P026 Neurofascin antibodies complicating a case of severe systemic lupus erythematosus
Authors: Yee Philip , Mouyis Maria 
Published: April 2024

Abstract

Background/Aims
Juvenile-onset systemic lupus erythematosus (jSLE) is an autoimmune disease that results in increased disease activity and damage compared to adult-onset SLE. There is increased medication burden, severe organ manifestations and higher incidence of renal, cardiovascular and neuropsychiatric (NP) involvement.
Anti-nervous system (NS) antibodies are seen across immune mediated diseases including SLE. Myelin oligodendrocyte glycoprotein (MOG) and neurofascin (NF) 186 antibodies are particularly associated with higher frequencies of NP-SLE. These patients can present with the distinct clinical phenotype associated with that antibody (i.e., demyelination with MOG, neuropathy with NF186).

Methods
We present an SLE patient with progressive neurological features and anti-NF antibodies who responds well to ocrelizumab after modest response to initial immunotherapy.

Results
An 18 year old female has active jSLE including malar rash, alopecia, arthralgia, aphthous ulcers, headaches. She presents with lower limb and ascending abdominal paraesthesia and left 6th cranial nerve palsy alongside a recent respiratory tract infection. ANA 1:5120 homogenous pattern, high dsDNA, low C3 and C4, thrombocytopenia and antibodies to Sm, Ro, RNP, anti-Rib-P and strongly positive lupus anticoagulant antibodies and low titre anti-cardiolipin (aCL) IgG and IgM. Lumbar puncture is unremarkable. Nerve conduction studies (NCS) demonstrate progressive predominant motor inflammatory neuropathy without demyelination. CT, MRI brain and MRI spine are normal. She is treated as atypical Guillain-Barre Syndrome (GBS)/ Miller-Fischer with 5 days IV immunoglobulin 2g/kg and also for active SLE with 3 days 500mg IV methylprednisolone. She is intubated following worsening dysphagia, dysarthria, muscle weakness and reduced consciousness. Plasma exchange and pulsed cyclophosphamide are subsequently given.
Eye and facial movements worsen with NCS showing worsening patchy axonal sensorimotor polyneuropathy. Serial MRI brain is suggestive of posterior reversible encephalopathy syndrome (PRES). Autonomic instability is seen with labile blood pressure and tachycardia. Given the unusual presentation, anti-NF antibodies are tested and identified at 1:3200 positive, NF155 and 186, both IgG1 and IgG2. Given previous adverse reaction to rituximab, she received ocrelizumab which lead to a marked improvement in her sensorimotor symptoms and functionality. C3 and C4 levels show considerable improvement which is sustained and dsDNA levels normalise. B cell depletion therapy was chosen following a small case series of patients with neurofascin antibodies who developed severe autoimmune neuropathies. Half of these patients responded well to rituximab. One proposed mechanism being the targeting of immature CD20+ B cells inhibits plasmablast generation, which may be responsible for neurofascin antibody production early on in the disease.

Conclusion
Anti-NS antibodies are seen in SLE patients and their presence can suggest increased frequency of NP-SLE suggesting a potential future role as a biomarker. One should consider anti-NF antibody testing in patients with a GBS-like illness with progressive neuropathy, respiratory involvement and autonomic dysfunction despite standard immunotherapy.

Disclosure
P. Yee: None. M. Mouyis: None.