Elizabeth R. Volkmann
Among patients with interstitial lung disease related to systemic sclerosis, diminished forced vital capacity and a decline in the diffusing capacity for carbon monoxide through 2 years is a better predictor of mortality than the same data at baseline, according to findings published in the Annals of the Rheumatic Diseases.
“Interstitial lung disease is the leading cause of death in patients with systemic sclerosis,” Elizabeth R. Volkmann, MD, MS, of the University of California, Los Angeles, told Healio Rheumatology. “This was the first study to identify predictors of long-term survival in systemic sclerosis-related interstitial lung disease using data from two of the largest clinical trials published in systemic sclerosis: The Scleroderma Lung Studies 1 and 2.”
To analyze survival and identify its predictors among patients with systemic sclerosis-interstitial lung disease (SSc-ILD), Volkmann and colleagues conducted a long-term follow-up to the previous Scleroderma Lung Studies (SLS) 1 and 2. All participants enrolled in the two studies — which included adult patients with SSc with suspected ILD with a disease duration of no more than 7 years — were eligible for the follow-up.
Among patients with interstitial lung disease related to SSc, diminished forced vital capacity and a decline in the diffusing capacity for carbon monoxide through 2 years is a better predictor of mortality than the same data at baseline, according to findings.
In SLS 1, 158 patients were randomly assigned to receive 1 year of either oral cyclophosphamide or placebo. In SLS 2, 142 patients were randomly assigned to 1year of oral cyclophosphamide followed by 1year of placebo, or 2 years of mycophenolate mofetil. Using mortality data from these studies, Volkmann and colleagues using counting process Cox proportional hazard modelling to find variables associated with long-term death. The primary outcome was survival.
According to the researchers, 42% of patients in SLS 1 died after a median follow-up of 8 years. In cases in which the cause of death was known, it was most often attributable to SSc, the researchers wrote. There was no significant difference in the time to death between treatment arms in SLS 1 or 2. In SLS 1, a higher baseline skin score, older age and a decline in the forced vital capacity and the diffusing capacity for carbon monoxide during a 2-year period were independently associated with an increased risk for mortality. The Cox model used by the researchers found the same mortality predictor variables related to data in SLS 2.
“The results of this research may change how we manage patients with systemic sclerosis related interstitial lung disease in the future,” Volkmann said. “Patients with systemic sclerosis related interstitial lung disease who experience an early decline in lung function and have an increased risk of death may benefit from receiving a more aggressive treatment approach that could include escalation of immunosuppression, addition of anti-fibrotic therapy and/or evaluation for hematopoietic stem cell transplant. 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.” – by Jason Laday
Disclosure: Volkmann reports research support from the NIH. Please see the study for all other authors’ relevant financial disclosures.