Neuromyelitis optica spectrum disorder complicated with pure red cell aplasia: A case report

Background: Pure red cell aplasia (PRCA) in a patient with neuromyelitis optica spectrum disorder (NMOSD) has not been reported before. This study presents a patient with NMOSD who developed PRCA. Case presentation: A 54-year-old female was admitted to the Second Affiliated Hospital of Baotou Medical College in January 2023 for dysuria and progressive numbness and weakness of both lower limbs. Physical examination showed she had difficulty standing and walking in a straight line. Both lower limbs showed positive Babinski and Chaddock signs. MRI showed abnormal signals in the spinal cord. Aquaporin-4-IgG (AQP-4-IgG) was positive (1:320), and NMOSD was confirmed. Intravenous immunoglobulin and methylprednisolone were given, and the symptoms improved. She was readmitted for fatigue, palpitations, and shortness of breath in May 2023. Bone marrow aspiration and biopsy showed elevated erythroid precursors and erythroid hypoplasia, while megakaryocytes and myeloid precursors were normal. Chest CT examination showed no mediastinal lymph node enlargement and thymoma. PRCA secondary to NMOSD was diagnosed. Recombinant human erythropoietin was given, and her condition was improved after 1.5 months, as indicated by blood cell count and imaging. Conclusions: : As PRCA may be secondary to NMOSD, a comprehensive evaluation of immune function and bone marrow biopsy may be necessary if abnormal blood cells are found while managing NMOSD.