Ganglionic acetylcholine receptor autoantibodies in patients with Guillain-Barré syndrome

Although standardized autonomic tests are useful for diagnosing autonomic failure in patients with Guillain-Barré syndrome (GBS), they cannot be used as predictive markers. Thus, serological markers may correctly identify patients with GBS who are at risk for autonomic dysfunction.

We validated a luciferase immunoprecipitation system that detects IgG antibodies in patient serum that specifically bind to the α3 or β4 subunits of ganglionic neuronal nicotinic acetylcholine receptors (gAChR). We then used luciferase-conjugated ligands specific to antibodies against two gAChR subunits to test 79 sera samples from patients with GBS, 34 from subjects with other neurological diseases (OND), and 73 from healthy controls (HC). 1) In the first analysis, patients were classified into two groups according to the presence or absence of autonomic symptoms (AS). We compared the frequency of the anti-gAChR antibodies between these two groups (AS+ and AS-). 2) In the second analysis, furthermore, patients were classified depending on the presence or absence of anti-glycolipid antibodies (AGA). We compared the frequency of the anti-gAChR antibodies between the four categories of GBS (AS+/AGA+, AS+/AGA-, AS-/AGA+, and AS-/AGA-), OND, and HC.

Eight subjects with GBS were positive for α3 subunits, while one was positive for β4 subunits. Anti-α3 and -β4 gAChR antibodies were also detected in 13.6% of AS+ GBS group in the first analysis. Two of 35 patients in AS-GBS group were seropositive for the anti-gAChR antibodies and AGA in the second analysis. Patients with GBS that were positive for serum antibodies to the α3 and/or β4 subunits of gAChRs showed a range of clinical features including AS and AGA.

Patients with GBS may have circulating antibodies against gAChR, which may contribute to the autonomic dysfunction associated with this disease.