Immune thrombocytopenia in patients with connective tissue disease.

Immune thrombocytopenia (ITP) is a secondary autoimmune complication that can develop in patients with connective tissue diseases (CTDs). Its pathogenesis involves autoantibody-mediated platelet destruction and immune complex deposition, constituting a distinct clinical manifestation of CTD-related autoimmune abnormalities in the hematologic system. Among the subtypes of CTD-related immune thrombocytopenia (CTD-ITP), systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) are the most prevalent. CTD-ITP occurs within the unique clinical context of being a secondary condition to systemic diseases such as SLE or primary pSS, resulting in more complex clinical management and an increased risk of adverse outcomes. At present, no disease-specific treatment guidelines exist for CTD-ITP, and clinical management is largely based on therapeutic strategies established for primary ITP. However, conventional therapies, including glucocorticoids, often fail to achieve durable clinical remission, and prolonged use is associated with serious adverse effects. In recent years, the introduction of targeted agents such as thrombopoietin receptor agonists (TPO-RAs) and rituximab has markedly improved treatment response rates in CTD-ITP. Meanwhile, emerging targeted therapies, such as spleen tyrosine kinase (Syk) and Bruton's tyrosine kinase (BTK) inhibitors, as well as neonatal Fc receptor (FcRn) inhibitors, have shown considerable clinical promise. This narrative review, based on recent literature, focuses on SLE-ITP and pSS-ITP, summarizing their clinical heterogeneity, disease-specific pathophysiological mechanisms, and recent therapeutic advances. The objective is to provide evidence-based guidance for the personalized management of CTD-ITP.