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.