Inclusion Criteria:  Patient over 18 years old, and less than 85 years old. Patient with positive AAN (AAN ≥ 1/160) with the following specificity: anti-Scl70 or anti-centromere or anti-RNApolIII. Patient with RP reported by the subject and confirmed by the physician. Patient affiliated to a health insurance system. Patient who accepts to participate to the study and signs an inform consent form.  Exclusion Criteria:  Patient with an SSc diagnosis according to ACR/EULAR 2013 criteria. Patient with skin fibrosis at screening. Patient with antiplatelet treatment at screening. Patient with contraindications to clopidogrel. Patient treated by immunosuppressive agent at screening. Pregnant or breastfeeding women. Women of childbearing age refusing effective contraception method during the study. Incompetent adults (i.e. Individuals under the protection of a conservator)