Introduction: Connective Tissue Disease Related Interstitial Lung Disease (CTD-ILD) is often treated with immunosuppressant medications; common among these is Mycophenolate Mofetil (MMF). We hypothesized that co-treatment with corticosteroids would impact disease progression.
Methods: We examined a consecutive cohort of CTD-ILD patients followed at Temple University Hospital in Philadelphia, PA since 2015 who had pulmonary function tests (PFTs) performed by American Thoracic Society (ATS)/European Respiratory Society (ERS) Criteria at least one year apart. All patients were treated for CTD-ILD with MMF used either as sole therapy or as combination therapy with prednisone. Univariate logistic analyses were performed revealing the odds ratio (OR) for improvement or worsening of several PFT values (including forced vital capacity (FVC), diffusion capacity of carbon monoxide (DLCO), and six-minute walk (6MW)) greater than the minimal clinically important difference (MCID) for each value.
Results: We included 103 patients (74 women) with an average age of 60 ± 11 years, 49% of our cohort were current or former smokers, and mean BMI was 29 ± 7 kg/m2. Patients were observed on treatment for an average of 23 months. CTD distribution included 25% mixed connective tissue disease (MCTD), 24% systemic sclerosis (SSc), 17% rheumatoid arthritis (RA), 14% systemic lupus erythematosus (SLE), 10% other idiopathic inflammatory myositis (IIM) syndromes, 7% Antisynthetase Syndrome, 5% Sjӧgren’s syndrome. Non-specific interstitial pneumonia (NSIP) was the majority (45%) ILD pattern noted, Usual Interstitial Pneumonia (UIP) 35%, and other types were less prevalent (20%). The majority of patients received corticosteroids as co-treatment with MMF (75 patients (72%)) with a mean daily dose of 15 ± 16 mg of prednisone. Mean daily MMF dose was 1144 ± 675 mg. Glucocorticoid treatment was not associated with significant improvements in PFT values, including FVC, DLCO, and 6MW distance walked.
Conclusion: In this small cohort, patients with CTD-ILD receiving MMF did not demonstrate improved lung function when receiving co-treatment with corticosteroids, but larger prospective studies are needed to better elucidate the effect of corticosteroids on this vulnerable group of patients.