This study aims to measure a blood protein called fibroblast activation protein (FAP), which is linked to tissue scarring and inflammation. A small blood sample will be taken from participants (RA , SSc patients and healthy people ), and the FAP level will be measured and compared with routine clinical examinations, imaging studies, and lung function tests.
The purpose of this study is to improve understanding of disease activity and lung involvement in these conditions and to explore whether FAP could be useful as a blood marker for future patients. Participation in this study will not change the participant's usual medical care.
Age ≥18 years. Confirmed diagnosis of RA (ACR/EULAR) or SSc (ACR/EULAR).
Ability and willingness to provide informed consent. Cooperative patient able to answer questions.
Patients under 18 years' old
Active cancer or history of cancer within 5 years.
Other major fibrotic systemic disease that could confound circulating FAP levels.
Acute infection at time of sampling.