Management of Aspirin-Exacerbated Respiratory Disease: What Does the Future Hold?

Aspirin-exacerbated respiratory disease (AERD) is a subtype of chronic rhinosinusitis with polyps (CRSwNP) and asthma with higher recurrence of nasal polyps after surgery and severe asthma. Patients with CRSwNP and asthma should be screened for AERD by detailed history of aspirin/nonsteroidal anti-inflammatory drug reactions and review of medications that may mask aspirin reaction or directly by aspirin challenge. Treatment of AERD may require more intensive therapy, including endoscopic sinus surgery, daily aspirin therapy, leukotriene modifiers, or biologics.

Sex, Ethnicity, Body Mass Index, and Environmental Exposures Associated With NSAID-Exacerbated Respiratory Disease Symptom Sequence.

BACKGROUND: Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) has a triad of symptoms: nasal polyposis, asthma, and NSAID hypersensitivity. Little is known about symptom timing and disease progression. OBJECTIVE: The aim of this study is to characterize disease progression in N-ERD. METHODS: Patients with N-ERD were prospectively interviewed and classified into 4 groups based on their first symptom at initial N-ERD onset (asthma, nasal polyps, NSAID hypersensitivity, or all concurrently). Associations of patient characteristics with the 4 groups were examined, along with associations within the "asthma first" group. RESULTS: Patients (N = 240) were mostly female (68%) and self-identified as non-White (77%). Half (N = 119) reported asthma as the earliest symptom in the N-ERD triad. Compared with other groups, "asthma first" was associated with younger age of onset (25 years, standard error ±1.3, P < .001) and higher body mass index (BMI) (odds ratio [OR] = 1.3, 95% confidence interval [CI]: 1.06-1.7, P = .02). In this group, age of onset <20 years was associated with female sex, Latino ethnicity, and higher BMI (all P < .05). The "NSAID sensitivity first" group was significantly associated with male sex (OR = 3.3, 95% CI: 1.5-7.4, P = .004) and pollution exposure (OR = 4.4, 95% CI: 1.6-11.9, P = .003). At the initial presentation, 27% of patients were unaware of their N-ERD diagnosis. Black and Latino patients were more likely to be unaware of their N-ERD diagnosis compared with White (P = .003). The median diagnostic delay was 3 years (interquartile range: 0-5 years). CONCLUSIONS: In this cohort, N-ERD is highly variable in onset and progression, with sex, BMI, race and ethnicity, and environmental exposures significantly associated with disease patterns and diagnostic delay.

Perioperative management of mastocytosis.

PURPOSE: Patients with mastocytosis have an increased risk of anaphylaxis during surgical procedures with general anesthesia. Therefore, we reviewed the anesthesia course of a large cohort of patients with mastocytosis. METHODS: We retrospectively reviewed adult and pediatric patients with mastocytosis who underwent surgical procedures with general anesthesia at Mayo Clinic from January 1, 2000, through June 30, 2021. We also included any procedures with general anesthesia that occurred during the 3-year period preceding mastocytosis diagnosis and designated the patients who underwent these procedures as having an unknown diagnosis at the time of their surgical procedure. We analyzed whether patients received chronic antimediator treatment for mastocytosis and/or prophylactic medications before the procedures. We also determined whether medications indicative of mastocytosis-related adverse events were intraoperatively administered. RESULTS: We identified 113 patients who underwent 219 procedures during the study period; 25 procedures were performed before mastocytosis diagnosis. Of 194 procedures in patients with known mastocytosis, patients received chronic antimediator therapy and/or perioperative prophylactic medications for 178 (91.8%) procedures. Among these procedures, 10 were potentially complicated by mast cell activation, which was inferred from administration of inhaled albuterol (n = 3) or intravenous diphenhydramine (n = 8). In addition, there was only one case of intraoperative anaphylaxis which occurred in a patient who underwent anesthesia before mastocytosis diagnosis and therefore did not receive prophylaxis. CONCLUSION: Intraoperative anaphylaxis can be the first presenting sign of mastocytosis. Patients with mastocytosis who received chronic antimediator therapy and/or preoperative prophylactic medications had an uneventful surgical course.

Unified Airway Disease: Diagnosis and Subtyping.

The concept of a unified airway posits that pathology affects the respiratory tract in a continuum and that disease in one part of the respiratory tract may be associated with or directly or indirectly affect the function of a different part. Transcriptomic analysis has shown 91% homology between the genes expressed in the upper and the lower airway. Approaching inflammatory airway disorders using the unified airway hypothesis allows for a better clarification of disease process and provides a detailed and a high-level overview of dysfunction. There are several tools available to the clinician to use to subtype and diagnose accurately the abnormal pathways operating in inflammatory airway disorders. These tools include clinical history, physical examination findings, imaging (computed tomography and MRI), allergy and laboratory testing, pulmonary function testing (PFT), and tissue histopathology. Tests can be categorized based on platform, by specimen, or the marker being studied.

Aspirin-Exacerbated Respiratory Disease and the Unified Airway: A Contemporary Review.

Aspirin-exacerbated respiratory disease (AERD) is characterized by abnormal arachidonic acid metabolism leading to chronic rhinosinusitis with nasal polyposis (CRSwNP), asthma, and upper and/or lower respiratory symptoms after ingestion of cyclooxygenase-1 inhibiting nonsteroidal antiinflammatory drugs. Diagnosis is clinical and may involve an aspirin challenge. Inflammatory biomarkers may be useful for diagnosis and treatment monitoring. Conventional medical management for asthma and CRSwNP is often inadequate. Endoscopic sinus surgery followed by continued medical management with or without aspirin desensitization frequently improves symptoms and objective disease measures. Biological agents targeting eosinophilic inflammation are promising alternatives to conventional management.

Quantitative B and T cell abnormalities in four patients presenting with mucormycosis and prior asymptomatic COVID-19 infection.

India saw an unprecedented and rapid rise of invasive coronavirus-associated mucormycosis (CAM) during the delta COVID-19 surge. There is little known about the pathophysiology and if there is a direct causation between the COVID-19 infection and invasive CAM. While the traditional risk factors such as uncontrolled diabetes and other immunocompromising conditions are recognised, there could be several COVID-19-induced phenomena that may predispose the patients to develop CAM and are yet unrecognised. It has been proposed that prior severe COVID-19 is associated with invasive CAM. This could be due to the increased use of immunomodulators or the direct effects of the COVID-19 infection. We report four patients with CAM during the delta surge who did not have prior known COVID-19 infection but on subsequent testing had positive antibodies suggesting past asymptomatic infection. We report the quantitative abnormalities in lymphocyte subsets in all four patients and report CD19+ B cell lymphopenia and reduced percentage of CD27+ CD45RA+ naïve helper T cells. CAM may occur in patients after asymptomatic COVID-19 infection, in the absence of systemic corticosteroid and immunomodulator use, and may reflect underlying immune abnormalities possibly attributable to or unmasked by prior COVID-19 infection.

Risk for Postmarket Black Box Warnings in FDA-Approved Monoclonal Antibodies.

OBJECTIVE: To estimate the potential risk for a future postmarket black box warning (BBW) of US Food and Drug Administration (FDA)-approved monoclonal antibodies (mAbs) because of the importance for medical clinicians to understand mAb risks and benefits, including unknown future risks, especially for recently approved mAbs. METHODS: The complete dates of the study were March 16, 2020, through May 12, 2021. We searched the FDALabel database online and reviewed the scientific literature to determine current and previous FDA-approved mAbs as of March 2020. The BBWs and initial FDA-issued safety warnings were identified. The BBWs were categorized as premarket or postmarket. For mAbs with specific postmarket BBWs, previous FDA labels were evaluated to identify the presence or absence of an initial corresponding specific FDA warning. RESULTS: In March 2020, a total of 83 mAbs had FDA approval; 33 had BBWs (27 premarket and 13 postmarket BBWs). Of these 33 mAbs, 55 individual specific BBWs existed (36 premarket and 19 postmarket specific warnings). On average, the specific BBWs occurred in the postmarket period at a rate of 3.4% (19/562) per year. Most (73.7%; 14/19) specific postmarket BBWs were preceded by an FDA warning in a median time of 3.61 (interquartile range, 1.36-5.78) years. Specific postmarket BBWs not preceded by a specific FDA product label warning occurred at an average rate of 0.9% (5/562) per year. CONCLUSION: Specific postmarket BBWs occurred in FDA-approved mAbs at a rate of 3.4% per year. Specific postmarket BBWs not preceded by a specific FDA product label warning had a rate of 0.9% per year.

Urine Leukotriene E4: Implications as a Biomarker in Chronic Rhinosinusitis.

OBJECTIVE: To provide a comprehensive state-of-the-art review of the emerging role of urine leukotriene E4 (uLTE4) as a biomarker in the diagnosis of chronic rhinosinusitis (CRS), aspirin-exacerbated respiratory disease (AERD), and asthma. DATA SOURCES: Ovid MEDLINE(R), Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. REVIEW METHODS: A state-of-the-art review was performed investigating the role of uLTE4 as a diagnostic biomarker, predictor of disease severity, and potential marker of selected therapeutic efficacy. CONCLUSIONS: uLTE4 has been shown to be a reliable and clinically relevant biomarker for CRS, AERD, and asthma. uLTE4 is helpful in ongoing efforts to better endotype patients with CRS and to predict disease severity. IMPLICATIONS FOR PRACTICE: Aside from being a diagnostic biomarker, uLTE4 is also able to differentiate aspirin-tolerant patients from patients with AERD and has been associated with objective disease severity in patients with CRS with nasal polyposis. uLTE4 levels have also been shown to predict response to medical therapy, particularly leukotriene-modifying agents.

Outcomes among patients with COVID-19 and asthma: A systematic review and meta-analysis.

Background: It remains unclear if asthma is a risk factor associated with worse outcomes among patients with coronavirus disease 2019 (COVID-19). Methods: We performed a comprehensive database search for studies published from January 1, 2019, to October 2, 2020. We included studies that evaluated outcomes among patients with COVID-19 and underlying asthma. Outcomes of interest included the need for hospitalization, length of hospitalization, intensive care unit (ICU) admission, and death. The meta-analysis was conducted by using random-effects methodology. Results: A total of 389 studies were identified through data base searches. After abstract and full-text screening, 16 observational studies with 92,275 patients were included in the analysis. Of the 16 studies, 15 were retrospective and 1 was a prospective cohort study. The average age was 39.6 years, with 48% female patients. Six of the studies included pediatric patients, and one of these studies only evaluated pediatric patients. One study only evaluated pregnant patients. Among patients with COVID-19, the presence of asthma was not associated with any significant increase in risk of hospitalization (odds ratio [OR] 1.46 [95% confidence interval {CI}, 0.29-7.28]), length of hospitalization (1.59 days [-0.55 to 3.74]), ICU admission (OR 1.65 [95% CI, 0.56-4.17]), or death (OR 0.73 [95% CI, 0.38-1.40]). The overall risk of bias of the included studies was high. Conclusion: Among the patients with COVID-19, asthma did not seem to significantly increase the risk of hospitalization, length of hospitalization, ICU admission, or death.

A diagnostic codes-based algorithm improves accuracy for identification of childhood asthma in archival data sets.

OBJECTIVE: While a single but truncated ICD code (493) had been widely used for identifying asthma in asthma care and research, it significantly under-identifies asthma. We aimed to develop and validate a diagnostic codes-based algorithm for identifying asthmatics using Predetermined Asthma Criteria (PAC) as the reference. METHODS: This is a retrospective cross-sectional study which utilized two different coding systems, the Hospital Adaptation of the International Classification of Diseases, Eighth Revision (H-ICDA) and the International Classification of Diseases, Ninth Revision (ICD-9). The algorithm was developed using two population-based asthma study cohorts, and validated in a validation cohort, a random sample of the 1976-2007 Olmsted County Birth Cohort. Performance of the diagnostic codes-based algorithm for ascertaining asthma status against manual chart review for PAC (gold standard) was assessed by determining both criterion and construct validity. RESULTS: Among eligible 267 subjects of the validation cohort, 50% were male, 70% white, and the median age at last follow-up was 17 (interquartile range, 8.7-24.4) years. Asthma prevalence by PAC through manual chart review was 34%. Sensitivity and specificity of the codes-based algorithm for identifying asthma were 82% and 98% respectively. Associations of asthma-related risk factors with asthma status ascertained by the code-based algorithm were similar to those by the manual review. CONCLUSIONS: The diagnostic codes-based algorithm for identifying asthmatics improves accuracy of identification of asthma and can be a useful tool for large scale studies in a setting without automated chart review capabilities.

Elevated Urine Leukotriene E4 Is Associated With Worse Objective Markers in Nasal Polyposis Patients.

OBJECTIVES: Urine leukotriene E4 (uLTE4) is a biomarker of leukotriene synthesis and is elevated in patients with aspirin-exacerbated respiratory disease (AERD). It can also be useful to help delineate aspirin-tolerant chronic rhinosinusitis with nasal polyposis (CRSwNP) patients from AERD patients. The purpose of this study is to determine if uLTE4 biomarker levels are associated with objective and subjective markers of disease severity in patients with CRSwNP. METHODS: A retrospective analysis of CRSwNP patients who underwent uLTE4 testing was completed to determine the association of uLTE4 levels to markers of disease severity. uLTE4 levels, as well as presenting subjective (Sinonasal Outcome Test 22 [SNOT22] scores, asthma control test [ACT] scores) and objective data (Lund-Mackay CT score, spirometry and lab values) were collected. RESULTS: Among the 157 CRSwNP patients who met inclusion criteria, uLTE4 levels were associated with history of asthma (P < .001), aspirin sensitivity (P < .001), worse Lund-Mackay CT scores (P = .002) and other objective markers of disease severity including serum IgE (P = .05), presenting blood eosinophil level (P < .001), and the highest recorded eosinophil level (P < .001). In subgroup analysis, associations of uLTE4 to disease markers had stronger correlations in the aspirin sensitive CRSwNP group (R range 0.31-0.52) than the aspirin tolerant CRSwNP group (R range -0.30-0.24). uLTE4 levels were not associated with subjective symptom scores (SNOT22 and ACT scores). CONCLUSION: Elevated uLTE4 biomarker levels are associated with worsened objective markers of disease severity in CRSwNP patients but not patient-reported symptom measures. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:961-966, 2021.

How High-Risk Comorbidities Co-Occur in Readmitted Patients With Hip Fracture: Big Data Visual Analytical Approach.

BACKGROUND: When older adult patients with hip fracture (HFx) have unplanned hospital readmissions within 30 days of discharge, it doubles their 1-year mortality, resulting in substantial personal and financial burdens. Although such unplanned readmissions are predominantly caused by reasons not related to HFx surgery, few studies have focused on how pre-existing high-risk comorbidities co-occur within and across subgroups of patients with HFx. OBJECTIVE: This study aims to use a combination of supervised and unsupervised visual analytical methods to (1) obtain an integrated understanding of comorbidity risk, comorbidity co-occurrence, and patient subgroups, and (2) enable a team of clinical and methodological stakeholders to infer the processes that precipitate unplanned hospital readmission, with the goal of designing targeted interventions. METHODS: We extracted a training data set consisting of 16,886 patients (8443 readmitted patients with HFx and 8443 matched controls) and a replication data set consisting of 16,222 patients (8111 readmitted patients with HFx and 8111 matched controls) from the 2010 and 2009 Medicare database, respectively. The analyses consisted of a supervised combinatorial analysis to identify and replicate combinations of comorbidities that conferred significant risk for readmission, an unsupervised bipartite network analysis to identify and replicate how high-risk comorbidity combinations co-occur across readmitted patients with HFx, and an integrated visualization and analysis of comorbidity risk, comorbidity co-occurrence, and patient subgroups to enable clinician stakeholders to infer the processes that precipitate readmission in patient subgroups and to propose targeted interventions. RESULTS: The analyses helped to identify (1) 11 comorbidity combinations that conferred significantly higher risk (ranging from P<.001 to P=.01) for a 30-day readmission, (2) 7 biclusters of patients and comorbidities with a significant bicluster modularity (P<.001; Medicare=0.440; random mean 0.383 [0.002]), indicating strong heterogeneity in the comorbidity profiles of readmitted patients, and (3) inter- and intracluster risk associations, which enabled clinician stakeholders to infer the processes involved in the exacerbation of specific combinations of comorbidities leading to readmission in patient subgroups. CONCLUSIONS: The integrated analysis of risk, co-occurrence, and patient subgroups enabled the inference of processes that precipitate readmission, leading to a comorbidity exacerbation risk model for readmission after HFx. These results have direct implications for (1) the management of comorbidities targeted at high-risk subgroups of patients with the goal of pre-emptively reducing their risk of readmission and (2) the development of more accurate risk prediction models that incorporate information about patient subgroups.

Temozolomide desensitization followed by metronomic dosing in patients with hypersensitivity.

PURPOSE: Temozolomide is the most effective chemotherapy for malignant glioma. Hypersensitivity requiring interruption of therapy may significantly impact patient survival. We have successfully employed temozolomide desensitization followed by metronomic dosing of temozolomide. Our purpose was to report patient characteristics and outcomes in patients with glioma (Grade 2-4) and temozolomide hypersensitivity managed by desensitization and metronomic dosing. METHODS: We performed an observational study of 15 patients at Mayo Clinic (Rochester) with a diagnosis of glioma who underwent temozolomide desensitization with subsequent metronomic dosing from May 2012 to January 2017. We calculated overall and progression-free survival using the Kaplan-Meier method, and log-rank analyses to assess for differences in survival by WHO Grade or treatment initiation. RESULTS: Median age at time of desensitization was 49.3 years (26.8-64.7 years). Median follow-up after desensitization was 35.5 months. One patient (6.7%) was unable to resume temozolomide due to recurrent allergy. The median time from first desensitization to discontinuation of metronomic temozolomide was 4.2 months (0-15.2 months). Median OS and PFS for the whole sample were 181.7 months and 44.9 months. For Grade 4, OS was 100% at 1 year, 40% at 3 years, 20% at 5 years; and PFS was 60% at 1 year, 40% at 3 years, and 20% at 5 years. CONCLUSION: Our results suggest that rapid-desensitization followed by metronomic temozolomide should be considered in patients with glioma who experience hypersensitivity. This strategy provides comparable outcomes to therapy with standard protocols, with the majority of patients able to tolerate temozolomide after desensitization with favorable disease control.

Asthma in the older adult.

Objective: The older adult population is increasing worldwide, and a significant percentage has asthma. This review will discuss the challenges to diagnosis and management of asthma in older adults. Data Sources: PubMed was searched for multiple terms in various combinations, including asthma, older adult, elderly, comorbid conditions, asthma diagnosis, asthma treatment, biologics and medication side effects, and adverse events. From the search, the data sources that were utilized included peer reviewed scholarly review articles, peer reviewed scientific research articles, and peer reviewed book chapters. Study Selections: Study selections that were utilized included peer reviewed scholarly review articles, peer reviewed scientific research articles, and peer reviewed book chapters. Results: Asthma in older adults is frequently underdiagnosed and has higher morbidity and mortality rates compared to their younger counterparts. A detailed history and physical examination as well as judicious testing are essential to establish the asthma diagnosis and exclude alternative ones. Medical comorbidities, such as cardiovascular disease, cognitive impairment, depression, arthritis, gastroesophageal reflux disease (GERD), rhinitis, and sinusitis are common in this population and should also be assessed and treated. Non-pharmacologic management, including asthma education on inhaler technique and self-monitoring, is vital. Pharmacologic management includes standard asthma therapies such as inhaled corticosteroids (ICS), inhaled corticosteroid-long acting ß-agonist combinations (ICS-LABA), leukotriene antagonists, long acting muscarinic antagonists (LAMA), and short acting bronchodilators (SABA). Newly approved biologic agents may also be utilized. Older adults are more vulnerable to polypharmacy and medication adverse events, and this should be taken into account when selecting the appropriate asthma treatment. Conclusions: The diagnosis and management of asthma in older adults has certain challenges, but if the clinician is aware of them, the morbidity and mortality of this condition can be improved in this growing population.

Relationship between asthma status and antibody response pattern to 23-valent pneumococcal vaccination.

Objective: Asthma poses an increased risk for serious pneumococcal disease, but little is known about the influence of asthma status on the 23-valent serotype-specific pneumococcal antibody response. We examined differences in antibody titers between pre- and post-vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV-23) in relation to asthma status. Methods: Asthma status was retrospectively ascertained by the Predetermined Asthma Criteria in an existing vaccine cohort through comprehensive medical record review. Twenty-three serotype-specific pneumococcal antibody titers measured at baseline and 4-6 weeks post-vaccination were analyzed. Vaccine responses to PPSV-23 were calculated from pre- to post-vaccine titers for each of the serotypes. Results: Of the 64 eligible and enrolled subjects, 18 (28%) had asthma. Controls (i.e., subjects without asthma) demonstrated a statistically significant fold change response compared to their baseline for all serotypes, while those with asthma did not mount a significant response to serotypes 7F, 22F, and 23F. The overall vaccine response as measured by fold change over baseline was lower in subjects with asthma than controls. Conclusions: Poorer humoral immune responses to PPSV-23 as measured by fold change were more likely to be observed in subjects with asthma compared to controls. We recommend the consideration of asthma status when interpreting vaccine response for immune competence workup through larger studies. Further studies are warranted to replicate these findings.

Revision endoscopic sinus surgery rates by chronic rhinosinusitis subtype.

BACKGROUND: Revision surgery rates following endoscopic sinus surgery (ESS) range between 7% and 50% and are influenced by many factors. This study investigates ESS outcomes for chronic rhinosinusitis (CRS) subtypes. METHODS: Retrospective review of adult CRS patients undergoing ESS with a single surgeon (2010-2015) was conducted. Outcomes were analyzed by CRS subtypes. RESULTS: ESS was performed in 424 CRS patients (CRS with nasal polyps [CRSwNP], n = 170; CRS without polyps [CRSsNP], n = 254). Most patients (309; 72.9%) could not be specifically subtyped; 115 (27.1%) were subtyped as follows: aspirin-exacerbated respiratory disease (AERD), n = 47 (11.1%); allergic fungal sinusitis (AFS), n = 39 (9.2%); immunodeficiency, n = 21 (5.0%); granulomatosis with polyangiitis (GPA), n = 5 (1.2%); and eosinophilic granulomatosis with polyangiitis (EGPA), n = 3 (0.7%). All subgroups experienced clinically meaningful reduction in postoperative 22-item Sino-Nasal Outcome Test (SNOT-22) scores. At median follow-up of 28 months (interquartile range [IQR], 10-47 months), 19 patients (4%) underwent revision ESS (CRSwNP, n = 6; CRSsNP, n = 13). Revision ESS rates were 3.5% and 5.1% for CRSwNP and CRSsNP, respectively. Revision ESS rate for subtypes were: AERD 2%; AFS 2%; immunodeficiency 14%; GPA 40%; EGPA 0%; and "all other CRS" 4% at median follow-up duration of 36, 28, 41, 37, 44, and 26 months, respectively. CONCLUSION: All CRS subtypes demonstrated clinically meaningful improvement in postoperative SNOT-22 scores following ESS. Our overall revision ESS rate was 4% (3.5% in CRSwNP). AFS, AERD, and EGPA groups demonstrated low revision rates, while immunodeficiency and GPA patients required more revision surgery. A contemporary understanding of CRSwNP subtypes facilitated surgical and medical strategies in improving outcomes for AERD, AFS, and EGPA patients. CRSsNP subtypes with immunodeficiency and GPA merit further investigation to optimize outcomes.

Recent advances in biologic therapy of asthma and the role in therapy of chronic rhinosinusitis.

Great strides have been made in the last five years in understanding the pathology of chronic rhinosinusitis (CRS). CRS is now accepted to be the end-stage manifestation of inflammation resultant from various pathogenetic mechanisms. This has resulted in increasing recognition of distinct CRS endotypes. Such endotypes encompass a cluster of patients with similar pathogenic mechanisms that may have common therapeutic targets and responsiveness to interventions. The elucidation of mechanisms leading to the development of chronic upper (sino-nasal) airway inflammation has to some extent paralleled investigations of aberrant pathways operant in asthma. In this review, we focus on recent developments in understanding the innate immune pathways as well as adaptive (late) immune responses in CRS and asthma and their implication as potentially modifiable targets in CRS. Specific biologic therapy (that is, monoclonal antibodies targeting cytokines, cytokine receptors, or specific key molecules targeting inflammation) is an exciting proposition for the future of medical management of CRS. As of the writing of this article, the agents described are not approved for use in CRS; many have partial approval for use in asthma or are considered experimental.