Should Plasma Exchange Be Offered to Patients With Multiple Sclerosis–Associated Optic Neuritis?

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.

Trends in Plasma Exchange Use in Optic Neuritis Hospitalizations in the United States

PURPOSE

To report use trends of plasma exchange (PLEX) as well as sociodemographic and medical comorbidities associated with PLEX in the United States.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Adult patients (≥ 18 years) admitted for inpatient hospitalization with a primary diagnosis of optic neuritis (ON).

METHODS

Data from the National Inpatient Sample database was compiled to assess PLEX use rates between 2000 and 2020. The cohorts of patients receiving PLEX versus not receiving PLEX were analyzed between quarter 4 of 2015 through 2020 (International Classification of Diseases, Tenth Revision [ICD-10], only) for patient sociodemographic variables, medical diagnoses, insurance types, hospital characteristics, cause of disease, time to therapy, length of stay (LOS), and total charges incurred.

MAIN OUTCOME MEASURES

Incidence of ON, incidence of PLEX, demographics, diagnoses associated with PLEX therapy, total charges, and LOS.

RESULTS

From 2000 through 2020, 11 209 patients hospitalized with a primary diagnosis of ON were identified, with a significant majority managed at urban teaching hospitals. Use of PLEX increased steadily over 2 decades from 0.63% to 5.46%. Use was greatest in the western United States and least in the eastern United States. In the subset of ICD-10 cases, 3215 patients were identified. The median time to therapy of PLEX was 1 day after admission, and PLEX use was highest in patients with neuromyelitis optica spectrum disorder (NMOSD) (21.21%) and lowest in multiple sclerosis-associated ON (3.80%). Use of PLEX was associated with significantly longer LOS and higher total charges incurred. Medical comorbidities associated with PLEX included adverse reaction to glucocorticoids (adjusted odds ratio [aOR], 31.50), hemiplegia (aOR, 28.48), neuralgia (aOR, 4.81), optic atrophy (aOR, 3.74), paralytic strabismus (aOR, 2.36), and psoriasis (aOR, 1.76).

CONCLUSIONS

Over the last 2 decades in the United States, PLEX therapy for ON has increased, with the highest use in the western United States and for patients with the diagnosis NMOSD ON.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Acute Management of Optic Neuritis: An Evolving Paradigm

The current management of acute optic neuritis (ON) is focused on expediting visual recovery through the use of high-dose intravenous corticosteroids. The recent identification of specific autoantibodies associated with central nervous system inflammatory disorders has provided novel insights into immune targets and mechanisms that impact the prognosis, treatment, and recurrence of ON. Therefore, neurologists and ophthalmologists need to be aware of clinical, laboratory, and imaging findings that may provide important clues to the etiology of ON and the potential need for aggressive management. Moving forward, rapid and accurate diagnosis of inflammatory ON will likely be critical for implementing clinical care that optimizes short-term and long-term therapeutic outcomes.