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Thromb Haemost 2007; 97(05): 586-861
DOI: 10.1160/TH06-12-0740
New Technologies, Diagnostic Tools and Drugs
Schattauer GmbH

Multicentre ISI assignment and calibration of the INR measuring range of a new point-of-care system designed for home monitoring of oral anticoagulation therapy

Ingrid Leichsenring
1   Roche Diagnostics, Mannheim, Germany
,
Winfried Plesch
1   Roche Diagnostics, Mannheim, Germany
,
Volker Unkrig
1   Roche Diagnostics, Mannheim, Germany
,
Steve Kitchen
2   Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
,
Dianne P. Kitchen
2   Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
,
Rhona Maclean
2   Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
,
Bert Dikkeschei
3   Department of Clinical Chemistry, Isala Klinieken, Zwolle, The Netherlands
,
Anton M. H. P. van den Besselaar
4   Haemostasis and Thrombosis Research Centre, Department of Haematology, Leiden University Medical Centre, Leiden, The Netherlands
› Author AffiliationsFinancial support: This study was sponsored by Roche Diagnostics which is the manufacturer of the system. Financial support was given to the institutions participating in the studies.
Further Information

Publication History

Received 29 December 2006

Accepted after revision 01 March 2007

Publication Date:
24 November 2017 (online)

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Summary

The new CoaguChek XS system is designed for use in patient selftesting. It is the successor of the current CoaguChek S system. The detection principle is based on the amperometric measurement of the thrombin activity initiated by starting the coagulation cascade using a human recombinant thromboplastin. This study was performed to assign the International SEnsitivity Index (ISI) to the new test according to the WHO guidelines for thromboplastins and plasmas used to control anticoagulant therapy, and to establish the measuring range of the new system. At four study sites a total of 90 samples of normal donors and 291 samples of warfarin-, phenprocoumon- or acenocoumarol-treated patients were included in the study.The ISI value of the new test was assigned against the human recombinant reference thromboplastin rTF/95 at each site using the samples from stabilized patients in the International Normalized Ratio (INR) range between 1.5 and 4.5 only. The new point-of-care system’s measuring range between 0.8 and 8 INR was calibrated against the mean INR of rTF/95 and AD149 using polynomial regression. ISIs were (CV of the slope): Site 1: ISI 0.99 (1.1%); Site 2: ISI 1.02 (2.0%); Site 3: ISI 1.03 (1.1%); Site 4: ISI 1.00 (1.4%). All regression lines calculated from patient-only data pass through the normal donor data points.All CVs of the slopes of the orthogonal regression lines are well below 3%,thus fulfilling the requirements of the WHO guidelines. The mean ISI for the new CoaguChek XS PT Test is 1.01.

Keywords

INR calibration - ISI assignment - point-of-care testing - patient selftesting - CoaguChek

Ingrid Leichsenring, Winfried Plesch, and Volker Unkrig are employees of Roche Diagnostics GmbH, Mannheim, Germany. COAGUCHEK is a trademark of Roche.


 

  • References

  • 1 Plesch W, Klimpel P. Performance evaluation of the CoaguChek S system. Haematologica 2002; 87: 557-559.
    PubMedGoogle Scholar
  • 2 World Health Organization Committee on Biological Standardization: Guidelines for thromboplastins and plasmas used to control anticoagulant therapy. WHO Technical Report Series 1999; 889: 64-93.
    PubMedGoogle Scholar
  • 3 Tripodi A, Arbini AA, Chantarangkul V. et al. Are capillary whole blood coagulation monitors suitable for the control of oral anticoagulant treatment by the international normalized ratio?. Thromb Haemost 1993; 70: 921-924.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 4 van den Besselaar AMHP, Breddin K, Lutze G. et al. Multicenter evaluation of a new capillary blood pro- thrombin time monitoring system. Blood Coagul Fibrinol 1995; 06: 726-732.
    CrossrefPubMedGoogle Scholar
  • 5 Kaatz SS, White RH, Hill J. et al. Accuracy of laboratory and portable monitor international normalized ratio determinations. Arch Intern Med 1995; 155: 1861-1867.
    CrossrefPubMedGoogle Scholar
  • 6 van den Besselaar AMHP. A comparison of INRs determined with a whole blood prothrombin time device and two international reference preparations for thromboplastin. Thromb Haemost 2000; 84: 410-412.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 7 Tripodi A, Chantarangkul V, Mannucci PM. Nearpatient testing devices to monitor oral anticoagulant therapy. Br J Haematol 2001; 113: 847-852.
    CrossrefPubMedGoogle Scholar
  • 8 Poller L, Keown M, Chauhan N. et al. European Concerted Action on Anticoagulation (ECAA): Multicentre international sensitivity index calibration of two types of point-of-care prothrombin time monitor systems. Br J Haematol 2002; 116: 844-850.
    CrossrefPubMedGoogle Scholar
  • 9 Poller L, Keown M, Chauhan N. et al. European Concerted Action on Anticoagulation. A multicentre calibration study of WHO international reference preparations for thromboplastin, rabbit (RBT/90) and human (rTF/95). J Clin Pathol 2005; 58: 667-669.
    CrossrefPubMedGoogle Scholar
  • 10 Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 01: 307-310.
    PubMedGoogle Scholar
  • 11 Passing H, Bablok W. A new biometrical procedure for testing the equality of measurements from different analytical methods, Part I. J Clin Chem Clin Biochem 1983; 21: 709
    PubMedGoogle Scholar