Alain Lescoat, MD, PhD

Credit: traccrcenter.medicine.umich.edu

Individuals with systemic sclerosis sine scleroderma (ssSSc) have higher survival rates versus those with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), according to new findings on this subgroup of systemic sclerosis patients.¹

These findings were the result of research into the main clinical features, manifestations, and survival rates of ssSSc as compared with lcSSc and dcSSc in the EUSTAR database. The investigators of this study note that there is little current information with large enough sample sizes on the natural history of skin manifestations and involvement in individuals with ssSSc.²

Consequently, the research was conducted by the investigators and it was authored by Alain Lescoat, MD, PhD, from the Department of Internal Medicine and Clinical Immunology at CHU Rennes of the University of Rennes in France.

“The present study aimed to characterize the main clinical features, with a specific focus on cutaneous manifestations, of patients with ssSSc in comparison with lcSSc and dcSSc within the international EUSTAR (European Scleroderma Trials and Research) database,” Lescoat and colleagues wrote.

Background and Findings

The investigators conducted a longitudinal observational cohort study in which they utilized data drawn from the international EUSTAR database. The database prospectively gathers data from centers which participate, using a data set that is predetermined.

The research team’s study included all patients who met the classification criteria for SSc and were evaluated using the modified Rodnan Skin score (mRSS) at the beginning of the study, with at least one follow-up visit.

For the purpose of this study, a subgroup of patients with ssSSc was identified, characterized by the absence of skin fibrosis (mRSS = 0) and no sclerodactyly throughout all available visits. The data extraction was carried out in November of 2020, and data analysis was conducted between April of 2021 and April of 2023.

The study aimed to compare the survival rates and clinical attributes of patients diagnosed with ssSSc, dcSSc, and lcSSc, with a focus on matching individuals based on disease duration at their most recent available visit. Some of the attributes of specific skin manifestations included the onset of puffy fingers, skin fibrosis, digital ulcers, and telangiectasias.

Overall mortality rates in those diagnosed with ssSSc were assessed and compared with patients diagnosed with dcSSc and lcSSc. The assessment was conducted until the most recent visit recorded, but specific causes of death related to systemic sclerosis were not accessible in the EUSTAR database and were therefore not investigated.

In a study involving 4,263 patients who met the inclusion criteria, 8.8% were found by the investigators to have been diagnosed with ssSSc (mean age: 55.3 years, 91.8% female). Comparisons were made by the team between those with ssSSc, lcSSc, and dcSSc of similar disease duration.

The ssSSc group showed a lower prevalence of previous or current digital ulcers (28.2% vs. 53.1% in lcSSc and 68.3% in dcSSc), as well as puffy fingers (63.8% vs. 82.4% in lcSSc and 87.6% in dcSSc). However, the prevalence of interstitial lung disease was found to have been similar between ssSSc and lcSSc (49.8% vs. 57.1%) but significantly higher in dcSSc (75.0%).

Skin telangiectasias were linked to diastolic dysfunction in ssSSc patients, while the presence of anti-Scl-70 antibodies was identified as an independent factor for the onset of skin fibrosis in ssSSc. The survival rate after up to 15 years of follow-up was higher in patients with ssSSc (92.4%) compared to lcSSc (69.4%) and dcSSc (55.5%).

“Dermatologists should be aware of the prevalence of these visceral associations in ssSSc and their associations with cutaneous findings,” they wrote. “Even in patients without skin fibrosis, the assessment of other dermatological features, such as skin telangiectasias, is of utmost importance, as such nonfibrotic manifestations were also associated with visceral manifestations, such as diastolic dysfunction.”

References

1. ^{Lescoat A, Huang S, Carreira PE, et al. Cutaneous Manifestations, Clinical Characteristics, and Prognosis of Patients With Systemic Sclerosis Sine Scleroderma: Data From the International EUSTAR Database. JAMA Dermatol. Published online June 28, 2023. doi:10.1001/jamadermatol.2023.1729.}
2. ^{Diab S, Dostrovsky N, Hudson M, et al; Canadian Scleroderma Research Group. Systemic sclerosis sine scleroderma: a multicenter study of 1417 subjects. J Rheumatol. 2014;41(11):2179-2185. doi:10.3899/jrheum.140236.}