The usefulness of the mannitol challenge test for asthma

Abstract

The mannitol test was developed as an easy-to-use, safe, standardized bronchial challenge test for diagnosing asthma in a wide range of clinical settings. The mannitol test has a moderate sensitivity and will only detect approximately 60% of asthma cases. Hence, a negative mannitol test cannot be used to rule out asthma. The advantage of the mannitol test is a high specificity. In an individual with symptoms suggestive of asthma, a positive test indicates a high likelihood of asthma with ongoing airway inflammation and seems useful for detecting asthma requiring regular anti-inflammatory therapy. In this review, the current knowledge on the usefulness of the mannitol in a clinical setting as well as in clinical trials is presented and outstanding questions on the usefulness of the test are discussed.

Keywords::

• airway hyperresponsiveness
• airway inflammation
• asthma
• bronchial challenge
• diagnosis
• management
• mannitol

Financial & competing interests disclosure

C Porsbjerg and V Backer have received honorarium within the past 5 years from Pharmaxis and Nigaard for presentations on the mannitol test. V Backer has received unrestricted research grants from Pharmaxis. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• • The mannitol test was developed as a simple, user-friendly bronchial challenge test kit that requires only the use of a spirometer.

• • The mannitol test is a safe bronchial challenge test that may be used in a wide range of settings.

• • The standardized test protocol ensures comparability of test results within and between patients.

• • The mannitol test is thought to act through the release of bronchoconstricting mediators from inflammatory cells in the airways, and hence, the response to mannitol may reflect AIR that is related to active airway inflammation.

• • The mannitol test has a moderate sensitivity for detecting asthma, but a high specificity, and a positive test confirms a suspicion of asthma.

• • A positive response to the mannitol test indicates a lack of inflammation control in asthma.

• • The EMEA guidelines on approval of medicinal products in Europe recommend the use of the mannitol test as an objective marker of asthma control in clinical trials of anti-asthmatic medications.

• • Further studies are needed to elucidate the optimal use of the mannitol test in conjunction with other commonly used diagnostic tests for asthma, in an overall diagnostic strategy for asthma.

• • Finally, there is a need for further studies on the mannitol test as a tool for guiding asthma management.