Serum anti‐GM2 and anti‐GalNAc‐GD1a ganglioside IgG antibodies are biomarkers for immune‐mediated polyneuropathies in cats.

Recent work identified anti‐GM2 and anti‐GalNAc‐GD1a IgG ganglioside antibodies as biomarkers in dogs clinically diagnosed with acute canine polyradiculoneuritis, in turn considered a canine equivalent of Guillain‐Barré syndrome. This study aims to investigate the serum prevalence of similar antibodies in cats clinically diagnosed with immune‐mediated polyneuropathies. The sera from 41 cats clinically diagnosed with immune‐mediated polyneuropathies (IPN), 9 cats with other neurological or neuromuscular disorders (ONM) and 46 neurologically normal cats (CTRL) were examined for the presence of IgG antibodies against glycolipids GM1, GM2, GD1a, GD1b, GalNAc‐GD1a, GA1, SGPG, LM1, galactocerebroside and sulphatide. A total of 29/41 IPN‐cats had either anti‐GM2 or anti‐GalNAc‐GD1a IgG antibodies, with 24/29 cats having both. Direct comparison of anti‐GM2 (sensitivity: 70.7%; specificity: 78.2%) and anti‐GalNAc‐GD1a (sensitivity: 70.7%; specificity: 70.9%) antibodies narrowly showed anti‐GM2 IgG antibodies to be the better marker for identifying IPN‐cats when compared to the combined ONM and CTRL groups (P =.049). Anti‐GA1 and/or anti‐sulphatide IgG antibodies were ubiquitously present across all sample groups, whereas antibodies against GM1, GD1a, GD1b, SGPG, LM1 and galactocerebroside were overall only rarely observed. Anti‐GM2 and anti‐GalNAc‐GD1a IgG antibodies may serve as serum biomarkers for immune‐mediated polyneuropathies in cats, as previously observed in dogs and humans. [ABSTRACT FROM AUTHOR]