Therapeutic Efficacy of Plasma Exchange in Neuromyelitis Optica

Plasma exchange in inflammatory demyelinating disorders of the central nervous system: reasonable use in the clinical practice

Plasma exchange (PLEX) is a therapeutic apheresis modality in which the plasma is separated from inflammatory factors such as circulating autoreactive immunoglobulins, the complement system, and cytokines, and its therapeutic effect is based on the removal of these mediators of pathological processes. Plasma exchange is well established for various neurological disorders, and it is applied successfully in central nervous system inflammatory demyelinating diseases (CNS-IDD). It mainly modulates the humoral immune system; thus, it has a greater theoretical effect in diseases with prominent humoral mechanisms, such as neuromyelitis optica (NMO). However, it also has a proven therapeutic effect in multiple sclerosis (MS) attacks. Several studies have suggested that patients with severe attacks of CNS-IDD have poor response to steroid therapy but show clinical improvement after the PLEX treatment. Currently, PLEX is generally established only as a rescue therapy for steroid unresponsive relapses. However, there are still research gaps in the literature regarding plasma volume, number of sessions, and how early the apheresis treatment needs to started. Thus, in the present article, we summarize the clinical studies and meta-analyses, especially about MS and NMO, outlining clinical data regarding the experience with therapeutic PLEX in severe attacks of CNS-IDD, the clinical improvement rates, the prognostic factors of a favorable response, and highlighting the likely role of the early apheresis treatment. Further, we have gathered this evidence and suggested a protocol for the treatment of CNS-IDD with PLEX in the routine clinical practice.

Timing of plasma exchange for neuromyelitis optica spectrum disorders: A meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSDs) are autoimmune astrocytopathies with predominant involvement of the optic nerves and spinal cord. The current management is high-dose intravenous methylprednisolone, followed by apheresis therapy if it fails. We aimed to investigate plasma exchange (PE) benefits in corticosteroid-refractory NMOSDs.

METHODS

From Embase, PubMed, Cochrane, Web of Science, and Clinical Trials, we identified PE-based studies published between Jan 2007 and Dec 2019. We pooled the information of these studies in a binomial meta-analysis. We investigated the factors affecting the efficacy of PE and its adverse events. The effectiveness of PE was assessed using the Expanded Disability Status Scale (EDSS). The timing of PE initiation was assessed using Spearman correlation analysis.

RESULTS

We included 561 records and identified 8 observational studies, including 228 NMOSD patients. The mean time to the initiation of PE was 11 days, and the average volume of each exchange was 1.5-2 L. PE treatment reduced the mean EDSS score by -1.04 (95% CI, -1.44 to -0.64). The initiation time of PE significantly affected the outcome (EDSS reduction) (P = 0.01; 95% CI, -1.30 to 0.28). In the ≤ 7-day and 8-23-day groups, the mean EDSS decreased by 0.64 (95% CI, -0.93 to -0.34) and 1.41 (95% CI, -1.79 to -1.02), respectively. In addition, PE showed the same efficacy for alleviating the symptoms of NMOSDs, regardless of the day between 8 to 23 days on which it was performed (P = 0.29). Thirty-five (20.8%) of the 168 patients had adverse events.

CONCLUSION

PE can ameliorate severe NMOSDs. PE effectiveness was associated with the duration between disease and the initiation of PE, and the optimal timing for PE initiation is 8 to 23 days after the onset of the disease.

Efficacy of plasma exchange in acute attacks of neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

BACKGROUND

Plasma exchange (PE) has usually to be considered as a rescue therapy when intravenous corticosteroids is insufficient in acute attacks of neuromyelitis optica spectrum disorders (NMOSD). The efficacy of PE has not been quantified. This system review and meta-analysis was aimed to evaluate the efficacy of PE therapy in acute attacks of NMOSD.

METHODS

Studies evaluating the efficacy of PE in patients with NMOSD were identified from PubMed and Embase. Changes of Expanded Disability Status Scale (EDSS) score between before and after PE therapy, and the rate of response to PE, were defined as the main efficacy outcomes. Meta-regression was performed to identify the sources of heterogeneity. Subgroup meta-analysis were performed based on the interval of initiation PE after attack onset and AQP4-IgG serostatus of patients.

RESULTS

Twenty-four studies containing 528 patients with NMOSD were included in this meta-analysis. As a rescue therapy when patients failed to respond to intravenous corticosteroids (PE rescue), PE treatment resulted in a reduction in the mean EDSS score by 1.69 (95% CI: 0.88-2.50), with a response rate of 75%(95%CI: 66%-83%). As a first-line therapy being used alone or simultaneously with intravenous corticosteroids (PE first-line), PE resulted in a reduction in the mean EDSS score by 2.34 (95% CI: 1.69-2.98), with a response rate of 71%(95%CI: 44%-93%). Overall, PE resulted in a reduction in the mean EDSS score by 1.83 (95% CI: 1.19-2.47), with a response rate of 74% (95%CI: 66%-82%). Subgroup analysis suggested that earlier PE initiation and AQP4-IgG seronegative patients seemed to be associated with a superior response to PE therapy.

CONCLUSION

Plasma exchange, whether used as rescue or as first-line therapy, is an effective therapeutic method in patients during acute attacks of NMOSD.

Effect of plasma exchange in neuromyelitis optica spectrum disorder: A systematic review and meta-analysis

OBJECTIVE

To conduct systematic review and meta-analysis for the efficacy of therapeutic plasma exchange (TPE) for neuromyelitis optica spectrum disorder (NMOSD) with an acute attack.

METHODS

Systematic review was performed using EMBASE and OVID/Medline database. The eligible studies must be the studies of NMOSD patients treated with TPE during the acute phase. They must report treatment outcomes using either Expanded Disability Status Scale (EDSS) or visual acuity (VA) before and after the therapy. Pooled mean difference (MD) was then calculated by combining MDs of each study using the random-effects model.

RESULTS

Fifteen studies were identified; eleven with 241 NMOSD patients reported EDSS outcome and four studies with 103 NMOSD reported visual outcomes. The meta-analysis demonstrated a significantly decreased in EDSS after TPE treatment for NMOSD with an acute attack with the pooled MD of 0.83 (95% CI, 0.26-1.40; I² 69%) comparing pretreatment to immediate posttreatment and 2.13 (95% CI, 1.55-2.70; I² 31%) comparing pretreatment to posttreatment at 6 months to 1-year follow-up. Unfortunately, only one of the four studies evaluating visual outcomes reported standard deviation in association with mean LogMAR; therefore, the meta-analysis cannot be conducted. Nonetheless, all studies consistently demonstrated the benefit of TPE with improved VA and/or LogMAR after treatment.

INTERPRETATION

This systematic review and meta-analysis showed the benefit of TPE during the NMOSD attack with a significantly improved disability status immediately after treatment and during follow-up.

Plasma Exchange or Immunoadsorption in Demyelinating Diseases: A Meta-Analysis

Multiple sclerosis (MS) is an inflammatory disease mainly affecting the central nervous system. In MS, abnormal immune mechanisms induce acute inflammation, demyelination, axonal loss, and the formation of central nervous system plaques. The long-term treatment involves options to modify the disease progression, whereas the treatment for the acute relapse has its focus in the administration of high-dose intravenous methylprednisolone (up to 1000 mg daily) over a period of three to five days as a first step. If symptoms of the acute relapse persist, it is defined as glucocorticosteroid-unresponsive, and immunomodulation by apheresis is recommended. However, several national and international guidelines have no uniform recommendations on using plasma exchange (PE) nor immunoadsorption (IA) in this case. A systematic review and meta-analysis was conducted, including observational studies or randomized controlled trials that investigated the effect of PE or IA on different courses of MS and neuromyelitis optica (NMO). One thousand, three hundred and eighty-three patients were included in the evaluation. Therapy response in relapsing-remitting MS and clinically isolated syndrome was 76.6% (95%CI 63.7–89.8%) in PE- and 80.6% (95%CI 69.3–91.8%) in IA-treated patients. Based on the recent literature, PE and IA may be considered as equal treatment possibilities in patients suffering from acute, glucocorticosteroid-unresponsive MS relapses.

Retrospective study of the adverse events of the treatment for an acute attack of neuromyelitis optica spectrum disorder

Intravenous methylprednisolone (IVMP) is an initially recommended therapy for an acute attack of neuromyelitis optica spectrum disorder (NMOSD). For those who do not respond to steroid treatment, plasma exchange (PLEX) is generally added-on. We evaluated adverse events of an acute treatment in NMOSD patients in a university-based hospital during January 2009 and December 2017. Ninety-seven patients with 177 attacks were collected. The therapy included IVMP alone (123 events, 62.4%), IVMP followed by PLEX (46 events, 23.4%) and, PLEX alone (8 events, 4.5%). Adverse events occurred in 36.7% of the IVMP group and 61.1% of the PLEX group. The most common adverse event was hyperglycemia (43.5%) followed by infection (29%) in the former and hypocalcemia (63.6%) followed by hypofibrinogen (42.4%), hypotension (30.3%), and infection (21.2%) in the latter. One severe adverse event was documented in the IVMP group and 13 events in the PLEX groups, nevertheless, all were manageable.

Plasma Exchange as a First Line Therapy in Acute Attacks of Neuromyelitis Optica Spectrum Disorders

Background and Aims:

Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating disorder of central nervous system with deleterious effects. At present Intravenous corticosteroids are used for the relapse as the first line of treatment, but with only a class evidence III-IV. Having an underlying humoral immune mechanism in the pathogenesis of NMOSD and as it is rightly said that “Time is Cord and Eyes”, delaying the time to start plasma exchange (PLEX) awaiting favorable outcome in response to corticosteroids is detrimental for the patient. Hence, PLEX may be a promising first line therapeutic approach in the management of severe attacks of NMOSD. The aim of this study is to evaluate the efficacy of PLEX as the first line of treatment for the acute attacks in patients with NMOSD that is being largely used as an add-on therapy for more than 10 years, and also to define the time opportunity window for the starting of PLEX.

Methods:

The study analysed the therapeutic efficacy and safety profile of PLEX as a first line therapy in 30 patients diagnosed with NMOSD over a period of 30 months. PLEX was performed using a Hemonetics Mobile Collection System plus machine with due written consent including the risks and benefits of the treatment that is being proposed to the patient/relative in their own language.

Results:

A total of 30 patients were analysed, out of which 16 were females and rest males. 85% of the patients were in the age group of 25-35 years. All the patients had severe Expanded Disability Status Scale (EDSS) scores at the baseline, and 73.33% showed significant improvement following PLEX. The only predictor of good outcome was the time to PLEX i.e shorter delay betters the outcome.

Conclusion:

The study ascertained the importance of early PLEX as a therapeutic intervention in severe attacks of NMOSD irrespective of their Anti-Aquaporin 4 (AQP4) antibody status.