Prognostic Factors for Chronic Thrombocytopenia in Systemic Lupus Erythematosus with Immune Thrombocytopenia.

Introduction: We aimed to identify the clinical characteristics and risk factors for chronic immune thrombocytopenia (ITP) in patients with systemic lupus erythematosus (SLE).

Methods: We retrospectively reviewed patients diagnosed with SLE-associated ITP between January 2000 and December 2021. Patient characteristics were analyzed according to the progression of chronic thrombocytopenia. No response was defined as a platelet count <30 × 109/L or less than double the baseline count after treatment. Factors associated with chronic ITP were evaluated by logistic regression analysis.

Results: Among the 121 patients with SLE-associated ITP, 27 progressed to chronic ITP lasting more than 1 year after initial diagnosis. The median initial platelet count was significantly lower in patients with chronic thrombocytopenia than in those without the disease (16 vs. 51 × 109/L). Patients who did not achieve a response within 1 month of treatment exhibited a high probability of progressing to chronic ITP (55.6 vs. 22.3%, p < 0.001). Multivariable analysis revealed that severe thrombocytopenia at baseline (<20 × 109/L) (adjusted odds ratio [aOR] = 13.628, 95% confidence interval [CI] = 3.976-46.791) and no response within 1 month (aOR = 9.171, 95% CI = 2.776-30.298) were significantly associated with the risk of progression to chronic ITP in patients with SLE. Approximately one-quarter of the patients with SLE-associated ITP progressed to chronic ITP.

Conclusion: Severe thrombocytopenia and failure to achieve a response within 1 month were risk factors for the development of chronic ITP in those patients.