LOSING SIGHT OF THE DIAGNOSIS: A CASE REPORT OF NEUROMYELITIS OPTICA SPECTRUM DISEASE AND SYSTEMIC LUPUS ERYTHEMATOSUS-NEUROAUTOIMMUNITY IN FOCUS, CORRELATION OR COINCIDENCE?

PV284 / #590 Case Report Poster Topic: AS05 - CNS Lupus Introduction Optic Neuritis is a rare, albeit, severe manifestation of Systemic Lupus Erythematosus (SLE). It causes immune-mediated inflammation in the central nervous system (CNS), leading to demyelination and vision loss. It is also a prominent feature of Neuromyelitis Optica Spectrum Disease (NMOSD), which can affect both the optic nerves and the spinal cord. These 2 conditions share overlapping traits, causing neurologic manifestations that complicate the diagnosis and may require distinct therapeutic approach, especially in refractory cases.[1] Case Presentation With Investigation A 64-year-old female with a medical history of arterial hypertension and mild thrombocytopenia, first noted 4 years ago, presented with progressively deteriorating vision loss that began 2 months before her visit. Ophthalmological examination revealed severe loss of visual acuity: only light perception in the right eye and finger counting at 2 meters in the left, with no signs of inflammation or macular edema on fundoscopy. Brain CT and CT-A revealed no significant abnormalities other than a mild narrowing of the right internal carotid artery (22%). Clinical examination, aside from vision loss, was unremarkable Laboratory findings revealed mild thrombocytopenia (PLT: 80×10^3), normal inflammatory markers (ESR:18 mm/1st h; CRP:1.8 mg/L), urinalysis and biochemical panel. T2-weighted brain MRI demonstrated mild enhancement of the right optic nerve near the optic canal, consistent with optic neuritis (Figure 1). Cerebrospinal fluid analysis showed normal cell count. Serologic testing revealed elevated anti-aquaporin-4 antibodies (32× ULN), hypocomplementemia (C3:73.7 mg/dL; C4:10 mg/dL) and high anti-dsDNA binding (2× ULN). A diagnosis of coexistent NMOSD and SLE was established. Treatment with pulses of glucocorticoids and Rituximab led to mild visual improvement (left eye: 8/10; right eye: 2/10) and resolution of thrombocytopenia (PLT: 326×10^3). The patient received maintenance therapy with Rituximab plus Azathioprine and was tapered of steroids succesfully. No relapses were observed over a 2-year follow-up period. Repeat brain MRI showed atrophy of the right optic nerve without active inflammation or new lesions (Figure 2). Figure 1: T2-weighted axial orbital brain MRI (fat suppression) Figure 2: T2-weighted axial brain MRI. Consent for publication obtained directly from patient. Literature Review Optic neuritis, as a manifestation of NMOSD, is associated with systemic autoimmune disorders such as SLE, and may also present alongside transverse myelitis. It is often linked with specific antibodies against Aquaporin-4 (AQP-4) or against Myelin-Oligodendrocyte-Glycoprotein (MOG).[1] NMOSD presents with longitudinally extensive myelitis lesions and lacks systemic involvement, which is commonly seen in SLE. Both conditions require treatment with high doses of glucocorticoids and immunosuppressive therapy, but first-line treatments differ. First-line treatment for NMOSD includes biologic therapies such as Eculizumab (anti-C-5a), Inebilizumab (anti-CD19), Satralizumab (anti-Interleukin-6 receptor inhibitor) and Plasma Exchange. In contrast, CNS SLE therapy includes cyclophosphamide and Rituximab in refractory cases.[1,2] Discussion This case highlights the complex coexistence of NMOSD and SLE, 2 distinct autoimmune diseases that may overlap. While optic neuritis is a common manifestation of NMOSD, its occurrence in SLE is rare, leading to diagnostic confusion. Early recognition and appropriate management are crucial for preventing irreversible organ damage and improving overall prognosis. Effective treatment hinges on identifying the predominant disease in each clinical setting and prompts further inquiry into the overlapping characteristics of these conditions. References: [1.] Ochi MGS. Case Rep Rheumatol 2020;2020:8820071. [2.] Adawi M. Clin Med Insights Case Rep 2014;7:41-7.