Determining the minimal clinically important difference for the questionnaire of olfactory disorders in people with cystic fibrosis and factors associated with improvement after highly effective modulator therapy

INTRODUCTION

Olfactory dysfunction (OD) is common among people with cystic fibrosis (PwCF). The Questionnaire of Olfactory Disorders (QOD) is a validated instrument that evaluates olfactory-specific quality-of-life. The QOD minimal clinically important difference (MCID) and factors associated with olfactory improvement after elexacaftor/tezacaftor/ivacaftor have not been determined for PwCF.

METHODS

Prospective observational data were pooled from three studies that enrolled adult PwCF with chronic rhinosinusitis (CRS). QOD scores and disease characteristics were assessed. To evaluate internal consistency and calculate the QOD MCID, Cronbach's alpha and four distribution-based methods were employed. For participants who enrolled prior to elexacaftor/tezacaftor/ivacaftor, QOD scores were obtained at baseline and after elexacaftor/tezacaftor/ivacaftor initiation. Multivariable regression was used to identify factors associated with QOD improvement.

RESULTS

Of 129 PwCF included, 65 had QOD scores before and 3-6 months after starting elexacaftor/tezacaftor/ivacaftor. Mean baseline QOD score was 6.5 ± 7.9. Mean Cronbach's alpha was ≥0.85. The MCID estimates were as follows: Cohen's effect size = 1.6, standard error of measurement = 2.5, ½ baseline standard deviation = 4.0, and minimal detectable change = 6.9. Mean MCID was 3.7. Of those with pre/post elexacaftor/tezacaftor/ivacaftor QOD scores, the mean change in QOD was -1.3 ± 5.4. After elexacaftor/tezacaftor/ivacaftor, QOD improvement surpassed the MCID in 22% of participants (14/65). Worse baseline QOD scores and nasal polyps were associated with improved QOD scores after elexacaftor/tezacaftor/ivacaftor (both p < 0.04).

CONCLUSION

The QOD MCID in PwCF was estimated to be 3.7. Elexacaftor/tezacaftor/ivacaftor led to qualitative but not clinically meaningful improvements in QOD score for most PwCF; PwCF with worse baseline QOD scores and nasal polyps improved in a clinically significant manner.

Complications and Practice Variation in the Use of Peripherally Inserted Central Venous Catheters in People With Cystic Fibrosis: The Prospective Study of Peripherally Inserted Venous Catheters in People With Cystic Fibrosis Study

BACKGROUND

Peripherally inserted central catheters (PICCs) are used commonly to administer antibiotics to people with cystic fibrosis (CF), but their use can be complicated by venous thrombosis and catheter occlusion.

RESEARCH QUESTION

Which participant-, catheter-, and catheter management-level attributes are associated with increased risk of complications of PICCs among people with CF?

STUDY DESIGN AND METHODS

This was a prospective observational study of adults and children with CF who received PICCs at 10 CF care centers in the United States. The primary end point was defined as occlusion of the catheter resulting in unplanned removal, symptomatic venous thrombosis in the extremity containing the catheter, or both. Three categories of composite secondary outcomes were identified: difficult line placement, local soft tissue or skin reactions, and catheter malfunction. Data specific to the participant, catheter placement, and catheter management were collected in a centralized database. Risk factors for primary and secondary outcomes were analyzed by multivariate logistic regression.

RESULTS

Between June 2018 and July 2021, 157 adults and 103 children older than 6 years with CF had 375 PICCs placed. Patients underwent 4,828 catheter-days of observation. Of the 375 PICCs, 334 (89%) were ≤ 4.5 F, 342 (91%) were single lumen, and 366 (98%) were placed using ultrasound guidance. The primary outcome occurred in 15 PICCs for an event rate of 3.11 per 1,000 catheter-days. No cases of catheter-related bloodstream infection occurred. Other secondary outcomes developed in 147 of 375 catheters (39%). Despite evidence of practice variation, no risk factors for the primary outcome and few risk factors for secondary outcomes were identified.

INTERPRETATION

This study affirmed the safety of contemporary approaches to inserting and using PICCs in people with CF. Given the low rate of complications in this study, observations may reflect a widespread shift to selecting smaller-diameter PICCs and using ultrasound to guide their placement.

The gut microbiome, short chain fatty acids, and related metabolites in cystic fibrosis patients with and without colonic adenomas

BACKGROUND

Adults with cystic fibrosis (CF) are at increased risk for colon cancer. CF patients have reductions in intestinal bacteria that produce short chain fatty acids (SCFAs), although it is unclear whether this corresponds with intestinal SCFA levels and the presence of colonic neoplasia. The aim of this study was to compare gut microbiome and SCFA composition in patients with and without CF, and to assess associations with colonic adenomas.

METHODS

Colonic aspirates were obtained from adults with and without CF undergoing colon cancer screening or surveillance colonoscopy. Microbiome characterization was performed by 16S rRNA V3-V4 sequencing. Targeted profiling of SCFAs and related metabolites was performed by LC-MS.

RESULTS

42 patients (21 CF, 21 control) were enrolled. CF patients had significantly reduced alpha diversity and decreased relative abundance of many SCFA-producing taxa. There were no significant differences in SCFA levels in CF patients, although there were reduced levels of branched chain fatty acids (BCFAs) and related metabolites. CF patients with adenomas, but not controls with adenomas, had significantly increased relative abundance of Bacteroides fragilis. CF microbiome composition was significantly associated with isovalerate concentration and the presence of adenomas.

CONCLUSIONS

CF patients have marked disturbances in the gut microbiome, and CF patients with adenomas had notably increased relative abundance of B. fragilis, a pathogen known to promote colon cancer. Reductions in BCFAs but not SCFAs were found in CF. Further studies are warranted to evaluate the role of B. fragilis as well the biological significance of reductions in BCFAs in CF.

The Precision Interventions for Severe and/or Exacerbation-Prone (PrecISE) Asthma Network: An overview of Network organization, procedures, and interventions

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.

The challenge of addressing obesity in people with poorly controlled asthma

Objective

There is a high prevalence of obesity in people with asthma, and obesity is associated with poorly controlled asthma. Significant weight loss might improve asthma control: the purpose of this study was to investigate patient characteristics and factors that might affect implementation of a weight loss and/or roflumilast intervention, to target both obesity and asthma.

Methods

A cross-sectional study of people with obesity and poorly controlled asthma performed at 13 sites across the United States.

Results

One hundred and two people participated in this study. Median BMI was 37 (IQR 35-42). The majority, 55%, were African American and 76% were female. Fifty two percent had very poorly controlled asthma. Most participants were quite sedentary (70% reported being inactive or participating only in light-intensity activities according to the Stanford Brief Activity Survey). Participants reported significant impairments related to physical function on the Impact of Weight on Quality of Life-Lite questionnaire (median score 67 [IQR 41-84]). Thirty-five percent of participants reported mild, and 2 % moderate, depressive symptoms as assessed by the Patient Health Questionnaire-9.

Conclusions

Poorly controlled asthma and obesity often affect minority populations and are associated with significant impairments in health related to physical function and low levels of physical activity that might complicate efforts to lose weight. Interventions targeted at poorly controlled asthma associated with obesity in the United States need to address factors complicating health in underserved communities, such as increasing opportunities for physical activity, while also managing activity limitations related to the combination of asthma and obesity.

Baloxavir treatment of oseltamivir-resistant influenza A/H1pdm09 in two immunocompromised patients

Few treatment options are available for oseltamivir-resistant influenza. It has been proposed that baloxavir can be effective in this setting due to its distinct mechanism of action but clinical experience is lacking for immunocompromised patients. We report two such cases treated with baloxavir after failure of oseltamivir and detection of oseltamivir resistance mutations. Baloxavir/zanamivir combination therapy was effective in one patient, but persistent viral shedding was noted with baloxavir monotherapy in the other patient.

PrecISE: Precision Medicine in Severe Asthma: An adaptive platform trial with biomarker ascertainment

Severe asthma accounts for almost half the cost associated with asthma. Severe asthma is driven by heterogeneous molecular mechanisms. Conventional clinical trial design often lacks the power and efficiency to target subgroups with specific pathobiological mechanisms. Furthermore, the validation and approval of new asthma therapies is a lengthy process. A large proportion of that time is taken by clinical trials to validate asthma interventions. The National Institutes of Health Precision Medicine in Severe and/or Exacerbation Prone Asthma (PrecISE) program was established with the goal of designing and executing a trial that uses adaptive design techniques to rapidly evaluate novel interventions in biomarker-defined subgroups of severe asthma, while seeking to refine these biomarker subgroups, and to identify early markers of response to therapy. The novel trial design is an adaptive platform trial conducted under a single master protocol that incorporates precision medicine components. Furthermore, it includes innovative applications of futility analysis, cross-over design with use of shared placebo groups, and early futility analysis to permit more rapid identification of effective interventions. The development and rationale behind the study design are described. The interventions chosen for the initial investigation and the criteria used to identify these interventions are enumerated. The biomarker-based adaptive design and analytic scheme are detailed as well as special considerations involved in the final trial design.

A phase 3, randomized, double-blind, parallel-group study to evaluate tezacaftor/ivacaftor in people with cystic fibrosis heterozygous for F508del-CFTR and a gating mutation

BACKGROUND

Tezacaftor (TEZ)/ivacaftor (IVA) is an approved CFTR modulator shown to be efficacious and generally safe and well tolerated in people ≥12 years of age with cystic fibrosis (CF) homozygous for the F508del-CFTR mutation or heterozygous for the F508del-CFTR mutation and a residual function mutation. Although previous studies with IVA alone showed clinical benefits in people with CFTR gating mutations, TEZ/IVA has not yet been evaluated in a Phase 3 study of participants heterozygous for F508del-CFTR and a gating mutation (F/gating genotypes). Here, we present results from a randomized, double-blind, IVA-controlled, parallel-group, Phase 3 study assessing the efficacy, safety, and pharmacokinetics (PK) of TEZ/IVA in participants ≥12 years of age with F/gating genotypes.

METHODS

Enrolled participants entered a 4-week IVA run-in period to create a stable IVA baseline. Participants were then randomized to receive IVA or TEZ/IVA for 8 weeks in an active comparator treatment period (ACTP). The primary endpoint was absolute change in percent predicted forced expiratory volume in 1 second (ppFEV₁). Key secondary endpoints were relative change in ppFEV₁ and absolute change in CF Questionnaire-Revised respiratory domain score. Secondary endpoints included absolute change in sweat chloride (SwCl) concentration, PK parameters, and safety. All endpoints except PK parameters and safety were assessed from baseline through Week 8.

RESULTS

Sixty-nine participants (92.0%) in the IVA group and 75 participants (98.7%) in the TEZ/IVA group completed treatment. No improvements were seen in efficacy endpoints from baseline at the end of the IVA run-in period through the end of the ACTP in the IVA group. No significant differences in ppFEV₁ or any key secondary endpoint were observed between the IVA and TEZ/IVA groups. SwCl concentrations decreased more in the TEZ/IVA versus IVA group during the ACTP. The safety profile and PK parameters of TEZ/IVA were consistent with those of previous studies in participants ≥12 years of age with CF.

CONCLUSIONS

This Phase 3 study showed that the dual-combination regimen of TEZ/IVA demonstrated clinical efficacy but did not have significantly greater clinical efficacy than IVA alone in participants ≥12 years of age with F/gating genotypes. However, as reported in other studies, TEZ/IVA was generally safe and well tolerated (NCT02412111).

The precision interventions for severe and/or exacerbation-prone asthma (PrecISE) adaptive platform trial: statistical considerations

The Precision Interventions for Severe and/or Exacerbation-prone Asthma (PrecISE) study is an adaptive platform trial designed to investigate novel interventions to severe asthma. The study is conducted under a master protocol and utilizes a crossover design with each participant receiving up to five interventions and at least one placebo. Treatment assignments are based on the patients' biomarker profiles and precision health methods are incorporated into the interim and final analyses. We describe key elements of the PrecISE study including the multistage adaptive enrichment strategy, early stopping of an intervention for futility, power calculations, and the primary analysis strategy.

Abstract 5055: Earlier birth cohort, lower BMI, and increased FEV1 are risk factors for cancer in adults with cystic fibrosis

Introduction: Adults with cystic fibrosis (CF) have a higher risk of multiple cancer types compared to the general population, and this risk appears to be particularly increased in transplant recipients. However, other risk factors for malignancy have not been well-described. This study assessed patient factors associated with cancer in adults with CF.

Methods: This was a retrospective study of prospectively collected data from the CF Foundation Patient Registry from 1992 - 2015. All adults cancer-free at 18 years of age were followed until either their most recent year in the registry or the year of their cancer diagnosis. Age, sex, CFTR mutation class, history of transplant, birth cohort, and BMI and FEV1 five years prior to cancer diagnosis or most recent registry entry were assessed as predictors of cancer using multivariable logistic regression. Analyses were repeated stratified by history of transplant. Data on cancer type was unavailable in the registry.

Results: Of 26,453 adults with CF, 525 (2.0%) had cancer diagnosed by histology at a mean age of 40.5 (SD=12.8) years. Of cancer patients, 183 (35.1%) were transplant recipients and 302 (64.7%) had a severe CFTR mutation (Class I-III). Among all CF adults, factors independently associated with cancer included lower BMI, higher FEV1, history of transplant, and birth cohort (Table). Among non-transplanted patients, cancer was associated with higher FEV1, unknown mutation class, and birth cohort. Among transplanted patients, cancer was only associated with birth cohort.

Conclusion: A history of transplant, lower BMI, higher FEV1, and earlier birth cohorts are associated with cancer in adults with CF. More recent birth cohorts have lower risks of cancer even after adjustment for age, possibly related to major improvements in CF care. Future studies are warranted to identify risk factors associated with specific cancer types and to better refine cancer screening recommendations in this patient population.

Factors associated with cancer in CF (models include associated variables on univariate analyses)All CF patients (n=12,019)Non-transplanted CF patients (10,790)Transplanted CF patients (n=2,402)Adjusted odds ratio95% confidence intervalAdjusted odds ratio95% confidence intervalAdjusted odds ratio95% confidence intervalAge0.990.98-1.010.980.96-1.001.000.98-1.02Sex (male)0.980.76-1.270.800.59-1.071.160.83-1.62BMI0.950.91-0.99FEV1 percent predicted1.011.00-1.021.011.00-1.02History of transplant2.862.07-3.96N/AN/AN/AN/ABirth cohort&lt;19701.00Referent1.00Referent1.00Referent1970-19740.370.25-0.550.340.21-0.530.500.30-0.841975-19790.270.17-0.410.180.11-0.310.380.21-0.691980-19840.080.05-0.140.070.04-0.140.240.12-0.471985-19890.060.03-0.110.040.02-0.090.120.05-0.311990-19940.010.00-0.050.010.00-0.040.100.03-0.33&gt;1994--0.080.01-0.68CFTR Mutation classClass I-III1.00Referent1.00Referent1.00ReferentClass IV-V0.880.59-1.320.780.50-1.210.760.39-1.49Unknown0.170.54-1.090.660.44-1.001.270.83-1.93

Citation Format: John B. Doyle, Rita M. Knotts, Claire L. Keating, Emily A. DiMango, Julian A. Abrams. Earlier birth cohort, lower BMI, and increased FEV1 are risk factors for cancer in adults with cystic fibrosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5055.

Adults with cystic fibrosis have deficits in bone structure and strength at the distal tibia despite similar size and measuring standard and relative sites

Individuals with cystic fibrosis (CF) have lower bone mineral density (BMD) by DXA and are at higher risk of fracture than healthy controls. However, the 2-dimensional measurement of areal BMD (aBMD) provided by DXA is influenced by bone size and the true extent of the bone deficit is unclear. Our objective was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) and individual trabecula segmentation (ITS) analysis to compare volumetric BMD (vBMD), microarchitecture and estimated strength at the distal radius and tibia in 26 young adults with CF and 26 controls matched for age, gender, and race. To assess the effect of limb length and minimize the confounding effects of size on HR-pQCT outcomes, we scanned participants at both the standard fixed HR-pQCT measurement sites and at a subject-specific relative site that varied according to limb length. CF participants did not differ significantly in age, height, weight, or BMI from controls. Ulnar and tibial lengths were 9mm shorter in CF patients, though differences were not significant. CF patients had significantly lower BMI-adjusted aBMD by DXA at the lumbar spine (8.9%, p<0.01), total hip (11.5%, p<0.01) and femoral neck (14.5%, p<0.01), but not at the forearm. At the fixed radius site, thickness of trabecular plates and torsional stiffness were significantly lower in CF participants than controls. At the relative radius site, only torsional stiffness was significantly lower in CF participants. At the tibia, total, trabecular and cortical vBMD were significantly lower at both fixed and relative sites in CF participants, with fewer, more widely-spaced trabecular plates, lower trabecular connectivity, and lower axial and torsional stiffness. Our results confirm that aBMD is lower at the spine and hip in young adults with CF, independent of BMI and body size. We also conclude that vBMD and stiffness are lower at the weight-bearing tibia. The pathogenesis of these differences in bone density and strength at the tibia appear to be related to trabecular drop-out and reduced trabecular connectivity and to be independent of differences in limb length, as assessed by scanning participants at both standard and relative sites. We concluded that significant deficits in bone structure and strength persist in young adults with CF, despite advances in care that permit them to attain relatively normal height and weight.

Comparison of physician-, biomarker-, and symptom-based strategies for adjustment of inhaled corticosteroid therapy in adults with asthma: the BASALT randomized controlled trial

CONTEXT

No consensus exists for adjusting inhaled corticosteroid therapy in patients with asthma. Approaches include adjustment at outpatient visits guided by physician assessment of asthma control (symptoms, rescue therapy, pulmonary function), based on exhaled nitric oxide, or on a day-to-day basis guided by symptoms.

OBJECTIVE

To determine if adjustment of inhaled corticosteroid therapy based on exhaled nitric oxide or day-to-day symptoms is superior to guideline-informed, physician assessment-based adjustment in preventing treatment failure in adults with mild to moderate asthma.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, parallel, 3-group, placebo-controlled, multiply-blinded trial of 342 adults with mild to moderate asthma controlled by low-dose inhaled corticosteroid therapy (n = 114 assigned to physician assessment-based adjustment [101 completed], n = 115 to biomarker-based [exhaled nitric oxide] adjustment [92 completed], and n = 113 to symptom-based adjustment [97 completed]), the Best Adjustment Strategy for Asthma in the Long Term (BASALT) trial was conducted by the Asthma Clinical Research Network at 10 academic medical centers in the United States for 9 months between June 2007 and July 2010.

INTERVENTIONS

For physician assessment-based adjustment and biomarker-based (exhaled nitric oxide) adjustment, the dose of inhaled corticosteroids was adjusted every 6 weeks; for symptom-based adjustment, inhaled corticosteroids were taken with each albuterol rescue use.

MAIN OUTCOME MEASURE

The primary outcome was time to treatment failure.

RESULTS

There were no significant differences in time to treatment failure. The 9-month Kaplan-Meier failure rates were 22% (97.5% CI, 14%-33%; 24 events) for physician assessment-based adjustment, 20% (97.5% CI, 13%-30%; 21 events) for biomarker-based adjustment, and 15% (97.5% CI, 9%-25%; 16 events) for symptom-based adjustment. The hazard ratio for physician assessment-based adjustment vs biomarker-based adjustment was 1.2 (97.5% CI, 0.6-2.3). The hazard ratio for physician assessment-based adjustment vs symptom-based adjustment was 1.6 (97.5% CI, 0.8-3.3).

CONCLUSION

Among adults with mild to moderate persistent asthma controlled with low-dose inhaled corticosteroid therapy, the use of either biomarker-based or symptom-based adjustment of inhaled corticosteroids was not superior to physician assessment-based adjustment of inhaled corticosteroids in time to treatment failure.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00495157.

Tiotropium bromide step-up therapy for adults with uncontrolled asthma

BACKGROUND

Long-acting beta-agonist (LABA) therapy improves symptoms in patients whose asthma is poorly controlled by an inhaled glucocorticoid alone. Alternative treatments for adults with uncontrolled asthma are needed.

METHODS

In a three-way, double-blind, triple-dummy crossover trial involving 210 patients with asthma, we evaluated the addition of tiotropium bromide (a long-acting anticholinergic agent approved for the treatment of chronic obstructive pulmonary disease but not asthma) to an inhaled glucocorticoid, as compared with a doubling of the dose of the inhaled glucocorticoid (primary superiority comparison) or the addition of the LABA salmeterol (secondary noninferiority comparison).

RESULTS

The use of tiotropium resulted in a superior primary outcome, as compared with a doubling of the dose of an inhaled glucocorticoid, as assessed by measuring the morning peak expiratory flow (PEF), with a mean difference of 25.8 liters per minute (P<0.001) and superiority in most secondary outcomes, including evening PEF, with a difference of 35.3 liters per minute (P<0.001); the proportion of asthma-control days, with a difference of 0.079 (P=0.01); the forced expiratory volume in 1 second (FEV1) before bronchodilation, with a difference of 0.10 liters (P=0.004); and daily symptom scores, with a difference of -0.11 points (P<0.001). The addition of tiotropium was also noninferior to the addition of salmeterol for all assessed outcomes and increased the prebronchodilator FEV1 more than did salmeterol, with a difference of 0.11 liters (P=0.003).

CONCLUSIONS

When added to an inhaled glucocorticoid, tiotropium improved symptoms and lung function in patients with inadequately controlled asthma. Its effects appeared to be equivalent to those with the addition of salmeterol. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00565266.).

A trial of clarithromycin for the treatment of suboptimally controlled asthma

BACKGROUND

PCR studies have demonstrated evidence of Mycoplasma pneumoniae and Chlamydophila pneumoniae in the lower airways of patients with asthma.

OBJECTIVE

To test the hypothesis that clarithromycin would improve asthma control in individuals with mild-to-moderate persistent asthma that was not well controlled despite treatment with low-dose inhaled corticosteroids.

METHODS

Adults with an Asthma Control Questionnaire score ≥1.5 after a 4-week period of treatment with fluticasone propionate were entered into a PCR-stratified randomized, controlled trial to evaluate the effect of 16 weeks of either clarithromycin or placebo, added to fluticasone, on asthma control in individuals with or without lower airway PCR evidence of M pneumoniae or C pneumoniae.

RESULTS

A total of 92 participants were randomized. Twelve (13%) subjects demonstrated PCR evidence of M pneumoniae or C pneumoniae in endobronchial biopsies; 80 were PCR-negative for both organisms. In PCR-positive participants, clarithromycin yielded a 0.4 ± 0.4 unit improvement in the Asthma Control Questionnaire score, with a 0.1 ± 0.3 unit improvement in those allocated to placebo. This between-group difference of 0.3 ± 0.5 (P = .6) was neither clinically nor statistically significant. In PCR-negative participants, a nonsignificant between-group difference of 0.2 ± 0.2 units (P = .3) was observed. Clarithromycin did not improve lung function or airway inflammation but did improve airway hyperresponsiveness, increasing the methacholine PC(20) by 1.2 ± 0.5 doubling doses (P = .02) in the study population.

CONCLUSION

Adding clarithromycin to fluticasone in adults with mild-to-moderate persistent asthma that was suboptimally controlled by low-dose inhaled corticosteroids alone did not further improve asthma control. Although there was an improvement in airway hyperresponsiveness with clarithromycin, this benefit was not accompanied by improvements in other secondary outcomes.

T-cell responses and hypersensitivity to influenza and egg antigens among adults with asthma immunized with the influenza vaccine

BACKGROUND

The American Lung Association Asthma Clinical Research Centers (ALA-ACRC) reported that the inactivated influenza vaccine is safe for patients with asthma and recommended its use to reduce the morbidity associated with infection.

OBJECTIVE

Because the ALA-ACRC's recommendation would include vaccination of all patients with asthma, including those with severe asthma and first-time vaccinees, we conducted a parallel study to address whether patients with asthma who report bronchospasm after vaccination might be demonstrating a hypersensitivity response to the vaccine.

METHODS

Thirty-two adult patients with asthma from the ALA-ACRC cohort were recruited. Subjects were randomly assigned to receive influenza vaccine or placebo and then recorded asthma symptoms and peak expiratory flow rates for 14 days. On day 14, influenza vaccine and egg antigen-induced mononuclear cell proliferation and IFN-gamma, IL-5, and IL-4 production were measured and compared with symptoms.

RESULTS

Increased influenza but not egg antigen-induced mononuclear cell proliferation was present among vaccinated subjects. These responses were unrelated to asthma exacerbations after vaccine. There were no differences in cytokine production in response to either influenza or egg antigen in association with asthma exacerbations.

CONCLUSIONS

Episodes of bronchospasm after influenza vaccination do not seem related to hypersensitivity to the vaccine.

Assessment of bronchial wall thickening on posteroanterior chest radiographs in acute asthma

A central bronchus that is readily visible end-on in approximately 50% of normal frontal chest radiographs is the bronchus to the anterior segment of either upper lobe. Bronchial wall thickening, or "cuffing," is considered to be a radiographic sign of an asthmatic exacerbation and is cited as a useful sign in a number of leading textbooks; however, to the authors' knowledge, no prior chest radiographic study has quantitatively assessed this specific sign in a population of asthmatics suffering an acute exacerbation. Posterior chest radiographs were reviewed retrospectively for 51 nonasthmatic, nonsmoking control subjects and for 45 adult asthmatic subjects during an acute exacerbation of moderate to severe asthma. Readers were blinded as to whether the radiograph was from an asthmatic or control subject. If visible end-on, the bronchus to the anterior segment of either upper lobe was assessed by measuring the diameter of the lumen and the thickness of the bronchial wall. At least one clearly defined bronchus to the anterior segment of an upper lobe was visible end-on in 22 patients (43%) in the control group and in 21 patients (47%) in the asthma group (p = NS). Mean wall thickness was 0.7 +/- 0.1 mm in the control group and 0.8 +/- 0.1 mm in the asthma group (p = 0.04). Lumen/wall thickness was 3.1 +/- 0.2 (SEM) in the control group and 2.5 +/- 0.2 in the asthma group (p = 0.055). The presence of bronchial wall thickness does not reliably distinguish radiographs of acutely asthmatic from normal individuals.