PMID- 11523938
OWN - NLM
STAT- MEDLINE
DCOM- 20020115
LR  - 20191210
IS  - 0031-3025 (Print)
IS  - 0031-3025 (Linking)
VI  - 33
IP  - 3
DP  - 2001 Aug
TI  - A comparison of the sensitivity of APTT reagents to the effects of enoxaparin, a 
      low-molecular weight heparin.
PG  - 347-52
AB  - Low-molecular weight heparin (LMWH) is the product of enzymatic or chemical 
      degradation of unfractionated heparin (UFH). It has been found to have better 
      bio-availibility, more predictable dose response and can be used as an 
      alternative to UFH for prophylaxis and treatment of thrombotic disorders. It is 
      claimed that no laboratory monitoring is necessary for LMWH therapy; however, for 
      the aged, renal impaired, obese or grossly underweight, monitoring of dose effect 
      with anti-Xa assay is recommended. The activated partial thromboplastin time 
      (APTT), which is the test of choice for UFH monitoring, is believed to be 
      insensitive to the effect of LMWH. The sensitivity of the APTT to heparin lies in 
      the APTT reagent used. In this study, eight different APTT reagents were used to 
      compare the APTT with anti-Xa activity in ex vivo plasma from patients who were 
      on enoxaparin (LMWH, Clexane) therapy. It was found that, as with UFH, APTT 
      reagents show variable sensitivity to LMWH. The APTTs from all eight reagents 
      were found to have a linear relationship to anti-Xa activity. The APTT results 
      using three of the reagents gave an indication of the use of LMWH therapy. It was 
      also found that patients who were lupus anticoagulant (LA)-positive had much more 
      prolonged APTTs when on LMWH therapy; however, a linear correlation between APTT 
      and anti-Xa was not present in these patients.
FAU - Ip, B K
AU  - Ip BK
AD  - Haematology, Concord Repatriation General Hospital, Concord, NSW, Australia. 
      ipb@email.cs.nsw.gov.au
FAU - Thomson, A R
AU  - Thomson AR
FAU - Moriarty, H T
AU  - Moriarty HT
LA  - eng
PT  - Comparative Study
PT  - Evaluation Study
PT  - Journal Article
PL  - England
TA  - Pathology
JT  - Pathology
JID - 0175411
RN  - 0 (Anticoagulants)
RN  - 0 (Enoxaparin)
RN  - 0 (Factor Xa Inhibitors)
RN  - 0 (Indicators and Reagents)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Animals
MH  - Anticoagulants/*blood
MH  - Enoxaparin/*blood
MH  - Factor Xa Inhibitors
MH  - Female
MH  - Humans
MH  - *Indicators and Reagents
MH  - Male
MH  - Middle Aged
MH  - *Partial Thromboplastin Time
MH  - Sensitivity and Specificity
EDAT- 2001/08/29 10:00
MHDA- 2002/01/16 10:01
CRDT- 2001/08/29 10:00
PHST- 2001/08/29 10:00 [pubmed]
PHST- 2002/01/16 10:01 [medline]
PHST- 2001/08/29 10:00 [entrez]
PST - ppublish
SO  - Pathology. 2001 Aug;33(3):347-52.