In addition to known risk factors, early reductions in lung function and diffusing capacity increased mortality risk in patients with systemic sclerosis and comorbid interstitial lung disease over 2 years in an analysis of data from the Scleroderma Lung Studies I and II.
Dr. Elizabeth Volkmann
First author Elizabeth R. Volkmann, MD, of the University of California, Los Angeles, and her colleagues also reported that although early treatment with cyclophosphamide or mycophenolate mofetil in these studies led to shorter-term improvement in surrogate measures of outcomes for systemic sclerosis and comorbid interstitial lung disease (SSc-ILD), either medication might not improve long-term outcomes. The findings were reported in the Annals of the Rheumatic Diseases.
The investigators identified specific factors linked to an increased risk of death over a median follow-up of 8 years in 158 systemic sclerosis-interstitial lung disease patients in the Scleroderma Lung Study I and median follow-up of 3.6 years in 142 patients in Scleroderma Lung Study II, both of which were randomized, controlled trials.
After follow-up was complete, 42% of participants in Scleroderma Lung Study I and 21% of participants in Scleroderma Lung Study II died, with the most common cause of death being complications related to systemic sclerosis. In addition, no statistical difference was seen in time to death between the intervention arms of both trials.
In building a risk prediction model based on findings from both trials, the investigators confirmed several known mortality risk predictors in systemic sclerosis, including increased age and baseline skin score, but also found that changes in forced vital capacity and diffusing capacity for carbon monoxide over 2 years were separately linked with a greater risk of death.
“These findings suggest that short-term changes in surrogate measures of systemic sclerosis-interstitial lung disease progression may have important effects on long-term outcomes,” the researchers wrote.
The researchers acknowledged the results emphasize the need to determine optimal length of treatment in patients with systemic sclerosis and comorbid interstitial lung disease.
“Systemic sclerosis providers should closely monitor lung function when interstitial lung disease is present to accurately identify declines in lung function and promptly intervene to improve patient outcomes,” the researchers concluded.
The study was funded by the National Institutes of Health and the Scleroderma Foundation. The authors reported no conflicts of interest.
SOURCE: Volkmann ER et al. Ann Rheum Dis. 2018 Nov 8. doi: 10.1136/annrheumdis-2018-213708.