Characteristics and treatment responses of immune thrombocytopenia in patients with primary Sjögren syndrome

This study aims to describe patients' characteristics and treatment responses with primary Sjögren's syndrome (pSS) who experience immune thrombocytopenia (ITP) and ITP with clinical significance (ITPCS). A retrospective study was conducted involving 164 patients diagnosed with pSS-related ITP after excluding secondary ITP. Patients were categorized into subgroups based on the risk of bleeding: major bleeding event (MBG), non-hemorrhagic group (NHG), and hematological involvement-only SS group (HOSG). 57 (34.8%) were diagnosed with ITP simultaneously with pSS, while 60 (36.6%) were diagnosed with ITP before pSS. ITP patients exhibited a high prevalence of interstitial lung disease (19.5%), and an up to 96.3% positive presence of anti-SSA/Ro-52 antibody. ITPCS was identified in 58.5% of patients, with 22.0% experiencing high-risk hemorrhagic events. A median (range) of 2 (1, 3) treatment lines for maintenance therapies were administered. Corticosteroids and hydroxychloroquine (HCQ) led to an ITP response in 76.1% of patients. Ciclosporin A (CsA) and other medicines contributed to a 76.6% response. The MBG, NHG, and HOSG groups consisted of 36 (22.0%), 68 (41.5%) and 53 (32.3%) patients, respectively. Notably, patients of MBG were more frequently diagnosed before SS onset (p = 0.035). They required more treatment lines (p = 0.001) with a lower risk of relapse (p < 0.001), which is confirmed in patients with only hematological involvement (HOSG group). Patients with pSS-related ITP face an increased risk of bleeding, particularly in the MBG group, which necessitates more extensive treatment. Heterogeneous treatment regimens were observed for pSS-related ITP, and combinations involving corticosteroids, HCQ, and/or CsA appear viable options.