ILD frequency, cardiac symptoms distinguish diffuse, limited juvenile scleroderma subtypes
The classically defined diffuse subtype of juvenile systemic sclerosis demonstrates more globally severe disease and higher interstitial lung disease frequency, whereas the limited cutaneous subtype has more frequent cardiac symptoms, data shows.
“Only a few publications are available summarizing clinical variables in larger cohorts of [juvenile systemic sclerosis (jSSc)] (n > 50),” Ivan Foeldvari, MD, of the Hamburg Centre for Pediatric and Adolescent Rheumatology and the Schön Klinik Hamburg Eilbek, in Germany, and colleagues wrote. “More recently, there are reports from two prospective registries for jSSc patients: The Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry and the juvenile systemic sclerosis inception cohort (jSScC), both with original description of baseline characteristics of n=64 and n=80 jSSc subjects, respectively.
“One limitation of the recent CARRA cohort was the lack of designation, and therefore description, of limited vs. diffuse cutaneous clinical phenotypes in jSSc. Overcoming this limitation in our jSScC cohort, organ systems manifestations were extensively captured and compared between limited and diffuse cutaneous subtypes since the extent of skin involvement has been universally accepted to categorize patients with adult onset SSc and has been strongly linked to certain organ manifestations, augmenting patient care guidance.”
To analyze the baseline clinical characteristics of juvenile SSc in patients enrolled in the international jSScC and compare them between those with classically defined diffuse and limited cutaneous subtypes, Foeldvari and colleagues conducted a cross-sectional study of visit data. According to the researchers, jSScC is an international prospective observational cohort study with participants from 25 centers across Europe, five from Asia, six from North America and six from South America, representing a total of 42 academic institutions. In all, the cohort included 150 patients with juvenile SSc at data extraction.
For their own study, Foeldvari and colleagues examined demographic information, organ system evaluations, treatments and patient- and physician-reported outcomes. The researchers used Chi‐square and Mann Whitney U‐tests to compare subtypes and patients with and without overlap features.
According to the researchers, 72% of the patients demonstrated the classically defined diffuse subtype, while 17% had overlap features. There were “significant differences” between the classically defined diffuse and limited cutaneous subtypes regarding the modified Rodnan Skin Score, the presence of Gottron’s papules, digital tip ulceration, 6-minute walk test, composite pulmonary and cardiac involvement, they wrote. Specifically, all, save for cardiac involvement, were more frequent in the classically defined diffuse group.
In addition, patients in the classically defined diffuse subtype demonstrated significantly worse scores for physician rated disease activity and damage. Meanwhile, a significantly higher occurrence of Gottron’s papules, musculoskeletal involvement and composite pulmonary involvement, and significantly lower frequency of Raynaud's phenomenon, were reported in patients with overlap features.
“Juvenile systemic sclerosis patients demonstrate significant differences between diffuse jSSc and limited jSSc subtype regarding frequency of skin, vascular, pulmonary and cardiac involvement,” Foeldvari told Healio Rheumatology. “Physician global assessment of disease activity and damage is higher in the dcjSSc group. We could show that jSSc patients with overlap features are not ‘protected’ from major internal organ involvement and have a higher frequency of lung disease compared to those without overlap features.
“This publication demonstrates that diffuse subset patients have more frequently interstitial lung disease, while those with limited subtype jSSc have more frequent cardiac involvement,” he added. “Those with overlap features had an unexpected higher frequency of interstitial lung disease. These data emphasize that it should be especially closely monitored for this organ involvement in the different subtypes. This paper shows the importance of creating a bigger cohort of jSSc patients, to be able to make a more defined conclusion. If you follow a jSSc patient, please include in the cohort by contacting firstname.lastname@example.org. Every patient counts for this kind of orphan disease.”