Ab1701 Is There a Difference in the Number of Involved Organ Systems Between Juvenile Diffuse and Limited Subtype Systemic Sclerosis Patients?

Background: Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of 3 in 1 000 000 children. In adult patients diffuse subtype is associated with higher number of organ systems involvement. In a CARRA North American study, it was noted that 38% of jSSc patients had four or more organ systems involved. This topic has not yet been assessed in a large juvenile scleroderma inception cohort (jSSc) cohort. Objectives: To assess the number of organ systems involved in the diffuse and limited jSSc patients at the time of inclusion in the cohort. Methods: The jSSc is a prospective cohort including patients, who fulfill the adult SSc criteria1, with first non-Raynaud symptom before the age of 16 years and under 18 years of age at the time of inclusion. We reviewed the number of organ systems involved at the time of inclusion into the cohort. The categorization of the organ system involvement was skin, vascular, muscular, articular, pulmonary, cardiac, gastrointestinal, renal and nervous system. We compared the number of involved systems between diffuse and limited jSSc subtype. Results: Until 1st of December 2023, 253 patients were enrolled and 177 of them had diffuse subtype. The median age at the onset of Raynaud´s was 10.4 years. The median age of the first non-Raynaud organ involvement was 10.9 years. The median disease duration was 2.5 years. The distribution of the cumulative organ involvement in the whole group and in the diffuse and limited subtype can be seen in Table 1. Similar to the CARRA study, a large number of jSSc patient had 4 or more organ systems involved, almost half of the cohort (46%). There was no significant difference between the cumulative number of organ systems involved between the SSc subtypes in the Inception cohort. Conclusion: In this largest jSSc cohort in the world, approximately half the enrolled children have 4 or more organ systems involved, which highlights the overall severity of the disease. There was no significant difference in jSSc children skin subtypes, lcSSc or dcSSc regarding, the cumulative number of organ systems involved, although as shown in our publications2 the diffuse subtype presented more severe disease. This project was supported by an unrestricted grant from "Joachim Herz Stiftung" REFERENCES: 1 van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American college of rheumatology/European league against rheumatism collaborative initiative. Ann Rheum Dis. 2013 Nov;72(11):1747-55. 2 Foeldvari I, Klotsche J, Kasapcopur O, et al. Differences Sustained Between Diffuse and Limited Forms of Juvenile Systemic Sclerosis in an Expanded International Cohort. Arthritis Care Res (Hoboken). 2022 Oct;74(10):1575-1584. Acknowledgements: NIL. Disclosure of Interests: None declared.