Abstract
Lupus anticoagulant (LA) testing is a demanding laboratory test. The most common among recommended tests for LA are dilute Russell viper venom time (dRVVT) and LA sensitive activated partial thromboplastin time (LA-aPTT). Although integrated test systems come with manufacturer assigned cut-off, but according to guidelines cut-off should be locally-derived. This study was carried out to find normative range of LA using LA-aPTT and dRV VT tests in south Indian population (n = 100) and using locally derived cut-off values to interpret patient samples (n = 152) in a one-year study period. Cut-off (mean+2.3 SD) for aPTT, LA-aPTT, dRVVT screen and dRVVT confirm assays were 37.5, 45.7, 45.5 and 41.3 s and for normalized ratio and percentage correction of ratio were 1.16 and 15.8% respectively. Among patients, 25 (16.4%) were positive of whom 14 were positive by normalized ratio, seven by LA-aPTT and four were positive by both. Four additional patients could be identified using local cut-off. While the specificity of all screening tests was high, sensitivity of only dRVVT screen was high. All testing laboratories should attempt to derive normative range and locally-derived cut-off. While dRVVT is a good screening test with high sensitivity, however combining LA-aPTT offers advantage of picking up cases negative by dRVVT.
References
Moore GW (2014) Recent guidelines and recommendations for laboratory detection of lupus anticoagulants. Semin Thromb Hemost 40(2):163–171
Pengo V, Tripodi A, Reber G, Rand J, Ortel T, Galli M et al (2009) Update of the guidelines for lupus anticoagulant detection. J Thromb Haemost 7:1737–1740
Keeling D, Mackie I, Moore GW, Greer IA, Greaves M (2012) Guidelines on the investigation and management of antiphospholipid syndrome. Br J Haematol 157:47–58
CLSI. Laboratory testing for the lupus anticoagulant; Approved Guideline. (2014) CLSI document H60-A, Wayne, P.A: Clinical and Laboratory Standards Institute.
Saldarriaga M, Lozada M, Lopez G (2014) Determination of cut-off values in healthy donors for lupus anticoagulant detection protocol in the laboratorio medico echavarrria, according to the international guidelines. Pathol clin med lab 61:145–149
Gardiner C, Mackie I, Malia R, Jones D, Winter M, Leeming D et al (2008) The importance of locally derived reference ranges and standardised calculation of dilute Russell's viper venom time results in screening for lupus anticoagulant. Br J Haematol 111:1230–1235
Funding
JIPMER intramural grant in support of MSc-MLT dissertation.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflicts of interest.
Ethical Approval
Informed consent was taken from all the study participants and the study was approved by the Institute Ethics Committee.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Ramaraj, A., Negi, V.S. & Kar, R. Assessment of Normative Range and Deriving Cut-Off Values for Lupus Anticoagulant Testing: An Experience from a Tertiary Care Center in Southern India. Indian J Hematol Blood Transfus 35, 485–488 (2019). https://doi.org/10.1007/s12288-019-01079-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12288-019-01079-9