Novel Use of Seraph-100™ Blood Purification Therapy in Heat Stroke.

The Seraph-100™ is a purification filter that blunts cytokine storm, providing a more favorable environment to establish immune homeostasis. We present a novel case of compassionate use of Seraph filter in a young, healthy active duty service member with heat injury-induced massive inflammatory response. The patient is a previously healthy 26-year-old male with altered mental status, tachycardia, fever to 40.3 °C, and hypotension after losing consciousness during a 4-mile run. He had a history of one heat injury in college and took no medications or supplements. Initial workup demonstrated hemoconcentration, leukocytosis, and hyperkalemia. He was intubated, received isotonic crystalloid fluid, and was admitted to the intensive care unit. The patient developed vasopressor-resistant shock and multiorgan failure with rhabdomyolysis requiring continuous renal replacement therapy. The addition of the Seraph resulted in improved hemodynamic stability, decreased inflammatory markers, and improved organ function. Approximately 1 week after the final Seraph treatment, the patient had an abrupt massive lower gastrointestinal bleed and was transitioned to comfort care by family. We present the novel use of Seraph in the setting of multiorgan failure and hyperinflammatory state due to heat injury. The patient's vasopressor refractory distributive shock was believed to be secondary to heat stroke-induced massive inflammatory response, leading to a trial of Seraph therapy. This case demonstrates that the Seraph filter has the potential to improve hemodynamic instability and reduce cytokine storm in nonsepsis patients.

Boronic Acid Pairs for Sequential Bioconjugation.

Boronic acids can play diverse roles when applied in biological environments, and employing boronic acid structures in tandem could provide new tools for multifunctional probes. This Letter describes a pair of boronic acid functional groups, 2-nitro-arylboronic acid (NAB) and (E)-alkenylboronic acid (EAB), that enable sequential cross-coupling through stepwise nickel- and copper-catalyzed processes. The selective coupling of NAB groups enables the preparation of stapled peptides, protein-protein conjugates, and other bioconjugates.

Copper-mediated peptide arylation selective for the N-terminus.

Polypeptides present remarkable selectivity challenges for chemical methods. Amino groups are ubiquitous in polypeptide structure, yet few paradigms exist for reactivity and selectivity in arylation of amine groups. This communication describes the utilization of boronic acid reagents bearing certain o-electron withdrawing groups for copper-mediated amine arylation of the N-terminus under mild conditions and primarily aqueous solvent. The method adds to the toolkit of boronic acid reagents for polypeptide modification under mild conditions in water that shows complete selectivity for the N-terminus in the presence of lysine side chains.

Nickel(II)-Promoted Amide N-H Arylation of Pyroglutamate-Histidine with Arylboronic Acid Reagents.

Small and simple bioorthogonal reactive handles that can be readily encoded by natural processes are important for bioconjugation. A rapid nickel-promoted N-H arylation of pyroglutamate-histidine sequences with 2-nitroarylboronic acids proceeds under mild aqueous conditions. Chemoselective activation of a lactam amide N-H within a peptide or protein provides a new approach to selective conjugation in polyamide structures.

Rapid nickel(ii)-promoted cysteine S-arylation with arylboronic acids.

S-Arylation of cysteine residues is an increasingly powerful tool for site-specific modification of proteins, providing novel structure and electronic perturbation. The present work demonstrates an operationally-simple cysteine arylation reaction 2-nitro-substituted arylboronic acids, promoted by a simple nickel(ii) salt. The process exhibits strikingly fast reaction rates under physiological conditions in purely aqueous media with excellent selectivity toward cysteine residues. Cysteine arylation of natural proteins and peptides allows attachment of useful reactive handles for stapling, imaging, or further conjugation.

Metabolic responses to high-fat diets rich in MUFA v. PUFA.

Dietary fatty acid (FA) composition may influence metabolism, possibly affecting weight management. The purpose of this study was to compare the effects of a 5-d diet rich in PUFA v. MUFA. A total of fifteen normal-weight men participated in a randomised cross-over design with two feeding trials (3 d lead-in diet, pre-diet visit, 5-d PUFA- or MUFA-rich diet, post-diet visit). The 5-d diets (50 % fat) were rich in either PUFA (25 % of energy) or MUFA (25 % of energy). At pre- and post-diet visits, subjects consumed breakfast and lunch test meals, rich in the FA for that 5-d diet. Indirect calorimetry was used for 4 h after each meal. There were no treatment differences in fasting metabolism acutely or after the 5-d diet. For acute meal responses before diet, RER was higher for PUFA v. MUFA (0·86 (sem 0·01) v. 0·84 (sem 0·01), P<0·05), whereas diet-induced thermogenesis (DIT) was lower for PUFA v. MUFA (18·91 (SEM 1·46) v. 21·46 (SEM 1·34) kJ, P<0·05). After the 5-d diets, the change in RER was different for PUFA v. MUFA (-0·02 (sem 0·01) v. 0·00 (sem 0·01), P<0·05). Similarly, the change in fat oxidation was greater for PUFA v. MUFA (0·18 (sem 0·07) v. 0·04 (sem 0·06) g, P<0·05). In conclusion, acutely, a MUFA-rich meal results in lower RER and greater DIT. However, after a 5-d high-fat diet, the change in metabolic responses was greater in the PUFA diet, showing the metabolic adaptability of a PUFA-rich diet.

A Three-Component Organometallic Tyrosine Bioconjugation.

Metal-based bioconjugation linkages represent a little-studied approach to protein functionalization that provides novel reactivity, stability, and function. Described is an organometallic bioconjugation, employing rhodium(III) salts, to link boronic acids with tyrosine residues by an arene complex. Both peptides and proteins are amenable to the mild bioconjugation in aqueous media, allowing incorporation of useful functionalities, such as affinity handles or fluorophores. Because of the metastability of the inorganic linkage, the conjugates are susceptible to cleavage by nucleophilic redox mediators but are stable toward typical biological conditions.

A PUFA-rich diet improves fat oxidation following saturated fat-rich meal.

PURPOSE: To determine substrate oxidation responses to saturated fatty acid (SFA)-rich meals before and after a 7-day polyunsaturated fatty acid (PUFA)-rich diet versus control diet. METHODS: Twenty-six, normal-weight, adults were randomly assigned to either PUFA or control diet. Following a 3-day lead-in diet, participants completed the pre-diet visit where anthropometrics and resting metabolic rate (RMR) were measured, and two SFA-rich HF meals (breakfast and lunch) were consumed. Indirect calorimetry was used to determine fat oxidation (Fox) and energy expenditure (EE) for 4 h after each meal. Participants then consumed a PUFA-rich diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 21 % of total energy was PUFA) or control diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 7 % of total energy was PUFA) for the next 7 days. Following the 7-day diet, participants completed the post-diet visit. RESULTS: From pre- to post-PUFA-rich diet, there was no change in RMR (16.3 ± 0.8 vs. 16.4 ± 0.8 kcal/20 min) or in incremental area under the curve for EE (118.9 ± 20.6-126.9 ± 14.1 kcal/8h, ns). Fasting respiratory exchange ratio increased from pre- to post-PUFA-rich diet only (0.83 ± 0.1-0.86 ± 0.1, p < 0.05). The postprandial change in Fox increased from pre- to post-visit in PUFA-rich diet (0.03 ± 0.1-0.23 ± 0.1 g/15 min for cumulative Fox; p < 0.05), whereas controls showed no change. CONCLUSIONS: Adopting a PUFA-rich diet initiates greater fat oxidation after eating occasional high SFA meals compared to a control diet, an effect achieved in 7 days.

A prospective observational study of oseltamivir safety and tolerability in infants and young children ≤24 months.

PURPOSE: Infants and young children are at elevated risk of influenza-associated complications, but information on the safety of antiviral therapies is limited in this age group. METHODS: In this prospective open-label observational safety study, children aged ≤24 months with a clinical diagnosis of influenza in routine practice received either no antiviral treatment ('unexposed' group) or oseltamivir treatment or prophylaxis ('exposed' group), according to the physician's judgment. Patients were followed up for 30 days after the baseline visit. RESULTS: Adverse events (AEs) were analysed in 1065 patients; they were reported in 390/711 (54.9%) in the unexposed group, 167/340 (49.1%) patients in the exposed group, and 6/14 prophylaxis patients. Cough and rhinitis were the most common events, reported more often in unexposed children (22.9 and 20.3% respectively) than in exposed children (13.2 and 10.0%; p < 0.001); pyrexia, diarrhoea and vomiting were less common, occurring at similar rates in exposed and unexposed patients. Nasal congestion (3.5%), bronchitis (5.6%) and upper respiratory tract infection (1.5%) were reported more frequently in exposed patients than in unexposed patients (0.7, 2.7 and 0.1% respectively; p < 0.05). In the exposed group, 11.2% of patients (n = 38) experienced 41 AEs considered at least possibly related to oseltamivir, none being assessed as serious. Overall, there were 79 serious AEs in 59 patients. Eleven discontinued treatment because of an AE. CONCLUSIONS: Oseltamivir has a good tolerability profile in infants and children aged ≤24 months. These findings contributed to the recent FDA approval of oseltamivir for treating infants aged 2-51 weeks.

Use of anti-malarial drugs and the risk of developing eye disorders.

BACKGROUND: Ocular toxicity was described in the late 1950s for some anti-malarial drugs, but only limited information is available on the comparison of ocular toxicity of different anti-malarials. METHODS: We conducted a follow-up study with a nested case-control analysis using the General Practice Research Database to compare the risk of developing a first-time diagnosis of an eye disorder during exposure of mefloquine, chloroquine and/or proguanil or atovaquone/proguanil use to non-users. We calculated incidence rates with 95% confidence intervals (CI) and odds ratios using multivariate conditional logistic regression analyses. RESULTS: We included 83,148 patients and identified 652 cases with an incident eye disorder. The incidence rates with 95% CI of all eye disorders combined in users of mefloquine, chloroquine and/or proguanil, atovaquone/proguanil or travellers not using anti-malarials were 5.3 (4.3-6.5), 7.1 (5.0-9.9), 6.3 (5.6-7.2) and 5.1 (4.6-5.7), per 1000 person-years, respectively. As compared to non-users of anti-malarials, the adjusted odds ratio with 95% CI in the nested case-control analysis for users of mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil were 1.33 (1.01-1.75), 1.61 (1.06-2.45), and 1.25 (1.03-1.52), respectively. CONCLUSIONS: The study provides evidence that there was an increased risk of eye disorders in users of all anti-malarials compared to non-users of anti-malarials.

Sex differences matter in the gut: effect on mucosal immune activation and inflammation.

BACKGROUND: Women and men have diverse responses to many infectious diseases. These differences are amplified following menopause. However, despite extensive information regarding the effects of sex hormones on immune cells, our knowledge is limited regarding the effects of sex and gender on the function of the mucosal immune system. Sex differences also manifest in the prevalence of gut associated inflammatory and autoimmune disorders, including Crohn's disease, ulcerative colitis and Celiac disease. It is thus hypothesized that a baseline sex-associated difference in immune activation may predispose women to inflammation-associated disease. METHODS: Peripheral blood samples and small intestinal biopsies were obtained from 34 healthy men and women. Immunophenotypic analysis of isolated lymphocytes was performed by flow cytometry. Oligonucleotide analysis was used to study the transcriptional profile in the gut mucosal microenvironment while real-time PCR analysis was utilized to identify differential gene expression in isolated CD4+ T cells. Transcriptional analysis was confirmed by protein expression levels for genes of interest using fluorescent immunohistochemistry. Data was analyzed using the GraphPad software package. RESULTS: Women had higher levels of immune activation and inflammation-associated gene expression in gut mucosal samples. CD4+ and CD8+ T cells had a significantly higher level of immune activation-associated phenotype in peripheral blood as well as in gut associated lymphoid tissue along with higher levels of proliferating T cells. CD4+ T cells that showed upregulation of IL1ß as well as the TH17 pathway-associated genes contributed a large part of the inflammatory profile. CONCLUSION: In this study, we demonstrated an upregulation in gene expression related to immune function in the gut microenvironment of women compared to men, in the absence of disease or pathology. Upon closer investigation, CD4+ T cell activation levels were higher in the LPLs in women than in men. Sex differences in the mucosal immune system may predispose women to inflammation-associated diseases that are exacerbated following menopause. Our study highlights the need for more detailed analysis of the effects of sex differences in immune responses at mucosal effector sites.

Antimalarial chemoprophylaxis and the risk of neuropsychiatric disorders.

BACKGROUND: Case reports and epidemiological studies have associated the use of mefloquine with neuropsychiatric adverse events. METHODS: We used the General Practice Research Database to conduct a follow-up study with a nested case-control analysis. We assessed the risk of developing first-time anxiety, stress-related disorders/psychosis, depression, epilepsy or peripheral neuropathies in patients using mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil for malaria chemoprophylaxis, as compared to unexposed travelers. RESULTS: Compared to non-users of antimalarials, the adjusted odds ratio in the nested case-control analysis for users of mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil were 0.71 (95% CI 0.56-0.90), 1.04 (95% CI 0.74-1.46), and 0.73 (95% CI 0.61-0.86) for anxiety or stress-related disorders combined, 0.54 (95% CI 0.41-0.71), 1.06 (95% CI 0.71-1.59), and 0.75 (95% CI 0.62-0.91) for depression, 0.69 (95% CI 0.35-1.36), 1.41 (95% CI 0.54-3.67), and 0.75 (95% CI 0.42-1.36) for epilepsy, and 1.22 (95% CI 0.50-2.99), 1.59 (95% CI 0.41-6.15), and 1.05 (95% CI 0.54-2.03) for neuropathies, respectively. The risk of all outcomes was higher in females than in males across all exposure categories. CONCLUSIONS: The risk of neuropsychiatric disorders was similar for users and for non-users of anti-malarial chemoprophylaxis, with evidence for elevated risks in some subgroups.

Adult asthma and risk of coronary heart disease, cerebrovascular disease, and heart failure: a prospective study of 2 matched cohorts.

Asthma has been associated with increased cardiovascular disease (CVD) risk. The authors ascertained the association of asthma with CVD and the roles that sex, concurrent allergy, and asthma medications may play in this association. They assembled a cohort of 203,595 Northern California adults with asthma and a parallel asthma-free referent cohort (matched 1:1 on age, sex, and race/ethnicity); both cohorts were followed for incident nonfatal or fatal CVD and all-cause mortality from January 1, 1996, through December 31, 2008. Each cohort was 66% female and 47% white. After adjustment for age, sex, race/ethnicity, cardiac risk factors, and comorbid allergy, asthma was associated with a 1.40-fold (95% confidence interval (CI): 1.35, 1.45) increased hazard of coronary heart disease, a 1.20-fold (95% CI: 1.15, 1.25) hazard of cerebrovascular disease, a 2.14-fold (95% CI: 2.06, 2.22) hazard of heart failure, and a 3.28-fold (95% CI: 3.15, 3.41) hazard of all-cause mortality. Stronger associations were noted among women. Comorbid allergy predicted CVD but did not synergistically increase the CVD risk associated with asthma. Only asthma patients using asthma medications (particularly those on oral corticosteroids alone or in combination) were at enhanced risk of CVD. In conclusion, asthma was prospectively associated with increased risk of major CVD. Modifying effects were noted for sex and asthma medication use but not for comorbid allergy.

Longitudinal changes in asthma control with omalizumab: 2-year interim data from the EXCELS Study.

BACKGROUND: Asthma guidelines emphasize the importance of achieving and maintaining asthma control; however, many patients with moderate to severe asthma fail to achieve adequate control. OBJECTIVE: This 2-year interim analysis evaluated the longitudinal effects of omalizumab on asthma control in patients treated in real-world clinical practice settings. METHODS: EXCELS is an ongoing observational cohort study of approximately 5000 omalizumab-treated and 2500 non-omalizumab-treated patients aged ≥12 years with moderate to severe asthma. Asthma control was measured using the Asthma Control Test (ACT) every 6 months. RESULTS: Subgroups of the omalizumab cohort included those who initiated omalizumab at baseline (new starts, n = 549) and those treated with omalizumab >7 days before baseline (established users, n = 4421). For reference, data are also presented for patients who were not receiving omalizumab prior to or at the time of enrolment (non-omalizumab, n = 2867). Over half of the new starts (54%) achieved improvement in ACT consistent with the minimally important difference (MID, defined as ≥3-point improvement) by Month 6 and this proportion increased throughout the follow-up period, reaching 62% at Month 24. Similar results were observed in patients stratified by moderate and severe asthma. Established users of omalizumab maintained asthma control throughout the observation period. CONCLUSION: Over a 2-year period, patients initiating omalizumab therapy experienced clinically relevant improvements in asthma control, which were maintained during 2 years of longitudinal follow-up. Established users of omalizumab maintained asthma control over the 2-year period with a small improvement similar to that seen in non-omalizumab users.

Asthma and the prospective risk of anaphylactic shock and other allergy diagnoses in a large integrated health care delivery system.

BACKGROUND: The association between asthma and anaphylaxis remains poorly understood. OBJECTIVE: To ascertain, in a managed care organization in northern California, the association of asthma and asthma severity with future risk of anaphylactic shock and other selected allergy diagnoses. METHODS: Using electronic data and validated algorithms, we assembled a cohort of 526,406 patients who met the criteria for asthma between 1996 and 2006 and a referent cohort (with no utilization for asthma) individually matched on age, sex, and race/ethnicity. In each cohort, 54% of patients were female and 55% were white; their mean (SD) age was 24 (20) years. The main outcome measures were anaphylactic shock (caused by an adverse food reaction, caused by serum, or other/idiopathic), allergic urticaria, anaphylaxis after sting(s), and angioedema. RESULTS: The incidence of anaphylactic shock was 109.0 per 100,000 person-years in the asthma cohort and 19.9 per 100,000 person-years in the referent cohort. After adjustment for age, sex, race/ethnicity, comorbidities, and immunotherapy, asthma was associated with a 5.2-fold (95% confidence interval, 4.7- to 5.6-fold) increased hazard of anaphylactic shock. Asthma was also significantly associated with an increased risk of the 3 selected allergy diagnoses, with hazard ratios of 1.4 to 1.9. A significant trend by severity of asthma was apparent for food-related and other/idiopathic anaphylactic shock and for anaphylaxis after sting(s). CONCLUSIONS: In this insured population, asthma was prospectively associated with increased risk of anaphylactic shock and other allergy diagnoses. However, the effect of asthma severity was not consistent across outcome measures.

Baseline characteristics of patients enrolled in EXCELS: a cohort study.

BACKGROUND: The Epidemiologic Study of Xolair (omalizumab): Evaluating Clinical Effectiveness and Long-term Safety in Patients with Moderate-to-Severe Asthma (EXCELS) is a unique opportunity to evaluate the prospective, long-term clinical safety and effectiveness of the anti-IgE antibody omalizumab (Xolair) in real-world clinical practice. OBJECTIVES: To describe the study design and study cohorts of EXCELS at baseline and to compare the characteristics of this population with other large asthma cohorts. METHODS: Patients with moderate-to-severe persistent asthma and a positive skin test result or in vitro reactivity to a perennial aeroallergen were eligible for EXCELS. Two cohorts of patients with asthma were enrolled: those treated with omalizumab and those not treated with omalizumab. We analyzed baseline demographic and clinical characteristics, including asthma history and control and allergy history. RESULTS: Large proportions of patients enrolled in EXCELS had historically severe and poorly or not well-controlled asthma at the time of enrollment, objective evidence of airway obstruction, a history of long-term oral corticosteroid use, and/or other allergic disorders. Minor differences were observed between the omalizumab and nonomalizumab cohorts. Our total patient cohort was generally similar to other large cohorts. In a subgroup analysis, patients who had received omalizumab within 7 days before enrollment had more severe asthma and greater degrees of impairment at baseline than nonomalizumab patients. CONCLUSIONS: This study of baseline characteristics in EXCELS offers a unique opportunity to better understand the history of allergic patients with moderate-to-severe asthma in a real-world treatment setting. This analysis of EXCELS baseline data sets the foundation for long-term assessment of the safety and effectiveness of omalizumab.

Churg-strauss syndrome in patients treated with omalizumab.

BACKGROUND: Churg-Strauss syndrome (CSS) is a rare systemic vasculitis associated with asthma, eosinophilia, sinusitis, and pulmonary infiltrates. CSS has been reported in association with asthma therapies. MATERIALS AND METHODS: The objective is to describe the characteristics of CSS in patients treated with the anti-IgE antibody omalizumab (Xolair; Genentech Inc; South San Francisco, CA). A retrospective review of available data to identify cases of CSS was performed using the Novartis Argus global drug safety database for omalizumab in asthma patients. RESULTS: We identified 34 potential cases of CSS. Of these, 13 cases fulfilled at least four of the six criteria identified in the American College of Rheumatology classification criteria. Eight of the patients in these 13 definite or probable cases (62%) had CSS symptoms prior to receiving omalizumab or described symptom onset just after corticosteroid weaning. Six of the 13 patients (46%) were confirmed as having been treated with corticosteroids for what was perceived to be severe asthma; when corticosteroids were tapered in conjunction with omalizumab treatment, CSS symptoms appeared just after the tapering. There were 4 other cases of possible CSS, and the remaining 17 patients were judged to not have CSS. CONCLUSIONS: CSS may develop in patients receiving asthma medications who have an underlying eosinophilic disorder that is unmasked by the withdrawal of therapy with corticosteroids, or in patients who delay therapy in favor of other medications. Omalizumab treatment may unmask CSS due to the weaning of corticosteroids in some asthma patients or may delay corticosteroid treatment allowing for CSS to manifest. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00252135.

Measurements of birth defect prevalence: which is most useful as a comparator group for pharmaceutical pregnancy registries?

Pharmaceutical pregnancy registries document birth defects and other complications reported in pregnancies exposed to specific medications or diseases. A baseline estimate of birth defect prevalence is necessary for comparison. To identify potential teratogenic signals, the pregnancy registry must have a comparator that most closely matches the exposed population and data collection methodology, which are characteristics that vary among the multiplicity of birth defect surveillance systems. The system that yields the most accurate prevalence data may be different from that most closely matching the pregnancy registry methods. State public health programs have highly accurate and precise statistics, but their populations are broader than those of a pharmaceutical pregnancy registry. Large collaborative databases may have a more useful covered population, but there are secondary problems related to data precision. Health care databases enroll large numbers of patients and have good information about exposures and health problems, but the data can be difficult to access and lack useful detail. Exposure-related databases are closer in population definition and collection methods, though the presence of different diseases and exposures can be problematic. Internal comparators are likely to be most useful in formal statistical analysis, but added cost and management burden and may require significantly increased registry enrollment. There is no ideal comparator, and this must be taken into account when planning a single-exposure or single-disease pregnancy registry.

Safety outcomes of Alteplase among acute ischemic stroke patients with special characteristics.

BACKGROUND: Although tissue plasminogen activator (tPA) has been approved for use in acute ischemic stroke, concerns linger regarding its safety. We analyzed whether patients in special subgroups (i.e., age >70 years, baseline National Institute of Health Stroke Scale (NIHSS) score >20, diabetes, congestive heart failure (CHF), and of Hispanic origin) have a higher risk of symptomatic intracerebral hemorrhage (SICH) than patients without these characteristics. METHODS: Four prospective observational studies of acute ischemic stroke patients treated within 3 h with Alteplase were identified and individual patient data were pooled for this analysis. These included the Standard Treatment with Alteplase to Reverse Stroke Study [STARS, N = 389], Epidemiology Study of Ischemic Stroke [ESIS, N = 236], University Of Texas Houston Stroke Study [UT, N = 241], and Canadian Activase For Stroke Effectiveness Study [CASES, N = 1100]. The risk of SICH was calculated for all patients and for each of five subgroups. RESULTS: A total of 1966 patients were studied. Overall the risk of symptomatic ICH was 4.7% (95%CI, 3.8-5.8%) and the risk was similar among patients with and without each of the five characteristics. Patients with advanced age, baseline NIHSS score >20, CHF or diabetes had increased mortality and significantly lower rate of functional recovery. CONCLUSIONS: The present study suggests that these specified subgroups of patients are not at increased risk of SICH after stroke thrombolysis compared to those without these characteristics.

Recent asthma exacerbations: a key predictor of future exacerbations.

OBJECTIVE: The objective of this analysis was to investigate whether patients with severe or difficult-to-treat asthma who experienced recent severe asthma exacerbations are at increased risk of future asthma exacerbations. METHODS: We conducted a 1.5-year prospective analysis of 2780 patients 12 > or =years of age from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study. Severe exacerbations were defined as either an asthma-related emergency department visit or night of hospitalization in the 3 months prior to study visit; a secondary analysis assessed prior steroid bursts as an independent predictor and outcome. Potential confounding was assessed by statistical adjustment for demographic and clinical factors, as well as asthma severity and asthma control. RESULTS: Compared with patients without a recent severe exacerbation, patients with a recent exacerbation were at increased risk of future exacerbation (odds ratio=6.33; 95% CI 4.57, 8.76), even after adjustment for demographics and clinical factors (odds ratio=3.77; 95% CI 2.62, 5.43), asthma severity (physician-assessed: odds ratio=5.62; 95% CI 4.03, 7.83), National Asthma Education and Prevention Program (odds ratio=5.07; 95% CI 3.62, 7.11), Global Initiative for Asthma (odds ratio=5.32; 95% CI 3.80, 7.47), and asthma control (odds ratio=3.90; 95% CI 2.77, 5.50). CONCLUSION: This analysis suggests that recent severe asthma exacerbations are a strong independent factor predicting future exacerbations and, as such, should be considered as part of the clinical assessment of patients with severe or difficult-to-treat asthma.