A sensitive rosetting assay for detection of acetylcholine receptor antibodies using BC3H-1 cells: positive results in 'antibody-negative' myasthenia gravis.
Antibodies to acetylcholine receptor (AChR) were measured in a group of patients with myasthenia gravis (MG), some of whom had previously been classified as 'antibody negative' using the standard anti-AChR radioimmunoassay (RIA). AChR antibodies were measured using the rosetting assay, a new detection method which utilizes protein A-coated red blood cells and live BC3H-1 cells, a murine cell line which expresses muscle nicotinic AChR. The results of the rosetting assay were compared with those obtained in the anti-AChR RIA. 76% of all myasthenic sera tested showed rosetting at titers higher than any of the control sera (from patients with non-myasthenic neurologic disease and normal individuals). Of the myasthenic patients previously classified as 'antibody negative' in the RIA using human AChR, 71% demonstrated positive rosetting. There was no correlation between the anti-AChR antibody titer obtained in the rosetting assay and that obtained in the RIA using either human or denervated rat AChR. The results suggest that the rosetting assay may measure a subpopulation of antibodies that differs from those detected in the RIA.
Brooks
E B
EB
Department of Internal Medicine, Yale University School of Medicine, New Haven, CT.
Pachner
A R
AR
Drachman
D B
DB
Kantor
F S
FS
D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D002038:Bungarotoxins; D002460:Cell Line; D006801:Humans; D009157:Myasthenia Gravis / Q000276:immunology*; D011863:Radioimmunoassay; D011950:Receptors, Cholinergic / Q000276:immunology*; D012397:Rosette Formation / Q000379:methods; D013205:Staphylococcal Protein A
D001323:Autoantibodies; D002038:Bungarotoxins; D011950:Receptors, Cholinergic; D013205:Staphylococcal Protein A