Brain magnetic resonance imaging in adults with asthma

In individuals with asthma, potential central nervous system changes can occur as a consequence of their asthma or therapy. Clinical trials of anti-asthmatic therapies might benefit from using magnetic resonance imaging (MRI) to assess potential brain abnormalities.

As part of the clinical safety evaluation of a monoclonal antibody directed against interleukin-9 for the treatment of asthma, we assessed whether brain MRI is an appropriate screening tool to evaluate potential neurotoxicity.

Brain MRIs were conducted as part of a prespecified safety evaluation in adults aged 19 to 47 years with mild to moderate asthma treated with either the investigational monoclonal antibody or placebo. An independent neuroradiologist performed a blinded review of brain MRI scans obtained at baseline before dosing and day 28 after dosing from two separate clinical studies.

Fifteen brain MRI abnormalities were noted in 13 of 21 subjects with asthma (62%). Nonspecific deep white matter hyperintensities (24%), perivascular space (24%), and abnormal anatomic findings (14%) were noted either at baseline or follow-up. Only 8 of 21 subjects (38%) with asthma had normal brain MRI results.

The high rate of incidental brain MRI findings suggests that these abnormalities are relatively common in patients with asthma. Thus, brain MRI may not be an appropriate screening tool to evaluate potential neurotoxicity in subjects during routine clinical studies without a baseline examination. Due to artifacts simulating lesions, an experienced radiologist should interpret all brain MRI results.