Frequency of anti-AChR epsilon subunit-specific antibodies in MG.
A definite diagnosis of myasthenia gravis (MG) relies heavily on acetylcholine receptor (AChR) antibody testing. The relatively high number of antibody-negative patients therefore, causes frequent uncertainty in confirming the diagnosis. We evaluated the sensitivity and specificity of a new, commercially available AChR antibody test that uses an approximately equal mixture of AChR from TE671-epsilon (adult type) and TE671-gamma (fetal type) cells. This assay was used to re-examine 365 seronegative MG sera in which AChR antibody had not been detected by the standard assay that uses fetal type AChR. The new assay detected anti-AChR antibodies in 17 (15.5%) of 110 patients with ocular type and in 33 (12.9%) of 255 patients with generalized type MG. Anti-AChR epsilon subunit-specific antibodies were present in 13.7% of the patients in whom no AChR antibody had been detected by the standard assay, showing an increase from 79 to 82% in overall diagnostic sensitivity.
Ohta
Kiyoe
K
Clinical Research Center, Utano National Hospital, Kyoto 616-8255, Japan.
Fujinami
Aya
A
Saida
Takahiko
T
Nishimura
Masataka
M
Kuno
Sadako
S
Ohta
Mitsuhiro
M
D000906:Antibodies / Q000097:blood / Q000276:immunology*; D006801:Humans; D009157:Myasthenia Gravis / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology*
D000906:Antibodies; D011950:Receptors, Cholinergic