Multi-site analytical evaluation of a chemiluminescent magnetic microparticle immunoassay (CMIA) for sirolimus on the Abbott ARCHITECT analyzer.
OBJECTIVE
This study evaluated a new chemiluminescent magnetic microparticle immunoassay (CMIA) for sirolimus on the ARCHITECT analyzer.


METHODS
Patient and laboratory proficiency samples were tested at three European sites and one site in the United States.


RESULTS
The CMIA total %CV's were all <8% and the Limit of Quantification (LOQ) was <1.52 ng/mL across the four sites. It cross-reacts to sirolimus metabolites F4 and F5 and showed no hematocrit interference over a range of 25% to 55%. Patient specimen correlations to three LC/MS/MS methods gave R>or=0.91 at three sites and mean biases of 14%, 25% and 39%. CMIA patient specimen correlations to the Abbott IMx gave R>or=0.94 at 2 sites and mean biases of 5.4% and 6.9%.


CONCLUSIONS
CMIA is a precise and sensitive immunoassay method without hematocrit interference. It correlates well to both LC/MS/MS and immunoassay results, but shows an expected positive bias to LC/MS/MS.
Schmid
Rainer W
RW
Medical University Vienna, Vienna, Austria.
Lotz
Johannes
J
Schweigert
Rosemarie
R
Lackner
Karl
K
Aimo
Giuseppe
G
Friese
Judith
J
Rosiere
Thomas
T
Dickson
Diana
D
Kenney
Daniel
D
Maine
Gregory T
GT
D000918:Antibody Specificity; D002853:Chromatography, Liquid / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D007166:Immunosuppressive Agents / Q000097:blood*; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008280:Magnetics; D010316:Particle Size; D012680:Sensitivity and Specificity; D020123:Sirolimus / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000379:methods
D007166:Immunosuppressive Agents; D020123:Sirolimus