About Systemic sclerosis
Systemic sclerosis (SSc) is a prototypic disease characterized by autoimmunity, fibrosis and vasculopathy. It is one of the most disabling and disfiguring diseases among the systemic diseases and compared to other rheumatic diseases, SSc is associated with the highest loss of life expectancy amounting to more than 30 years in female patients and 16 years im male patients. With a prevalence of approximately 1 in 2,000 of the general population, SSc is an orphan, multi-organ disease affecting the connective tissue of the skin and all internal organs, driven by alterations of both the immune system and the microvasculature. Among the different immune-mediated rheumatic diseases, SSc is one of the most incapacitating and life-threatening diseases for the affected patients. Aside from the clinically prominent thickening of the skin and the development of digital ulcers (DU), the progressive deterioration of internal organs, particularly the lungs, heart, kidneys and gastrointestinal tract, as well as the frequently underestimated polyarthritis result in a high morbidity and mortality ranging up to 30% over 5 years. The juvenile onset form is rarer than the adult onset form and approximately 5 - 10% of SSc patients develop the disease in childhood, usually around the age of 9 years.
In rare diseases, up to ~90% drug use is off-label, due to lack of adequate clinical research data. This is particularly true for SSc and neither truly disease-modifying drugs nor orphan drugs are available at present.. Due to the severity of this disease, several immunomodulating drugs such as cyclophosphamide, methotrexate, azathioprine etc. are used off-label in SSc but their use is mostly based on case reports or small trials, which usually do not meet the standards of controlled clinical trials, as is frequently the problem in rare diseases. Thus, it has only been possible to establish preliminary guidelines for the management of SSc so far.