I received this message from Roche Coaguchek when I asked them if their new machine was more accurate with antiphospholipid patients.
"We advise all patients with Anti-phospholipid Syndrome that the meter may not be suitable for self-testing, due to the nature of the condition and method of testing. If you do decide to self-test, it should be with the full support and awareness of your health care professional. In the pack insert provided with the test strips, there is information advising patients with APS that the product not be suitable for them as it may give falsely high INR values, where APS is known to be present. It is imperative that the result be obtained using a APS sensitive laboratory method for comparison.
With regard to the thromboplastin, Roche uses a type of recombinant human thromboplastin 1.5u which gives a consistent ISI (International Sensitivity Index) of 1.0 which is the ideal score for accuracy as recommended by the World Health Organisation and the British Society for Haematology. Therefore Roche is not currently using or having future plans to use different types of thromboplastins. I hope this information is of help to you. We wish you the best of luck for the future, and if you have any further questions, please do not hesitate to ask."