[Aspirin hypersensitivity: characteristics and diagnostic approach]

Validation of an HPLC Assay Method for Routine QC Testing and Stability Study of Compounded Low-Dose Capsules of Acetylsalicylic Acid

Background

The intolerance to Acetylsalicylic Acid (ASA) can be detected by conducting oral provocation testing (OPT), which is to gradually introduce low doses of ASA. To perform this test, hospital pharmacies compound small batches of different low-dosage ASA capsules. This work aims to validate a method for fast HPLC-UV assay that allows routine quality control and physicochemical stability studies of capsules.

Methods

The chromatographic separation is performed using a C18 column Kinetex (100 A, 50×4.6 mm, 2.6 µm) equipped with a precolumn C18. Separation is achieved using a mobile phase composed of water-acetonitrile-orthophosphoric acid (68:32:0.2 v/v/v) at a flow rate of 0.8 mL/min and UV detection at 237 nm.

Results

Validation shows that the method was suitable for routine analysis and could be used to perform stability studies.

Conclusions

The 5, 25, 100 and 250 mg dosed capsules show acceptable stability over 12 months, while the 1 mg dosed capsule show an unacceptable degradation of more than 15 % after 3 months. Therefore, hospital pharmacy can plan the manufacture of capsules and anticipate the requests of doctors.

[The usefulness of nasal provocation tests for respiratory physicians]

Rhinitis and asthma are common diseases that are strongly linked from both the epidemiological and patho-physiological point of view. A precise aetiological diagnosis is required in order to optimize treatment. Nasal provocation tests (NPT) determine precisely the role of the allergen in the initiation of the symptoms of rhinitis particularly when the history does not produce convincing evidence of the clinical relevance of an allergen. It may also have important consequences for the choice of an allergenic immunotherapy. NPT are not standardized but simple methods based on international recommendations provide us with good diagnostic accuracy. In this paper, we will discuss the practical aspects of NPT as well as the clinical or research situations where they may be useful for the respiratory physician.

Urinary Leukotriene E4 to Determine Aspirin Intolerance in Asthma: A Systematic Review and Meta-Analysis

BACKGROUND

Urinary leukotriene E4 (ULTE4) may be a biomarker that distinguishes aspirin-intolerant asthma from other asthma subtypes.

OBJECTIVE

To estimate the diagnostic testing accuracy of ULTE4 as a marker of aspirin intolerance in patients with asthma using previously published studies.

METHODS

We identified relevant clinical studies from a systematic review of English and non-English articles using MEDLINE, EMBASE, and CENTRAL (inception to February 10, 2015). Articles were screened at the abstract and full-text level by 2 independent reviewers. We included previously published studies that analyzed ULTE4 in human subjects with asthma characterized as having or not having aspirin intolerance on the basis of a specified definition: convincing history of aspirin intolerance, positive aspirin challenge, or both as the criterion standard. Individual-level data points from all included studies were obtained and analyzed.

RESULTS

The search strategy identified 867 potential articles, of which 86 were reviewed at the full-text level and 10 met criteria for inclusion. The sensitivity, specificity, positive predictive value, and negative predictive values of ULTE4 to determine aspirin intolerance in subjects with asthma were 0.55, 0.82, 0.75, and 0.66 (Amersham-enzyme immunoassay); 0.76, 0.77, 0.70, and 0.78 (Cayman-enzyme immunoassay); 0.70, 0.81, 0.86, and 0.79 (mass spectrometry); and 0.81,0.79, 0.65, and 0.88 (radioimmunoassay) at optimal thresholds of 192, 510, 167 to 173, and 66 to 69 pg/mg Cr, respectively. The diagnostic odds ratio for each methodology was 6.0, 11.9, 10.5, and 19.1, respectively.

CONCLUSIONS

ULTE4 is a marker for aspirin-intolerant asthma and could potentially be used as a clinical test to identify the risk of aspirin intolerance in subjects with asthma.