title: Autoantibodies against muscarinic cholinergic receptor in chronic fatigue syndrome.
abstract: The disturbance of the central nervous system and immunological abnormalities have been suggested in patients with chronic fatigue syndrome (CFS). We focused on immunological abnormalities against neurotransmitter receptors in CFS. Using a sensitive radioligand assay, we examined serum autoantibodies to recombinant human muscarinic cholinergic receptor 1 (CHRM1), mu-opioid receptor (OPRM1), 5-hydroxytryptamine receptor 1A (HTR1A), and dopamine receptor D2 (DRD2) in patients with CFS (n=60) and results were compared with those in patients with autoimmune disease (n=33) and in healthy controls (n=30). The mean anti-CHRM1 antibody index was significantly higher in patients with CFS (p<0.0001) and autoimmune disease (p<0.05) than that in healthy controls, and positive reaction was found in 53.3% of patients with CFS. Anti-OPRM1 antibodies, anti-HTR1A antibodies, and anti-DRD2 antibodies were found in 15.2, 1.7, and 5.0% of patients with CFS, respectively. Anti-nuclear antibodies were found in 56.7% (34/60) of patients with CFS, but anti-nuclear antibody titers did not correlate with the activities of the above four autoantibodies. The patients with positive autoantibodies to CHRM1 had a significantly higher mean score (1.81) of 'feeling of muscle weakness' than negative patients (1.18) among CFS patients (p<0.01). Higher scores on 'painful node', 'forgetfulness', and 'difficulty thinking' were also found in CFS patients with anti-CHRM1 antibodies but did not reach statistical significance. In conclusion, autoantibodies to CHRM1 were detected in a large number of CFS patients and were related to CFS symptoms. Our findings suggested that subgroups of CFS are associated with autoimmune abnormalities of CHRM1.
authors.affiliation: Department of Laboratory Medicine, Osaka University Graduate School of Medicine (D2), Suita-shi, Osaka 565-0871, Japan. tanaka@labo.med.osaka-u.ac.jp
authors.forename: Susumu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kuratsune
authors.forename: Yoh
authors.initials: Y
authors.lastname: Hidaka
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hakariya
authors.forename: Ke-Ita
authors.initials: KI
authors.lastname: Tatsumi
authors.forename: Toru
authors.initials: T
authors.lastname: Takano
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Kanakura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Amino
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology; D016022:Case-Control Studies; D015673:Fatigue Syndrome, Chronic / Q000209:etiology / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D043643:Receptor, Muscarinic M1; D017448:Receptors, Dopamine D2 / Q000276:immunology; D011976:Receptors, Muscarinic / Q000276:immunology*; D017450:Receptors, Opioid, mu / Q000276:immunology; D011985:Receptors, Serotonin / Q000276:immunology; D044263:Receptors, Serotonin, 5-HT1
chemical_list: D001323:Autoantibodies; C086088:CHRM1 protein, human; D043643:Receptor, Muscarinic M1; D017448:Receptors, Dopamine D2; D011976:Receptors, Muscarinic; D017450:Receptors, Opioid, mu; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1