Re: what does a negative ANA test actually mean?
Burnt Bees, Here's what I've read & have been told. In all cases, figures vary from source to source & maybe even change as more understanding is gained about all the varying forms of the disease.
In SLE, ANA is "almost always" positive (over 95%, maybe over 97%---figures vary).
In the SCLE subset, ANA is positive perhaps only 2/3 of the time or so.
In the DLE subset, ANA is positive perhaps only 50% of the time or so.
(Not sure about the odds neo-natal & drug-induced lupus. Sorry.)
BUT---even with the rough "facts" above, it can take multiple tests before a positive result is found, due to flares, due to someone seeing a dr. very early on in the disease process, due to differences in lab procedures, etc.