Dragonslayer is referring to the *technique* by which the test is performed.

It used to be always done by the ELISA method (go google it if you want more info). It did have a high false NEGATIVE rate and rarely a false POSITIVE. This is more likely in smaller pathology lab - where the volume (or lack thereof) of that specific test performed was low - so the staff were therefore less experienced at doing it and accurately deciphering the result.

50% of the TESTS DONE were NOT inaccurate - but 50% of those where a negative result was obtained went on to be HLA B27 +ve on re-testing.

Nowadays, most larger labs will do a test for HLA B27 protein via a method known as FLOW CYTOMETRY - this has a very high accuracy rate and will therefore yield a far more reliable result.

Be aware that FC is a sophisticated (and VERY EXPENSIVE!) way of testing for this, so some low budget labs are still likely to be doing the ELISA method.

Thanks for the info. I'll have to look into the company's methods. She was more than willing to re-test CRP and ESR, which came back normal again. But she flat out refused another gene test. Right now she thinks there is no way I can have AS.