Eosinophilic granulomatosis with polyangiitis (Churg–Strauss syndrome) imitating Guillain–Barre syndrome (GBS): a case report

Background Eosinophilic granulomatosis with polyangiitis (EGPA) is associated with vasculitic neuropathy and being rare can present as subacute symmetric sensorimotor quadriparesis mimicking Guillain–Barre syndrome (GBS). It warrants timely diagnosis as treatment for both conditions is different and vasculitic neuropathy needs long-term immunosuppression. Nerve biopsy of our patient showed eosinophilic infiltration along with mononuclear infiltrate. Typical histopathological presentations of EGPA are different among different organs and eosinophilic infiltration is rarely observed in peripheral nerve and kidney involvements. Case presentation A 49-year-old female with a history of asthma with 3-week duration of acute onset ascending weakness, preceded by severe pain and burning in glove and stocking pattern. Nerve conduction studies could not rule out Guillain–Barre syndrome initially, but subsequent studies show axonal affection and she received intravenous immunoglobulin (IVIg) but her weakness progressed after slight improvement. Her bloodwork revealed marked eosinophilia (> 50%) with computed tomography (CT) paranasal sinuses showing pansinusitis with background history of asthma led us towards eosinophilic granulomatosis with polyangiitis and later antineutrophil cytoplasmic antibodies came out positive with nerve biopsy showing perivascular mononuclear inflammation with eosinophils. She was started on steroids immediately and then received intravenous rituximab in view of long-term immunosuppression with maintenance steroids and on follow-up she improved. Conclusion Eosinophilic granulomatosis with polyangiitis is a small-vessel vasculitis associated with antineutrophil cytoplasmic antibodies with significant paranasal sinuses involvement. Mononeuritis multiplex is the most common presentation of vasculitic neuropathy of eosinophilic granulomatosis with polyangiitis, but they can mimic Guillain–Barre syndrome and should always be considered in the differential diagnosis, since the treatment strategies for these conditions are radically different.

P.060 Immunoglobulin Use For Neuromuscular Conditions: Updating British Columbia Provincial Guidelines Through Focused Literature Review

Background: Immune-mediated neuromuscular conditions often cause significant disability and may require ongoing immunomodulating therapies such as immunoglobulin (Ig). Ig use in several neuromuscular conditions such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is supported by robust evidence, however Ig is increasingly used for other disorders. In British Columbia (BC), Ig use has increased annually; last year, expenditure exceeded 51 million dollars, 35% relating to neurological disease. Within the context of the pandemic, Ig supply is at risk of shortages. Methods: A focused literature review was conducted of CIDP, Guillain-Barré Syndrome (GBS), Multifocal Motor Neuropathy (MMN), Myasthenia Gravis (MG), and other neuromuscular conditions to compare BC Ig guidelines with international best practices. Provincial recommendations for Ig use were updated accordingly. Results: Evidence-based practices include acute and chronic Ig use in CIDP and MMN, and acute or relapse-related treatment in GBS and MG. Ig may be beneficial in other treatment-refractory inflammatory disorders such as Lambert-Eaton Myasthenic Syndrome and vasculitic neuropathy. Objective outcome measures can optimize patient care and ensure appropriate resource utilization. Conclusions: Updated BC guidelines emphasize using established diagnostic criteria, objective outcome measures and minimum effective Ig doses for neuromuscular conditions. Periodic literature reviews on Ig use allow guidelines to remain evidence-based.

Fluid Biomarkers for Monitoring Structural Changes in Polyneuropathies: Their Use in Clinical Practice and Trials

Reliable and responsive tools for monitoring disease activity and treatment outcomes in patients with neuropathies are lacking. With the emergence of ultrasensitive blood bioassays, proteins released with nerve damage are potentially useful response biomarkers for many neurological disorders, including polyneuropathies. In this review, we provide an overview of the existing literature focusing on potential applications in polyneuropathy clinical care and trials. Whilst several promising candidates have been identified, no studies have investigated if any of these proteins can serve as response biomarkers of longitudinal disease activity, except for neurofilament light (NfL). For NfL, limited evidence exists supporting a role as a response biomarker in Guillain-Barré syndrome, vasculitic neuropathy, and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Most evidence exists for NfL as a response biomarker in hereditary transthyretin-related amyloidosis (hATTR). At the present time, the role of NfL is therefore limited to a supporting clinical tool or exploratory endpoint in trials. Future developments will need to focus on the discovery of additional biomarkers for anatomically specific and other forms of nerve damage using high-throughput technologies and highly sensitive analytical platforms in adequality powered studies of appropriate design. For NfL, a better understanding of cut-off values, the relation to clinical symptoms and long-term disability as well as dynamics in serum on and off treatment is needed to further expand and proceed towards implementation.

P208 A case of double positivity

Background/Aims In the absence of renal or lung involvement, the investigation of small vessel vasculitis does not routinely include checking of anti-glomerular basement membrane (GBM) antibodies. We present a patient with an MPO-ANCA positive vasculitic neuropathy who later developed anti-GBM positive glomerulonephritis. We review the literature on patients who are “double-positive” for ANCA and GBM antibodies and speculate on the utility of routinely screening all vasculitis patients for GBM antibodies in the absence of manifestations of Goodpasture’s syndrome. Methods We describe a 70 year old female who presented feeling generally unwell with reduced mobility due to discomfort in her feet. Examination was unremarkable, except for reduced temperature and joint position sense in the feet. CRP was elevated and she was found to have a weakly positive MPO titre of 32. She was treated as an MPO-ANCA positive vasculitis and neuropathy with steroids and Mycophenolate Mofetil, with a good clinical and biochemical response. Fifteen months into her treatment, routine monitoring revealed an acute kidney injury with a creatinine of 459 umol/l from a baseline of 88. Anti GBM titres were requested for the first time as part of the renal screen. MPO antibody titres were only 9, but GBM antibody titres were markedly elevated (>200). Renal biopsy showed focal necrotising glomerulonephritis, in keeping with anti-GBM disease. She was treated with steroids, cyclophosphamide and plasma exchange by the renal physicians. She remains dialysis dependant. Results In our patient, GBM antibodies were only requested once she developed relevant clinical manifestations of anti-GBM disease. This in contrast to nephrology practise, where ANCA and GBM antibodies are routinely requested simultaneously in the context of nephritis. It could be speculated that if the GBM antibody status had been detected sooner, we may have altered her management and possibly improved her disease course. Anti-GBM disease and ANCA-associated vasculitis are both rare conditions. However, co-existence of the two uncommon diseases in individual patients is well-described and more than chance occurrence. A study showed that 5% of ANCA-positive cases were also positive for anti-GBM antibodies, while one-third of anti-GBM positive samples had detectable ANCA. Multiple studies have shown that low level ANCA antibodies develop months to years before onset of anti-GBM disease, as seen in our patient as well.The dominant disease phenotype in double positive patients is anti-GBM disease rather than vasculitis. It is very rare for isolated anti-GBM disease to relapse. In contrast, half of double positive patients experience disease relapse and therefore, require long-term follow-up and maintenance immunosuppression. Conclusion Awareness of this double positive phenomenon is important. Rheumatologists do not routinely check anti-GBM in all vasculitis. This case highlights the importance of doing so, especially in atypical presentation of vasculitis or in relapse and refractory disease. Disclosure S. Khalid: None. J. Li: None. S. Young Min: None.

Microscopic Polyangiitis Presenting with Splenic Infarction: A Case Report

Microscopic polyangiitis (MPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The splenic involvement in AAV is known to be rare, and that in MPA has not been reported to date. A 74-year-old woman was admitted owing to left arm numbness and weakness. The patient was diagnosed as MPA with vasculitic neuropathy. Her abdominal computed tomography (CT) revealed splenic infarction incidentally. The splenic infarction had been resolved at follow-up CT after treatment. If splenic involvement of MPA was not considered, treatment may have been delayed in order to differentiate other diseases. Herein, I report the first case of splenic involvement of MPA.

Combination rituximab and intravenous immunoglobulin for treatment of refractory vasculitic neuropathy: a case series

Objective Limited evidence exists to guide treatment of refractory vasculitic neuropathy. While rituximab (RTX) and IVIG have both been proposed as individual treatment options for these patients, combination therapy has never been reported. Methods Written informed consent was obtained from three patients with refractory vasculitic neuropathy who were treated with combination RTX and IVIG. Their electronic medical records were reviewed and clinical and functional outcomes were reported. Results Two male patients with non-systemic vasculitic neuropathy and one male patient with granulomatosis with polyangiitis were treated with combination RTX and IVIG therapy. All three patients demonstrated clinical improvement with at least partial functional recovery and a reduction in corticosteroid dose. This combination was generally well tolerated. Conclusions Combination RTX and IVIG therapy may be a safe and effective treatment option for patients with refractory vasculitic neuropathy. Further studies are needed to better characterize the risks and benefits of this combination.

Mechanisms of Nerve Damage in Neuropathies Associated with Hematological Diseases: Lesson from Nerve Biopsies

Despite the introduction of non-invasive techniques in the study of peripheral neuropathies, sural nerve biopsy remains the gold standard for the diagnosis of several neuropathies, including vasculitic neuropathy and neurolymphomatosis. Besides its diagnostic role, sural nerve biopsy has helped to shed light on the pathogenic mechanisms of different neuropathies. In the present review, we discuss how pathological findings helped understand the mechanisms of polyneuropathies complicating hematological diseases.