Primary Sjögren's syndrome (pSS) can affect various organs, sometimes leads to life-threatening conditions and is always responsible for a decreased quality of life. Its evolution is chronic, with flares and relapses, and the need for reliable biomarkers to be carried out routinely is major in patients' follow-up. Because of the existence of autoreactive immunoglobulins E (IgE) in autoimmune diseases, the recently described role for anti-Ro/SSA antibodies in inducing interferon alpha (IFNα) signaling and the specific pharmacologic properties of IgE, anti-Ro/SSA IgE should be an interesting biomarker to determine pSS's activity. The aim of the study is to evaluate whether the proportion of anti-Ro/SSA IgE positive patients is higher in patients with active disease (i.e. Eular Sjögren Syndrome Disease Activity Index≥ 5). All consecutive patients with pSS (new or already known diagnosis) will be included, Anti-Ro/SSA IgE titers will be determined, the disease's features will be collected (including Eular Sjögren Syndrome Disease Activity Index/Eular Sjogren's Syndrome Patient Reported Index).