I was just advised of my first + lupus anticoagulant antibody test this week, so I really can understand all the questions that are popping into your brain!
According to most of the published guidelines I've read, 2 + tests at least 12 weeks apart are required for definitive diagnosis as the LAC antibodies can be transient and present due to issues that do not present a risk of thrombophilia. LAC is considered an autoimmune issue; the body abnormally produces a immune protein that effects blood clotting. The exact mechanism that causes this is not yet known, nor is the trigger for this abnormal immune response.
My dad tested positive for LAC some years ago, and at the time his hematologist recommended all first degree relatives be tested as well. It took me a while, but better late than never, right? Due to the severity of his condition (recurrent arterial clots that ultimately led to below the knee amputation, plus severely diseased heart valves) my doc & I decided the best plan was to start anticoagulation now (Coumadin AND Lovenox....hooray!) I'll be headed to a hematologist in a month, then high risk OB as hubs and I were just about to start working on starting our family. While I am not 100% pleased with having to deal with this, it hasn't escaped my memory that my dad had his first blood clot at my age.....and I'd like to prevent that from happening to me thankyouverymuch
As far as your labs go, your best option is to have a face to face discussion with your doc. She will be better able to interpret your results based on health history than I can. But as far as the puropse of those tests: Basically she was testing you for disorders related to LAC that can also cause abnormal blood clotting. Google antiphospolipid syndrome for more info.
My apologies for the length of this post; hope you got SOMETHING useful out of this!