Modified and improved anti-acetylcholine receptor (AchR) antibody assay: comparison of analytical and clinical performance with conventional anti-AChR antibody assay.
We developed a modified anti-acetylcholine receptor (AChR) antibody (Ab) assay based on a radioreceptor assay and a calibration curve. We compared the analytical and clinical performances of this modified assay with those of the conventional anti-AChR Ab radioreceptor assay. Serum specimens were from patients with myasthenia gravis (MG) (n = 156) and from control subjects (n = 106). The modified assay demonstrated lower within-assay (4.0-6.6%) and between-assay (5.3-7.8%) CVs, greater linearity, lower cost, and shorter assay time than the conventional method. ROC curve analysis indicated almost identical specificity and sensitivity (> 0.92) for these two anti-AChR Ab assays. The modified and conventional assays were also equivalent for blocking anti-AChR Ab assay. Moreover, the modified anti-AChR Ab assay, differently from the conventional assay, allowed us to reveal anti-AChR Ab concentration differences among different clinical grades of MG.
Ferrero
B
B
Department of Neurosciences, University Hospital Molinette, Turin, Italy. chinigo@golgi.molinette.unito.it
Aimo
G
G
Pagni
R
R
Bergamasco
B
B
Bongioanni
M R
MR
Bergamini
L
L
Durelli
L
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D002417:Cattle; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000737:chemistry; D009157:Myasthenia Gravis / Q000276:immunology*; D012372:ROC Curve; D011869:Radioligand Assay / Q000379:methods* / Q000706:statistics & numerical data; D011950:Receptors, Cholinergic / Q000032:analysis / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D011950:Receptors, Cholinergic