Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation.
The first generation of troponin T ELISA (TnT 1) can yield false-positive results in patients with severe skeletal muscle injury. Therefore, a cardiac-specific second-generation troponin T ELISA (TnT 2) was developed, in which the cross-reactive antibody 1B10 has been replaced by a high-affinity cardiac-specific antibody M11.7. No cross-reactivity of TnT 2 was observed with purified skeletal muscle troponin T (1000 micrograms/L) or in test samples from 43 marathon runners and 24 patients with rhabdomyolysis and highly increased creatine kinase. TnT 2 was increased > 0.2 microgram/L in 5 of 40 patients with renal failure and in 4 of 20 muscular dystrophy patients. The detection limit is 0.012 microgram/L. Day-to-day imprecision (CV) within the range 0.19-14.89 micrograms/L was < 5.8%. In 4955 patients without myocardial damage, 99.6% had TnT < 0.10 microgram/L. Assay comparison (TnT 1 vs TnT 2) over the whole concentration range (i.e., in 323 samples from AMI-suspected patients) showed a slope, intercept, and standard error of estimate (Sey) of 1.18, 0.01 micrograms/L, and 0.81 microgram/L, respectively.
Müller-Bardorff
M
M
Medizinische Klinik II, University of Lübeck, Germany.
Hallermayer
K
K
Schröder
A
A
Ebert
C
C
Borgya
A
A
Gerhardt
W
W
Remppis
A
A
Zehelein
J
J
Katus
H A
HA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D003402:Creatine Kinase / Q000032:analysis; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D007676:Kidney Failure, Chronic / Q000175:diagnosis; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000737:chemistry / Q000276:immunology; D009136:Muscular Dystrophies / Q000175:diagnosis; D009203:Myocardial Infarction / Q000175:diagnosis; D009206:Myocardium / Q000737:chemistry / Q000276:immunology; D015203:Reproducibility of Results; D012206:Rhabdomyolysis / Q000175:diagnosis; D012680:Sensitivity and Specificity; D014336:Troponin / Q000276:immunology* / Q000302:isolation & purification; D020107:Troponin T
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D014336:Troponin; D020107:Troponin T; D003402:Creatine Kinase