Background Methotrexate (MTX) immunosuppressive therapy is selectively used to assist with the reduction of the oral corticosteroid demand thereby decreasing the risk of potential side effects in individuals with steroid dependant asthma. Previous reported data has demonstrated similar significant reduction in corticosteroid load, asthma exacerbation and hospital admission rate. This study aims to compare similar variables collated from UK severe asthma specialist centres to further generate evidence for the continued use of MTX as an effective aid in the reduction of corticosteroid burden in a severe asthma cohort.

Methods A retrospective data collection was performed across two UK severe asthma centres with data from a third pending. Patients included had a confirmed diagnosis of severe asthma and had been treated with MTX for at least 12 months to allow sufficient analysis. Variables assessed included mean average daily corticosteroid dose, overall percentage reduction of corticosteroid, exacerbation frequency and acute admission events both twelve months prior to and post commencement of MTX therapy. Data collection was examined for each individual centre then combined and examined for consistency of results.

Results N = 29 (21/8) Average daily corticosteroid dose was reduced by 6 mg combined across both centres [p = 0.004] (6.4 mg/5 mg) a percentage of overall reduction of corticosteroid equated to 34.8% jointly across both centres and 39.3% and 30.0% individually. Exacerbation frequency decreased from 4.8 to 2.5 annually combined across both centres [p = 0.003] although conflict in result is identified as one centre reports a 1.0 increase in exacerbations compared to 3.4 decrease in the other centre. Combined admission decreased from 1.3 to 0.3 annually [p = 0.004] 1.1 and 0.4 decrease in each individual centre.

Conclusion When monitored and supervised in the correctly chosen severe asthma patient, MTX can significantly reduce the demand for corticosteroids and consequently reduce steroid related side effects, admission and exacerbation this has been demonstrated across two specialist centres with correlating data.