Safety and efficacy of plasma exchange for the treatment of optic neuritis in neuromyelitis optica spectrum disorders: A protocol for systematic review and meta-analysis

Visual Function Improvement after Plasma Exchange Therapy for Acute Optic Neuritis in Neuromyelitis Optica Spectrum Disorders: Case Series and Review

OBJECTIVE

Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune-mediated central nervous system disorders distinguished by the presence of serum aquaporine-4 IgG antibody (AQP4-Ab). The clinical panel comprises severe optic neuritis (ON) and transverse myelitis, which can result in incomplete recovery and a high risk of recurrence.

METHODS

This study aimed to evaluate the visual outcomes of three patients with severe acute ON in NMOSD that was non-responsive to intravenous methylprednisolone (IVMP), who received plasma exchange therapy (PLEX). We included three patients (P1, P2 and P3) with severe acute ON who had no improvement after IVMP treatment and were admitted to the ophthalmology department at the Emergency University Hospital Bucharest from January 2022 to September 2023. All three patients with ON were diagnosed in accordance with the criteria described by the Optic Neuritis Treatment Trial. All the subjects were experiencing their first attack.

RESULTS

The mean recruitment age was 35.3 ± 7.71. All patients were seropositive for the AQP4 antibody. All patients were tested for serum myelin oligodendrocyte glycoprotein (MOG) antibody but only one showed a positive test (P3). Lesions visible in orbital MRI indicated the involvement of retrobulbar, canalicular and/or intracranial segments. All three subjects had no response or incomplete remission after an IVMP protocol (5 days of 1000 mg intravenous methylprednisolone in sodium chloride 0.9%). The mean time from onset of optic neuritis to PLEX was 37.6 days. The PLEX treatment protocol comprised five cycles of plasma exchange treatment over 10 days, with a plasma exchange session every other day. An amount of 1 to 1.5 volumes of circulating plasma were dialyzed for 2-4 h. At 1 month after the completion of PLEX therapy, BCVA and VF parameters were improved in all three patients.

CONCLUSION

The treatment of ON remains subject to debate and is somewhat controversial. Plasma exchange must be considered as a rescue therapy when IVMP is insufficient for AQP4-ON patients. This study revealed that PLEX treatment effectively improves the visual outcomes of patients experiencing their first attack of severe acute isolated ON after high-dose IVMP treatment. This study suggests that PLEX may be associated with improved visual outcomes in NMOSD acute optic neuritis.

The Treatment of Acute Optic Neuritis

Despite the high incidence of optic neuritis (ON), and the growing number of therapeutic options for the long-term treatment of diseases associated with ON including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody associated disease (MOGAD), there are still only limited therapeutic options for treating an acute event of optic neuritis. These include steroids, plasma exchange (PLEX) and intravenous immunoglobulin (IVIG). High-dose steroids remain the mainstay of acute treatment. However, evidence is emerging that when optic neuritis is accompanied with certain atypical features that suggest a more unfavorable outcome this mandates special consideration such as early addition of other therapeutic agents or tapering the steroid very slowly. This review will distinguish between typical and atypical neuritis and discuss acute treatment options.

Efficacy and safety of plasma exchange or immunoadsorption for the treatment of option neuritis in demyelinating diseases: A systematic review and meta-analysis

BACKGROUND

There are no systematic reviews yet that evaluated the effects of PE/IA in patients with optic neuritis (ON) in demyelinating diseases. A meta-analysis of available study is needed to further explore the value of plasma exchange (PE) or immunoadsorption (IA) in treating ON in demyelinating diseases.

METHODS

All relevant articles published on PubMed, Web of Science, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), VIP Database, Wanfang, Sinomed and ophthalmology professional websites were searched. Study characteristics, demographic characteristics, clinical features and outcome measures were extracted. Response rate, adverse events (AE) rate, serious adverse event (SAE) rate, the log of the minimum angle of resolution (logMAR), visual outcome scale (VOS) and expanded disability status scales (EDSS) were evaluated using a random-effects model.

RESULTS

35 studies were included between 1985 and 2020, containing 1191 patients. The response rates of PE and IA in acute attack of ON were 68% and 82% respectively. LogMAR (-0.60 to - 1.42) and VOS (-1.10 to -1.82) had been significantly improved from within 1 month to more than 1 month after PE treatment. Besides, we found that logMAR improved 1.78, 0.95 and 0.38, respectively ,when the time from symptom onset to the first PE/IA was less than 21 days, 21-28 days, and more than 28 days. The pooled mean difference of EDSS was -1.14.Adverse effects rate in patients with PE or IA were 0.20 and 0.06, respectively.

CONCLUSION

The meta-analysis provided evidence that PE/IA treatment was an effective and safe intervention, and it is recommended that early initiation of PE/IA treatment is critical.