Comparison of Clinical Characteristics and Outcomes of Systemic Lupus Erythematosus-associated Thrombotic Thrombocytopenic Purpura and Idiopathic Thrombotic Thrombocytopenic Purpura: A Single Centre Study from Eastern India

Objective: To investigate the clinical characteristics and outcomes of thrombotic thrombocytopenic purpura (TTP) in patients with systemic lupus erythematosus (SLE) compared to idiopathic TTP (I-TTP). Methods: This retrospective cohort study included adult patients with SLE-TTP ( n = 9) and I-TTP ( n = 7) treated at a tertiary care centre in East India from January 2019 to July 2024. Patients with SLE-TTP fulfilled the 2019 American College of Rheumatology criteria for SLE, and TTP was defined if microangiopathic haemolytic anaemia and thrombocytopenia (platelet count <100,000 cells/µl) were present with an intermediate-to-high-risk PLASMIC score. Clinical characteristics, treatment details and outcomes were extracted from medical records. Treatment response was assessed using complete remission criteria and survival analysis. Results: The SLE-TTP group consisted of all female patients with a median age of 27 years, significantly younger compared to the I-TTP cohort (median age of 55 years, P = .01). Haematological parameters were comparable between groups. Complete response rate was achieved in eight out of nine patients (89%) in SLE-TTP and five out of seven patients (71%) in the I-TTP group ( P = .4). The median time to complete response was 27 and 45 days for SLE-TTP and I-TTP groups, respectively ( P = .31). Conclusion: SLE-TTP patients were younger at diagnosis compared to I-TTP. The findings are exploratory, and further research with a larger sample size and additional biomarkers is warranted to enhance understanding and management of SLE-TTP and I-TTP.