Clinical characteristics of immune thrombocytopenia associated with autoimmune disease: A retrospective study.

To clarify clinical characteristics of immune thrombocytopenia (ITP) subsets associated with autoimmune diseases (AIDs). Five thousand five hundred twenty patients were reviewed retrospectively. One hundred four ITP patients were included for analysis. Clinical manifestations at first thrombocytopenic episode were recorded. Systemic lupus erythematosus (SLE) and primary Sjogren syndrome (pSS) accounted for a large part in AIDs associated with secondary ITP. SLE-ITP, pSS-ITP, and primary ITP (pITP) patients were different in several aspects in clinical and immunological characteristics. A subgroup of patients in pITP patients with some obvious autoimmune features (defined as AIF-ITP) such as positive ANA but failing to meet the diagnosis criteria now used for a specific kind of connective tissue diseases were also different with other pITP patients in some immunological features, indicating the difference in the pathogenesis mechanism of those autoimmune featured ITP patients. ITP patients were heterogeneous in clinical characteristics. Further study about the different pathogenesis of ITP subsets especially those AIF-ITP patients who only presented with thrombocytopenia will help us have a better understanding of pathogenesis of ITP and a better management of ITP patients.