Frequency and relevance of IgM, and IgA antibodies against MOG in MOG-IgG-associated disease

Abstract

Objective: To determine the frequency and relevance of IgM, and IgA antibodies against myelin oligodendrocyte glycoprotein (MOG) in MOG-IgG-associated disease.

Methods: Evaluation of IgM, and IgA MOG antibodies in serum of 120 patients with MOG-IgG (53 pediatric and 67 adults), and 114 patients with seronegative-MOG-IgG (35 children with first demyelinating syndrome, 20 adults with clinically isolated syndrome, and 59 adults with other diseases). Antibodies were examined by cell-based assays.

Results: IgM or IgA MOG antibodies were identified in 23/120 (19%) patients with MOG-IgG (13/53 [24.5%] pediatric, and 10/67 [15%] adult patients), and 2/114 (1.7%) patients with seronegative-MOG-IgG (2/35 [5.7%] pediatric patients). Of the 25 patients, 14 had IgA, 9 IgM, and 2 both antibodies. Fourteen of the 15 (93%) children with IgM (4), IgA (9), or both (2) had acute demyelinating encephalomyelitis (ADEM), and 7 of the 10 (70%) adults with IgM (5) or IgA (5) had optic neuritis at onset. At the last follow-up, the final diagnoses remained as ADEM in 14 (100%) children and optic neuritis in 6 (86%) adults. The outcome was not different between patients with or without additional classes of antibodies.

Conclusion: Coexisting IgM and IgA antibodies occurs in 19% of children and adult patients with MOG-IgG-associated disease. The presence of these antibodies does not seem to play a relevant clinical role in the disorder.

Keywords: ADEM; Antibody classes; Cell-based assay; MOG antibodies; Optic neuritis; Pediatric.