Specimen recentrifugation and elevated troponin I levels.

OBJECTIVE To compare troponin I levels in plasma before and after specimen recentrifugation. METHODS Over a period of 24 consecutive days, we recentrifuged 189 plasma specimens in which the troponin I level was higher than the positivity cut off (60 ng/L) and then remeasured the troponin I. RESULTS Two-tailed Wilcoxon matched-pairs test results identified a statistically significant difference between troponin I concentrations before and after recentrifugation (P <.01). For 94 specimens close to the cut-off value (below the 50th percentile among the overall sample of 189 specimens), Passing-Bablok regression analysis showed a median reduction of 10 ng/L (95% confidence interval, -37.5 ng/L - -10.0 ng/L) in the concentrations of troponin I after recentrifugation. CONCLUSION Specimen recentrifugation is followed by a reduction in troponin I concentrations in specimens with elevated cardiac troponin I, posing a risk for misclassification of patients. Moreover, this practice gives rise to unnecessary prolongation of turnaround time.

[1]  S. Vasikaran,et al.  Outliers affecting cardiac troponin I measurement: comparison of a new high sensitivity assay with a contemporary assay on the Abbott ARCHITECT analyser , 2014, Annals of clinical biochemistry.

[2]  Xiaoming Wang,et al.  Rapid identification of falsely elevated serum cardiac troponin I values in a stat laboratory. , 2014, Laboratory medicine.

[3]  Mario J. Garcia,et al.  ACCF 2012 expert consensus document on practical clinical considerations in the interpretation of troponin elevations: a report of the American College of Cardiology Foundation task force on Clinical Expert Consensus Documents. , 2012, Journal of the American College of Cardiology.

[4]  H. Sadrzadeh,et al.  The effect of recentrifugation of serum separator tubes on concentration of serum analytes. , 2012, Annals of clinical and laboratory science.

[5]  Frederick G. Strathmann,et al.  Use of the BD vacutainer rapid serum tube reduces false-positive results for selected beckman coulter Unicel DxI immunoassays. , 2011, American journal of clinical pathology.

[6]  G. Dimeski.  Evidence on the cause of false positive troponin I results with the Beckman AccuTnI method , 2011, Clinical chemistry and laboratory medicine.

[7]  P. O’Rourke,et al.  Outliers as a cause of false cardiac troponin results: investigating the robustness of 4 contemporary assays. , 2011, Clinical chemistry.

[8]  L. Bilić-Zulle,et al.  Comparison of methods: Passing and Bablok regression. , 2011, Biochemia medica.

[9]  P. O’Rourke,et al.  Falsely elevated troponin I results due to outliers indicate a lack of analytical robustness , 2010, Annals of clinical biochemistry.

[10]  Fred S Apple,et al.  A new season for cardiac troponin assays: it's time to keep a scorecard. , 2009, Clinical chemistry.

[11]  G. Lum,et al.  False Positive Cardiac Troponin Results in Patients Without Acute Myocardial Infarction , 2006 .

[12]  Y. Jong,et al.  Falsely elevated troponin I attributed to inadequate centrifugation using the Access® immunoassay analyzer , 2006, Clinical chemistry and laboratory medicine.

[13]  S. Fleming,et al.  False-positive cardiac troponin I in a routine clinical population. , 2002, The American journal of cardiology.

[14]  T. Fukui,et al.  Pseudonormokalaemia caused by recentrifugation of blood samples after storage in gel-separator tubes , 2001, Annals of clinical biochemistry.

[15]  M. Vidaud,et al.  Comparison of single and repeat centrifugation of blood specimens collected in BD evacuated blood collection tubes containing a clot activator for cardiac troponin I assay on the ACCESS analyzer. , 2000, Clinical chemistry.

[16]  T. Fukui,et al.  High serum potassium concentrations after recentrifugation of stored blood specimens. , 2000, The New England journal of medicine.

[17]  L. Voipio‐Pulkki,et al.  Degradation of cardiac troponin I: implication for reliable immunodetection. , 1998, Clinical chemistry.

[18]  F. Apple,et al.  Prevention of analytical false-positive increases of cardiac troponin I on the Stratus II analyzer. , 1997, Clinical chemistry.

[19]  A. Pfäfflin.  Doubt on prevention of false-positive results of cardiac troponin I by recentrifugation , 2009, Clinical chemistry and laboratory medicine.

[20]  W. Bablok,et al.  A New Biometrical Procedure for Testing the Equality of Measurements from Two Different Analytical Methods. Application of linear regression procedures for method comparison studies in Clinical Chemistry, Part I , 1983, Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie.