P164 Rituximab intervention in management of thrombocytopenia in patients with systemic lupus erythematosus: a single center experience

Objective Systemic lupus erythematosus is a prevalent autoimmune disease, with 20 to 40 percent of cases exhibiting thrombocytopenia. Conventional treatments involve corticosteroids and disease-modifying antirheumatic drugs, yet effectively managing thrombocytopenia remains challenging.1 This study evaluates rituximab's efficacy, side effects, and reliability in lupus patients with inadequate responses to conventional treatments. Methods From 2002 to 2023, we conducted a retrospective analysis of patients diagnosed with lupus at our center with patients' records. Rituximab was administered on days 0 and 15 per six-months, defining one course of treatment. We investigated the number of rituximab courses each patient received and evaluated their platelet count following each course. Comprehensive information on the patients' clinical characteristics and treatment responses was extracted from their medical files. Results A total of 29 patients were included in this study. Among them, 24 were females, 5 were males, with an average age of 49.55 ± 13.58 years, all displaying persistent thrombocytopenia despite appropriate conventional treatment. The distribution of patients based on organ involvement revealed 18 with mucocutaneous involvement (62.1%), 4 with renal involvement (13.8%), 6 with joint involvement (20.7%), 3 with serositis (10.3%), and 4 with antiphospholipid syndrome (13.79%). Among these patients, 18 were using mycophenolate mofetil, 18 were on azathioprine, and 3 were on cyclophosphamide. Out of the 12 patients receiving IVIG, 4 responded to the therapy, and 3 patients underwent splenectomy. Twenty-nine patients received rituximab. The average number of rituximab courses administered was 3.51 ± 2.65. A positive response to the initial course, defined as a platelet count exceeding 100,000, was observed in 24 patients (82.8%), with 8 experiencing relapse. Notably, 1 patient reported an allergic reaction as a side effect during rituximab administration. Furthermore, 5 patients did not respond to the initial course, prompting continued rituximab treatment. Corticosteroid dose was reduced in 13 individuals after the first course. At the last visit, 22 individuals are in remission, while 7 still exhibit thrombocytopenia. Conclusions In patients with thrombocytopenia in systemic lupus erythematosus who do not respond to conventional therapy, rituximab has demonstrated effectiveness and reliability. Therefore, rituximab can be considered as an alternative treatment for individuals who do not respond to conventional therapies. Reference Galanopoulos N, Christoforidou A, Bezirgiannidou Z. Lupus Thrombocytopenia: pathogenesis and therapeutic implications. Mediterranean Journal of Rheumatology 2017;28(1): 20–26.