Antibodies to muscle and ganglionic acetylcholine receptors (AchR) in celiac disease

Background: About 2.5% of patients with idiopathic peripheral neuropathy or idiopathic dysautonomia have underlying celiac disease (CD). Antibodies to ganglioside have been reported in CD patients with neuropathy. No data are so far available on the presence in CD of acetylcholine receptor (AChR) antibodies. Muscle AChR antibodies are found in patients with myasthenia gravis, and ganglionic AChR antibodies in patients with autoimmune autonomic neuropathy. Objective: To determine the frequency of AChR antibodies in CD patients and assess possible correlations with neurological manifestations. Methods: Seventy CD patients (16 M, 54 F, mean age 36 years) underwent neurological and electrophysiological evaluation. AChR antibodies were detected with radioimmunoprecipitation assay. Sera from 15 age-matched patients with systemic lupus erythematosus (SLE) and 10 with Sjogren syndrome were studied as controls. Results: None of our CD patients complained of autonomic symptoms or fatigable weakness. Borderline titres (0.03-0.05 nmol/l) of ganglionic AChR antibodies were present in 4 patients, one affected with type I diabetes and one with subclinical neuropathy. Three of the 4 patients underwent cardiovascular autonomic function tests, which showed no abnormalities. Low levels of ganglionic AChR antibodies (0.05-0.10 nmol/l) were found in 2 SLE control patients, one of whom had a severe sicca complex. Muscle AChR antibodies (>1.0 nmol/l) were found in two CD patient and one control patient with SLE. Neither had symptoms or signs of myasthenia gravis. Discussion and conclusions: CD is occasionally associated with neurologic disease, and with antibody reactivity to neuronal antigens. None of our CD patients had autonomic failure or significant levels of ganglionic AChR antibodies. Two CD patient and one control with SLE had muscle AChR antibodies without clinical evidence of myasthenia. The presence of antibodies in CD and in SLE patients may reflect a non-specific autoimmune response in these patients or may indicate subclinical autoimmune autonomic and neuromuscular involvement.