Tag: muscarinic cholinergic receptor

Reduction of [11C](+)3-MPB binding in brain of chronic fatigue syndrome with serum autoantibody against muscarinic cholinergic receptor

Abstract:

BACKGROUND: Numerous associations between brain-reactive antibodies and neurological or psychiatric symptoms have been proposed. Serum autoantibody against the muscarinic cholinergic receptor (mAChR) was increased in some patients with chronic fatigue syndrome (CFS) or psychiatric disease. We examined whether serum autoantibody against mAChR affected the central cholinergic system by measuring brain mAChR binding and acetylcholinesterase activity using positron emission tomography (PET) in CFS patients with positive [CFS(+)] and negative [CFS(-)] autoantibodies.

METHODOLOGY: Five CFS(+) and six CFS(-) patients, as well as 11 normal control subjects underwent a series of PET measurements with N-[(11)C]methyl-3-piperidyl benzilate [(11)C](+)3-MPB for the mAChR binding and N-[(11)C]methyl-4-piperidyl acetate [(11)C]MP4A for acetylcholinesterase activity. Cognitive function of all subjects was assessed by neuropsychological tests. Although the brain [(11)C](+)3-MPB binding in CFS(-) patients did not differ from normal controls, CFS(+) patients showed significantly lower [(11)C](+)3-MPB binding than CFS(-) patients and normal controls. In contrast, the [(11)C]MP4A index showed no significant differences among these three groups. Neuropsychological measures were similar among groups.

CONCLUSION: The present results demonstrate that serum autoantibody against the mAChR can affect the brain mAChR without altering acetylcholinesterase activity and cognitive functions in CFS patients.

 

Source: Yamamoto S, Ouchi Y, Nakatsuka D, Tahara T, Mizuno K, Tajima S, Onoe H, Yoshikawa E, Tsukada H, Iwase M, Yamaguti K, Kuratsune H, Watanabe Y. Reduction of [11C](+)3-MPB binding in brain of chronic fatigue syndrome with serum autoantibody against muscarinic cholinergic receptor. PLoS One. 2012;7(12):e51515. doi: 10.1371/journal.pone.0051515. Epub 2012 Dec 11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3519853/ (Full article)

 

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.

 

Source: Tanaka S, Kuratsune H, Hidaka Y, Hakariya Y, Tatsumi KI, Takano T, Kanakura Y, Amino N. Autoantibodies against muscarinic cholinergic receptor in chronic fatigue syndrome. Int J Mol Med. 2003 Aug;12(2):225-30. http://www.ncbi.nlm.nih.gov/pubmed/12851722