Successful Treatment of Pure Red Cell Aplasia in Systemic Lupus Erythematosus With a Combination of Rituximab and Mycophenolate Mofetil.

Pure red cell aplasia (PRCA) is a rare cause of severe anaemia characterized by selective erythroid suppression in the bone marrow with preservation of other haematopoietic lineages. Its association with systemic lupus erythematosus (SLE) is uncommon and presents significant diagnostic and therapeutic challenges. We describe a 37-year-old female patient with SLE who developed profound isolated anaemia with severe reticulocytopenia, in the absence of other overt clinical manifestations. Laboratory findings revealed active immunological disease, including hypocomplementaemia and elevated anti-double-stranded DNA titres, as well as haemolysis. Although the initial presentation suggested autoimmune haemolytic anaemia, the persistence of reticulocytopenia despite immunosuppressive therapy prompted bone marrow evaluation, which confirmed PRCA. Treatment with high-dose corticosteroids and intravenous immunoglobulin was ineffective, and sustained haematological remission was achieved only after initiation of rituximab, with subsequent incorporation of mycophenolate mofetil (MMF) to maintenance therapy. This case underscores the importance of recognising PRCA as a cause of severe anaemia in SLE and highlights the potential role of B-cell-targeted therapy and MMF as an effective treatment strategy in refractory disease.