PMID- 22978522
OWN - NLM
STAT- MEDLINE
DCOM- 20130917
LR  - 20220318
IS  - 1751-553X (Electronic)
IS  - 1751-5521 (Linking)
VI  - 35
IP  - 2
DP  - 2013 Apr
TI  - Lupus anticoagulant detection: out of control?
PG  - 128-36
LID - 10.1111/ijlh.12006 [doi]
AB  - INTRODUCTION: Expert guidelines indicate that normalised ratios are preferred to 
      clotting times for lupus anticoagulant (LA) assays to mitigate analytical 
      variation. We investigated the effects of deriving normalised ratios from the 
      reference interval (RI) mean or different normal pooled plasmas (NPP). METHODS: 
      Screen, confirm and mixing tests for dilute Russell's viper venom time and APTT 
      were converted to normalised ratios and interpreted for LA. RESULTS: Of 1000 
      clinical samples, 824 generated identical interpretations using RI mean or 
      NPP-derived ratios and 57 identified LAs in one or both assays via either 
      denominator. Separate RIs were applied for normalised ratios derived from the NPP 
      or RI mean. Applying percentage correction index (PCI) to screen and confirm 
      assays irrespective of screen elevation increased agreement to 92.5%. Two frozen 
      and one lyophilised NPP were then used to derive ratios for 204 samples and 130 
      generated identical interpretations with all NPPs, 14 had overall interpretation 
      parity and 19 overall agreement via PCI, giving 79.9% overall agreement. The 
      results derived from each NPP were interpreted against RIs derived from RI means 
      to reflect differences resulting from NPPs with clotting times dissimilar to RI 
      means. CONCLUSIONS: Disparities were largely a function of closeness of NPP 
      clotting times to test RI means and not owing to clotting factor level 
      differences and likely related to manufacturing variables. Diagnostic benefit of 
      normalised ratios can be maximised by matching NPP values to RI means. If RI mean 
      is employed, and it likely requires re-establishing with new reagent batches.
CI  - (c) 2012 Blackwell Publishing Ltd.
FAU - Moore, G W
AU  - Moore GW
AD  - Department of Haemostasis and Thrombosis, GSTS Pathology, Guy's & St. Thomas' 
      Hospitals, London, UK. gary.moore@gsts.com
FAU - Brown, K L
AU  - Brown KL
FAU - Bromidge, E S
AU  - Bromidge ES
FAU - Drew, A J
AU  - Drew AJ
FAU - Ledford-Kraemer, M R
AU  - Ledford-Kraemer MR
LA  - eng
PT  - Journal Article
DEP - 20120917
PL  - England
TA  - Int J Lab Hematol
JT  - International journal of laboratory hematology
JID - 101300213
RN  - 0 (Lupus Coagulation Inhibitor)
SB  - IM
MH  - Antiphospholipid Syndrome/*diagnosis
MH  - Blood Coagulation Tests/*standards/*statistics & numerical data
MH  - Data Interpretation, Statistical
MH  - Diagnostic Errors
MH  - Humans
MH  - Lupus Coagulation Inhibitor/*blood
EDAT- 2012/09/18 06:00
MHDA- 2013/09/18 06:00
CRDT- 2012/09/18 06:00
PHST- 2012/03/26 00:00 [received]
PHST- 2012/08/08 00:00 [accepted]
PHST- 2012/09/18 06:00 [entrez]
PHST- 2012/09/18 06:00 [pubmed]
PHST- 2013/09/18 06:00 [medline]
AID - 10.1111/ijlh.12006 [doi]
PST - ppublish
SO  - Int J Lab Hematol. 2013 Apr;35(2):128-36. doi: 10.1111/ijlh.12006. Epub 2012 Sep 
      17.