Development of systemic lupus erythematosus in patients with immune thrombocytopenic purpura: A systematic meta-analysis

Background: Recent population-based cohort studies suggest that the incidence of systemic lupus erythematosus (SLE) is increased in patients with immune thrombocytopenic purpura (ITP). We performed a systematic review and meta-analysis to evaluate the development of SLE in patients with ITP.Methods: Literature search was performed in PubMed, Web of Science and Cochrane Library for studies published prior to October 2022. Studies were included that reported development of SLE in ITP patients. Forest plot was used to detect overall SLE frequency in ITP and compare risk ratios for SLE development in different ITP sub-groups. Study heterogeneity was assessed by using I2 statistics.Results: 26 eligible studies comprising 14867 ITP patients were included in analysis. 311 ITP patients developed SLE during the follow-up period (range: 1.1-14 years) (2.09%, 95%CI: 1.87-2.33). Relative risk (RR) for developing SLE was significantly higher in female ITP patients (RR: 4.23, 95%CI: 2.52-7.12, p < 0.0001). Anti-nuclear antibody (ANA) was reported in 23 studies, there were 766/4377 ANA positive patients with ITP (17.5%). The risk of SLE development in ANA positive ITP patients was significant (RR: 26.29, 95%CI: 14.45-47.81, p < 0.0001).Conclusions: Our study suggests ITP patients are at high risk of developing SLE in future. Pooled data revealed that females and patients with a positive ANA titer are at a significantly high risk of developing SLE.