Apheresis Therapy Outperforms Intravenous Methylprednisolone in Long-Term Treatment of NMOSD Attacks

Recently published data from a real-world cohort study showed that treatment with either plasma exchange (PE) and immunoadsorption (IA) in combination with intravenous methylprednisolone (IVMP) resulted in better and continuous improvement than IVMP alone in patients with active neuromyelitis optica spectrum disorder (NMOSD).¹

In the study, 411 attacks of 336 patients with NMSOD were screened for propensity score matching (PSM), and 90 attacks (30 PE/IA+IVMP and 60 IVMP) were included in the analysis. Led by De-Cai Tian, of the Beijing Tiantan Hospital, the study primarily looked at changes in Expanded Disability Status Scale (EDSS) scores between the 2 treated groups, in addition to safety and laboratory tests. PSM was used to reduce selection bias by matching baseline characteristics such as gender, age, time to IVMP, and EDSS at attack between the PE/IA+IVMP and IVMP groups.

At attack, median EDSS in PE/IA+IVMP and IVMP groups was similar (median EDSS: 6.25 vs 6.75; IQR [4.50-8.38] VS [5.00-8.00]; P = .671). At 6 months, the EDSS of both groups had significantly improved, but the EDSS improvement of the PE/IA+IVMP group was better than that of the IVMP group (median EDSS: 3.00 vs 4.50; IQR [2.00-4.00] vs [3.00-6.50]; P = .003).

At discharge, visual acuity was greater improved in the PE/IA+IVMP group than that in the IVMP groups (median logMAR: 0.82 vs 1.85; P = .025). Six months out, the PE/IA+IVMP group showed significantly lower logMAR than IVMP group (median logMAR: 0.35 vs 1.00; P = .002). In a subgroup analysis of patients with different number of attacks, PE/IA+IVMP therapy showed a more pronounced effect on those with first attacks.

As for the reasons why certain patients on PE/IA+IVMP had more pronounced and earlier improvement in visual acuity, the investigators wrote that, "This may be related to the role of PE/IA in clearing pathogenic antibodies, complement, and immune regulation to reduce the damage to the optic nerve in the early stage."

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Within the PE/IA group, 26 of 30 attacks were free from any adverse event (AE). The remaining 4 adverse reactions were attributed to transient hypotension during apheresis treatment (n = 2), nosebleed (n = 1), and bleeding at the catheter site (n = 1). Of note, hypokalemia was more frequent in the PE+IVMP (n = 8) than IA+IVMP (n = 22; 25.00% vs 9.09%). In addition, patients with fibrinogen decrease (50.00%) and thrombocytopenia (6.67%) were all from IA+IVMP group.

In the IVMP group, univariate analyses revealed that improvement was predicted by age (OR, 0.959 95% CI 0.925–0.994; P = 0.022), BMI (OR 0.826; 95% CI 0.692–0.986; p = 0.035), EDSS at attack (OR 0.229; 95% CI 0.114-0.458; p < 0.001), serum AQP4-IgG titer at attack (OR 0.996; 95% CI 0.992–1.000; p = 0.047). In contrast, factors like annual relapse rate (OR, 0.963; 95% CI, 0.747-1.240; P = .768), attack times (OR, 0.870; 95% CI, 0.605-1.252; P = .454) and delay from onset to IVMP (OR, 1.056; 95% CI, 0.962-1.158; P = .252) demonstrated no significant difference.

The study was small-scale, and thus investigators concluded that development of a randomized controlled trial related to PE/IA treatment of NMOSD is needed in the future. In addition, the authors noted a few limitations, including the real-world nature of the trial, the fact that it was conducted in an urban specialty tertiary medical center, and that PE/IA was only used as a rescue therapy in daily practice, which may result in no significant difference of outcome parameters between PE/IA+IVMP and IVMP groups at discharge.

REFERENCE
1. Hu Y, Wang H, Song T, et al. Efficacy and safety of apheresis therapy in AQP4 antibody-positive NMOSD attack: a propensity score-matched cohort study. CNS Neurosci & Ther. 2024;30(5):e14780. doi:10.1111/cns.14780.