Technical evaluation of the first fully automated assay for the detection of TSH receptor autoantibodies.
BACKGROUND
Graves' disease (GD) is mediated by autoantibodies which bind to the TSH receptor (TRAb). The aim of the present study was to evaluate the technical performance of the first fully automated immunoassay for TRAb detection.


METHODS
The Elecsys Anti-TSHR immunoassay utilizes a porcine TSH receptor (TSHR) and the human thyroid stimulating monoclonal TSHR autoantibody M22.


RESULTS
Intraassay and total imprecision CV were determined between 1.4%-14.9%, and 2.4%-28.8%, respectively. Using the 20% CV criteria the functional sensitivity was found at 0.73 IU/L. The median CV at the cut-off (1.75 IU/L) was found to be 11%. Comparison studies with five TRAb immunoassays yielded slopes and intercepts between 1.02-1.48, and -0.74-0.56, respectively. Correlation coefficients were determined between 0.895 and 0.978. ROC plot analysis of patients with GD, patients with other thyroid disorders and healthy controls revealed an AUC of 0.99 resulting in a sensitivity of 97% and a specificity of 99% at a TRAb level of 1.75 IU/L.


CONCLUSIONS
The evaluation of the TRAb immunoassay generated homogeneous performance data and demonstrated a high degree of comparability to established TRAb assays. The automated TRAb assay represents a major improvement of thyroid testing in clinical practice.
Hermsen
Derik
D
Central Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Duesseldorf, Germany. hermsen@med.uni-duesseldorf.de
Broecker-Preuss
Martina
M
Casati
Marco
M
Mas
Jordi Camara
JC
Eckstein
Anja
A
Gassner
Dieter
D
van Helden
Josef
J
Inomata
Keiko
K
Jarausch
Jochen
J
Kratzsch
Jürgen
J
Mann
Klaus
K
Miyazaki
Naoko
N
Navarro Moreno
Miguel Angel
MA
Murakami
Tsukasa
T
Roth
Heinz-Jürgen
HJ
Noh
Jaeduk Yoshimura
JY
Scherbaum
Werner A
WA
Schott
Matthias
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D006111:Graves Disease / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007118:Immunoassay; D008163:Luminescent Measurements; D051379:Mice; D011989:Receptors, Thyrotropin / Q000276:immunology*; D012680:Sensitivity and Specificity; D013552:Swine
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D011989:Receptors, Thyrotropin