The registry of the German Network for Systemic Scleroderma: frequency of disease subsets and patterns of organ involvement

Objective. Systemic sclerosis (SSc) is a rare, heterogeneous disease, which affects different organs and therefore requires interdisciplinary diagnostic and therapeutic management. To improve the detection and follow-up of patients presenting with different disease manifestations, an interdisciplinary registry was founded with contributions from different subspecialties involved in the care of patients with SSc. Methods. A questionnaire was developed to collect a core set of clinical data to determine the current disease status. Patients were grouped into five descriptive disease subsets, i.e. lcSSc, dcSSc, SSc sine scleroderma, overlap-syndrome and UCTD with scleroderma features. Results. Of the 1483 patients, 45.5 of patients had lcSSc and 32.7 dcSSc. Overlap syndrome was diagnosed in 10.9 of patients, while 8.8 had an undifferentiated form. SSc sine scleroderma was present in 1.5 of patients. Organ involvement was markedly different between subsets; pulmonary fibrosis for instance was significantly more frequent in dcSSc (56.1) than in overlap syndrome (30.6) or lcSSc (20.8). Pulmonary hypertension was more common in dcSSc (18.5) compared with lcSSc (14.9), overlap syndrome (8.2) and undifferentiated disease (4.1). Musculoskeletal involvement was typical for overlap syndromes (67.6). A family history of rheumatic disease was reported in 17.2 of patients and was associated with early disease onset (P < 0.005). Conclusion. In this nationwide register, a descriptive classification of patients with disease manifestations characteristic of SSc in five groups allows to include a broader spectrum of patients with features of SSc.