Skin thickness regression linked to better lung health in dcSSc
Study points to skin improvement as indicator of better outcome
Reduction in skin thickness may indicate better lung health and survival outcomes in people with diffuse cutaneous systemic sclerosis (dcSSc), according to an analysis of patients from the European Scleroderma Trials and Research (EUSTAR) registry.
“Skin regressive patients have a lower probability of lung progression, better survival,” the investigators wrote. Skin improvement may be used as an indicator to predict long-term outcomes in dcSSc patients, they added.
The study, “Does regression of skin thickening predict improvement of internal organ involvement and survival in patients with diffuse cutaneous systemic sclerosis? A EUSTAR analysis,” was published in Arthritis Research & Therapy.
Systemic sclerosis, also known as scleroderma, is an autoimmune disease in which the body’s immune system attacks its own tissues. It can lead to scarring and thickening of the skin as well as damage to internal organs such as the lungs, heart, kidneys, and digestive system. dcSSc is characterized by a higher risk of internal organ damage early in the disease.
The extent of skin thickening is routinely measured using the modified Rodnan Skin Score (mRSS), which assesses skin fibrosis (hardening and scarring) in various areas of the body. Higher scores indicate more severe skin involvement. Changes in the mRSS over time can provide insights into disease progression. “Discovering associations between regression of mRSS and consecutive changes in […] organ function would therefore be practically relevant,” the researchers wrote.
Patients grouped by skin thickening
Their study analyzed data from 1,257 patients with dcSSc, grouping them based on changes in their skin thickening over about one year. Patients whose mRSS scores decreased significantly (more than 5% and up to 25% in the mRSS score) were classified as having regressive skin thickening. Those with no significant change were considered stable, while participants whose skin thickened further (up to 25%) were categorized as progressive. Of the participants, 22.4% showed regressive skin thickening, 70.2% were stable, and 7.3% were progressive.
Results showed that those with regressive skin thickening were less likely to experience declines in lung function than those in the progressive group. Lung function was tested using measures such as the forced vital capacity, which indicates the maximum amount of air a person can forcefully exhale after a deep breath.
Survival rates were better among participants with regressive changes in skin thickness. During the follow-up period, 14.1% of patients with progressive skin thickening died, compared with 5.7% of those with regressive skin changes. Significant differences in the probability of death due to any cause were found when adjusting the analysis for mRSS at study start, use of immunosuppressants and disease duration.
“This allows individual stratification of patients into lower risk groups and may support decision making to initiate or continue with therapies,” the scientists wrote. They suggested that these insights could improve the design of clinical trials.
“For example, patients with regression of skin fibrosis in the year before inclusion in a clinical trial targeting SSc-ILD should be avoided based on our data, as a lower number of progressive ILD is expected during the study,” the researchers wrote. ILD refers to interstitial lung disease, a group of disorders marked by inflammation and scar tissue buildup in the lungs.
The study found no significant association between changes in skin thickness and the progression of other organ complications, such as intestinal involvement, cardiac problems, or new onset of scleroderma renal crisis, which is marked by a rapid decline in kidney function and an abrupt rise in blood pressure.
While the large number of patients in the study allowed comparisons to be made, there were also limitations, the researchers wrote. Among these is a lack of data on co-existent lung diseases, “which could possibly influence our lung outcomes,” they wrote. The impact of treatment also could not be assessed, they noted.
About the Author
