CLINICAL CHARACTERISTICS OF JUVENILE ONSET SYSTEMIC SCLEROSIS PATIENTS FROM THE JUVENILE SCLERODERMA INCEPTION COHORT COMPARED TO ADULT AGE JUVENILE-ONSET PATIENTS FROM EUSTAR. ARE THESE DIFFERENCES SUGGESTING RISK FOR MORTALITY?

Background Juvenile systemic sclerosis (jSSc) is an orphan autoimmune disease with a prevalence of 3 in 1 000 000 children. Information on long-term development of organ involvement and clinical characteristics of jSSc patients in adulthood are lacking. It was believed that patients in adult cohorts may represent a survival biased population. Objectives To assess differences in clinical characteristics of jSSc-onset patients from the pediatric age group, with a mean disease duration of 3 years, compared to the adult age jSSc-onset group, with a mean disease duration of 18.5 years. Methods We extracted clinical data at time of inclusion into the cohorts from the Juvenile Scleroderma Inception Cohort (jSScC) and data from juvenile-onset adult SSc patients from the European Trials and Research Group (EUSTAR) cohort. We compared the clinical characteristics of the patients by descriptive statistics. Results We extracted data of 187 jSSc patients from the jSScC and 236 patients from EUSTAR. The mean age at time of assessment was 13.4 years old in the jSScC and 32.4 years old in EUSTAR. The mean disease duration since first non-Raynaud was 3.0 years in jSScC and 18.5 years in the EUSTAR (Table 1). We found significant differences between the cohorts. There were more female patients in EUSTAR (87.7% versus 80.2%, p=0.04). More patients had diffuse subtype in jSScC (72.2% versus 40%, p<0.001). The modified Rodnan skin score (mRSS) was significantly higher in jSScC (14.2 versus 12.1, p=0.02). Active digital ulceration occurred more often in EUSTAR (26.6%, versus 17.8% p=0.01), but history of active ulceration was more frequent in jSScC (54.1% versus 43%, p<0.001). Mean DLCO was lower in jSScC (75.4 versus 86.3, p<0.001). Intestinal involvement was significantly more common in jSSc (33.2% versus 23.8%, p=0.04). Esophageal involvement was more common in EUSTAR (63.7% versus 33.7%, p<0.001). (Table 1). Table 1. Clinical characteristics of juvenile onset SSc patients at time point of the inclusion into the juvenile scleroderma inception (jSScC) cohort and in the adult EUSTAR- cohort jSScC EUSTAR Cohort P value Number of patients 187 236 0.04 Age in years, mean (SD) 13.4 (3.6) 32.4 (15.4) Female patients, n (%) 150 (80.2%) 207 (87.7%) jSSC Subtype, n (%) diffuse 135 (72.2%) 87 (38.1%) <0.001 limited 52 (27.8%) 121 (53.3%) Age at Raynaud onset in years, mean (SD) 10.0 (3.9) 13.7 (9.1) Age at non-Raynaud onset in years, mean (SD) 10.3 (3.9) 11.7 (3.7) Duration since first Raynaud symptoms in years, mean (SD) 3.4 (2.7) 20.6 (15.9) Duration since first non-Raynaud symptoms in years, mean (SD) 3.0 (2.7) 18.5 (15.6) Raynaud´s, n (%) 170 (90.9%) 222 (94.9%) ANA positive, n (%) 166 (91.7%) 210 (92.9%) 0.99 Anti-Scl 70 positive, n (%) 62 (34.4%) 73 (33.3%) 0.68 Modified Rodnan Skin Score, mean (SD) 5% Data missing Modified Rodnan Skin Score, mean (SD) 14.2 (11.7) 12.1 (14.5) 0.02 Digital ulceration, n (%) At the time of inclusion 33 (17.8) 21 (26.6%) 0.01 In the past history 100 (54.1%) 34 (43%) <0.001 Telangiectasia 62 (37.4% ) 42 (53.2% ) 0.04 FVC, mean (SD) 84.1 (18.6) 84 (22.4) 0.96 DLCO, mean (SD) 75.4 (19.2) 86.3 (19.9) <0.001 Arterial hypertension, n (%) 10 (5.4%) 20 (8.5%) 0.26 Renal crisis, n (%) 0 3 (1.3%) 0.26 Esophageal involvement, n (%) 63 (33.7%) 149 (63.7%) <0.001 Intestinal involvement, n (%) 62 (33.2%) 56 (23.8%) 0.04 Articular involvement, n (%) 34 (18.3%) 27 (11.6%) 0.06 Muscular involvement, n (%) 31 (19.3%) 46 (19.8%) 0.45 Conclusion Patients with jSSc-onset who are currently adult age (defined as >18 years of age) are less frequently male and from the diffuse subset, have lower mRSS, less digital ulcers and intestinal involvement. This might represent a combination of both survival bias and/or be explained by the longer observation time with less active disease (i.e. natural progression decreased mRSS over time). Further long-term observational studies with jSSc patients are required to address this issue. Disclosure of Interests None declared