testing for APS and other clotting disorders??

  I have been told that tests for antiphospholipid antibodies and anticardiolipin antibodies can be neg at some times and possitive at others.  How many times should they be checked to make sure that you are getting an accurate result if they are neg the first time and there are indications that a clotting disorder is likely?  Also is there some place where I could get info on all the different clotting disorders that can be checked? ie the protien c and s tests ect?  thanks again!!!
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Thanks for you question.  The information that you were given regarding
the inconsistance of detection of antiphospholipid and anticardiolipin
antibodies is correct.  So far, there isn't a definitive answer for the
phenomena, but there appears to be circulating proteins that can bind to
and temporarily "hide" those antibodies from detection.
Regarding sources for further information, the following Web site has
a heterogeneous mixture of information directed towards physicians and
layman, but some of the info is quite readable:
http://members.aol.com/AMAmail/Anti.html
I hope this information is helpful.
This information is provided for general medical education purposes only.
Please consult your doctor regarding diagnostic and treatment options.