with albuterol than during the placebo period, when albuterol use was limited (-10 L/min [-19 to -2]; p=0.0209). The genotype-attributable treatment difference was therefore -24 L/min (-37 to -12; p=0.0003). There were similar genotype-specific effects in FEV1, symptoms, and use of supplementary reliever medication.

INTERPRETATION

Genotype at the 16th aminoacid residue of the beta2-adrenergic receptor affects the long-term response to albuterol use. Bronchodilator treatments avoiding albuterol may be appropriate for patients with the Arg/Arg genotype.

Predicting asthma morbidity in Harlem emergency department patients

OBJECTIVES

To determine predictors of asthma morbidity in African American patients with asthma. Proxies for asthma morbidity were emergency department (ED) visits for asthma and hospitalizations for asthma.

METHODS

This was a prospective observational study that evaluated baseline predictors of asthma morbidity in adults in an urban, predominantly African American community in New York City. Potential predictors of asthma morbidity evaluated were education, gender, employment status, current smoking status, asthma severity, duration of asthma, daily use of a peak flow meter, presence or absence of pets at home, presence or absence of a significant other, presence or absence of medical insurance, and previous hospitalization for asthma in the past year. Follow-up consisted of a repeat questionnaire obtained between nine and 15 months after the baseline questionnaire. Follow-up data collection was limited to the last three-month history of ED visits or hospitalizations before the follow-up visit. At follow-up, the baseline predictors were related to the presence or absence of ED visits for asthma or hospitalizations for asthma. All predictors were evaluated individually (crude odds ratio [OR]) and simultaneously (adjusted OR) in a logistic regression model with the dichotomous outcome variable ED visits or hospitalization.

RESULTS

Return ED visits on follow-up were more likely to occur in asthma patients hospitalized in the previous year (adjusted OR, 3.9; 95% confidence interval [CI] = 1.7 to 9.0) and were less likely to occur in asthma patients with pets (OR, 0.4; 95% CI = 0.2 to 0.9). Patients with moderate/severe asthma, relative to patients with mild asthma, were more likely to be seen in the ED on follow-up on initial analysis (crude OR, 2.4; 95% CI = 1.1 to 1.5), but the adjusted OR was not significant. Follow-up hospitalizations were significantly more likely to occur only in subjects reporting daily use of a peak flow meter (OR, 6.8; 95% CI = 1.3 to 34.5). Subjects hospitalized for asthma in the previous year were more likely to be hospitalized subsequently on initial analysis (crude OR, 2.9; 95% CI = 1.0 to 8.1), but the adjusted OR was not significant.

CONCLUSIONS

It appears that African American patients with asthma who had previous hospitalizations for asthma within the past year or use a peak flow meter daily (a marker for more severe asthma) are more likely to visit the ED in the future or to be hospitalized for asthma, respectively. These patients need to be targeted and treated more aggressively to improve asthma care and decrease morbidity. The apparent protective effect of the presence of pets on reducing ED visits is unclear at this time, and the findings need to be replicated and evaluated further.

ADAM33 is not associated with asthma in Puerto Rican or Mexican populations

A recent study identified the ADAM33 gene as a promising candidate contributing to asthma. In Puerto Rican and Mexican populations, we have genotyped six single nucleotide polymorphisms (SNPs) that were used in the Genetics of Asthma in Latino Americans Study. We chose to study these two populations because in the United States, Puerto Ricans have the highest asthma prevalence, morbidity, and mortality and Mexicans the lowest. We used the transmission disequilibrium test to analyze associations between the ADAM33 gene variants and asthma, asthma severity, bronchodilator responsiveness, and total IgE levels using single SNPs, two to six SNP combinations, and specific haplotypes in 583 trios (proband with asthma and both biological parents). We also genotyped matched control samples to allow case-control analyses. None of the transmission disequilibrium test or case-control results showed significant association in either population. We found no evidence for association of single SNPs with asthma severity, bronchodilator response, or IgE levels in Mexicans or in the combined population. Two SNPs showed a modest association in Puerto Ricans, insignificant when the number of comparisons was taken into account. We conclude that the ADAM33 gene is not an important risk factor for asthma or for asthma-associated phenotypes in Mexicans or in Puerto Ricans.

Lower bronchodilator responsiveness in Puerto Rican than in Mexican subjects with asthma

In the United States, Puerto Ricans and Mexicans have the highest and lowest asthma prevalence, morbidity, and mortality, respectively. To determine whether ethnicity-specific differences in therapeutic response, clinical response, and/or genetic factors contribute to differences in asthma outcomes, we compared asthma-related clinical characteristics among 684 Mexican and Puerto Rican individuals with asthma recruited from San Francisco, New York City, Puerto Rico, and Mexico City. Puerto Ricans with asthma had reduced lung function, greater morbidity, and longer asthma duration than did Mexicans with asthma. Bronchodilator responsiveness, measured as percentage change from baseline FEV1, was significantly lower among Puerto Ricans with asthma than among Mexicans with asthma. Puerto Ricans with asthma had on average 7.3% (95% confidence interval [CI], 4.6 to 9.9; p < 0.001) lower bronchodilator reversibility in FEV1, higher risk of an emergency department visit in the previous year (odds ratio, 2.63; 95% CI, 1.6 to 4.3; p < 0.001), and of previous hospitalization for asthma (odds ratio, 1.94; 95% CI, 1.2 to 3.2; p = 0.009) than Mexicans. Subgroup analysis corroborated that Puerto Ricans with asthma had more severe disease than did Mexicans on the basis of lung function measurements, responsiveness to beta2-adrenergic agonists, and health care use. We conclude that Puerto Ricans with asthma respond less to albuterol than do Mexicans with asthma. These findings underscore the need for additional research on racial/ethnic differences in asthma morbidity and response to therapy.

Systemic effect comparisons of six inhaled corticosteroid preparations

The goal of this study was to establish a reliable method to evaluate systemic bioavailability and to determine equisystemic effects (microgram dose producing equal systemic cortisol suppression) of inhaled corticosteroids (ICS). Steroid naive asthma subjects (n = 156) were enrolled at six centers. A 1-week doubling dose design was used for each of six ICS and matched placebos for a total of four doses. Systemic effect was evaluated by hourly plasma cortisol concentrations (8 P.M. to 8 A.M.), 12- and 24-hour urine cortisol concentrations, and a morning blood osteocalcin. The area under the concentration-time curve for hourly cortisol concentrations was the best outcome variable to assess systemic effect. For the six ICS and matching placebos (beclomethasone-chlorofluorocarbon [CFC], budesonide dry powder inhaler [DPI], fluticasone DPI, fluticasone-CFC metered dose inhaler [MDI], flunisolide-CFC, and triamcinolone-CFC), only the placebo group and fluticasone DPI did not demonstrate a significant dose-response effect. Thus microgram comparison of all ICS could only be performed at a 10% cortisol suppression: flunisolide-CFC - 936; triamcinolone-CFC - 787; beclomethasone-CFC - 548; fluticasone DPI - 445; budesonide DPI - 268; fluticasone-CFC MDI - 111. This study represents the first step in evaluation of ICS efficacy based on equisystemic (cortisol suppression) effects of a given ICS, rather than doses judged arbitrarily to be comparable on a microgram basis.

Significant variability in response to inhaled corticosteroids for persistent asthma

BACKGROUND

A clinical model is needed to compare inhaled corticosteroids (ICSs) with respect to efficacy.

OBJECTIVE

The purpose of this investigation was to compare the relative beneficial and systemic effects in a dose-response relationship for 2 ICSs.

METHODS

A 24-week, parallel, open-label, multicenter trial examined the benefit-risk ratio of 2 ICSs in persistent asthma. Benefit was assessed by improvements in FEV(1) and PC(20); risk was assessed by overnight plasma cortisol suppression. Thirty subjects were randomized to either beclomethasone dipropionate (BDP) 168, 672, and 1344 microg/day (n = 15) or fluticasone propionate (FP) 88, 352, and 704 microg/day (n = 15), both administered by means of a metered dose inhaler (MDI) with chlorofluorocarbon propellant via a spacer, in 3 consecutive 6-week intervals; this was followed by 3 weeks of FP dry powder inhaler (DPI) 2000 microg/day.

RESULTS

Maximum FEV(1) response occurred with the low dose for FP-MDI and the medium dose for BDP-MDI and was not further increased by treatment with FP-DPI. Near-maximum methacholine PC(20) improvement occurred with the low dose for FP-MDI and the medium dose for BDP-MDI. Both BDP-MDI and FP-MDI caused dose-dependent cortisol suppression. Responsiveness to ICS treatment was found to vary markedly among subjects. Good (>15%) FEV(1) response, in contrast to poor (<5%) response, was found to be associated with high exhaled nitric oxide (median, 17.6 vs 11.1 ppb), high bronchodilator reversibility (25.2% vs 8.8%), and a low FEV(1)/forced vital capacity ratio (0.63 vs 0.73) before treatment. Excellent (>3 doubling dilutions) improvement in PC(20), in contrast to poor (<1 doubling dilution) improvement, was found to be associated with high sputum eosinophil levels (3.4% vs 0.1%) and older age at onset of asthma (age, 20-29 years vs <10 years).

CONCLUSIONS

Near-maximal FEV(1) and PC(20) effects occurred with low-medium dose for both ICSs in the subjects studied. High-dose ICS therapy did not significantly increase the efficacy measures that were evaluated, but it did increase the systemic effect measure, overnight cortisol secretion. Significant intersubject variability in response occurred with both ICSs. It is possible that higher doses of ICSs are necessary to manage more severe patients or to achieve goals of therapy not evaluated in this study, such as prevention of asthma exacerbations.

Reducing disparities in asthma care: priorities for research--National Heart, Lung, and Blood Institute workshop report

Minority groups with diverse racial and ethnic heritages and persons living in poverty are much more likely to die of asthma and to require emergency care for exacerbations of asthma than white persons not living in poverty. The National Heart, Lung, and Blood Institute convened a multidisciplinary group of expert scientists and clinicians to review current research aimed at understanding risk factors for these disparities in asthma health outcomes, to describe key barriers to improving asthma outcomes, and to establish priorities for future research. Education programs for asthma and other chronic diseases were reviewed. Successful elements of clinic and community-based programs were identified. Factors potentially involved in producing disparities include gene-environment interaction, psychologic and social factors, and socioeconomic status. Stress potentially contributes to asthma morbidity at both the individual and community level. Recommendations are made to stimulate research to understand risk factors for disparities and their mechanisms (e.g., gene-by-environment interactions and the role of stress), to define appropriate research designs and methods for evaluating behavioral and community interventions, and to examine how differential access to care contributes to morbidity. Research is encouraged to identify strategies that improve cultural adaptation and adoption of proven programs in a variety of populations.

Recruitment strategies in the Asthma Clinical Research Network

In any clinical trial, recruitment of trial participants usually requires an intense effort to reach the target sample size. The Asthma Clinical Research Network (ACRN) was keenly aware of this issue at its inception and therefore initiated and emphasized recruitment strategies for each of its clinical trials. This article describes the recruitment strategies for the ACRN's first four major clinical trials. Particular attention is given to the strategies for the recruitment of women and minorities. Finally, the specific strategies of each of the six ACRN clinical centers are presented.

Patterns and predictors of asthma-related emergency department use in Harlem

STUDY OBJECTIVES

To assess the roles of poor access to care, psychological risk factors, and asthma severity in frequent emergency department (ED) use.

DESIGN

A cross-sectional survey.

SETTING

Harlem Hospital Center ED and outpatient chest clinic.

PARTICIPANTS

Three hundred seventy-five adult residents of Harlem, a predominantly African-American community in New York City.

MEASUREMENTS

Asthma severity was assessed by self-reported symptoms using National Asthma Education and Prevention Program guidelines, health-care utilization, and psychometric scales.

RESULTS

Respondents with more severe asthma were more likely to have a primary asthma care provider, and to have had more scheduled office visits for asthma in the year prior to the interview (mean number of visits for patients with severe asthma, 3.6 visits; moderate asthma, 2.4 visits; and mild asthma, 1.7 visits). Despite having a regular source of care, 69% of respondents identified the ED as their preferred source of care; 82% visited the ED more than once in the year prior to interview (median, four visits). Persons with moderate or severe asthma were 3.8 times more likely to be frequent ED users compared to those with mild asthma (odds ratio [OR], 3.8; 95% confidence interval [CI], 2.2 to 6.6). This was the strongest predictor of frequent ED use. Other predictors of ED use were number of comorbid disorders (OR, 1.5; 95% CI, 1.1 to 2.1) and self-reported global health in the year prior to the ED visit (OR, 1.8; 95% CI, 1.2 to 2.7). Psychological characteristics were not predictive of frequent ED use when controlling for disease severity.

CONCLUSIONS

Frequent ED users present with serious medical conditions. They do not substitute physician care with ED care; they augment it to address serious health needs.

Characteristics and correlates of asthma knowledge among emergency department users in Harlem

We constructed a questionnaire to assess asthma knowledge, assessed its psychometric properties, and examined its association with demographic characteristics, psychosocial factors, and disease severity and management in 375 adults following an asthma-related emergency department visit. Overall knowledge was poor but varied widely among respondents. Better knowledge was related to younger age, higher education, and less severe disease. Chance-orientated health locus of control and low self-esteem were associated with lower asthma knowledge. Better knowledge was associated with better disease management. We conclude that asthma education can lead to improved disease outcomes, and psychosocial factors need to be considered when designing interventions for asthma education.

Prenatal exposure, maternal sensitization, and sensitization in utero to indoor allergens in an inner-city cohort

Primary sensitization to antigens may occur prenatally. We hypothesized that high prenatal exposure to indoor antigens increases the risk for sensitization in newborns in New York City populations with increased risk for asthma. We also investigated whether maternal sensitization is required for in utero sensitization to occur. One hundred sixty-seven pregnant African American or Dominican women residing in northern Manhattan were recruited and antigen was measured from home dust. After delivery, newborn cord and maternal blood were assayed for IgE and mononuclear cell proliferation and cytokine production in response to antigen. Cockroach, mouse, but not dust mite antigens, were commonly elevated in the kitchens and pregnant mothers' beds. Increased mononuclear cell proliferation occurred in 54% of newborns in response to cockroach, 25% in response to dust mite Dermatophagoides pteronyssinus, 40% in response to dust mite D. farinae, and 34% in response to mouse protein extracts. Antigen-induced mononuclear cell proliferation occurred in cord blood even in the absence of antigen-induced mononuclear cell proliferation in the mother. Proliferation in response to antigens did not correlate with IgE levels, but proliferation in response to dust mite extracts correlated with interluekin-5 (IL-5) production in cord blood. These results suggest that (1) high prenatal exposures to cockroach and mouse antigens are prevalent; (2) in utero sensitization to multiple indoor antigens is common, occurs to a different degree than maternal sensitization, and may involve IL-5 upregulation.

Catalytic asymmetric ring-opening metathesis/cross metathesis (AROM/CM) reactions. Mechanism and application to enantioselective synthesis of functionalized cyclopentanes

Studies regarding the first examples of catalytic asymmetric ring-opening metathesis (AROM) reactions are detailed. This enantioselective cleavage of norbornyl alkenes is followed by an intermolecular cross metathesis with a terminal olefin partner; judicious selection of olefin is required so that oligomerization and dimerization side products are avoided. Results outlined herein suggest that the presence of suitably positioned heteroatom substituents may be critical to reaction efficiency. Mo-catalyzed tandem AROM/CM affords functionalized cyclopentyl dienes in >98% ee and >98% trans olefin selectivity; both secondary and tertiary ether products can be obtained. The examples provided include the catalytic synthesis of an optically pure cyclopentyl epoxide and dimethyl acetal. Mechanistic studies suggest that it is the more substituted benzylidene or silylated alkylidenes that are involved in the catalytic process (vs the corresponding Mo-methylidenes). Although electron rich benzylidenes react more efficiently, the derived electron poor Mo complexes promote AROM/CM transformations as well; alkylidenes that bear a boron substituent are unreactive.

Il-13 and IFN-gamma: interactions in lung inflammation

Chronic inflammatory diseases of the lungs, such as asthma, are frequently associated with mixed (Th2 and Th1) T cell responses. We examined the impact of critical Th1 and Th2 cytokines, IFN-gamma and IL-13, on the responses in the lungs. In a mouse model of airway inflammation induced by mixed T cell responses, the number of Th1 (IFN-gamma-positive) cells was found to be negatively correlated with airway hyperreactivity. In these mice, blockade of IL-13 partially inhibited airway hyperreactivity and goblet cell hyperplasia but not inflammation. In contrast, in mice that responded with a polarized Th2 response to the same Ag, blockade of IL-13 inhibited airway hyperreactivity, goblet cell hyperplasia, and airway inflammation. These results indicated that the presence of IFN-gamma would modulate the effects of IL-13 in the lungs. To test this hypothesis, wild-type mice were given recombinant cytokines intranasally. IFN-gamma inhibited IL-13-induced goblet cell hyperplasia and airway eosinophilia. At the same time, IFN-gamma and IL-13 potentiated each other's effects. In the airways of mice given IL-13 and IFN-gamma, levels of IL-6 were increased as well as numbers of NK cells and of CD11c-positive cells expressing MHC class II and high levels of CD86. In conclusion, IFN-gamma has double-sided effects (inhibiting some, potentiating others) on IL-13-induced changes in the lungs. This may be the reason for the ambiguous role of Th1 responses on Th2 response-induced lung injury.

Safety and reproducibility of sputum induction in asthmatic subjects in a multicenter study

The safety of sputum induction and the reproducibility of measurements in induced sputum in multicenter studies is unknown. We examined the safety of sputum induction in a two-visit, six-center study in 79 subjects with moderate to severe asthma (mean +/- SD FEV(1) 71 +/- 12% predicted, 67% taking inhaled corticosteroids). In addition, we compared the reproducibility of markers of inflammation in induced sputum with the reproducibility of the FEV(1) and the methacholine PC(20). The FEV(1) decreased > or = 20% from the postbronchodilator baseline in 14% of all subjects and in 25% of subjects whose initial prebronchodilator baseline was 40 to 60% of predicted. All subjects responded promptly to additional albuterol treatment, and no subject developed refractory bronchoconstriction requiring treatment other than reversal of bronchospasm in the study laboratory. The reproducibility of measurements of the eosinophil percentage, eosinophil cationic protein, tryptase, and methacholine PC(20) were similar (concordance correlation coefficients of 0.74, 0.81, 0.79, and 0.74, respectively), without any significant among-center effect. We conclude that sputum induction can be performed safely in subjects with moderate to severe asthma in multicenter clinical trials when carried out under carefully monitored conditions. Importantly, we demonstrate that measurement of markers of inflammation in induced sputum is as reproducible as methacholine PC(20) and should prove useful in the assessment of airway inflammation in multicenter clinical trials.

Standards for assessment of lung function and respiratory health in minority populations: some challenges linger into the new millennium

Results of pulmonary function tests (as an indicator of respiratory health) are from 11 to 13 percent lower in African Americans and other racial ethnic populations than in Caucasians when controlled for gender, age, and height. Environmental factors influencing these indices are circadian variation, altitude, air pollutants, technology, state of nutrition, smoking history, and other indicators of lifestyle. A combination of subtle, genetically determined anthropometric variants may also be operative, the extent of which is controversial. Population-based, population-specific standards are required to avoid erroneous diagnosis of cardiorespiratory disease, erroneous assessment of operative risk, unfair hiring practices when lung function tests are used for preemployment evaluation in dusty occupations, and unfair labeling when workers apply for disability compensation. Tailoring of statistical prediction standards from simple linear to more complex polynomial regression models will increase the accuracy of population prediction standards for pulmonary function variables into the 21st century.

Inhaled corticosteroid reduction and elimination in patients with persistent asthma receiving salmeterol: a randomized controlled trial

CONTEXT

Inhaled long-acting beta(2)-agonists improve asthma control when added to inhaled corticosteroid (ICS) therapy.

OBJECTIVE

To determine whether ICS therapy can be reduced or eliminated in patients with persistent asthma after adding a long-acting beta(2)-agonist to their treatment regimen.

DESIGN AND SETTING

A 24-week randomized, controlled, blinded, double-dummy, parallel-group trial conducted at 6 National Institutes of Health-sponsored, university-based ambulatory care centers from February 1997 through January 1999.

PARTICIPANTS

One hundred seventy-five patients aged 12 through 65 years with persistent asthma that was suboptimally controlled during a 6-week run-in period of treatment with inhaled triamcinolone acetonide (400 microg twice per day).

INTERVENTION

Patients continued triamcinolone therapy and were randomly assigned to receive add-on therapy with either placebo (placebo-minus group, n = 21) or salmeterol xinafoate, 42 microg twice per day (n = 154) for 2 weeks. The entire placebo-minus group was assigned and half of the salmeterol group (salmeterol-minus group) was randomly assigned to reduce by 50% (for 8 weeks) then eliminate (for 8 weeks) triamcinolone treatment. The other half of the salmeterol group (salmeterol-plus group) was randomly assigned to continue both salmeterol and triamcinolone for the remaining 16 weeks (active control group).

MAIN OUTCOME MEASURE

Time to asthma treatment failure in patients receiving salmeterol.

RESULTS

Treatment failure occurred in 8.3% (95% confidence interval [CI], 2%-15%) of the salmeterol-minus group 8 weeks after triamcinolone treatment was reduced compared with 2.8% (95% CI, 0%-7%) of the salmeterol-plus group during the same period. Treatment failure occurred in 46.3% (95% CI, 34%-59%) of the salmeterol-minus group 8 weeks after triamcinolone therapy was eliminated compared with 13.7% (95% CI, 5%-22%) of the salmeterol-plus group. The relative risk (95% CI) of treatment failure at the end of the triamcinolone elimination phase in the salmeterol-minus group was 4.3 (2.0-9.2) compared with the salmeterol-plus group (P<.001).

CONCLUSIONS

Our results indicate that in patients with persistent asthma suboptimally controlled by triamcinolone therapy alone but whose asthma symptoms improve after addition of salmeterol, a substantial reduction (50%) in triamcinolone dose can occur without a significant loss of asthma control. However, total elimination of triamcinolone therapy results in a significant deterioration in asthma control and, therefore, cannot be recommended.

Long-acting beta2-agonist monotherapy vs continued therapy with inhaled corticosteroids in patients with persistent asthma: a randomized controlled trial

CONTEXT

Long-acting beta(2)-agonists are prescribed for patients with persistent asthma and are sometimes used without inhaled corticosteroids (ICSs). No evidence exists, however, to support their use as monotherapy in adults with persistent asthma.

OBJECTIVE

To examine the effectiveness of salmeterol xinafoate, a long-acting beta(2)-agonist, as replacement therapy in patients whose asthma is well controlled by low-dose triamcinolone acetonide, an ICS.

DESIGN AND SETTING

A 28-week, randomized, blinded, placebo-controlled, parallel group trial conducted at 6 National Institutes of Health-sponsored, university-based ambulatory care centers from February 1997 to January 1999.

PARTICIPANTS

One hundred sixty-four patients aged 12 through 65 years with persistent asthma that was well controlled during a 6-week run-in period of treatment with inhaled triamcinolone (400 microg twice per day).

INTERVENTIONS

Patients were randomly assigned to continue triamcinolone therapy (400 microg twice per day; n = 54) or switch to salmeterol (42 microg twice per day; n = 54) or to placebo (n = 56) for 16 weeks, after which all patients received placebo for an additional 6-week run-out period.

MAIN OUTCOME MEASURES

Change in morning and evening peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV(1)), self-assessed asthma symptom scores, rescue albuterol use, asthma-specific quality-of-life scores, treatment failure, asthma exacerbation, bronchial reactivity, and markers of airway inflammation, compared among the 3 treatment groups.

RESULTS

During the 16-week randomized treatment period, no significant differences between the salmeterol and triamcinolone groups were observed for conventional outcomes of clinical studies of asthma therapy-morning PEF, evening PEF, asthma symptom scores, rescue albuterol sulfate use, or quality of life. Both active treatments were superior to placebo. However, the salmeterol group had more treatment failures than the triamcinolone group (13/54 [24%] vs 3/54 [6%]; P =.004), as well as more asthma exacerbations (11/54 [20%] vs 4/54 [7%]; P =.04), greater increases in median (interquartile range) sputum eosinophils (2.4% [0.0% to 10.6%] vs -0.1% [-0.7% to 0.3%]; P<.001), eosinophil cationic protein (71 [-2 to 430] U/L vs -4 [-31 to 56] U/L; P =.005), and tryptase (3.1 [2.1 to 7.6] ng/mL vs 0.0 [0.0 to 0.7] ng/mL; P<.001). The duration of benefit when patients were switched from active treatment to placebo after 22 weeks of randomized treatment was not significantly longer in the triamcinolone group than in the salmeterol group.

CONCLUSIONS

Patients with persistent asthma well controlled by low doses of triamcinolone cannot be switched to salmeterol monotherapy without risk of clinically significant loss of asthma control.

Effect of polymorphism of the beta(2)-adrenergic receptor on response to regular use of albuterol in asthma

BACKGROUND

Regular use of inhaled beta-adrenergic agonists may have adverse effects in some asthma patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect its regulation; however, results of smaller studies of the effects of such polymorphisms on response to beta-agonist therapy have been inconsistent.

METHODS

We examined the possible effects of polymorphisms at codons 16 (beta(2)-AR-16) and 27 (beta(2)-AR-27) on response to albuterol by genotyping 190 asthmatics who had participated in a trial of regular versus as-needed albuterol use.

RESULTS

During the 16-week treatment period, patients homozygous for arginine (Arg/Arg) at beta(2)-AR-16 who used albuterol regularly had a small decline in morning peak expiratory flow (AM PEF). This effect was magnified during a 4-week run-out period, when all patients returned to as-needed albuterol only. By the end of the study, Arg/Arg subjects who had used albuterol regularly had an AM PEF 30.5 +/- 12.1 liters/min lower (p = 0.012) than Arg/Arg patients who had used albuterol as needed only. Subjects homozygous for glycine at beta(2)-AR-16 showed no such decline. Evening PEF also declined in the Arg/Arg regular but not in as-need albuterol users. No significant differences between regular and as-needed treatment were associated with polymorphisms at beta(2)-AR-27.

CONCLUSIONS

Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.

Dopamine and intraocular pressure in critically ill patients

BACKGROUND

A recently released dopamine-1 receptor agonist, fenoldopam, increases intraocular pressure (IOP) in both healthy volunteers and patients with chronic ocular hypertension. Dopamine, a potent agonist at both dopamine-1 and -2 receptors, is frequently infused in critically ill patients for its inotropic, renal vasodilatory, and natriuretic effects. The authors hypothesized that low doses of dopamine would significantly increase IOP.

METHODS

Patients in the intensive care unit who were currently receiving dopamine infusions of less than 5 microg x kg(-1) x min(-1) were studied After local ocular anesthesia was obtained, baseline IOP was measured in each eye with a hand-held tonometer. IOP was then determined after dopamine was discontinued.

RESULTS

Twenty-three patients received a mean dopamine infusion of 2.6 +/- 0.2 microg x kg(-1) x min(-1). Twelve of the 23 patients were receiving mechanical ventilation during the study. Mean IOPs in nonventilated patients (n = 11) off dopamine were 13.1 +/- 0.9 mmHg (left eye) and 12.6 +/- 0.9 mmHg (right eye). Mean IOPs for the same patients receiving dopamine were significantly higher at 16.1 +/- 0.9 mmHg (left eye) and 15.9 +/- 1.1 mmHg (right eye). Mean IOPs in intubated patients (n = 12) off dopamine were 12.3 +/- 0.7 mmHg (left eye) and 12.5 +/- 1.2 mmHg (right eye). Mean IOPs for the same patients while receiving dopamine were significantly higher in intubated patients at 17.8 +/- 1.3 mmHg (left eye) and 17.3 +/- 1.3 mmHg (right eye). The average mean elevation in IOP in patients while receiving dopamine was significantly higher in intubated patients as compared with nonintubated patients (5.2 +/- 0.9 mmHg vs. 3.1 +/- 0.6 mmHg).

CONCLUSIONS

Commonly used doses of dopamine are associated with increased IOP in critically ill patients. Although normal patients should be able to tolerate this elevation safely for several weeks, there may be a potential risk in patients with preexisting glaucomatous nerve damage or ocular hypertension, especially if they are sedated and mechanically ventilated.

5-Fluorouracil for the treatment of intraepithelial neoplasia of the conjunctiva and cornea

OBJECTIVE

To evaluate the efficacy of pulse dosing of topical 5-fluorouracil (5-FU) in the treatment of conjunctival and corneal intraepithelial neoplasia.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Seven patients with histologic evidence of intraepithelial neoplasia were identified by conjunctival biopsy or tumor excision.

METHODS

Seven patients with a minimum of 7 months of follow-up were treated with pulsed dosing of 1% 5-FU. Topical 1% 5-FU was administered four times daily for 2 to 4 days for each cycle. The number of initial treatment cycles was two to six, with the time between cycles being 30 to 45 days.

MAIN OUTCOME MEASURES

The presence or absence of clinically evident intraepithelial neoplasia was evaluated after each treatment interval. Patients were also monitored for adverse reactions to the use of topical 5-FU.

RESULTS

Four patients remain disease free with a mean follow-up of 18.5 months (range, 7-36 months) with no additional treatment after the initial treatment cycles (mean, 3.75 cycles; range, 2-5 cycles). Three patients had recurrence of disease after the initial treatment cycles. Two patients were treated with additional cycles for recurrent disease (six cycles in one patient and five cycles in the other patient) and are free of disease at 20 and 21 months after treatment, respectively. One patient had persistent disease despite treatment with topical 5-FU and was treated with topical mitomycin C with resolution of the disease without recurrence for 16.5 months. No adverse reactions to pulse dose treatment with topical 5-FU were noted.

CONCLUSIONS

Pulsed dosing with 1% topical 5-FU for the treatment of conjunctival and corneal intraepithelial neoplasia, alone or as an adjunct to excision of bulky disease, is a well-tolerated and effective method of treatment.

Glutathione S-transferase M1 polymorphism and lung cancer risk in African-Americans

Glutathione S:-transferase M1 (GSTM1) can detoxify many carcinogens, including polycyclic aromatic hydrocarbons such as those from cigarette smoke. Though a number of studies have been published about the association between GSTM1 polymorphism and lung cancer, this association has received limited attention in the African-American population. We conducted a case-control study to investigate the role of GSTM1 polymorphism in the development of lung cancer in African-Americans. Specimens of DNA from 117 lung cancer cases and 120 controls were assayed for detection of GSTM1 genotype by polymerase chain reaction (PCR). The odds ratios (ORs) and 95% confidence intervals (CIs) for lung cancer associated with homozygous deletion of the GSTM1 gene and other risk factors were estimated by logistic regression. Thirty-seven of the 117 cases (31. 6%) and 24 of the 120 controls (20.0%) had the GSTM1 null genotype; the OR was 2.10 (95% CI 1.07-4.11) after adjustment for age, gender and smoking. The association was higher for squamous cell carcinoma (OR 2.98, 95% CI 1.09-8.19) than for adenocarcinoma (OR 1.95, 95% CI 0.81-4.66). We observed a stronger association between GSTM1 null genotype and lung cancer among heavy smokers with > or =30 pack-years (OR 4.35, 95% CI 1.16-16.23). This association was also found in squamous cell carcinoma (OR 6.26, 95% CI 1.31-29.91). In the analysis combining GSTM1 polymorphism and smoking, smokers with the null genotype had high risk (OR 8.19, 95% CI 2.35-28.62) compared with non-smokers with the wild-type genotype, and the risk increased with smoking cigarette pack-years (P: = 0.0001 for trend). Our results suggest that GSTM1 polymorphism plays a role in the development of lung cancer and modifies the risk for smoking-related lung cancer in African-Americans.

The effect of polymorphisms of the beta(2)-adrenergic receptor on the response to regular use of albuterol in asthma

Inhaled beta-adrenergic agonists are the most commonly used medications for the treatment of asthma although there is evidence that regular use may produce adverse effects in some patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect regulation of the receptor. Smaller studies examining the effects of such polymorphisms on the response to beta-agonist therapy have produced inconsistent results. We examined whether polymorphisms at codon 16 (beta(2)-AR-16) and codon 27 (beta(2)-AR-27) of the beta(2)-AR might affect the response to regular versus as-needed use of albuterol by genotyping the 190 asthmatics who had participated in a trial examining the effects of regular versus as needed albuterol use. During the 16-wk treatment period there was a small decline in morning peak expiratory flow in patients homozygous for arginine at B(2)-AR-16 (Arg/Arg) who used albuterol regularly. This effect was magnified during a 4-wk run out period, during which all patients returned to using as-needed albuterol, so that by the end of the study Arg Arg patients who had regularly used albuterol had a morning peak expiratory flow 30. 5 +/- 12.1 L/min lower (p = 0.012) than Arg/Arg patients who had used albuterol on an as needed basis. There was no decline in peak flow with regular use of albuterol in patients who were homozygous for glycine at beta(2)-AR-16. Evening peak expiratory flow also declined in the Arg/Arg patients who used albuterol regularly but not in those who used albuterol on an as-needed basis. No significant differences in outcomes between regular and as-needed treatment were associated with polymorphisms at position 27 of the beta(2)-AR. No other differences in asthma outcomes that we investigated occurred in relation to these beta(2)-AR polymorphisms. Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.

Combined intraepithelial squamous neoplasia and atypical fibroxanthoma of the cornea and limbus

PURPOSE

To investigate a case of an unusual neoplasm of the cornea and limbus.

METHODS

A 59-year-old man presented with a highly vascularized, nodular mass involving the left cornea and limbus. An excisional biopsy and, subsequently, a superficial lamellar keratectomy and multiple conjunctival biopsies were performed. At the 6-month follow-up examination, repeat conjunctival biopsies were performed.

RESULTS

Histopathologic examination of the corneal specimen showed a high-grade intraepithelial squamous neoplasia (in situ carcinoma) overlying an atypical fibroxanthoma.

CONCLUSION

We report the clinical and histologic appearance of a corneal/limbal neoplasm consisting of an intraepithelial squamous neoplasia and an atypical fibroxanthoma.

Wound healing following anterior keratectomy and lamellar keratoplasty in the pig

PURPOSE

To examine corneal wound healing in an animal model of two types of mechanical lamellar keratectomy.

METHODS

One eye from each of 28 pigs was studied. Using a motorized keratome, corneas were subjected to an anterior lamellar keratectomy with removal of anterior stroma and epithelium, or to automated lamellar keratoplasty (ALK) with reapposition of a corneal flap. The exposed stromal surfaces were labeled intraoperatively with a fluorescent dye (DTAF) to assess deposition of stromal components during subsequent wound healing. Examination before surgery and enucleation included measurement of corneal curvature and intraocular pressure, and assessment of corneal haze. Eyes were prepared for histological examination, fluorescence microscopy, and for fibronectin immunohistochemistry.

RESULTS

Both keratectomy procedures produced flattening of corneas by up to 3.80 diopters, 28 days after surgery. Corneal haze was more pronounced in eyes from which epithelium was removed (anterior lamellar keratectomy group). The increased haze in this group was associated histologically with appearance of many reactive keratocytes and inflammatory cells, deposition of new stromal material, and more widespread appearance of fibronectin immunoreactivity. In the lamellar keratoplasty group, only the edges of the corneal wound showed significant reactivity, and included keratocyte activation and epithelial ingrowth.

CONCLUSIONS

The pig provides a useful model for studies of refractive surgical techniques using procedures and instruments designed for use in humans. Mechanized keratectomy procedures that minimize disruption of the epithelium and Bowman's layer produce a less reactive corneal wound than procedures in which an expanse of epithelium and anterior stroma are removed.

Association between a sequence variant in the IL-4 gene promoter and FEV(1) in asthma

Recent family-based studies have revealed evidence for linkage of human chromosome 5q31 to the diagnosis of asthma, elevated serum IgE levels, and bronchial hyperresponsiveness. Among the candidate genes in this region is the gene encoding for human interleukin-4 (IL-4). We reasoned that this gene could also serve as a candidate gene with respect to asthma severity as indicated by the FEV(1) measured when bronchodilator treatment was withheld. To test this hypothesis, we examined a large population of patients with asthma (ascertained without respect to genetic characteristics), for associations between a genetic variant in the IL-4 promoter region (C-589T) and asthma severity, as indicated by FEV(1). We used amplification by the polymerase chain reaction followed by BsmF1 restriction digestion to assign genotypes at the IL-4 promoter C-589T locus. We compared genotypes at this locus in 772 Caucasian and African American patients with asthma of varying severity, and we used multiple regression analysis to relate genotypic findings to FEV(1). Among white individuals, the homozygous presence of the C-589T IL-4 promoter genotype (TT) was associated with a FEV(1) below 50% of predicted (p = 0.013; OR, 1.44; 95% CI: 1.09 to 1.90). Subjects with the TT genotype had mean FEV(1) (% predicted) values 4.5% lower than those of subjects with the wild-type (CC) genotype at this locus. FEV(1) values of white patients with a CC or CT genotype were broadly distributed, whereas the TT genotype was associated with a narrow distribution of low FEV(1) values. The frequency of the T allele was significantly greater (p = 1 x 10(-)(23)) among African American asthmatics (0.544) than among white asthmatics (0.183). These data provide the first evidence associating FEV(1) in patients with asthma and genetic determinants at any locus. Our data are consistent with the idea that the FEV(1) in asthma is the result of multiple factors; one of these factors is the genotype at the IL-4 C-589T locus. This locus is associated with a small but significant decrement in pulmonary function among white asthmatic subjects.