Detection of shortened activated partial thromboplastin times: An evaluation of different commercial reagents

ten Boekel, Edwin; Böck, Martine; Vrielink, Gert-Jan; Liem, Robert; Hendriks, Henriet; Kieviet, Wim de

doi:10.1016/j.thromres.2007.05.006

« Previous Next »Thrombosis Research
Volume 121, Issue 3 , Pages 361-367, 2007

Detection of shortened activated partial thromboplastin times: An evaluation of different commercial reagents

Department of Clinical laboratory, Sint Lucas Andreas Hospital Amsterdam, The Netherlands

Received 14 February 2007; received in revised form 2 May 2007; accepted 5 May 2007.

Abstract

Introduction

Abnormally shortened activated partial thromboplastin times (aPTT) are associated with significantly increased risk of thrombotic disorders and in-hospital mortality. Shortened aPTTs have been related to increased levels of factor (F) VIII and thrombin-antithrombin complex (TAT). In the current study, four different commercial aPTT reagents were evaluated for their performance to detect shortened aPTTs.

Materials and methods

aPTT of 400 patients was determined using Actin-FS (Dade Behring), APTT-SP (Instrumentation Laboratory), Automated-APTT (bioMerieux) and Platelin-LS (bioMerieux) reagents. FVIII, FIX, FXI and TAT levels were measured in shortened and normal aPTT samples.

Results

An association between shortened aPTTs and elevated levels of coagulation factors (FVIII, FIX and FXI) and thrombin generation (TAT) was found with all tested aPTT reagents. Method-comparison studies demonstrated good agreement between Instrumentation Laboratory and bioMerieux reagents. However, 53 to 59% of the patients with a shortened aPTT measured with Actin-FS reagent was determined as a normal aPTT with APTT-SP, Automated-APTT and Platelin-LS reagents. These patients had increased levels of FVIII, FIX and FXI and moderately increased levels of TAT.

Conclusion

Overall, an acceptable agreement between the different commercial reagents was found with respect to detection of short aPTTs. However, a disparity between some of reagents existed. Actin-FS reagent appeared to be more sensitive in inducing shortened aPTT reactions than APTT-SP, Automated-APTT and Platelin-LS reagents.

Abbreviations:: aPTT, activated partial thromboplastin time, CV, coefficient of variance, FVIII, coagulation factor VIII, FIX, coagulation factor IX, FXI, coagulation factor XI, IQR, inter-quartile range, TAT, thrombin-antithrombin complex.