TY - JOUR
T1 - Impact of preanalytical factors on the stability of acetylcholine receptor antibodies in serum
AU - Overgaard, David Lyse
AU - Parkner, Tina
AU - Jul Jarbæk Nielsen, Josefine
AU - Andersen, Henning
AU - Knudsen, Cindy Soendersoe
PY - 2025
Y1 - 2025
N2 - This study investigated the preanalytical stability of acetylcholine receptor antibodies (AChRAb) in patient samples, a crucial biomarker for diagnosing Myasthenia Gravis (MG). The objective was to evaluate the impact of delayed centrifugation, storage temperature, and repeated freeze-thaw cycles on the accuracy of AChRAb test results. Blood samples were collected from nine MG patients, and four stability studies were conducted. These studies examined: (I) the effect of delayed centrifugation on whole blood (up to 7 h at room temperature), (II) storage of serum at room temperature (up to 7 days), (III) storage of serum at −20 °C (up to 26 weeks), and (IV) the impact on serum of repeated freeze-thaw cycles (up to 3 cycles). AChRAb levels were measured using ELISA, and the results were analysed for statistical variation against baseline measurements using bias limits of ±15%. The findings revealed that AChRAb remained stable for up to 7 hours of delayed centrifugation, 5 days at room temperature, 13 weeks at −20 °C, and after 3 freeze-thaw cycles. However, the antibody levels showed instability after 7 days at room temperature and 26 weeks at −20 °C, where the percentage differences exceeded acceptable limits. Analytical variation, especially at low antibody levels, and differences between ELISA kit lots were potential factors contributing to these findings. In conclusion, AChRAb shows good stability if care is taken to avoid prolonged storage and handling times to maintain diagnostic accuracy.
AB - This study investigated the preanalytical stability of acetylcholine receptor antibodies (AChRAb) in patient samples, a crucial biomarker for diagnosing Myasthenia Gravis (MG). The objective was to evaluate the impact of delayed centrifugation, storage temperature, and repeated freeze-thaw cycles on the accuracy of AChRAb test results. Blood samples were collected from nine MG patients, and four stability studies were conducted. These studies examined: (I) the effect of delayed centrifugation on whole blood (up to 7 h at room temperature), (II) storage of serum at room temperature (up to 7 days), (III) storage of serum at −20 °C (up to 26 weeks), and (IV) the impact on serum of repeated freeze-thaw cycles (up to 3 cycles). AChRAb levels were measured using ELISA, and the results were analysed for statistical variation against baseline measurements using bias limits of ±15%. The findings revealed that AChRAb remained stable for up to 7 hours of delayed centrifugation, 5 days at room temperature, 13 weeks at −20 °C, and after 3 freeze-thaw cycles. However, the antibody levels showed instability after 7 days at room temperature and 26 weeks at −20 °C, where the percentage differences exceeded acceptable limits. Analytical variation, especially at low antibody levels, and differences between ELISA kit lots were potential factors contributing to these findings. In conclusion, AChRAb shows good stability if care is taken to avoid prolonged storage and handling times to maintain diagnostic accuracy.
KW - Acetylcholine receptor antibodies (AChRAb)
KW - ELISA
KW - Myasthenia Gravis (MG)
KW - preanalytical stability
KW - serum storage
UR - https://www.scopus.com/pages/publications/105004451300
U2 - 10.1080/00365513.2025.2500011
DO - 10.1080/00365513.2025.2500011
M3 - Comment/debate/letter to the editor
C2 - 40336244
AN - SCOPUS:105004451300
SN - 0036-5513
VL - 85
SP - 308
EP - 312
JO - Scandinavian Journal of Clinical and Laboratory Investigation
JF - Scandinavian Journal of Clinical and Laboratory Investigation
IS - 4
ER -