A20 (TNFAIP3) Distinguishes Attack From Remission in Pediatric Patients With Monophasic MOGAD

Acquired demyelinating syndromes associated with serum antibodies against myelin oligodendrocyte glycoprotein have been recognized as MOG-IgG-associated disorders (MOGADs). Patients with MOGAD show distinct features compared with individuals with multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSDs). Up to 50% of patients experience relapsing disease courses, usually associated with persisting high MOG-IgG titers. However, further biomarkers are needed to discriminate monophasic from multiphasic MOGAD. Recently, lowered levels of tumor necrosis factor α-induced protein 3 (TNFAIP3, or A20) have been shown to be associated with attack in a small group of pediatric patients with MOGAD. The aim of this study was to evaluate A20 as a possible biomarker discriminating attack from remission in a larger cohort of pediatric patients with MOGAD.

In this cohort study, we tested 162 serum samples from 62 pediatric patients with MOGAD for A20 levels using commercially available ELISA kits. To compare A20 levels with those in non-MOGAD patients, we further included 46 serum samples from 37 pediatric patients with MS, NMOSD with AQP4-IgG, clinically isolated syndrome, or other neurologic disorders.

In grouped analysis, A20 serum levels were significantly lower during attack compared with remission in patients with monophasic MOGAD. In grouped analysis of patients with multiphasic MOGAD, there was no such significant difference in A20 levels at attack vs remission. Among patients (n = 10) with paired attack and remission time points, there was a significant difference in A20 levels (p = 0.029). A20 levels were tendentially higher in patients on immunomodulatory treatments compared with untreated patients.

Reflecting the anti-inflammatory role of A20, its relative decrease during attacks might even start before the patient's first symptoms. Thus, longitudinal evaluation of A20 at (yet to identifiable) standardized time points might have prognostic implications. Serum A20 levels in pediatric patients with MOGAD may help to distinguish attacks from remission in monophasic disease courses. Consequently, A20 needs to be prospectively investigated in standardized multicentric longitudinal study designs, with a focus on diagnostic, prognostic, and therapeutic implications.