Salicylate pre-treatment attenuates intensity of bronchial and nasal symptoms precipitated by aspirin in aspirin-intolerant patients

Clinical evaluation and diagnosis of aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a condition composed of chronic rhinosinusitis with nasal polyposis and asthma that is defined by respiratory hypersensitivity reactions to the cyclooxygenase 1-inhibitory effects of nonsteroidal anti-inflammatory drugs. It is diagnosed in 5% to 15% of patients with asthma and is even more common in those with comorbid nasal polyposis. Diagnosis is confirmed after an aspirin challenge procedure, yet many patients present with all components and can reliably be diagnosed by history. Patients with AERD commonly experience severe uncontrolled nasal polyposis and require multispecialty evaluation to properly stage and treat this condition. The presence of nasal polyposis plays a large component in the diminished quality of life in patients with AERD. In the last decade, multiple new therapeutic areas have been approved for type 2 airway diseases, offering patients with AERD many more options for control. This makes an early and accurate diagnosis of AERD important in the care of the larger population of type 2 airway diseases.

Aspirin and Nonsteroidal Antiinflammatory Drugs Hypersensitivity and Management

Aspirin and nonsteroidal antiinflammatory drugs (NSAIDs) are widely used in the United States and throughout the world for a variety of indications. Several unique hypersensitivity syndromes exist to this class of medications, making them one of the common reasons for consultation to the allergist. The lack of any laboratory-based diagnostic studies to assist in identifying the culprits in these reactions make evaluation of aspirin and NSAID hypersensitivity challenging. Identifying patients appropriate for oral challenge and/or desensitization protocols is the standard pragmatic approach to this issue when it arises.

NSAID-exacerbated respiratory disease: a meta-analysis evaluating prevalence, mean provocative dose of aspirin and increased asthma morbidity

BACKGROUND

The prevalence and mean provocative dose of oral aspirin (MPDA) triggering respiratory reactions in people with asthma have been inconsistently reported, and the relationship between NSAID-exacerbated respiratory disease (NERD) and asthma morbidity was less well quantified.

METHODS

A systematic review was performed by identifying studies diagnosing NERD using blinded, placebo-controlled oral provocation challenge tests (OPCTs) or by self-reported history in people with asthma. Data were extracted, and effect estimates for changes in respiratory function, MPDA and asthma morbidity were pooled using random-effects meta-analysis.

RESULTS

The prevalence of NERD in adults with asthma was 9.0% (95% CI 6-12%) using OPCTs and 9.9% (95% CI 9.4-10.5%) using self-reported history from questionnaires. The MPDA in adults with NERD was 85.8 mg (95% CI 73.9-97.6). In people with NERD, the risk of: uncontrolled asthma was increased twofold (RR 1.96 (95% CI 1.25-3.07)); severe asthma and asthma attacks was increased by 60% (RR 1.58 (95% CI 1.15-2.16) and RR 1.59 (95% CI 1.21-2.09), respectively); emergency room visits was increased by 80% (RR 1.79 (95% CI 1.29-2.49)); and asthma hospitalization was increased by 40% (RR 1.37 (95% CI 1.12-1.67)) compared to people with NSAID-tolerant asthma.

CONCLUSIONS

Respiratory reactions triggered by oral aspirin in people with asthma are relatively common. At the population level, the prevalence of NERD was similar when measured using appropriately conducted OPCTs or by self-reported history. On average, respiratory reactions were triggered by clinically relevant doses of oral aspirin. Asthma morbidity was significantly increased in people with NERD who potentially require more intensive monitoring and follow-up.

Respiratory symptoms in patients with inflammatory bowel disease and the impact of dietary salicylates

BACKGROUND

Respiratory symptoms are over-represented in inflammatory bowel disease. There are similarities between the epidemiology of inflammatory bowel disease and that of respiratory conditions for which an adverse influence of salicylate has been identified. Natural salicylates exist within our diet.

AIMS

To determine whether a lower intake of dietary salicylates is associated with less active inflammatory bowel disease and fewer concurrent respiratory symptoms.

PATIENTS AND METHODS

Respiratory status, inflammatory bowel disease activity, quality of life, and dietary habits were established in 73 patients with Crohn's disease and 69 with ulcerative colitis, using a self-administered questionnaire and peak expiratory flow rate readings. Harvey-Bradshaw and Simple Birmingham/Royal Free Colitis indices, an internally validated respiratory score, and estimated weekly dietary salicylate intake, were calculated for each patient.

RESULTS

There was at least one respiratory symptom in 63.4% of patients. The commonest underlying respiratory diagnosis was asthma. Respiratory impairment was similar in ulcerative colitis and Crohn's disease; 56.3% of Crohn's disease patients with an active respiratory diagnosis had other extra-intestinal manifestations. The dietary salicylate intake was independent of respiratory status, but inversely correlated with ulcerative colitis activity (dietary salicylate intake 37.0mg versus 21.4mg for low and higher Simple Birmingham/Royal Free Colitis index, respectively; p<0.02). A similar association was not seen in Crohn's disease.

CONCLUSIONS

Respiratory impairment is common in inflammatory bowel disease. Higher intake of dietary salicylates is associated with less active colitis and possibly causally so.

Natural history and clinical features of aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a clinical syndrome characterized by chronic rhinosinusitis, nasal polyposis, asthma and precipitation of asthma, and rhinitis attacks after ingestion of aspirin (ASA) and most other nonsteroidal antiinflammatory drugs (NSAIDs). Although precipitation of asthma attacks by ingestion of ASA and other NSAIDs is considered a hallmark of the syndrome, the respiratory mucosal inflammatory disease process begins and continues in the absence of ongoing or even intermittent exposure to ASA or NSAIDs. The typical patient with AERD is an adult who develops refractory chronic rhinitis in the third or fourth decade of life. The chronic rhinitis evolves into chronic eosinophilic rhinosinusitis with associated nasal polyposis. Anosmia appears in most patients. CT of the sinuses most often demonstrates pansinusitis and patients often undergo multiple sinus operations resulting in only limited temporary benefit. During the evolution of the sinus disease persistent asthma develops. Finally, if patients are exposed to ASA or NSAIDs acute respiratory reactions begin to occur. Despite subsequent avoidance of ASA and other NSAIDs, the respiratory mucosal inflammatory disease persists, often requiring systemic corticosteroids for control of both upper- and lower-respiratory tract symptoms. Adequate control of asthma can often only be accomplished with the simultaneous control of the associated rhinosinusitis. With few exceptions, once AERD develops it remains for the remainder of the patient s life.

Aspirin and salicylates inhibit the IL-4- and IL-13-induced activation of STAT6

Allergic diseases, including asthma, represent a major threat to human health. Over the three last decades, their incidence has risen in western countries. Aspirin treatment has been shown to improve allergic diseases, especially asthma, and the decreased use of aspirin has been hypothesized to contribute to the increase in childhood asthma. Because salicylate compounds suppress a number of enzymatic activities, and signaling through IL-4R participates in the development of allergic responses, we tested the effect of salicylates on IL-4 signal transduction. We found that treatment of cell lines and primary cells with aspirin and salicylates, but not acetaminophen, inhibited the activation of STAT6 by IL-4 and IL-13. This effect correlated with the inhibition of IL-4-induced CD23 expression. Although salicylates inhibited the in vivo activation of Janus kinases, their kinase activity was not affected in vitro by salicylates, suggesting that other kinases were involved in IL-4-induced STAT6 activation. Furthermore, we found that an Src kinase was involved in STAT6 activation because 1) Src kinase activity was induced by IL-4, 2) Src kinase activity, but not Janus kinase, was inhibited by salicylates in vitro, 3) cells expressing viral Src had constitutive STAT6 phosphorylation, and 4) cells lacking Src showed low STAT6 phosphorylation in response to IL-4. Because STAT6 activation by IL-4 and IL-13 participates in the development of allergic diseases, our results provide a mechanism to explain the beneficial effects of aspirin and salicylate treatment of these diseases.